Online ISSN: 1662-8985
Publications
To explore the effects of Juglone on proliferation and apoptosis of human cervical cancer Caski cells, and to further study the related mechanism of cell apoptosis. Cultured Caski cells were incubated with 20, 40, 60, 80 and 100 μmol/L juglone for 24 h. The proliferation of Caski cells was detected by methyl thiazolyl tetrazolium (MTT) assay. The cell apoptosis were detected by transmission electron microscope. The expression of Bcl-2 and Bax were detected by Western blot. MTT results showed that in different doses of juglone groups, the Caski cell growth was greatly inhibited (P < 0.05, P < 0.01) and showed dose dependent when compared with control group except 20 μmol/L. The IC50 of juglone was 42.4 μmol/L. After treatment on Caski cells with 40 μmol/L juglone, typical apoptosis characteristics was observed by transmission electronmicro scope. The expression of Bcl-2 was decreased while the expression of Bax was increased significantly when compared with control group (P < 0.05). Juglone significantly inhibits the proliferation and induces the apoptosis of Caski cells in vitro.

The aim of this study is to evaluate the injectable cross-linked chitosan (CS) microparticles (MPs) to apply for biomedical applications specifically for bone regeneration. The CS MPs were fabricated by emulsification method and formed the cross-links between the amide groups in the CS and phosphate groups in the sodium tripolyphosphate (TPP) ionic cross-linking agent. The MPS were analyzed for morphology by Scanning Electron Microscope (SEM). The fabricated CS MPs were in the spherical shape with the size range of 20-100 μm. These CS MPs were analyzed for biodegradation by immersing in phosphate buffered saline (PBS, pH = 7.4) at 37°C for 30 weeks. The biodegradation of CS MPs in PBS was initiated at week 25. Mesenchymal stem cells (MSCs) were harvested from the bone marrow of mice tibia and femurs. The MSC attachment on CS MPs was tested using LIVE/DEAD cell sassy with a Fluorescence Microscope. The murine MSCs attachment onto CS MPs at day 2 was confirmed by visualizing fluorescence images. The CS MPs were also analyzed for the injectability and retainability at the site using a subcutaneous injection in a rat model. The fabricated CS MPs possess injectability, biodegradability and biocompatibility. Therefore, these CS MPs have a great potential to apply for various biomedical applications including bone regeneration by injection.

In order to overcome shortcomings of the traditional PID controller for nuclear steam generator water level, we proposed a fuzzy controller by using fuzzy reasoning. By summing up the experience of skilled operators, we gave a set of fuzzy control rules, and determined some important control parameters. To verify the effectiveness of fuzzy controller, a simulation for a steam generator in Qinshan nuclear power plant, for example, was given. Simulation results show that the method can effectively improve the control quality.

This paper studies agile manufacturing based on the market orientation of manufacturing strategy. The paper proposes the decisions of agile manufacturing strategy of companies are based on the managerial cognition of the competitive strategic situation. The respective and interaction effects of the two key factors, the trend and the existing competitive priority, on agile manufacturing strategic decisions are analyzed using the research data collected in the fourth series of International Manufacturing Strategy Survey 2005. In this empirical study, the cognition of existing competitive priority is the key factor to affect agile manufacturing.

By using resampling methods this article processed the data of the four existing airlines safety Circumstances into 20 airlines, which were generated randomly and analog ground by using the Mat lab software. Then, we conducted analysis and calculation by using the method of factor analysis in the SPSS software based on the data from the 20 airlines, and made safety evaluation on the safety risk of the real existence four airlines of A, B, C and D. In conclusion, it helped airlines to determine their own unsafe through the evaluation results, and to find ways to improve.

Ant Colony Algorithm is a very good combination optimization method from mimic the swarm intelligence of ant colony behaviours. To extend the traditional Ant Colony Algorithm to continuous optimization problems, from the connections of continuous optimization and searching process of Ant Colony Algorithm, here one new Continuous Ant Colony Algorithm is proposed. To verify the new algorithm, the typical functions, such as Schaffer function and Percy function, are all used. And then, the results of new Continuous Ant Colony Algorithm are compared with that of traditional Continuous Ant Colony Algorithm and immunized evolutionary programming proposed by author. The results show that, the convergent speed and computing precision of the new algorithm are all very good.

The Internet is filled with opportunities for learning, communicating, and sharing information. It is a valuable resource for children and adults alike. Like any large community, however, the online world presents some underlying risks, especially for children. Parents need to be aware of some of the potential problems their children could encounter, and try to take adequate measures to protect their children from injury. In this paper, research will try to explore the relationship between parent's information literary, the confidence in child's ability of self-defense on the internet, and adequate measures to promote child using the internet more effectively. Association rules, a kind of data mining strategies, will be the main tool to manipulate the dataset. Apriori, a classic algorithm for learning association rules, is designed to operate on databases containing transactions.

At present, reported compensated sensor are lower strain transmission rate, or unable to test strain. At the same time, This paper presents a novel FBG strain sensor with a setf-compensating function. It can not only implement strain testing, but also has a temperature-compensated function The results are as follows: this package was shown to have a high strain sensitivity of 1.5pm/mu epsilon and the temperature intensity of the compensated sensor of 1pm/degrees C, which was decreased by 91.5%..

Crank block steering mechanism optimization is a nonlinear constrained optimization problem, which is important for forklift truck to get preferable steering performance. Particle swarm optimization (PSO) with feasibility-based rules is a swarm intelligent algorithm proposed to solve constrained optimization problems simply and effectively. Therefore, it is used to optimize crank block steering mechanism of forklift truck, which will try to minimize the maximal error of outer wheel steering angle, maximize the minimal transmission angle and improve the force transmission. Experimental results obtained by PSO with feasibility-based rules are compared with those obtained by enumeration algorithm which is reliable for optimization problems. The comparison results showed that particle swarm optimization with feasibility-based rules can get same optimal results as enumeration algorithm in much less calculation times.

A simulation model for the analysis of MEMS capacitor has been developed using mechanical equivalencies. The capacitor structure used in this paper has four parallel plates to improve the tuning range. Two of the plates are suspended and the other two plates are fixed. The developed mechanical model is validated with the help of structure simulations performed using PolyMumps process. The simulation results show good correlation between the equivalent mechanical model and the structural model. The tuning range of the mechanical model developed is 2.465:1 where as the PolyMumps fabricated capacitor produces a tuning range of 2.4555:1. The mechanical resonant frequencies of the top and bottom suspended plates are simulated as 501 rad/sec and 706 rad/sec respectively.

The streamer formation and propagation in high gain semi-insulating (SI) GaAs photoconductive semiconductor switches (PCSS) is analyzed in detail. This streamer model on the basis of photo-ionization, growing domain, and the collective impact ionization (CII) mechanism can explain the propagation velocity and the branch and the bend of streamer. This model is characterized by introducing the growing domain between photo-ionization and collective avalanche carrier generation during each stage in which the streamer forms. The calculated results of photo-ionization effects and the propagation velocities of streamer imply that this model is reasonable because the results are consistent with the reported experimental observations.

In this paper, we establish a global error bound for the generalized linear complementarity problem in engineering modeling (GLCP), based on we propose a new type of solution method to solve the GLCP. The global and quadratic rate of convergence is established without nondegenerate solution. These conclusions can be viewed as extensions of previously known results.

We present and implement a genetic algorithm (GA) based deliberative path planning algorithm using waypoints for navigation of robots and AGV's. The waypoint navigation system is advantageous as it does not require a complete knowledge of the environment and can replace traditional robot navigation systems. The proposed GA for robot navigation problem is NP-hard and multiobjective. The performance of the implemented GA is compared with the results obtained from two popular algorithms namely the Dijikstra's algorithm and A* algorithms. We propose a new representation that reduces the size of the chromosome array for large number of waypoints; the proposed GA has faster convergence and obtains near optimal solutions. The system has been developed for a near real-time experiment using a Matlab engine located on an online server. An integrated system complete with the required hardware was constructed for the purpose of testing the performance of the various algorithms using a real world geographical information system (GIS) and actual node data (waypoints) of Kuala Lumpur city. The proposed new system has been tested and is found to be suitable for adaptation in robot navigation, path planning and intelligent traffic guidance systems.

This paper introduces the principles and techniques of intelligent drilling which can be considered as a computer intelligent expert system with intelligent drill tools and information network system as the key technologies. In this paper, we have discussed the key technology of how to combine power transmission and high speed bidirectional information transmission “information superhighway” with drill tools, and also have introduced the design and development of intelligent drill tools specifically which Hilong company who possesses the independent intellectual property rights.

A comprehensive integrated electro-thermo coupling model is developed to investigate the electro-thermo-mechanical effects and electromigration analysis on Package-on-Package (POP) in this paper. POP packaging involves in ultra thin gold wire (Â¿=1mil) on wirebonding and Sn<sub>4.0</sub>Ag<sub>0.6</sub>Cu (SAC405) solder ball on package. The current density arising in the aluminum pad (wirebonding) and in the Copper trace above SAC405 solder ball imply the hot spot where results in an electromigration along the current direction. Finite element predictions reveal the maximum electro-thermo-mechanical effective stress is located at the regions where electromigration potentially occurred. Reliability on electro-thermo-mechanical for wirebonding and SAC405 solder ball is evaluated. Current crowding, temperature distribution and electro-thermo induced effective stress distribution are predicted. A series of comprehensive parametric studies were conducted in this research.

On PID control and fuzzy control in permanent magnet synchronous linear motor (PMLSM) there is some shortage. Control for linear motor characteristics of vulnerable parameter perturbation is proposed based on fuzzy self-optimizing control algorithm to reduce the dependence on the model. GA algorithm using the parameters of fuzzy algorithm self-optimizing tuning, the motor can be reduced to some extent the impact of changes in their model, and improve the control effect. Finally, Matlab simulation of the PMLSM traditional PID speed control with fuzzy parameters self-optimizing speed control comparison, the results show that the fuzzy parameters self-optimizing control is better than traditional PID control.

Existing e-learning courses are designed to guide users acquire information or to help users undertake specific tasks. User is expected to increase proficiency about the context via the stationary computer. However, such design cannot allow multiple users to access the system simultaneously, thus leading inefficiency and lack of expandability. A framework to support M-learning in RFID system is therefore proposed. A mobile user first can use a mobile computer to communicate with home agent to acquire the related server information the may be interested in. The framework can navigate mobile agents to the mobile computer when the tag is detected within the coverage of the reader. The framework enables a mobile user to directly access his/her personalized services from the mobile computer. The experimental simulation demonstrates its efficiency.

How to effectively locate resources is a very important factor affecting the performance of distributed system in wide area network environments. Some resource location methods have been already proposed, which utilize Small World phenomena, but have not show how to construct a Small World exactly. In this paper, on the base of Kleinberg Small World model, aimed power-law characteristics, an efficient decentralized construction approach PLSWCP (Power-law oriented Small World Construction Protocol) is proposed, which uses fairly small partial view instead of global knowledge of network. Theoretical analysis and simulations show that PLSWCP is scalable, self-adaptable, and load-balanced, improving the efficiency of resource location.

It is significance to identify and track convective clouds using satellite images in nowcasting and severe weather warning. This article applies ant colony algorithm to match and track convection clouds identified from infrared channel images of FY - 2C satellite. The preliminary results suggest that ant colony algorithm is simple and effective to gain satisfactory results with adjustable features. The results also show the feasibility and characteristics of ant colony algorithm in cloud tracking and provide reference of ant colony algorithm application in other related research areas. Keywordsant colony algorithm–convective clouds–FY-2C satellite

Large variety of optical full-field measurement techniques are being developed and applied to solve mechanical problems. Since each technique possess its own merits, it is important to know the capabilities and limitations of such techniques. Among these optical full-field methods, interferometry techniques take an important place. They are based on illumination with coherent light (laser). In shearing interferometry the difference of the out of-plane displacement in two neighboring object points is directly measured. Since object displacement does not result in interferometry fringes, the method is suited for localization of strain concentrations and is indeed used in industry for this purpose. Used quantitatively DSPSI possesses the advantage over conventional out-of-plane displacement-sensitive interferometry that only a single difference of the unwrapped phase map is required to obtain flexural strains, thereby relieving problems with noise and reduction in the field of view. The first publication on (DSPSI) was made in 1973, but the emergence of a system providing quantitative measurements is more recent. This work aims to present the results of strain measurements using digital speckle pattern shearing interferometry (DSPSI).

Epoxy is widely used primarily as a matrix material in the manufacture of polymer matrix composite. Epoxy behavior under compression load has to be understood before the mechanical behavior of polymer matrix composite can be accurately predicted. Simulation model combined with experiment and image analysis have been used to investigate internal response of epoxy polymeric materials subjected to compressive loads. In the experiment, small carbon-based material rods are inserted in the epoxy. The samples are held in one side and subjected to compressive load on the other side. All the samples swell at load sides. Image analysis on the carbon-based rods figures out the internal response, which seems to be isotropy in lateral direction. The results are compared to simulation results. The simulation is conducted using Abaqus FEA software. Similar condition is obtained when a brittle thin material is stuck to the top of simulation model. Keywords: Abaqus FEA, compression, epoxy, polymer matrix composites

The main objective of this paper is to establish a precision contouring control of a biaxial piezoelectric-actuated stage. The positioning accuracy of the piezoelectric-actuated stage is limited due to the hysteretic nonlinearity of the piezoelectric actuators (PEA). To compensate this hysteresis problem, a feedforward controller based on an evolution algorithm is proposed. The dynamics of the hysteresis is formulated by the Bouc–Wen model and the evolutionary algorithms (EAs) are studied to identify the optimal parameters of the Bouc–Wen model. To verify the consistency, two micro-contouring tasks are implemented by the proposed feedforward controller with the feedback of linear optical scales in DSP based real-time control architecture.

The adsorption and diffusion of polydimethylsiloxane (PDMS) with different chain lengths on a silicon (111) surface were studied by molecular dynamics simulations. The relative dielectric constant was selected to be 1 to mimic a vacuum. The chains were all present as two dimensional (2D) adsorption conformation on the surface but different conformations and dynamic properties were found in the two absolutely different environments. The relationship between the adsorption energy of the different chain lengths and the degree of polymerization follows a linear function and the average adsorption energy per segment is -0.42 kcal/mol. In addition, the diffusion coefficient (D) of these chains scales with the degree of polymerization (N) as N -3/2.

Self-piercing riveting as an alternative joining method to spot-welding has attracted considerable interest from the automotive industry and has been widely used in aluminium intensive vehicles. Pressing and stamping are important processes in automotive production and result in additional straining on the vehicle body sheet material. It is therefore important to have knowledge of the effect of sheet pre-straining on the quality of the self-piercing riveted joints and on the mechanical behaviour of the riveted aluminium alloy sheets. This paper reports the influence of sheet pre-straining on the static and fatigue behaviour of self-piercing riveted aluminium alloy sheet. Wrought aluminium alloy sheet, NG5754 with a nominal thickness value of 2 mm was used to obtain pre-strained NG5754 sheets with pre-straining levels of 3%, 5% and 10%. Pairs of pre-strained NG5754 sheets were joined to create single-riveted lap joints which subsequently underwent lap-shear and fatigue testing. Microscopic inspection showed that the joint quality was satisfactory despite the increasing sheet straining levels. The results showed that by increasing the pre-straining level up to 10%, the shear and fatigue strength also increased. The rate of increase of the static and fatigue strength differed as the pre-straining levels varied.

Martensitic and magnetic properties of ferromagnetic shape memory alloys are known to depend up on structural modulations and associated changes in the Fermi surface. These modulations although periodic and spanning over multiple unit cells, involve movement of atoms typically of the order of 0.01A. Therefore X-ray Absorption Fine Structure (XAFS) is an ideal tool to map both, local atomic movements and changes in density of states (DOS) due to changing hybridization as the system transforms from austenitic to martensitic phase. This paper presents a compilation of our XAFS studies on the Ni-Mn based shape memory alloys. A complete description of the changes in local structure around the constituent metal ions in the following alloy compositions: Ni2+xMn1-xGa, Ni2Mn1.4Sn0.6 and Ni2Mn1.4In0.6 in the austenitic and martensitic phases have been obtained. The results give the new experimental evidence for the crucial hybridization component that influences and leads to structural transition in these Ni-Mn based Heusler alloys.

Intermetallic Ti-Al-Cr layers with small additions of Si, Zr, W, and Y were deposited on gamma-TiAl specimens using magnetron sputtering. The oxidation behaviour of the coated gamma-TiAl alloy was studied in the temperature range between 950 and 1000 C under cyclic oxidation conditions in air. Compared to the bare substrate material, the coatings exhibited higher oxidation resistance. During prolonged exposure the intermetallic layers degraded losing their capability to form a protective alumina scale. On coated gamma-TiAl samples zirconia topcoats were deposited by electron beam physical vapour deposition. These thermal barrier coating systems exhibited lifetimes exceeding the maximum exposure length of 1000 1 h cycles at 950 degrees C, but failed at 1000 degrees C. Failure was caused by degradation of the bond coats resulting in spallation of the thermally grown oxides.

The technology problems of fabricating different, nanometers sized gold particles in the layered composites like light-sensitive chalcogenide glass/gold nanoparticles/transparent substrate or titanium/titanium oxide/gold nanoparticles were investigated in our work. Combination of ion implantation, plasma deposition with annealing processes results physical routes for creation of gold nanoparticles in the mentioned structures, which possess plasmon effects. These functionalized structures are planned to use for investigations of optical recording processes, biocompatibility of titanium implants.

We derive the general expression of the anisotropic magnetoresistance (AMR) ratio of ferromagnets for a relative angle between the magnetization direction and the current direction. We here use the two-current model for a system consisting of a spin-polarized conduction state (s) and localized d states (d) with spin-orbit interaction. Using the expression, we analyze the AMR ratios of Ni and a half-metallic ferromagnet. These results correspond well to the respective experimental results. In addition, we give an intuitive explanation about a relation between the sign of the AMR ratio and the s-d scattering process.

Objective To explore the influence of Asparagus polysaccharide on Band 3 proteins and glycophorin A(GPA) of S180 mice erythrocyte membrane by contrasting the groups treated with deferent ways. Methods The experiment was equipped with 5 groups: normal control group (physiological saline), negative control group (physiological saline), Asparagus polysaccharide group (25mg/kg), Asparagus polysaccharide group (50mg/kg) and Asparagus polysaccharide group (100mg/kg).The content of sialic acid(SA) was determined by spectrophotometric method; the negative charges were detected by high performance capillary electrophoresis(HPCE); the relative content of glycophorin A and Band 3 were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE; anion transportation function of Band 3 was examined by the fluorescence spectrophotometric method; Flow Cytometer(FCM) was needed to observe the potential of erythrocyte membrane. Results Asparagus polysaccharide increased the content of sialic acid; advanced the migration time; improved the relative content of GPA and Band 3;obviously enhanced the CI- transportation function of erythrocyte Band 3;and caused the membrane potential obviously to elevate, Asparagus polysaccharide has the simultaneously influence on the functions of glycophorin A and Band 3 which are closely connected. Conclusion It is assumed that the anti-tumor function of Asparagus polysaccharide partly concerns function adjustments of glycophorin A and Band 3 from S180 mice erythrocyte membrane.

Properties of nanoparticles have been studied within the framework of Ising model and the method of random-field interactions: the average magnetic moment and position of critical points of the magnetic and the concentration phase transitions depending on their size. It is shown that the Curie temperature is inversely proportional to the size of the particle. Critical concentration of the ordered state decreases with increasing of size of nanoparticles until the percolation threshold of "massive" particles.

In this paper, we utilize the deformation transformation optics (DTO) method to design electromagnetic beam bender, which can change the direction of electromagnetic wave propagation as desire. According to DTO, the transformed material parameters can be expressed by deformation tensor of the spatial transformation. For a beam bender, since the three principal stretches at each point induced by the spatial transformation are independent to each other, there are many possibilities to simplify the transformed material parameters of the bender by adjusting the stretches independently. With the DTO method, we show that the reported reduced parameters of the bender obtained by equivalent dispersion relation can be derived as a special case. An isotropic bender is also proposed according to this method, and it is fabricated by stacking dielectric materials in layered form. Experiments validate the function of the designed isotropic bender for a TE wave; it is also shown that the isotropic bender has a broadband with low loss, compared with the metamaterial bender. The isotropic bender has much easier design and fabrication procedures than the metamaterial bender. Comment: 9 pages, 9 figures

A dump located in the proximity of the Vlaikov Vrah mine, Bulgaria, and containing about 120,000 tons of run-of-mine mining wastes (low-grade ores and rock mass), since 1968 was subjected initially to spontaneous natural bioleaching based on the rains as irrigating leach solutions, then from 1972 to 2003 to commercial-scale bioleaching by means of irrigation with acidified leach solutions, and since 2004 again to spontaneous natural bioleaching. The monitoring of these processes during this 40-year period revealed considerable changes in the composition, geotechnical and acid–base properties of the dump material, as well as in the diversity, number and activity of its microflora. The data obtained during this study were used to stimulate the bioleaching process in the huge commercial-scale copper dump leaching operation at Vlaikov Vrah mine in which about forty million tons of such mining wastes were treated.

We present the fabrication and optical testing of a fine grating on a ZnS substrate to be used as a wideband infrared spectral disperser and for which the primary application is measurement of the composition of the atmospheres of transiting exoplanets using space-borne infrared astronomical telescopes. A grating with a blaze angle of 2.1 deg. and pitch of 166.667 um was constructed on a roughly flat 10 mm x 10 mm substrate with a maximum thickness of 1 mm. To obtain high accuracy, the sample was fabricated on a ZnS monocrystal using a high performance processing machine at Canon Inc. The surface roughness measured with a microscope interferometer was 2.6 nm rms. The shape of the fabricated grating edges was examined with a scanning electron microscope. The diffraction efficiency was evaluated by optical experiments at {\lambda}=633 nm, 980 nm, and 1550 nm, and compared with the efficiencies calculated using a Fourier Modal Method. The results showed that the differences between the diffraction efficiencies obtained from experiment and by calculation were between just 0.9 % and 2.4 %. We concluded that the quality of the fabricated ZnS grating was sufficiently high to provide excellent diffraction efficiency for use in the infrared wavelength region. We also present the design of a spectral disperser in CdTe for future more advanced performance.

The necessary conditions of quasi-bound state formation of $\eta$-meson with isotopes $^{3}$He, $^{4}$He have been found within the framework of optical potential model. These conditions have been compared with the findings about helium nucleus densities and with the available information about $\eta$N-scattering length. Thus, we have conclude that within the framework of discussed model $\eta-^{3}$He quasi-bound state formation is not possible, but $\eta-^{4}$He quasi-bound state formation is possible with the great probability.

Electrophoretic deposition (EPD) allows the fabrication of ceramic coatings at lower cost and higher speed than most other deposition techniques. The processing consists of powder deposition from a suspension under the influence of an electric field and subsequent consolidation of the coating by sintering. Adherent zirconia coatings with coating thicknesses up to 0.1 mm were obtained from different suspensions, one methyl-ethyl-ketone and the other ethanol based. The standard sintering temperature is 1200°C, which easily may damage or change the substrate and also means high production costs. In order to reduce the sintering temperature, suspensions with the addition of ZrN were investigated. Due to reaction bonding, sintering in air at a remarkable low temperature of 1000°C was successful. The elastic modulus of the EPD coatings has been derived from impulse excitation experiments and the thermal conductivity from laser flash analysis. The elastic modulus was about 22 GPa and the thermal conductivity between 0.4 and 0.6 W/(m·K) at room temperature, both decreasing slightly with temperature. Especially the exceptionally low thermal conductivity makes EPD coatings a promising candidate for thermal barrier coatings.

The general idea of this paper is to produce TiB2 (ceramic particles) reinforced steel matrix composites. These ceramic particles are the best reinforcements for steel matrix composites because of their high thermal stability at higher temperature, high modulus of elasticity, good wetability, low density and their relative stability with steel matrix. This type of new composite family has received much attention as potential structural materials for their high specific strength and stiffness. Therefore, there is a significant interest in developing iron and steel matrix composites and evaluating dynamic behaviours due to their potential usage in automotive industry in future. Final purpose of this paper is to use of the steel sheet for the manufacturing of the lighted structure and manufacturing processes of this sheet. Titanium carbide and titanium diboride TiB2 reinforced steel matrix composites was therefore characterised by optical and scanning electron microscopy. Dynamic behaviours of the base metal and welded specimens have been tested to simulate under the impact-crash test conditions. KeywordsSteel matrix composites-Ceramic particles-TiB2 -Dynamic crash test-Welding

The better understanding of the material cutting process has been shown with the benefit of the forces and moments measurement since some years ago. In paper, simultaneous six mechanical components and chip orientation measurements were realized during turning tests. During these tests, the influence of the depth of cut or feed rate has been observed and a link between the chip orientation and the moment vector orientation or the central axis characteristics has been shown. Nomenclature * corresponding author

In the dual-phase model of interacting nanoparticles stretching leads to a decrease in both coercive force $H_c$ and saturation remanence $I_{rs}$, and compression - to their growth. Magnetostatic interaction between particles also decreases both $H_c$ and $I_{rs}$. Theoretical analysis was carried out in the framework of the dual-phase system of interacting particles on the example of nanoparticles $\gamma$-$Fe_2O_3$, epitaxially coated with cobalt.

The theoretical analysis of the effect of uniaxial stress on the magnetization of the system of noninteracting nanoparticles is done by an example of heterophase particles of maghemite, epitaxially coated with cobalt ferrite. It is shown that stretching leads to a decrease in the coercive force $H_c$, and compression leads to its growth. The residual saturation magnetization $I_{rs}$ of nanoparticles does not change. With increasing of interfacial exchange interaction, coercive force varies nonmonotonically

For reducing the porosity of single crystal (SX) nickel-based superalloys, Hot Isostatic Pressing (HIP) is used. High pressures of about 100-170 MPa lead to local deformation, which close the pores. However, since HIP also requires high temperatures (1000-1200°C) it has a pronounced effect on the microstructure and the local distribution of elements. This contribution analyses the effect of different HIP treatments on both the microstructure and the segregation of the SX superalloy LEK94 in the as-precipitation-hardened state. In addition, the effects of rapid or slow cooling are analyzed. To distinguish the effect of pressure from those of temperature, the HIPed samples are compared with specimens annealed at atmospheric pressure.

The properties of ultrathin films have been studied within the framework of Ising model and the method of random-field interactions. It is shown that the Curie temperature is inversely proportional to the number of layers. Critical exponent nu has been obtained and it is shown that it does not depend on the type of crystalline lattice. As a characteristic, that allows to evaluate the smallness of magnetic objects, one can take the length of the spin-spin correlation xi. It is used to describe the spin fluctuations near the critical temperature. In the case when the film thickness is less than the correlation length of bulk samples, there appear various size effects. In particular, the decrease of film thickness can lead to a reduction of phase transition temperature: according to measurements on films of iron, nickel and cobalt [1-8], T-c, decreases with decreasing of film thickness N (here N is the number of monolayers). The experimentally observed dependence of the Curie temperature on the thickness T-c(N) can be described by the relation introduced in [6-7]: epsilon(N) =(def) T-c(N ->infinity) - T-c(N)/T-c(N ->infinity) = c(0)(N - (N) over tilde)(-lambda) where T-c(N -> infinity) =(def) T-infinity - temperature of bulk sample, c(0) and (N) over tilde - constants. The argument lambda is related to the critical exponent of the spin-spin correlation v as follows: lambda = 1/v [9]. And, as was shown in [10-12] the constants and argument of the dependency (1) essentially depend on the type and symmetry of the crystal lattice of sprayed film and its substrate. In this paper we assess the influence of film thickness and its crystal structure on the temperature of magnetic phase transition. To solve this problem we use the following model.

This paper deals with the modeling and control of discrete event robotic manufacturing cells using Petri nets, and proposes a methodology of model based design and implementation of hierarchical and distributed control. Hierarchical Petri net models are adopted; conceptual Petri net model and detailed Petri net model. The overall detailed Petri net model is decomposed into local Petri net models which are used by the local machine controllers. The upper level station controller coordinates the distributed local controllers so that the aggregate behavior of decomposed subnets is the same as that of the original Petri net. The overall control system is implemented using multithreaded programming based on Petri net based multitask processing. Simulation experiments show that the distributed Petri net model based control system can perform the overall multitask processing control by coincidence of the behavior of the real system with the local Petri net models.

This work presents the possibility of obtaining duplex stainless steels through powder metallurgy technology starting from austenitic X2CrNiMo 17-2-2, martensitic X6Cr13 powders by controlled addition of alloying elements, such as chromium, nickel, molybdenum and copper in the right quantity to obtain the chemical composition of the structure similar to biphasic one. In the studies behind the preparation of mixes, Schaffler's diagram was taken into consideration. Prepared mixes of powders have been compacted at 800 MPa and sintered in a vacuum furnace with argon backfilling at 1260 °C for 1 h; after sintering rapid cooling has been applied in N2, with an average cooling rate of 650 °C/min. Produced duplex stainless steels has been studied by SEM with EDS a light optical microscopy (LOM) and X-ray analysis to determine obtained structures. Mechanical properties such as tensile strength, impact energy, hardness and wear rate were evaluated.

The application of the Peng-Robinson equations of state (PR EOS) using Matlab and Mathematic has already been demonstrated. In this paper, using Mathematic to solve Soave-Redlich-Kwong (SRK) EOS, as well as the estimation of pure component properties, plotting of vapor-liquid equilibrium (VLE) diagram and calculation of chemical equilibrium, is presented. First the SRK EOS is used to predict several pure-component properties, such as liquid and gas molar volumes for isobutane. The vapor-liquid isobaric diagram is then plotted for a binary mixture composed of n-pentane and n-hexane under the pressures of 2*10^5 and 8*10^5 Pa respectively. KeywordsApplied Thermodynamics–Soave-Redlich-Kwong Equations of State–Mathematic

A study of the kinetics of ferrous iron oxidation by a free suspended culture of the bacterium Leptospirillum ferriphilum in batch regime at moderate to high iron concentrations was conducted. A circulating bed airlift bioreactor was used in order to obtain reliable biokinetic data, unaffected by biofilm growth. The two major factors in consideration were the effects of the pH and the total iron concentration in the range of 5–40 g/L. The optimal pH was found between 1.05 and 1.80. In this range a strictly growth associated biooxidation with constant yield coefficient was proven, while at suboptimal pH values non-growth associated iron biooxidation was shown at pH as low as 0.4. This effect was taken into consideration for the derivation of a Monod-type kinetic model, derived on first principles from the electrochemical-enzymatic model for ferrous iron biooxidation. Our model shows a linear dependence between the apparent half-saturation constant (Kapp) and the total iron concentration in studied range of iron concentration.

In this paper we investigate the dependence of the magnetic states of heterophase particles on mechanical multiaxial stresses. It is shown that for such particles, there are four possible states, and the conditions of stability of these states are determined.

In this paper we consider an approach, which allows researching a processes of order-disorder transition in various systems (with any distribution of the exchange integrals signs) in the frame of Ising model. A new order parameters, which can give a description of a phase transitions, are found. The common definition of these order parameters is the mean value of percolation cluster size. Percolation cluster includes spins with given energy. The transition from absolute disorder to correlated phase could be studied with using of percolation theory methods.

This research aims to investigate the effects of chemical blowing agent (CBA) contents and particle sizes on the properties of foamed poly(vinyl chloride) (PVC)/rice hull (RH) composites. Fine particles of azodicarbonamide (AC) at 5, 8, 11 and 22 μm were modified with 20% by weight of ZnO and used at 0–3.0% by weight. The average cell size and density of the PVC/RH foamed profiles were reduced as the content of modified azodicarbonamide (mAC) increased. Larger mAC particles lowered the density more effectively. Maximum reduction of density by 46% was achieved when mAC 22 μm was applied at 2.0% by weight. Larger blowing particles led to PVC/RH foam with greater flexural modulus and strength. Greater impact strength, observed when 5 μm mAC was applied, resulted from the rather thick cell wall created abundantly when fine mAC was applied.Graphical abstractThe changes in the cell size and the foam structure created by each particle size of mAC.Research highlights► Azodicarbonamide decomposed speedily in the presence of ZnO. ► At identical blowing agent content, the larger blowing agent particles lowered the foam density more than the smaller ones. ► The abundant surface openings were remnants depicting the passages of gas evolved during foaming.

This paper investigates the effects of oxidizer concentration, pH and slurry flow rate on the material removal rate (MRR) in chemo-mechanical polishing (CMP) of Si (1 0 0) wafers. The CMP was carried out in alkaline slurry using alumina and ceria particles with hydrogen peroxide. It was found that the applications of the two particle materials lead to very different results. When using the alumina particles, the MRR initially decreases with increasing the slurry pH value until pH = 9. Nevertheless, the application of the ceria particles increases the MRR before the pH of the slurry reaches 10. It was concluded that in the former, the effect was due to the particle agglomeration and the contact angle decrease of the oxidizer slurry with the wafer surface; whereas in the latter it was caused by the particle agglomeration and the modification of trivalent ceria ions. The influence of the slurry flow rate and oxidizer concentration, regardless of the particle type, was found to be similar—a higher flow rate or a higher oxidizer concentration brought about a greater MRR before reaching a plateau. Many of these were interpreted by an adhesive removal mechanism on the molecular scale.Research highlights▶ Effects of oxidizer concentration, pH and slurry flow rate on the material removal rate (MRR) in CMP of Si (1 0 0) wafers were investigated. ▶The applications of the two particle materials including alumina and ceria lead to very different results. ▶ An adhesive removal mechanism on the molecular scale was also addressed.

CNx–TiNx composite films were prepared on high-speed steel (HSS) substrate by pulsed KrF excimer laser co-deposition process with graphite/Ti combined targets and a substrate temperature of 200 °C. The composition, morphology and microstructure of the films were characterized by energy dispersive X-ray spectrum (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The adhesion and tribological performance of the films were investigated using a conventional scratch tester and a ball-on-disk tribometer, respectively. In the graphite/Ti range of 0.5–2.0 of the target, TiNx, a-CNx and metallic Ti phase were found in the composite films. The TiNx disappeared in the films at a high graphite/Ti ratio of the target. With increasing the graphite/Ti ratio of the target, the adhesion to substrate of the composite films deteriorated from 46 N to 26 N, and the friction coefficient decreased from 0.23 to 0.17. The composite film deposited at the graphite/Ti ratio of 1.0 showed a low friction coefficient, good adhesion and wear rate of 3.2 × 10−7 mm3/Nm in humid air.

Top-cited authors
• Universiti Teknologi MARA
• Universiti Malaysia Perlis
• Universiti Malaysia Pahang
• KU Leuven
• Carleton University