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The triple-negative breast cancer cell line MDA-MB-231 has been known as one of the most tenacious cancer cancer cells and paid attention by many researchers. A two-dimension quantitative structure-activity relationship (2D-QSAR) model of 131 benzimidazole derivatives was developed to relate the chemical–biological interactions and predicted the half maximal inhibitory concentration (IC50) against MDA-MB-231 cell line. The 2D-QSAR model was obtained satisfactory internal and external validation parameters such as the square of correlation coefficient R2 = 0.904 and concordance correlation coefficient CCC = 0.867. The model was and applied on 35 synthesized benzimidazoles to predict IC50 values. The results showed that benzimidazoles with IC50 less than 50 µM displayed a quite similarity between predicted and experimental IC50 values (Ra2 = 0.924). The molecular docking study was investigated to clarify the binding mode of the most potential synthesized benzimidazoles (BLMM, and BL3H) into topoisomerase I-DNA complex. The docking results revealed that they intercalated and interacted to crucial amino acids in the binding site of complex by hydrogen bonds and hydrophobic interactions and compared to standard drug camptothecin.

Aeroelasticity is a science to study interaction between aerodynamic, elastic and inertial forces. Flutter is the most dangerous aeroelasticity phenomena, that is defined as the dynamic instability of an object in an airstream. Following flutter phenomenon, unsteady aerodynamic forces generated from elastic deformations of structure. It can lead to a disastrous structural failure. This paper examined aeroelasticity properties of a flat copper alloy plate by combining simulation methods using ANSYS software and experimental methods with help of subsonic wind tunnel at M = 0.1. At the first stage, elastic properties of this thin plate were carried out by using vibrational experiments and modal method to determine the specific vibration frequencies. Then, these aeroelasticity properties were estimated at three different attack angles of 0o, 5o and 10o. Finally, instability phenomenon of this flat plate was investigated within limited experimental conditions to be able to select objects and experimental solutions to be feasible and effective.

Helicopter Unmanned Aerial Vehicle (HUAV) is recently used in agriculture due to its dynamic, flexible, vertically take-off/landing, hover and to laterally fly. The HUAV was researched and designed with purpose of greatly reducing manpower, limited direct contact of human with toxic substances, reducing time working in parallel with improving quality and yield. This paper focused on the main rotor blades of HUAV with 15 kg useful load. The main rotor was first designed and then numerically validated by using computational fluid dynamic (CFD) tool in ANSYS software. The aerodynamics characteristics of main rotor blades of HUAV such as pressure, velocity, thrust, drag ...were carried out at hovering flight mode. Finally, strengthen analysis of main rotor blades were checked using computational solid dynamic (CSD) tool in ANSYS software. The aim of this paper was to check whether the designed blades of main rotor were durable enough or not to continue the next design steps.

Aeroelasticity on airplane wing has a significant impact on the efficiency and the safety of a flight. Therefore, the study of aeroelasticity problems is a great attention in wing design process. To analyze this, three primary subjects of aeroelastic phenomena that the examination has to focus on, which are wingtip oscillation amplitude, flutter frequency and critical flutter velocity of the wing. [1] As these subjects are highly dependent on structures and materials of the wings, therefore, the aim of this paper is to introduce a structural calculation which is the combination of three experimental models and the infinite element method. Supercritical is chosen as the sample airfoils of the simulation. The model wings are made from different materials and size in order to create varied wing structures, thereby a comprehensive analysis is accomplished and the flutter velocity is also restricted to appropriate values within the working range of experiment devices. Simultaneously, Infinite element method using ANSYS software to simulate the phenomena on the same model wings is also conducted as a verification for the precision of the experimental models. In conclusion, obtained results from the structural calculation have a high applicability in the preliminary design stage of airplane wings, by making comparisons between two or more chosen airfoils to conclude which is the better one in term of wing sustainability and aeroelasticity resistance.

In the last several decades past, Helicopters UAVs (Unmanned Aerial Vehicles) have quickly developed and day by day, they play an important role in human life. As it is well-known, helicopters UAV make some outstanding characteristics such as light weight, flexibility and particularly automatically controlled. By applying these characteristics, we research and manufacture Helicopter UAV using for spraying pesticide in agriculture. One of the most important components is main rotor because main rotor generated thrust, drag and momentum. Helicopters UAV efficient changed depending on main rotor. The research works focus on aerodynamics characterization of main rotor in helicopter UAV. This work uses CFD tool in ANSYS CFX software to calculate the aerodynamics parameters generated by main rotor using in UAV. The aim is to characterize the aerodynamics characteristics such as thrust, drag, pressure, aerodynamics quality on the different flight modes (hover, vertical and forward flight). Firstly, the simulations are carried out in hover flight mode with different blade pitch angles. The results are compared to experiment date in another research to validate numerical results. Then, the simulations are carried out in vertical flight mode and forward flight mode. The results showed that thrust and drag coefficient creased with increasing blade pitch angle. When blade pitch angle started from 1800, thrust coefficient decreased but drag coefficient increased sharply. The rotor performance was measured by aerodynamics quality and numerical results showed that the best rotor performance was at 900. In the vertical flight mode, the thrust and drag coefficient decreased with increasing vertical velocity but rotor performance increased slightly. The best vertical velocity for vertical flight is around 2 m/s and 3 m/s. Finally, in forward flight mode, the aerodynamics characterizations of rotors depended on azimuthal angular position of blade or time. Our helicopter operates in environment with light gust. The results showed the change of aerodynamics coefficient to time. Both thrust and drag coefficient changed but the rotor performance did not change much.

This paper aims to estimate the effect of turbulent inlet flow to vortices on Delta wing with four different turbulence intensity from 0.5% to 15% and the effect of taper ratios to aerodynamic characteristics of Delta wings with four taper ratios: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7. The main purpose of this paper is to find out the formation, development, and breakdown of vortices on Delta wings when changing taper ratios and turbulence intensity thence determining the center of vortices with the range of attack angles from 5o to 40o in low velocities about 2.5 m/s. This research uses Delta wing models with a 40o swept-back leading edge, the root chord length 150 mm, and a thickness 5 mm. The problem is simulated by using ANSYS fluent and experiment in the subsonic wind tunnel to compare and validate results. The Delta wing models are meshed by using ICEM to improve the mesh quality and using the turbulence model for low Reynolds number flows Transition SST (4 equations) to calculate aerodynamic characteristics such as lift coefficient, drag coefficient, pressure coefficient... find the paths which connect centers of the vortices, and show the contours of pressures and velocities to evaluate the change of centers of the vortices. The results showed that the two vortices grow up and tend to move inward when the attack angle increase, the vortices are broken strongly in high attack angles, the aerodynamic quality of Delta wings change insignificantly when changing turbulent intensity at inlet. This research also carried out that the stall angle increase when increasing the taper ratio.

This study reports a simple process to synthesize and separate of 2-(substituted-phenyl) benzimidazole derivatives with high yield and efficiency. Specifically, by reacting ortho-phenylenediamines with benzaldehydes using sodium metabisulphite as an oxidation agent in a mixture of solvent under mild condition, twenty-three compounds of benzimidazoles were obtained and separated easily using hexane and water to wash, respectively. The structure of all obtained compounds was identified by FTIR, NMR and HRMS. The SAR analysis of synthesized benzimidazoles on human lung (A549), breast (MDA-MB-231) and prostate (PC3) cancer cell lines showed that the presence of methyl group at 5(6)-position on benzimidazole scaffold was a contributing factor influencing the anticancer activity. The presence of electron-donating groups (OH, OMe, –NMe2, –O–CH2–C6H5) also caused significant increase of anticancer activity, while the presence of electron-withdrawing groups (–NO2, –CF3) on the phenyl group at 2-position of benzimidazole ring decreased the ability of inhibition of synthesized benzimidazoles. The compounds 2f and 2g displayed the significant anticancer activity on both A549 and PC3 cell lines. Two series of 2-phenylbenzimidazoles were synthesized by simple process with high yield and efficiency and they were illumiated the effect of substituent groups in their structures on the bioactivity against three cancer cell line A549, MDA-MB-231 and PC3.

In order to explore and develop new anticancer agents, three series of 2-phenylbenzimidazoles, 15–46, were condensed under simple and mild conditions using sodium metabisulfite as an oxidation agent and another series, 47–55, were obtained via a reduction reaction using sodium borohydride. All the compounds synthesized were evaluated for their in vitro anticancer activities against three human cancer cell lines. The novel compound 38 was found to be the most potent multi cancer inhibitor against A549, MDA-MB-231, and PC3 cell lines (IC50 values 4.47, 4.68 and 5.50 μg mL−1, respectively). In addition, compound 40 exhibited the best IC50 value of 3.55 μg mL−1 against the MDA-MB-231 cell line. The results demonstrated that introducing a new substituent to compounds 37–55 could improve their antiproliferative activities.

In this study, magnetic snail shell (MSS) prepared by impregnating of iron oxide onto snail shell (SS) powder was used for removing Cr(VI) from aqueous solution. Among six different mass ratios of Fe/SS powder studied, the MSS25 produced at a ratio of 25% achieved the highest Cr(VI) adsorption capacity. Batch adsorption experiments were conducted to investigate the adsorption isotherm, kinetics, and mechanism of Cr(VI) onto MSS25. The results illustrated that adsorption of Cr(VI) onto MSS25 reached equilibrium after 150 min at pH 3. The adsorption kinetics could be well described by the pseudo-second order model (R2 = 0.986). The Langmuir model (R2 = 0.971) was the best-fitting model that described the adsorption isotherm of Cr(VI) onto MSS25. The maximum adsorption capacity was 46.08 mg Cr(VI) per gram of MSS25. Ion exchange, electrostatic attraction, and adsorption-coupled reduction were determined as the main adsorption mechanisms of Cr(VI) onto MSS25. The high percentages of CaCO3 and Fe3O4 found in the MSS25 structure made a significant contribution to the Cr(VI) adsorption process.

Aeroelasticity phenomena arise when structural deformations induce changes on aerodynamic forces due to airplane structures that are not completely rigid. The additional aerodynamic forces cause an increase in the structural deformations, which leads to greater aerodynamic forces in a feedback process. These interactions may become smaller until reaching a condition of equilibrium or may diverge catastrophically if resonance occurs. Flutter is an instability aeroelasticity phenomenon which is the most difficult to predict. In this chapter, a numerical method and an experimental method were realized to predict aeroelastic response and characteristic parameters of a wing structure. The numerical method was firstly developed based on the interaction between computational fluid dynamic and computational structural dynamic methods using a coupling system, fluid–solid interaction (FSI), in the ANSYS software. Then, an experiment was set up in suitable conditions to study aeroelasticity characteristics with the goal of comparing the numerical results with the experimental results on the same wing structure at low speed. After that, a developed code based on immersed boundary method (IBM) was realized to predict aeroelasticity response and characteristic parameters of the wing structure. AGARD 445.6 wing model was chosen for this developed procedure at high speed. Obtained results were compared to other numerical and experimental results.

In this paper, a simulation method was realized to predict aeroelastic response and characteristic parameters of wing structure. This method was developed base on interaction between Fluent solver and Mechanical APDL solver using a coupling system in ANSYS Workbench. AGARD 445.6 wing model was chose for this developed procedure at high speed. Obtained results were compared to other numerical result and experimental results. After that, experiment was also setup in suitable conditions to study aeroelacticity characteristics and specify quantitative parameters as frequency, amplitude of oscillation, wing root forces. Final goal was comparison between numerical results and experimental results on the same wing structure at low speed.

In this study, an experimentally and numerically investigation was carried out to obtain characteristics (lift force, drag force ...) on 74.5 degree Delta wing. The experiment tests were conducted at Hanoi University of Science and Technology low-speed wind tunnel facility, whereas the numerical tests were performed using the commercial computational fluid dynamics software ANSYS/FLUENT. The apparition of the vortices upon the Delta wing caused the negative pressure distribution on the wing which reached a maximum absolute value at the vortex core. The characteristics of high swept-back Delta wing were investigated at air velocity of 10 m/s and attack angle of 20 degree in changing the rolling angle of the wing from 0 to 20 degree.

Effects of turbulent flow to dynamic characteristic of high sweep-back angle Delta wing were performed by numerical (SIM) and experiment (EXP) method in subsonic flow. The numerical method was based on CFD methods using ANSYS/FLUENT software, while experiment method was conducted in low speed wind tunnel (Mach number M=0.1). At low Reynolds number, air velocity 2.5m/s, the Delta wing was investigated with attack angle of 20 degree within four cases of turbulence intensity, which varied from 0.5% to 15% due to parameter of grid. Decay of turbulence intensity with and without grid was considered. Change of dynamic characteristic of Delta wing caused by different change of turbulence intensity at inlet flow was also observed. Finally, distribution of pressure on Delta wing were measured and calculated; and then interaction between turbulent flow and vortex on upper wing was clarified.

Dendrimer, a new class of hyper-branched polymer with predetermined molecular weight, is being received much attention in nano biomedical applications such as anticancer drug delivery, gene therapy, disease diagnosis and etc. In this study, polyamidoamine (PAMAM)-based dendrimer generation 3.0 (G 3.0) was synthesized and subsequently pegylated. Obtained results showed that pegylation degree of the dendrimer was around 31% for its external amine groups. TEM image of the pegylated dendrimer exhibited spherical shape and nano sizes ranging from 30 to 40 nm. The fluorouracil (5-FU)-loaded pegylated dendrimer showed a slow release profile of the drug. In vitro study, at the primary screening concentration of 100 microg/mL, the PAMAM dendrimer presented higher toxicity in MCF-7 cells as compared to its pegylated counterpart. Meanwhile, the (5-FU)-loaded pegylated dendrimer exhibited the antiproliferative activity against the cell line with the IC50 of 9.92 +/- 0.19 microg/mL. In vivo tumor xenograft study, we succeeded in generating MCF-7 cells-derived cancer tumors on mice that was well-confirmed by using flow cytometer assay. The 5-FU encapsulated pegylated dendrimer exhibited a significant decrement in volume of the tumors which was generated by MCF-7 cancer cells.

Star-shaped poly(methyl acrylate) (PMA) was synthesized using tri(2-bromopropionate) glyceride as the initiator and methyl acrylate as the monomer via atom transfer radical polymerization (ATRP). The structures of tri(2-bromopropionate) glyceride and PMA were characterized by IR, GC-MS, 1H NMR, and 13C NMR. The reinforcing effects of this star-shaped PMA on polyvinylchloride (PVC) in various PMA/PVC blends were evaluated. The results indicated that a blend containing 1% star-shaped PMA exhibits an 18% increase in the elastic modulus and a 10% increase in tensile strength compared to PVC. Moreover, the impact resistance of the blend was 30% higher than that for PVC. The blend also exhibited high thermal stability. SEM images showed that the star-shaped PMA and PVC are highly compatible when blended, which causes the enhanced elasticity of the blend.