International Journal of Engineering
Volume:32 Issue: 4, Apr 2019

Boron neutron capture therapy (BNCT) is an effective clinical method in cancer treatment based on fission reactions and nuclear capturing. In this method, use of the best boron-containing agents for boron therapy and boron delivery agent for transfer to the infectious site are the key points for  efficienct treatment. Our research indicated that calcium fructoborate(CF) was the best compound as a boron-containing agent for boron therapy. Furthermore, studies have demonstrated that liposomes can selectively and effectively deliver large quantities of boron to cells and that the compounds delivered by liposomes have a longer cell retention time. Indeed, liposomal encapsulation technology of CF as nanostructured liposome carriers (NLCs) was extensively evaluated due to the ability of these nano-vehicles for the delivery of boron compounds. In this work, the molecular composition of the CF used as a carrier supplement for cancer therapy is deeply investigated. FTIR, XRD, TG, DSC and Raman spectroscopic analyses were used for the characterization of the carrier. The experimental measurements agreed very well with the molecular formula of Ca[(C6H10O6)2B]24H2O.

The Iranian plateau has been known as one of the most seismically active regions of the world, and it frequently suffers destructive and catastrophic earthquakes that cause heavy loss of human life and widespread damage. Earthquakes are regularly felt on all sides of the region. Prediction of the occurrence location of the future earthquakes along with determining the probability percentage can be very useful in decreasing the seismic risks. Determining predicted locations causes increasing attention to design, seismic rehabilitation and evaluating the reliability of the present structures in these locations. No exact method has been approved for predicting future earthquake parameters yet. In recent years, more attention is paid to the earthquake magnitude prediction, but no study has been done in the field of probable earthquake occurrence hazard zonation. In this study, locations of future earthquakes in Iran were predicted by self-organized artificial neural networks (ANN). Then probable seismic risk zoning map was drawn by the statistical analyses, and the results indicated that the maps can properly predict future seismic events.

Reinforced Concrete (RC) deep beams are commonly used in structural design to transfer vertical loads when there is a vertical discontinuity in the load path. Due to their deep geometry, the force distribution within the RC deep beams is very different than the RC shallow beams. There are some strut and tie model (STM) already been developed for RC deep beams. However, most of these models are developed for RC deep beams with the simply supported boundary condition, which do not apply for RC deep beams with the fix-ended condition. In this paper, five fixed-end RC deep beams have been tested experimentally which were subjected to monotonic and cyclic loads. Also, a simple STM was proposed to simulate the load capacity and failure mode of fix-ended RC deep beams. The proposed STM has the main strut and sub struts to simulate the force distribution within the RC deep beams. This STM were verified using five fixed-end RC deep beams subjected to monotonic and cyclic loads and compared to the response of 31 additional independent experimental tests. The result shows the newly proposed STM can simulate the load capacity and failure mode of fix-ended RC deep beams very well.

In this paper, a mesh-free approach called smooth particle hydrodynamics (SPH) is proposed to analyze the seepage problem in porous media. In this method, computational domain is discredited by some nodes, and there is no need for background mesh; therefore, it is a truly meshless method. The method was applied to analyze seepage flow through a concrete dam foundation. Using the SPH method, the computational boundary being coincident with the physical boundary, was numerically acquired by solving seepage flow govern in equations. The numerical results of the presented method were compared with ones calculated by the Geostudio-SEEPW (finite element based software). The water head values were calculated through the dam foundation, and there was a good agreement between results. Moreover, results showed that the SPH method is efficient and capable of analyzing seepage flow particularly in complex geometry problems.

Recently developed man-made structures have caused environmental pollutions, and unfortunately, in spite of the deteriorating affairs and repeated warnings by scientists and experts, the degree of contamination is increasing considerably. One of the natural sources undergoing changes is the coasts. It is mainly due to human activities which have led to a change in the quality and quantity of sediments. These regions can be contaminated by a variety of hazardous pollutants such as heavy metals and hydrocarbons. In this work, a combination of electrokinetic and MFC process was used for Cr removal from contaminated sediments. According to the obtained results, a maximum power density and current of 1.06 W/m3 and 52.05 A/m3 were achieved during the process. Given the presence of chromium in the catholyte, it can be concluded that the chromium migration from sediment sample to the cathode chamber has been taken. In addition, the maximum Cr measured in catholyte was 0.056 mg/l. Overall, the results confirmed the high efficiency of the proposed cell for contaminant removal from sediments.

Concentrically braced frames (CBFs) are one of the efficient lateral load resisting systems in high seismicity regions. One of the common problems with the use of concentrically braced frames is limitation in the architectural application and position of the openings. Two-story X braced frames have more advantages than other configurations of concentrically braced frames, since in many cases the position of the openings due to the need for architectural spaces and executive imperfections causes the use of asymmetric X-braced frames, present study tries to evaluate the seismic behavior of asymmetric two-story X braces. In this study,  the behavior of these braces has been studied. For this purpose, firstly, several symmetric two-story X braced frames are modeled by OpenSees software. Then, by changing the position of braces to beam connection, the new asymmetrical braces are obtained which initially designed. Finally, parameters such as stiffness, strength and stable hysteresis cycle of asymmetric systems are compared with symmetrical braces by nonlinear static and dynamic analysis. The results show that if asymmetric braces are distributed symmetrically in the structure, they do not lose their ability in comparison with the symmetrical models.

In this paper, a compact plasmonic metamaterial absorber for terahertz frequencies is proposed and simulated. The absorber is based on metamaterial graphene structures, and benefits from dynamically controllable properties of graphene. Through patterning graphene layers, plasmonic resonances are tailored to provide a dual band as well as an improved bandwidth absorption. Unit cell of the designed structure is made of four complementary square rings, on a thin grounded SiO2 layer of 5 µm thickness. Four splits are included in the square rings to provide continuity of graphene layer. Dual band absorption of 90% is provided, which frequency of peak absorption increases with increasing chemical potential of graphene layer. It is shown that with varying dimensions of the split rings an improved bandwidth absorber is also achieved, where absorption band increases with increasing graphene's chemical potential either. To better understand excitation of plasmonic resonances on the proposed structure, electric field distribution on the graphene layer as well as at the unit cell’s cross section is investigated and graphically demonstrated. Dependence of absorption on incidence and polarization angles of the incoming wave is studied and also graphically presented.

We have developed the effective algorithm for detecting digital binary phase-shift keyed signals. This algorithm requires a small number of arithmetic operations over the signal period. It can be relatively easy implemented based on the modern programmable logic devices. It also provides high interference immunity by identifying signal presence when signal-to-noise ratio is much less that its working value in the receiving path. The introduced detector has intrinsic frequency selectivity and allows us to form the estimate of the noise level to realize the adaptive determination of decision threshold. In order to get confirmation of the detector operability and performance, we suggest the expressions for false alarm and missing probabilities. In addition, we have examine, both theoretically and experimentally, the influence of the detector parameters on its characteristics.

In this paper, a new hybrid routing protocol is presented for low power Wireless Sensor Networks (WSNs). The new system uses an integrated piezoelectric energy harvester to increase the network lifetime. Power dissipation is one of the most important factors affecting lifetime of a WSN. An innovative cluster head selection technique using Cuckoo optimization algorithm has been used in the designed protocol. The residual energy of the nodes and the distances to the sink were used in the threshold calculations, besides to take advantage of the relay node for communication. A hybrid method using the optimized routing protocol and the integrated energy harvester results in 100% increase in the network lifetime compared to recent clustering-based protocols. The simulations results using MATLAB indicate that energy consumption was been decreased by more than 40%.

In this paper a voltage mode four quadrant analog multiplier (FQAM) using voltage differencing buffered amplifier (VDBA) based on quarter square algebraic identity is presented. In the proposed FQAM the passive resistor can be implemented using MOSFETs operating in saturationregion thereby making it suitable for integration. The effect of non idealities of VDBA has also been analyzed in this paper. Theoretical propositions are verified through SPICE simulations at 0.18μm CMOS technology node and the simulation results are found in close agreement with theoretical values. The supply voltage is taken as ± 1V and the value of the bias current is set to 40µA.The simulated total harmonic distortion (THD) is observed to be under 3% and the total power dissipation is found as 627µW. The workability of the proposed FQAM is also tested through two applications, namely, an amplitude modulator and a rectifier. The simulated results corroborate the theoretical propositions.

Doubly-fed induction generator (DFIG) based wind turbines with traditional maximum power point tracking (MPPT) control provide no inertia response under system frequency events. Recently, the DFIG wind turbines have been equipped with virtual inertia controller (VIC) for supporting power system frequency stability. However, the conventional VICs with fixed gain have negative effects on inter-area oscillations of regional networks. To cope with this drawback, this paper proposes a novel adaptive VIC to improve both the inter-area oscillations and frequency stability. In the proposed scheme, the gain of VIC is dynamically adjusted using fuzzy logic. The effectiveness and control performance of the adaptive fuzzy VIC is evaluated under different frequency events such as loss of generation, short circuit disturbance with load shedding. The simulation studies are performed on a generic two-area network integrated with a DFIG wind farm and the comparative results are presented between three cases: DFIG without VIC, DFIG with fixed gain VIC, and DFIG with adaptive fuzzy VIC. All the results confirm the proposed fuzzy VIC can improve both the inter-area oscillations and frequency stability.

We carried out a comparative analysis of the algorithms for detecting a rectangular impulse against Gaussian white noise under either authorized or unauthorized access to the transmitted data. We presupposed that for data transmission the binary communication system is used and that the useful information in the data is whether the signal is present or absent. The case is that unauthorized access by the outsider takes place in the situation when the signal parameters are completely or partially unknown. We then define the degree of the transmitted data secrecy by the secrecy ratio determining how highly the threshold signal-to-noise ratio increases when there is the unauthorized access instead of the authorized one.

In this research, Generalized Predictivecontrol (GPC) is proposed for the control of a stabilizing loop from a two axis gimbal seeker. In fact, there are some views about using GPC type controller which are two folds. First, it drives the stabilization loops that are made by a DC motor, Rate Gyro, inertia and cross coupling unit in between two channels using the predictive model type controller. Second, the theory is to excavate the results of flight simulation on the efficiency of two-axis gimbal seeker. The simulations, based on different scenarios, are valuated for the proficiency of the designed system considering the dynamic mass imbalance and the cross-coupling in between two channels and the flight simulation. The flight simulation results are explained the accuracy of the designed system with predictive control in opposite of conventional PI controller. For example, the simulation results in altitude of 2km show the suggested system in comparison with conventional PI controller improves miss-distance and flight time 11.98% and 1.5%  respectively. Moreover, the suggested system in maximum control signal is 72.61%, minimum control signal is 1.55% and final time is 80.43% (control effort parameter), which is better than PI type controller.

This paper focuses on the design of a 10 MW hybrid power plant using the technical specifications (data sheet) of an industrial solar panel. The main purpose was to find out the exact electrical properties of the solar panel specialy with conjunction to its temperature, to optimize overall output energy. We first describe the most important types of solar power plants and afterwards focus on electric plant. Subsequently, we use a suitable mathematical algorithm to find required, exact technical specifications for the photovoltaic panels from the manufacturer's general data set. After designing and optimizing the electric powered plant, explanation on the thermal power calculation is provided for using in the subsequent criteria. In the phase of thermal power design, the meteorological information related to the city of Arzoyeh of Kerman (28° 27′ 35.5″ N, 56° 21′ 56.88″ E) has been introduced into the Modelica, a powerful engineering open source software. Accordingly, a proper code was written to extract both interrelated thermal and electrical energies in the whole months during the year along with its corresponding efficiency. At the end of the work, trade off solutions for increasing the efficiency in different conditions and structures suggested, calculated, and compared.

Demand for high-performance cooling systems is one of the most challenging and virtual issues in the industry and Pulsating heat pipes are effective solutions for this concern. In the present study, the best predictor correlations of flow boiling and condensation are taken into account to model a single turn pulsating heat pipe mathematically. These considerations, result in derivation of more accurate results. The nucleate boiling phenomenon has been considered as the dominant mechanism of the boiling process in the evaporator. However, due to the annular flow assumption, a thin film of liquid is considered in calculation of the mass transfer out of the vapor plugs. All the fundamental relations such as momentum, mass and energy equations are solved implicitly, except the energy equation of liquid slug. The liquid slug displacement results are compared with the previous studies and the comparison indicates increase in both the frequency and the amplitude of the slug displacement. Moreover, the calculated heat flux is verified with the empirical results. The comparison shows an acceptable agreement between the findings, which is better than previous modelings without boiling and condensation. Furthermore, the effect of pipe diameter on the flow and heat transfer mechanisms has been derived. According to the results, by increasing the pipe diameter, despite a frequency decrease, the oscillation amplitude of liquid slug and total heat flux transferred into the pulsating heat pipe increases. Sensible heat contribution in the heat trasnfer mechanism reduces by higher pipe diameter values.

This paper investigated the moisture absorption, mechanical behavior and the dielectric performance of hybrid and non-hybrid polymeric composites. Hand lay-up technique was used for processing carbon; glass reinforced polyester resin composites (non-hybrid) and carbon-glass/polyester hybrid composites with various fiber configurations. The maximum resistance of water absorption was obtained for the hybrid composites with combinations [2C-2G], where the water absorption ratio reached to 1%. In addition, the maximum tensile, flexural strengths and ILSS of this combination were 123 MPa, 1397 MPa, and 22.35 MPa, respectively. This is due to the higher tensile strength of polyester matrix and good adhesion between the glass and carbon fabrics with the polyester matrix. The dielectric constant of non-hybrid composite with codes [C] is higher than non-hybrid composite with codes [G] and dielectric constant for all hybrid composites lies between non-hybrid composites.

Aluminum and magnesium alloys are of materials for decreasing vehicle weight and consequently reducing fuel consumption. However, forming limitations regarding their low formability at room temperature are found when being manufactured by conventional forming processes. For this reason, development of new forming techniques, such as warm tube hydroforming, is needed to overcome such limitations. In addition, production of parts with sharp corners is nearly impossible using conventional forming processes. This paper investigates the possibility of forming stepped tubes with high expansion ratio, sharp corner radii and precise geometric shape using a developed hybrid hydroforming and bending method. To assess tube formability, the bulge test was adopted with different forming temperatures and axial feeds. It is shown that using the feed of 35 mm and feed rate of 15 mm/min, a stepped tube with 47.6 % expansion ratio and corner filling ratio of about 100 % (part with sharp corners) could be achieved when adopting the developed hybrid hydroforming and bending method at 150 ᵒC.

Crack fault of rotor is one of the most prominent problems faced by magnetic bearing rotor system. In order to improve the safety performance of this kind of machinery, it is necessary to research the vibration characteristics of magnetic bearing cracked rotor system. In this paper, the stiffness model of the crack shaft element was established by the strain energy release rate (SERR) theory. The mathematical model of PD controller of AMBs cracked rotor system is based on the finite element method. The vibration characteristics of PD controller of AMBs rotor system were examined in the test rig under crack depth of rotor. The spectrum of vibration characteristics were detected in the AMBs cracked rotor system. The results of experiments showed that the 2× and 3× harmonic components can be used for fault diagnosis of crack fault of AMBs rotor systems under PD controller of AMB.

One of the most efficient methods of reducing drag on planing craft is the use of transverse step on the bottom of a hull. Applying steps on the hull reduces the contact area with water and as a result, it reduces drag of the craft. Planing craft are able to have one or two transverse steps. In this paper, numerical hydrodynamic performance of the stepped planing craft and its step height effect is investigated by making use of finite volume method (FVM). The Reynolds-Averaged Navier-Stokes (RANS) equations are coupled with the standard k- ε turbulence model and volume of fluid equations are solved to simulate transient turbulent free surface flow surrounding the hull by ANSYS-CFX. In order to predict the motion of the craft, equations of two degrees of freedom for rigid body are coupled with governing equations of fluid flow. In order to validate the numerical model presented in this paper, the obtained numerical results are compared with the available experimental data. The numerical results obtained for drag, dynamic trim, rising of center of mass and the pressure distribution on the body at different speeds and different heights of the steps are presented and discussed.

In this article, a fast and reliable map-merging algorithm is proposed to produce a global two dimensional map of an indoor environment in a multi-robot simultaneous localization and mapping (SLAM) process. In SLAM process, to find its way in this environment, a robot should be able to determine its position relative to a map formed from its observations. To solve this complex problem, simultaneous localization and mapping methods are required. In large and complex environments, using a single robot is not reasonable because of the error accumulation and the time required. This can explain the tendency to employ multiple robots in parallel for this task. One of the challenges in the multi-robot SLAM is the map-merging problem. A centralized algorithm for map-merging is introduced in this research based on the features of local maps and without any knowledge about robots initial or relative positions. In order to validate the proposed merging algorithm, a medium scale experiment has been set up consisting of two heterogeneous mobile robots in an indoor environment equipped with laser sensors. The results indicate that the introduced algorithm shows good performance both in accuracy and fast map-merging.

In large open pit mines prediction of Peak Particle Velocity (PPV) provides useful information for safe blasting. At Sungun Copper Mine (SCM), some unstable rock slopes facing to valuable industrial facilities are both expose to high intensity daily blasting vibrations, threatening their safty. So, controlling PPV by developing accurate predictors is essential. Hence, this study proposes improved strategies for prediction of PPV by maximum charge per delay and distance using the concept of Intelligent Committee Machine (ICM). Besides the Empirical Predictors (EPs) and two Artificial Intelligence (AI) models of ANFIS and ANN, four different ICMs models including Simple and Weighted Averaging ICM (SAICM and WAICM) and First and Second order Polynomial ICM (FPICM and SPICM) in conjunction with genetic algorithm, proposed for the prediction of PPV. Performance of predictors was studied considering R2, RSME and VAF indices. Results indicate that ICM methods have superiority over EPs, ANN and ANFIS, and among the ICM models while SAICM, WAICM and FPICM performing near to each other SPICM overrides all the models. R2 and RSME of the training and testing data for SPICM are 0.8571, 0.8352 and 11.0454, 12.3074, respectively. Finally, ICMs provides more accurate and reliable models rather than individual AIs.