Microwave absorption properties of carbonyl iron-based paint coatings for military applications

The paper explores the possibilities of using carbonyl iron in the form of a powder for the manufacture of radar-absorbing paints-reducing the radar signature of the objects that they cover.The attenuation values in the range of 4-18 GHz for various coating thicknesses,ranging from 0.5 to 2.00 mm with 0.5 mm increment,and for different absorber content-75%and 80%,as well as the use of two different binders in the form of epoxy resins with hardeners,were investigated.For the frequency of 18 GHz and a 1.5 mm thick coating with a 75%absorber content,Epidian 112 resin and Saduramid 10/50 hardener used as a binder,and the maximum attenuation level obtained equalled 20.2 d B at 16 GHz.Additionally,the absorber particle size ranging from 3 to 4μm and its higher mass content resulted in achieving the reflection loss above-12 d B in the entire 8-12.5 GHz range for layers between 1-and 1.5 mm thickness.The qualitative assessment of the tested samples in the context of camouflage in the radar range was also performed,using statistical analysis.

Control and Treatment of Bone Cancer: A Novel Theoretical Study

The human body has symmetric bones.This paper uses control engineering concepts to design a suitable controller to synchronize two symmetric bones of the human body to control and treat bone cancer.A Nonsingular Terminal Sliding Mode Control(NTSMC)method will be employed to design the proposed control inputs.The control inputs can be the chemical drugs that can be used to treat bone cancer.The dynamical equations of bone cancer will be used to apply the designed control method and test it.For testing the designed controller,Simulink/MATLAB software will be used.The proposed controller is chattering-free,robust against uncertainties and external disturbances,and finite-time stable in the control engineering view.Bone cancer will be treated for almost one year using the proposed control method.

Investigations on influence of rifle automatics system action on values of energetic efficiency coefficient of muzzle brakes

The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process was used.The motion of the rifle was detected by the use of the laser interferometer and the optical camera.The recoil velocity time courses were determined by smoothing and differentiation of experimental position records.The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient:the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle.The values of the coefficient,calculated using these two values of the recoil velocity,distinctly differ.However,it was shown that their values indicate the same relation between the efficiency of various muzzle brakes.The value of the efficiency coefficient,determined on the basis of the final recoil velocity value,is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system.

Coupler force reduction method for multiple-unit trains using a new hierarchical control system

During traction and braking of multiple-unit trains,substantial longitudinal dynamic forces might occur in couplers due to the non-optimal distribution of traction and braking forces generated by self-propelled carriages.These dynamic forces might create shocks affecting the reduction of endurance of the weakest train structural components primarily.Thus,the overall operational safety of the train is also lowered.The purpose of the paper is to develop a new control system to supervise the activities related to the longitudinal dynamics of each train carriage in a multiple-unit train to reduce the longitudinal coupler forces acting during train traction and braking.The hierarchical structure of the control system consists of two levels.The first master level of control works like standard cruise control.However,the reduction of longitudinal coupler forces is achieved by applying a second level of slave control systems with a control configuration of feedback compensation.

Ultra-high speed holographic shape and displacement measurements in the hearing sciences

The auditory system of mammals enables the perception of sound from our surrounding world.Containing some of the smallest bones in the body,the ear transduces complex acoustic signals with high-temporal sensitivity to complex mechanical vibrations with magnitudes as small as tens of picometers.Measurements of the shape and acoustically induced motions of different components of the ear are essential if we are to expand our understanding of hearing mechanisms,and also provide quantitative information for the development of numerical ear models that can be used to improve hearing protection,clinical diagnosis,and repair of damaged or diseased ears.We are developing digital holographic methods and instrumentation using an ultra-high speed camera to measure shape and acoustically-induced motions in the middle ear.Specifically we study the eardrum,the first structure of the middle ear which initializes the acoustic-mechanical transduction of sound for hearing.Our measurement system is capable of performing holographic measurement at rates up to 2.1 M frames per second.Two shape measurement modalities had previously been implemented into our holographic systems:(1)a multi-wavelength method with a wavelength tunable laser;and(2)a multi-angle illumination method with a single wavelength laser.In this paper,we present a third method using a miniaturized fringe projection system with a microelectromechanical system(MEMS)mirror.Further,we optimize the processing of large data sets of holographic displacement measurements using a vectorized Pearson's correlation algorithm.We validate and compare the shape and displacement measurements of our methodologies using a National Institute of Standards and Technology(NIST)traceable gauge and sound-activated latex membranes and human eardrums.