Showing papers by "Military Academy published in 2011"
TL;DR: In this paper, the residual compressive strength of RPC after heating from 200-300°C increases more than that at room temperature, but, significantly decreases when the temperature exceeds 300°C.
210 citations
TL;DR: In this paper, the authors conduct an analysis on the propagation law of a blast pressure wave and the dynamic response of reinforced concrete structures under explosive pressure wave effects and apply the nonlinear finite element analysis software LS-DYNA to conduct a numerical simulation of a free-field explosion model.
137 citations
TL;DR: In this article, a plate-like morphology, microstructure and magnetic properties of hematite (α-Fe 2 O 3 ) are discussed with respect to morphology and micro-structure of the particles.
109 citations
TL;DR: In this article, a practical and clean protocol for transesterification catalyzed by a 5-mol% cheap, non-toxic and moisture stable Fe(acac)3 or other iron(III) β-diketonate species in solvent, such as heptane under azeotropic condition is developed.
59 citations
TL;DR: In this paper, a gray relational grade obtained from gray relational analysis is used as the multiple performance characteristic for two plates of aluminum alloy AA5083 welded in butt joint, in order to achieve the aim of robustness in the multiple response process.
Abstract: Friction stir welding (FSW) can produce superior mechanical properties in the weld zone. The purpose of this article is to find the optimum FSW process operating conditions for two plates of aluminum alloy AA5083 welded in butt joint. In addition to optimizing the performance characteristics, the cost is considered in the optimal FSW process. In the FSW procedure, there are four major controllable four-level factors, i.e. the tool rotation speed, transverse speed (feed rate), tool tilt angle with respect to the workpiece surface, and pin tool length. The uncontrollable factors are the ultimate tensile strength and elongation rate which can be converted to signal-to-noise ratios the larger the better. In order to achieve the aim of robustness in the multiple response process, the gray-based Taguchi method is proposed. A gray relational grade obtained from gray relational analysis is used as the multiple performance characteristic. The resulting optimum process parameters are rotation speed at 1800 rpm, tra...
50 citations
TL;DR: To create immune status characteristic for the live infection by in vivo application of DCs educated with ES L1 antigens, which resulted in mixed Th1/Th2 cytokine response, with the dominance of the Th2 type and elevated levels of regulatory cytokines.
Abstract: Parasitic nematode Trichinella spiralis exert immunomodulatory effect on the host immune response through excretory-secretory products (ES L1) released from the encysted muscle larvae. Rat bone-marrow derived dendritic cells (DCs) stimulated with ES L1 antigens acquire semi-matured status and induce Th2 and regulatory responses in vitro and in vivo. Priming naive T cells in vitro with ES L1 pulsed DCs caused strong Th2 polarization, accompanied by elevated production of regulatory cytokines IL-10 and TGF-β and no increase in the proportion of CD4+CD25+Foxp3+ among the effector T cell population. In vivo T cell priming resulted in mixed Th1/Th2 cytokine response, with the dominance of the Th2 type and elevated levels of regulatory cytokines. Significant increase in the proportion of CD4+CD25+Foxp3+ cells was found among recipient's spleen cells. We have achieved to create immune status characteristic for the live infection by in vivo application of DCs educated with ES L1 antigens.
47 citations
08 Jun 2011
TL;DR: In this article, the authors describe how rapid developments in advanced manufacturing techniques and information technology have resulted in significant increases in the functionality, precision, and complexity of products, leading to an increase in the complexity of many products.
Abstract: Rapid developments in advanced manufacturing techniques and information technology have resulted in significant increases in the functionality, precision, and complexity of products. Most products ...
41 citations
TL;DR: Strontium zinc zirconium hexaferrites/polyaniline composites were synthesized by oxidative chemical polymerization of aniline in the presence of ammonium peroxydisulfate (APS) as mentioned in this paper.
37 citations
TL;DR: A wireless remote weather monitoring system based on Micro-Electro-Mechanical Systems (MEMS) and wireless sensor network (WSN) technologies comprising sensors for the measurement of temperature, humidity, pressure, wind speed and direction, integrated on a single chip is proposed.
Abstract: This study proposes a wireless remote weather monitoring system based on Micro-Electro-Mechanical Systems (MEMS) and wireless sensor network (WSN) technologies comprising sensors for the measurement of temperature, humidity, pressure, wind speed and direction, integrated on a single chip. The sensing signals are transmitted between the Octopus II-A sensor nodes using WSN technology, following amplification and analog/digital conversion (ADC). Experimental results show that the resistance of the micro temperature sensor increases linearly with input temperature, with an average TCR (temperature coefficient of resistance) value of 8.2 × 10−4 (°C−1). The resistance of the pressure sensor also increases linearly with air pressure, with an average sensitivity value of 3.5 × 10−2 (Ω/kPa). The sensitivity to humidity increases with ambient temperature due to the effect of temperature on the dielectric constant, which was determined to be 16.9, 21.4, 27.0, and 38.2 (pF/%RH) at 27 °C, 30 °C, 40 °C, and 50 °C, respectively. The velocity of airflow is obtained by summing the variations in resistor response as airflow passed over the sensors providing sensitivity of 4.2 × 10−2, 9.2 × 10−2, 9.7 × 10−2 (Ω/ms−1) with power consumption by the heating resistor of 0.2, 0.3, and 0.5 W, respectively. The passage of air across the surface of the flow sensors prompts variations in temperature among each of the sensing resistors. Evaluating these variations in resistance caused by the temperature change enables the measurement of wind direction.
33 citations
TL;DR: In this paper, the preparation and characterization of hypo-hyper d-electrocatalysts with a reduced amount of precious metals aimed for water electrolysis was discussed, and a reference electrocatalyst with pure Ru metallic phase was prepared.
25 citations
TL;DR: Body mass index, a crude indicator of obesity, should be combined with these parameters when assessing the risk for aortoiliac PAD in middle-aged men.
TL;DR: In this paper, an efficient fatigue life computation method under variable amplitude loading of structural components has been proposed, which is focused on total fatigue life estimation of aircraft structural components, defined as sum of fatigue crack initiation and crack growth life.
Abstract: In this investigation, an efficient fatigue life computation method under variable amplitude loading of structural components has been proposed. Attention in this study is focused on total fatigue life estimation of aircraft structural components. Flat specimens with central hole made of quenched and tempered steel 13H11N2V2MF were tested as representatives of different structural components. Total fatigue life of these specimens, defined as sum of fatigue crack initiation and crack growth life, was experimentally determined. Specimens were tested by blocks of positive variable amplitude loading. Crack initiation life was computed using theory of low-cycle fatigue (LCF) properties. Cyclic stress–strain curve, Masing’s curve and approximate Sonsino’s curve were used for determining stress–strain response at critical point of considered specimens. Computation of crack initiation life was realised using Palmgren–Miner’s linear rule of damage accumulation, applied on Morrow’s curves of LCF properties. Crack growth life was predicted using strain energy density method. In this method, the same LCF properties were used for crack initiation life and for crack growth life computations also. Computation results are compared with own experimentally obtained results.
06 Oct 2011
TL;DR: Recommendations are made to further enhance and improve the signature models and rendering equations in infrared scene simulators as well as the commonalities and differences between the different systems are investigated.
Abstract: The development and optimisation of modern infrared systems necessitates the use of simulation systems to create
radiometrically realistic representations (e.g. images) of infrared scenes. Such simulation systems are used in
signature prediction, the development of surveillance and missile sensors, signal/image processing algorithm
development and aircraft self-protection countermeasure system development and evaluation.
Even the most cursory investigation reveals a multitude of factors affecting the infrared signatures of realworld
objects. Factors such as spectral emissivity, spatial/volumetric radiance distribution, specular reflection,
reflected direct sunlight, reflected ambient light, atmospheric degradation and more, all affect the presentation of
an object's instantaneous signature. The signature is furthermore dynamically varying as a result of internal and
external influences on the object, resulting from the heat balance comprising insolation, internal heat sources,
aerodynamic heating (airborne objects), conduction, convection and radiation. In order to accurately render the
object's signature in a computer simulation, the rendering equations must therefore account for all the elements
of the signature.
In this overview paper, the signature models, rendering equations and application frameworks of three infrared
simulation systems are reviewed and compared. The paper first considers the problem of infrared scene simulation
in a framework for simulation validation. This approach provides concise definitions and a convenient context for
considering signature models and subsequent computer implementation. The primary radiometric requirements
for an infrared scene simulator are presented next.
The signature models and rendering equations implemented in OSMOSIS (Belgian Royal Military Academy),
DIRSIG (Rochester Institute of Technology) and OSSIM (CSIR & Denel Dynamics) are reviewed. In spite
of these three simulation systems' different application focus areas, their underlying physics-based approach is
similar. The commonalities and differences between the different systems are investigated, in the context of their
somewhat different application areas.
The application of an infrared scene simulation system towards the development of imaging missiles and
missile countermeasures are briefly described.
Flowing from the review of the available models and equations, recommendations are made to further enhance
and improve the signature models and rendering equations in infrared scene simulators.
TL;DR: Conventional Mason-Allen configuration can be applied with double-loaded suture anchor safely and recent modifications of the configurations offer no biomechanical advantage.
Abstract: Purpose
The purpose of the present study is to evaluate the mechanical performance and initial strength of the arthroscopic Mason-Allen, double mattress, inclined Mason-Allen, and lasso loop stitch configurations.
TL;DR: In this paper, the excitation spectra of ABC-stacked graphene superlattices are calculated by the gradient approximation based on the selection rule, only excitations between the conduction and valence bands of the same pairs are allowed.
Abstract: The excitation spectra of ABC-stacked graphene superlattices are calculated by the gradient approximation. Based on the selection rule, only excitations between the conduction and valence bands of the same pairs are allowed. These excitations occur at the critical points in the energy-wave vector space. Different polarization directions induce different spectra. The spectra of a parallel polarization are stronger than those of a vertical polarization. The strong electron-hole excitations cause special structures in the electron-hole excitation and reflectance spectra. However, only one plasmon peak exists in the loss spectra of the parallel polarization. Some properties are consistent with the experimental measurements.
Journal Article•
TL;DR: In this paper, the deformation of elasto-dissipative materials has been analyzed using dynamic models of overshooting the material with high speed, where the authors identify the value of deformation on the basis of changes in the speed of the projectile inside the material until it stops or overshoot this material.
Abstract: Purpose: Analysis of the process of overshooting the material with high speed refers to the identification of certain properties of elasto-dissipative materials. The result of this identification is to determine the value of deformation on the basis of changes in the speed of the projectile inside the material until it stops or overshoot this material. Design/methodology/approach: On the basis of the proposed dynamic models of piercing the material using energy balance equations, dissipation of the energy of mass which strikes the shield has been described. Findings: Dependence of the values of elastic energy and dissipative energy has been derived based on the energy balance equations whose values determine the sensitivity of the analyzed parameters of the dynamic models of the overshooting process. Research limitations/implications: Dynamic models have been analyzed and the impact energy balance equations have been derived. Those equations were the basis to determine the constants and to show their mathematical and graphical interpretation. Practical implications: Derivation of the dependence for the constants, which are characteristic for the energy balance equations, allowed to describe by dependencies the selected parameters of the model, whose identification may be performed using a special quasi-statistical tests on special stand or in the manner as described. Originality/value: Presented work including the identification of piercing the ballistic shield is a part of work on the implementation of the degenerated models to describe these phenomena.
TL;DR: In this article, it was shown that prior formation of TiO from Ti film can induce the formation of anatase by thermal oxidation in air; unless only rutile is formed, the TiO to anatase phase transformation is reversible as further annealing in a vacuum can turn the anatase back into TiO and eliminate the misfit dislocations.
Abstract: The TiO to anatase phase transformation has been studied by transmission electron microscopy in this Article. It is shown that prior formation of TiO from Ti film can induce the formation of anatase by thermal oxidation in air; otherwise only rutile is formed. Ti film deposited on the NaCl (001) surface is induced to form epitaxial TiO film by thermal oxidation in air. Further thermal oxidation in air partially transformed TiO into anatase (A) with a parallel orientation relationship of {200}A//{200}TiO. Detailed analysis of the lattice fringes image of the specimen reveals the presence of very high density of misfit dislocations. The TiO to anatase transformation is reversible as further annealing in a vacuum can turn the anatase back into TiO and eliminates the misfit dislocations. The transformation is analyzed in terms of the crystal structure, orientation relationship, and the dislocation distribution, which show that the TiO to anatase transformation is due to the close similarity between their stru...
27 Jun 2011
TL;DR: In this article, a sensor fault-tolerant control for a high performance induction motor drive that propels an electrical vehicle is described, which deals with instrument failure detection and isolation within a reconfigurable induction motor direct torque control scheme.
Abstract: This paper describes a sensor fault-tolerant control for a high performance induction motor drive that propels an electrical vehicle. The proposed strategy deals with instrument failure detection and isolation within a reconfigurable induction motor direct torque control scheme.
TL;DR: The experimental results show that the smart window incorporating an ITO/WO3/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750–1,500 Lux under typical summertime conditions in Taiwan.
Abstract: A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV) panel and an all-solid-state electrochromic (EC) stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO(3)/Ta(2)O(5)/ITO and one stack comprising ITO/WO(3)/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO(3)/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V). The experimental results show that the smart window incorporating an ITO/WO(3)/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750-1,500 Lux under typical summertime conditions in Taiwan.
TL;DR: Synergistic interaction of oxcarbazepine with ibuprofen and its additive interaction with etodolac provide new information about the combination pain treatment and could be explored further in patients with inflammatory pain.
Abstract: Oxcarbazepine, ibuprofen and etodolac have efficacy in inflammatory pain. The combination of different drugs activates both central and peripheral pain inhibitory pathways to induce additive or synergistic antinociception, and this interaction may allow lower doses of each drug combined and improve the safety profile, with lower side-effects. This study aimed to examine the effects of oxcarbazepine–ibuprofen and oxcarbazepine–etodolac combinations, in a rat model of inflammatory hyperalgesia, and determine the type of interaction between drugs. Rats were intraplantarly injected with carrageenan (0.1 ml, 1%) and the hyperalgesia was assessed by modified paw pressure test. The anti-hyperalgesic effects of oxcarbazepine, ibuprofen and etodolac and oxcarbazepine–ibuprofen and oxcarbazepine–etodolac combinations were examined. Drugs were co-administered in a fixed-dose fractions of the ED 50 and the type of interaction was determined by isobolographic analysis. Oxcarbazepine (40–160 mg/kg; p.o.), ibuprofen (10–120 mg/kg; p.o.) and etodolac (5–20 mg/kg; p.o.) produced a significant, dose-dependent anti-hyperalgesia in carrageenan-injected rats. ED 50 values (mean ± SEM) for oxcarbazepine, ibuprofen and etodolac were 88.17 ± 3.65, 47.07 ± 10.27 and 13.05 ± 1.42 mg/kg, respectively. Oxcarbazepine–ibuprofen and oxcarbazepine–etodolac combinations induced significant and dose-dependent anti-hyperalgesia. Isobolographic analysis revealed that oxcarbazepine exerts a synergistic interaction with ibuprofen, with almost 4-fold reduction of doses of both drugs in combination. In contrast, there was an additive interaction with etodolac. Synergistic interaction of oxcarbazepine with ibuprofen and its additive interaction with etodolac provide new information about the combination pain treatment and could be explored further in patients with inflammatory pain. Adverse effect analysis of the combinations is necessary to verify possible clinical use of the mixtures.
TL;DR: In this article, a finite element method was used to determine the stress state of the RS subjected to hinge moment ultimate load, resulting in the high stress concentration sites around the rivet holes.
29 Dec 2011
TL;DR: Results indicate that even in its basic form the proposed metric is perceptually meaningful and yields performance comparable with state-of-the art objective image quality metrics.
Abstract: An objective metric for grayscale image quality capable of both global and localized quality assessment and based on a direct comparison of visual information in the test and reference images is proposed. The measure associates visual information with edge, or gradient, information that is initially extracted at all locations of the test and reference images. A perceptual-information preservation model is then used to quantify the success of information transfer/loss. By considering the perceptual importance of different image regions, local image quality success estimates are integrated into a single, numerical quality score between 0 (total information loss) and 1 (ideal transfer). The proposed metric is validated using extensive subjective test results. Results indicate that even in its basic form the proposed metric is perceptually meaningful and yields performance comparable with state-of-the art objective image quality metrics.
TL;DR: In this article, the authors present a novel inverse method which efficiently and robustly estimates the vibration forces of a rotating machine mounted upon isolators under the operating condition, using a fuzzy weighting factor based on the fuzzy logic inference system.
11 May 2011
TL;DR: In this article, a DC-DC converter is used to emulate a Proton Exchange Membrane Fuel Cell (PEMFC) system by using a full-bridge converter experimentally achieved and controlled in DSP2812 environment.
Abstract: The Proton Exchange Membrane Fuel Cell (PEMFC) is being investigated as an alternate power source for various applications as transportation and emergency power supplies. Fuel cell systems are characterized by high costs and complex auxiliary devices. For this reason, a fuel cell emulator can be used as a suitable and economic alternative to a real one for developing and testing a fuel cell power conditioning system. The fuel cell emulator must be able to reproduce the FC nonlinear output voltage-current characteristic. This paper proposes then a possible solution to emulate a PEMFC system by using a DC-DC converter. The fuel cell system, including all its auxiliaries and related control systems, is emulated by a full-bridge converter experimentally achieved and controlled in the DSP2812 environment. The converter-based system allows the behavior of any fuel cell to be easily emulated and can be used in laboratory as a low-cost system for design and experimental purposes since only a DC-DC control modification is necessary.
TL;DR: Detergent applied at 1% concentration inhibited the bioproduction of proteins and the total biomass of the fungus, while AOC and TTP inhibited the production of proteins, but stimulatedl theProduction of Trichothecium.
Abstract: The degradation of detergents that are dispersed in water and soil partially
depends on the metabolic activities of fungi. Among the fungi that have this
ability, Deuteromycetes are particularly noted for their biochemical
characteristics. Taking this into account, it was of interest to analyze the
influence of detergent and its main compounds, ethoxyled oleylcetyl alcohol
(AOC) and sodium tripoly-phosphate (TTP), on the metabolism of the fungus
Trichothecium roseum. Our results revealed that both detergent and AOC had an
inhibitory effect on the bioproduction of free organic acids, while TTP
stimulated their production. Also, detergent inhibited the bioproduction of
basic amino acids, with the exception of alanine. In addition, detergent
applied at 1% concentration inhibited the bioproduction of proteins and the
total biomass of the fungus, while AOC and TTP inhibited the production of
proteins, but stimulatedl the production of Trichothecium.
Proceedings Article•
30 Aug 2011TL;DR: In this paper, the authors deal with sensor fault detection within a reconfigurable direct torque control of an induction motor-based electric vehicle, where current, voltage and speed sensors faults are detected and followed by control reconfiguration in order to allow the vehicle continuous operation.
Abstract: This paper deals with sensor fault detection within a reconfigurable direct torque control of an induction motor-based electric vehicle. The proposed strategy concerns current, voltage and speed sensors faults that are detected and followed by control reconfiguration in order to allow the vehicle continuous operation. The proposed approach is validated through experiments on an induction motor drive and simulations on an electric vehicle using a European urban and extra urban driving cycle.
TL;DR: The results of microhardness and compression strength (along with the statistical analysis of these results) as well as those of SEM and XRD analyses are presented in this article, where the results of this study showed that the material produced from sheep tooth dentine can be qualified as a promising source of HA needed to produce bioactive ceramics.
Abstract: Hydroxyapatite (HA) is a particularly attractive material for bone and tooth implants since it does not only closely resemble human tooth and bone mineral but it has also biologically proven to be compatible with these tissues. The applications of pure HA are restricted to non load bearing implants due to the poor mechanical properties of HA. Biomaterials of synthetic HA are highly reliable but the synthesis of HA is often complicate and expensive. Bioceramics of naturally derived biological apatites are more economic. Aim of the present work is to introduce sheep teeth dentine HA material as an alternative source of bioactive biomaterials for grafting purposes. The work was started with such a way that extracted sheep teeth were cleaned. The teeth were calcinated at 850°C in air. It was seen that enamel matter was easily separated from dentine after calcination. The collected dentine parts were crushed and ball milled. The powder was pressed between hardened steel dies to produce samples suitable for compression and microhardness tests. The obtained powder compacts were sintered at different temperatures, specifically 1000, 1100, 1200, and 1300°C in air. Results of microhardness and compression strength (along with the statistical analysis of these results) as well as those of SEM and XRD analyses are presented. In the literature, there is very little information about the mechanical properties of dentine and enamel matter derived from sheep, bovine and human. The highest compression strength value in the present study was measured around 146 MPa (from human dentine derived HA the highest value was almost 60 MPa after sintering at 1300°C). The best microhardness in the present study was found as nearly 125 HV. The results of this study showed that the HA material produced from sheep tooth dentine can be qualified as a promising source of HA needed to produce bioactive ceramics.
Journal Article•
TL;DR: In this paper, a review of dynamic modeling methods, computational strategies, control design, software exploitations, and experiments of multibody systems in recently years were reviewed. And the future directions of this field were indicated.
Abstract: Multibody system dynamics is an important branch in the field of the modern mechanicsIt provides a strong tool for dynamic performance estimation and optimizing design of many mechanical systems in a lot of important engineering fields,such as,weapon,aeronautics,astronautics,vehicle,robot,precision machinery,and so onThe study on dynamic modeling,design and control of complex multibody systems is the urgent demand of modern engineering problemsHere studies on dynamic modeling methods,computational strategies,control design,software exploitations,and experiments of multibody systems in recently years were reviewedThe future directions of this field were indicated
TL;DR: The Accelerated Lithium Migration Technique (ALMT) is an electrochemical method to remove Na + and K + from concrete, and simultaneously drive Li + into concrete to inhibit alkali-silica reaction (ASR) as mentioned in this paper.
Abstract: The Accelerated Lithium Migration Technique (ALMT) is an electrochemical method to remove Na + and K + from concrete, and simultaneously drive Li + into concrete to inhibit alkali-silica reaction (ASR). This study investigates the relationship between the applied voltage and the migration behavior of cations related to ASR. The results show that after the completion of Na + and K + removal, migration of Li + begins to enter a steady state. With the increase in applied voltage, the removal rate and removable amount of alkalis increases, the required time of alkalis removal and the time for Li + to pass through the specimen decreases, and the migration coefficients of Li + increase. Furthermore, the above migration parameters of cations have positive linear relationships with the average current density. After the ALMT process, the average Li/(Na + K) molar ratio of the specimen is sufficiently large to mitigate ASR problems.
TL;DR: The reaction is applied to a wide range of carboxylic esters and alcohols tolerating many functional groups as discussed by the authors, but it is not suitable for a wide variety of functional groups.
Abstract: The reaction is applied to a wide range of carboxylic esters and alcohols tolerating many functional groups.Benzyl thiol as a nucleophile requires 2 equiv.