Showing papers by "Military Academy published in 2012"

Rod-, flower-, and dumbbell-like MnO2: Highly active catalysts for the combustion of toluene

Abstract: The rod-like tetragonal α-MnO 2 , flower-like hexagonal ɛ-MnO 2 , and dumbbell-like tetragonal β-MnO 2 were prepared using the hydrothermal or water-bathing method under different conditions. It is shown that the α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 catalysts possessed a surface area of ca. 53, 30, and 114 m 2 /g, respectively. The oxygen adspecies concentration and low-temperature reducibility decreased in the order of α-MnO 2 > ɛ-MnO 2 > β-MnO 2 , coinciding with the sequence of their catalytic activities for toluene combustion. The well-defined morphological MnO 2 catalysts performed much better than the bulk counterpart. At a space velocity of 20,000 mL/(g h), the temperature for 90% toluene conversion was 238, 229, and 241 °C over α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 , respectively. The apparent activation energies of α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 were in the range of 20–26 kJ/mol. It is concluded that higher oxygen adspecies concentrations and better low-temperature reducibility were responsible for the good catalytic performance of the α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 materials.

Comparative evaluation of hyperspectral anomaly detectors in different types of background

Abstract: Anomaly detection (AD) in hyperspectral data has received a lot of attention for various applications. The aim of anomaly detection is to detect pixels in the hyperspectral data cube whose spectra differ significantly from the background spectra. Many anomaly detectors have been proposed in literature. They differ by the way the background is characterized and by the method used for determining the difference between the current pixel and the background. The most well-known anomaly detector is the RX detector that calculates the Mahalanobis distance between the pixel under test (PUT) and the background. Global RX characterizes the background of the complete scene by a single multi-variate normal distribution. In many cases this model is not appropriate for describing the background. For that reason a variety of other anomaly detection methods have been developed. This paper examines three classes of anomaly detectors: sub-space methods, local methods and segmentation-based methods. Representative examples of each class are chosen and applied on a set of hyperspectral data with different backgrounds. The results are evaluated and compared.

Effective inactivation of food pathogens Listeria monocytogenes and Salmonella enterica by combined treatment of hypericin-based photosensitization and high power pulsed light.

Abstract: Aims: The aim of this study was to evaluate the inactivation efficiency of Listeria monocytogenes ATCL3C 7644 and Salmonella enterica serovar Typhimurium strain DS88 by combined treatment of hypericin (Hyp)-based photosensitization and high power pulsed light (HPPL) Methods and Results: Cells were incubated with Hyp (1 × 10−5 or 1 × 10−7 mol l−1) in PBS and illuminated with a light λ = 585 nm For the combined treatment, bacteria were, after photosensitization, exposed to 350 pulses of HPPL (UV light dose = 0·023 J cm−2) Fluorescence measurements were performed to evaluate optimal time for cell–Hyp interaction Results indicate that Hyp tends to bind both Listeria and Salmonella After photosensitization treatment, Listeria population was reduced 7 log, whereas Salmonella was inactivated just 1 log Electron photomicrograps of Salmonella and Listeria confirmed that photosensitization induced total collapse of the Listeria cell wall, but not that of Salmonella After combined photosensitization–HPPL treatment, the population of Listeria was diminished by 7 log and Salmonella by 6·7 log Conclusions: Listeria can be effectively inactivated by Hyp-based photosensitization (7 log), whereas Salmonella is more resistant to photosensitization and can be inactivated just by 1 log in vitro Combined treatment of photosensitization and pulsed light inactivates effectively (6·7–7 log) both the Gram-positive and the more resistant to photosensitization Gram-negative bacteria Significance and Impact of the Study: A new approach to combat Gram-positive and Gram-negative bacteria is proposed, combining photosensitization with high power pulsed light

Existence and global exponential stability of pseudo almost periodic solution for SICNNs with mixed delays

Abstract: Shunting Inhibitory Artificial Neural Networks are biologically inspired networks in which the synaptic interactions are mediated via a nonlinear mechanism called shunting inhibition, which allows neurons to operate as adaptive nonlinear filters. This paper considers the problem of existence and exponential stability of the pseudo almost periodic solution for shunting inhibitory cellular neural networks with mixed delays. The Banach fixed point theorem and the variant of a certain integral inequality with explicit estimate are used to establish the results. The results of this paper are new and they complement previously known results.

Vocabulary Input from School Textbooks as a Potential Contributor to the Small Vocabulary Uptake Gained by English as a Foreign Language Learners in Saudi Arabia.

Abstract: Research repeatedly reports very little vocabulary uptake by English as a foreign language (EFL) learners in public schools in Saudi Arabia. Factors such as the teaching methodology employed and learner motivation have been suggested to explain this but a further explanation, the vocabulary input these learners receive, remains uninvestigated. An examination of the textbooks in the EFL program in Saudi Arabian public schools suggests they provide around 2800 words from the most frequent 5000 words and an additional 1000 less frequent words over a period of seven years. Most of these words are introduced before the secondary stage which suggests little input and much repetition in the final years of school learning. There is little thematic variation, which suggests the textbooks are dull and will demotivate learners. Surprisingly, portions of the Ministry of Education’s own target word-list are not presented at all. Poverty of input, therefore, helps explain the small volumes of vocabulary uptake. Among t...

Numerical Study on Hybrid Tubes Subjected to Static and Dynamic Loading

Abstract: The commercial finite element program LS-DYNA was employed to evaluate the response and energy absorbing capacity of cylindrical metal tubes that are externally wrapped with composite. The numerical simulation elucidated the crushing behaviors of these tubes under both quasi-static compression and axial dynamic impact loading. The effects of composite wall thickness, loading conditions and fiber ply orientation were examined. The stress–strain curves under different strain rates were used to determine the dynamic impact of strain rate effects on the metal. The results were compared with those of a simplified analytical model and the mean crushing force thus predicted agreed closely with the numerical simulations. The numerical results demonstrate that a wrapped composite can be utilized effectively to enhance the crushing characteristics and energy absorbing capacity of the tubes. Increasing the thickness of the composite increases the mean force and the specific energy absorption under both static and dynamic crushing. The ply pattern affects the energy absorption capacity and the failure mode of the metal tube and the composite material property is also significant in determining energy absorption efficiency.

Designing tomorrow’s snow park jump

Abstract: Recent epidemiological studies of injuries at ski resorts have found that snow park jumps pose a significantly greater risk for certain classes of injury to resort patrons than other normal skiing activities. Today, most recreational jumps are built by skilled groomers without an engineering design process, but the Snow Skiing Committee (F-27) of the American Society for Testing and Materials is considering the inclusion of recreational jumps in their purview which may lead to a greater role for engineering jump designs in the US in the future. Similar efforts are underway in Europe as well. The purpose of this work is to review the current state of the science of snow park jumps, describe the jump design process, and outline the role that modelling will play in designing tomorrow’s snow park jumps.

A simple and effective hardware-in-the-loop simulation platform for urban electric vehicles

Abstract: This paper deals with hardware-in-the-loop simulation of urban electric vehicles. The proposed platform, which is expected to be used for electric vehicle prototyping, is very simple and effective. Indeed, the induction motor-based powertrain is coupled to DC machine-based load torque emulator taking into account the electric vehicle mechanics and aerodynamics. Experiments are carried-out using the New European Driving Cycle (NEDC) to show that the proposed hardware-in-the-loop simulation system is effective and provides a simple configuration for prototyping electric vehicles.

An innovative approach integrating 2-tuple and lowga operators in process failure mode and effects analysis

Abstract: Process failure mode and effects analysis (FMEA) is used in the high-tech industry to assure process robustness. Traditionally, process FMEA uses the risk priority number (RPN) to evaluate the risk of failure. However, the RPN method has several main shortcomings. In order to improve the method of RPN evaluation, this paper proposes an innovative approach, integrating 2-tuple and the linguistic ordered weighted geometric averaging (LOWGA) operator in process FMEA. The main purpose of this study is to effectively resolve the main shortcomings of RPN evaluation to assure product and process robustness. In numerical verification, process FMEA of the color super-twisted nematic (CSTN) product is presented to further illustrate the proposed approach. After comparing the result that was obtained from the proposed method with both the traditional RPN method and the LOWGA method, it was found that the proposed approach provided a more accurate and reasonable ranking of the risk of failure. Moreover, the proposed method does not lose the useful information provided by the experts.

Evaluation system for factors affecting creativity in the Lithuanian Armed Forces

Abstract: In a constantly changing environment, factors influencing creativity and approaches to evaluating them, considered controversial in the scientific literature and in practice, are also experiencing changes Different authors evaluate and interpret factors affecting creativity differently Consequently, the problem how to identify and evaluate which of the approaches fully reflects the situation arises The present article deals with these problems by combining the approaches of different authors from the aspects of identification and evaluation of factors affecting creativity The aim of the article is to develop an evaluation system for factors affecting creativity in the Lithuanian Armed Forces In an attempt to identify and evaluate factors affecting creativity, expert and multicriteria methods for evaluation were applied A multi-level system for the evaluation of factors affecting creativity, that creates preconditions favourable for the identification of factors affecting creativity (by mean

New Pentacene Crystalline Phase Induced by Nanoimprinted Polyimide Gratings

Abstract: Control of the polymorphism of organic semiconductor films is very important in optoelectronic devices, such as organic thin-film transistors, solar cells, and organic light-emitting diodes. Here, we show the use of polyimide nanogratings (PI-NGs) patterned by nanoimprint lithography to control the polymorphism of deposited pentacene films. Interestingly, a new crystalline phase is first found in the pentacene thin-film formed on the PI-NGs. This new phase, with a d-spacing of 1.35 nm, is more stable than the bulk and thin-film phases in the pentacene film, discussed in terms of X-ray diffraction (XRD) measurements and quantum theory calculations. The response mechanism of the formation of this new phase is characterized by XRD and atomic force microscopy; the polymorphism and surface morphology show a strong dependence on the width of PI-NGs. The size-dependent PI-NG responses of the pentacene film can also control the phase transition from the thin-film to the bulk phase.

Experimental Investigation of High-Strength Structural Steel Welds

Abstract: Material's toughness become more significant material mechanical property, as well as design variable, with recent advances of fracture mechanics understanding. Also, toughness is particularly important parameter for novel structural materials such as high-strength steels. Furthermore, due to the fact that high-strength steels are mainly used in various welded structures, evaluation of welded joint mismatched properties, including toughness, become particularly important. Therefore, the following paper presents investigation results of impact and quasi-static toughness distribution and mismatch on high-strength steels welds. Welded joint’s characteristic heterogeneous zones are obtained by mean of real welding and welding simulation. Finally, relation terms between various mechanical properties, including toughness, for further simplified engineering prediction are provided.

Design of Terrain Park Jump Landing Surfaces for Constant Equivalent Fall Height Is Robust to “Uncontrollable” Factors

Abstract: Epidemiological studies of ski resort injuries have found that terrain parks, especially jumps, present a significantly greater injury risk to skiers and snowboarders than other more typical skiing activities. It has also been shown that the severity of impact risk can be characterized by equivalent fall height (EFH), a measure of jumper impact velocity normal to the slope, and that design algorithms exist to calculate landing-surface shapes that limit EFH to arbitrarily low values. Although proposals have been made recently to introduce design, the skiing industry and other authors have objected that analysis, design, and standards are impossible because of various "uncontrollable" factors that allegedly make the problem intractable to analytical design techniques. We consider the list of uncontrollable factors one by one and show that, to the contrary, each is either: (1) irrelevant to design, (2) has negligible effect, if any, on designed EFH, or (3) can be directly incorporated into the design process. Language: en

Experimental research on new grade of steel protective material for the light armored vehicles

Abstract: An investigation of new PROTAC 500 armour steel was conducted. Three plates were heat treated to different states. One was quenched, second and third were quenched and low temperature tempered at 220 °C and 280°C for 3 hours. A tensile test, hardness measurements, and an instrumented Charpy test were performed. Metallographic was performed by optical microscopy (OM). Ballistic resistances of all three steel plates were measured. The behaviour of steel was tested using armour piercing projectiles 7.62X39 mm API BZ. The best results were obtained in quenched state

Problem-based learning in formal and informal learning environments

Abstract: Problem-based learning (PBL) is a student-centered instructional strategy in which students solve problems and reflect on their experiences. Different domains need different approaches in the design of PBL systems. Therefore, we present one case study in this article: A Java Programming PBL. The application is developed as an additional module for the Learning Management System (LMS). This way the LMS is extended by PBL functionality and the LMS learning resources can be used in PBL.

Impact of organizational failure of relevance consolidated budget

Abstract: Financial concept of consolidated treasury account includes integration of basic factors of the business system’s budget and other public funds. In this way established the relevance of the organizational structure of the system causes a systematic approach to fully satisfy the request. Normative conflict with the actual situation of the organization of the budget system causes partial financial coverage of budgetary positions and the actual non-compliance with the bookkeeping records.