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The synergistic effect of functionalization of multi-walled carbon nanotubes (CNT) using KMnO4 oxidation and initial tensile deformation on the electrical resistance of nanotube network/polyurethane composite subjected to elongation was studied.

Though the initial deformation irreversibly changed the arrangement of carbon nanotube network, subsequent cyclic elongation confirmed stable resistance values. The increased strain-dependent resistance of stimulated nanotube network/polyurethane composite was demonstrated by monitoring vibration of tambour leather after a bead impact and finger flexion.

The results showed a tenfold composite resistance increase for the composite prepared from KMnO₄ oxidized nanotubes, quantified by a so-called gauge factor, from a value of about 20 in comparison to the network prepared from pristine nanotubes. This is a substantial increase, which ranks the stimulated composite among materials with the highest electromechanical response.

The results in this paper are new and have not been published yet. The paper combines different ideas which are developed together. It presents a new concept of synergistic effect of CNT oxidation and application of pre-strain simulation. Oxidation and pre-strain increases by several times the sensitivity of the tested composites which are predetermined for use as strain sensors of various sizes and shapes.

The main purpose of this study was to determine the basic aerodynamic characteristics of the airliner Tu-154M at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°.

Wind tunnel tests of the Tu-154M aircraft model at the scale 1:20 were performed in a low-speed wind tunnel T-3 by using a six-component internal aerodynamic balance. Several model configurations were also investigated.

The results of the presented studies showed that at the wide range of the overcritical angles of attack and sideslip angles, i.e. α = −900° ÷ 900° and β = −900° ÷ 900°, the Tu-154M aircraft flap deflection affected the values of the drag and lift coefficients and generally had no major effect on the values of the side force and pitching moment coefficients.

The model vibration which was the result of flow separation at high angles of attack was the wind tunnel test limitation.

Studies of the airliner aerodynamic characteristics at the wide range of the overcritical angles of attack and sideslip angles allow assessment of the aircraft aerodynamic properties during possible unexpected situations when the passenger aircraft is found to have gone beyond the conventional flight envelope.

There are no social implications of this study to report.

The presented wind tunnel test results of the airliner aerodynamic characteristics at overcritical angles of attack and sideslip angles is an original contribution to the existing not-too-extensive database available in the literature.

The purpose of this study was to analyze the possibility of using combat aircraft including decommissioned as a platform for launching and carrying space rockets with satellites (nano and microsatellites). Thus, an airborne-launcher-to-space-system may be attractive to countries without ground-based space rocket launch sites.

For considered launch-to-orbit system configurations, simulations of space rocket effects on aerodynamic characteristics were performed using computational fluid dynamics (CFD ANSYS Fluent) methods. In addition, experimental studies were performed in a wind tunnel to verify the numerical simulations. Discrete models of the aircraft structure were developed for analysis using finite element method (FEM). The analysis of simulated structural properties of the models was carried out to test its stiffness and mass characteristics important for solving the static and dynamic problems of the structure. The validation analyses of aircraft models were based on mass distribution estimation and matching the stiffness properties of the individual airframe structural assemblies.

The results of numerical analyses and tunnel tests indicate that the influence of carrier rockets on the change of aerodynamic and strength characteristics of the airframe is rather negligible. The aircraft can be used as launching platforms for space rockets. Simulations have indicated that the aircraft will successfully perform a mission of taking away and launching a rocket of at least about 1,000 kg total weight with a 10 kg space payload included.

The combat aircraft can be used as launch platforms for space rockets, and the air/rocket set can become the equivalent of responsive space assets for countries with small space budgets.

The work presents original results obtained by the authors during a preliminary design of a low-cost satellite launch system consisting of a carrier aircraft and a space rocket orbiter. The possibility of using decommissioned combat aircraft as air-launch-to-orbit platforms was taken into consideration. In the absence of aircraft design documentation, reverse engineering methods and techniques were used to develop aircraft geometry and airframe strength structure. Use of CFD, FEM and simulation methods to evaluate system capabilities was demonstrated. Numerical results from CFD simulations were finally verified in experimental tests.

The finite element model developed for a new-designed aircraft was used to solve some problems of structural dynamics. The key purpose of the task was to estimate the critical flutter velocities of the light airplane by performing numerical analysis with application of MSC Software.

Flutter analyses processed by Nastran require application of some complex aeroelastic model integrating two separate components – structural model and aerodynamic model. These sub-models are necessary for determining stiffness, mass and aerodynamic matrices, which are involved in the flutter equation. The aircraft structural model with its non-structural masses was developed in Patran. To determine the aerodynamic coefficient matrix, some simplified aerodynamic body-panel geometries were developed. The flutter equation was solved with the PK method.

The verified aircraft model was used to determine its normal modes in the range of 0-30 Hz. Then, some critical velocities of flutter were calculated within the range of operational velocities. As there is no certainty that the computed modes are in accordance with the natural ones, some parametric calculations are recommended. Modal frequencies depend on structural parameters that are quite difficult to identify. Adopting their values from the reasonable range, it is possible to assign the range of possible frequencies. The frequencies of rudder or elevator modes are dependent on their mass moments of inertia and rigidity of controls. The critical speeds of tail flutter were calculated for various combinations of stiffness or mass values.

The task described here is a preliminary calculational study of normal modes and flutter vibrations. It is necessary to prove the new airplane is free from flutter to fulfil the requirement considered in the type certification process.

The described approach takes into account the uncertainty of results caused by the indeterminacy of selected constructional parameters.

The paper describes the application of two different vibration measurement methods for the identification of natural modes of the miniature unmanned aerial vehicle (UAV). The purpose of this study is to determine resonant frequencies and modes of mini-airplane within the specified range of frequency values.

Special measuring equipment was used including both contact and non-contact techniques. The measuring systems on equipment of the Institute of Aviation Technology in the Faculty of Mechatronics, Armament and Aerospace of Military University of Technology (Warsaw, PL) were used to conduct measurements. In traditional ground vibration testing (GVT) methods a large number of sensors should be attached to the aircraft. The weight of sensors and cables is negligible in relation to the mass of the large aircraft. However, for small and lightweight unmanned aerial vehicles, this could bring a significant mass component in relation to the total mass of the tested object.

The real mini-UAV construction was used to investigate its resonant modes in the range of frequencies between 0 and 50 Hz. After receiving the output values it is possible to perform some flutter calculations within the range of operational velocities. As there is no certainty that the computed modes are in accordance with those natural ones some parametric calculations are recommended. Modal frequencies depend on structural parameters which are quite difficult to identify. Adopting their values from the reasonable range it is possible to assign the range of possible frequencies. The frequencies of rudder or elevator modes are dependent on their mass moments of inertia and rigidity of controls. The critical speeds of tail flutter were calculated for various combinations of stiffness or mass values.

In this paper, some specific techniques of performing the GVT test were presented. Two different measuring methods were applied, i.e. the contact method and the non-contact method. Using the dedicated apparatus in relation to the mini-airplane, properly prepared in terms of mass distribution, rudders deflection stiffness and proper support, some resonant characteristics can be determined. The contact measuring system consists of a multi-channel analyzer, piezoelectric accelerometers, electrodynamic exciters, amplifiers, impedance heads and a computer with the Test.Lab Software. As the non-contact method, a laser scanning vibrometer was used. The principle of its operation is based on the separation of the emitted laser beam. The returning beam reflected from a vibrating object is captured by the camera and compared to the reference beam. Dedicated software analyzes collected data and on the basis of it creates animations of structural vibrational shapes and spectral plots within the investigated frequency range.

The object used for research is the mini-UAV Rybitwa – composite mini-plane with a classic aerodynamic layout manufactured in Institute of Aviation Technology Military University of Technology. In the work, both measurement methods and some sample results were presented. Results referenced to dynamic properties of the mini-UAV can be applied in the future for its finite element model tuning, what would be useful for the needs of some parametric analyzes in case of some UAV modifications because of its structural or equipment modifications.

The purpose of this paper is to present an overview of the conceptual frameworks and concepts with which the research on internationalization patterns of small and medium‐sized enterprises (SMEs) should be conducted.

A comprehensive overview of concepts and a conceptual framework to study internationalization patterns of SMEs is offered.

The complexities of existing definitions and methodologies for researching internationalization patterns are highlighted, and a synthesis of the issues is provided. An integrative model of internationalization pathways, and their antecedents and outcomes is presented.

It is recommended that future research focuses especially on the time dimension of internationalization patterns. Future research can contribute to the literature by adopting a longitudinal approach with larger samples and more detailed cases to capture the dynamics of internationalization.

Practitioners might map their positions, and look for challenges and opportunities with regard to their chosen internationalization pattern. They can also benchmark other firms’ pathways and fine‐tune their own approach to internationalization.

The paper integrates a large body of research in an important research area in international marketing. It also provides guidance on how to conduct future research in the area, and introduces the content of this special issue of the International Marketing Review.

The purpose of this paper is to examine the effects of education and experiential learning on counseling student’s perceptions of substance use and counseling those with substance-related problems. Some counselors report having had negative experiences and beliefs about substance use, abuse, and persons with substance related-problems. A counselor’s negative beliefs and experiences can impair their capacities of working effectively and empathetically with persons who seek help for substance abuse problems. Research reports that education can assist helping professionals to be able to work more efficiently with clients with substance abuse struggles by increasing awareness of substance abuse problems, enhancing empathy, increasing professional’s ability to relate with what clients may be experiencing, training in appropriate interventions, and referral skills.

This study measured changes in students’ attitudes toward addictions following completion of a 15-week addictions counseling course, which incorporated multiple experiential activities in conjunction with information about the effects of various substances and different treatment modalities.

The results revealed significant changes in treatment intervention and non-stereotyping.

These changes suggest education might affect attitudes toward substance abuse. The implications of this study can guide counselor educators in designing effective addictions courses and can lead to future discussions on how to use experiential learning in the classroom.

The city as a form of spatial and social organization was in deep crisis for last years. Now in Poland we deal rather with the renaissance of urbanity. Increasing activity of social movements and the growing importance of civic participation are the most important evidence of this process. This chapter is about the role that public consultation on spatial planning can play in urban policy. The analysis is based on a case study of public consultations conducted with usage of active and innovative approaches. Authors describe the potential of such sociological intervention in solving the crisis of urban communities.

The purpose of this paper is to investigate how absorptive capacity mediates the relationship between ambidextrous organizational learning and performance among small and medium-sized enterprises (SMEs).

Based on the resource-based view (RBV) and the dynamic capability approach, this paper uses the resource-capability-performance framework to construct the theoretical model of this study and tests the theoretical model with the questionnaire survey data of 189 SMEs in mainland China.

Ambidextrous organizational learning has different effects on SMEs' performance in terms of survival performance and growth performance. Both exploitative learning and exploratory learning have positive effects on absorptive capacity, and absorptive capacity has positive influences on both the survival performance and growth performance of SMEs. Absorptive capacity plays different mediating roles in the relationships between ambidextrous organizational learning and SMEs' performance: absorptive capacity plays a partial mediating role in the relationship between exploratory learning and SME growth performance, while absorptive capacity plays complete mediating roles in other relationships.

Managers must stress the use of exploratory learning in order to promote SMEs' growth performance. However, to foster both absorptive capacity and SME performance in terms of survival and growth, managers must pay more attention to take advantage of ambidextrous organizational learning. Government as policymakers should create a favorable environment that enable SMEs to benefit much more from the deployment of ambidextrous organizational learning and absorptive capacity.

To the best of authors’ knowledge, this study is the first to theorize and test the mediating role of absorptive capacity in the linkage between ambidextrous organizational learning and SME performance in terms of survival and growth. Additionally, this study also is the first to provide empirical support for the impact of ambidextrous organizational learning on absorptive capacity among SMEs.