Experimental observations of topologically guided water waves within non-hexagonal structures

We investigate symmetry-protected topological water waves within a strategically engineered square lattice system. Thus far, symmetry-protected topological modes in hexagonal systems have primarily been studied in electromagnetism and acoustics, i.e. dispersionless media. Herein, we show experimentally how crucial geometrical properties of square structures allow for topological transport that is ordinarily forbidden within conventional hexagonal structures. We perform numerical simulations that take into account the inherent dispersion within water waves and devise a topological insulator that supports symmetry-protected transport along the domain walls. Our measurements, viewed with a high-speed camera under stroboscopic illumination, unambiguously demonstrate the valley-locked transport of water waves within a non-hexagonal structure. Due to the tunability of the energy's directionality by geometry, our results could be used for developing highly-efficient energy harvesters, filters and beam-splitters within dispersive media

Controversial advert perceptions in SNS advertising: the role of ethical judgement and religious commitment

This study attempts to advance knowledge in the area of controversial advertising by examining the antecedents and consequences of controversial advert perceptions in the context of social media, and particularly social networking sites (SNS). Specifically, we explore how ethical judgement and religious commitment shape controversial advert perceptions leading to attitudes towards the advert, brand attitudes and purchase intentions. Our results indicate that when a SNS advert is judged to be ethically acceptable, the level of perceived advert controversy is lower. However, the impact of ethical judgement on controversial advert perceptions becomes significant and positive when intra-personal commitment and inter-personal religious commitment are introduced as moderators. This result implies that the level of religious commitment changes the ethical judgement - controversial advert perceptions relationship. The results also highlight that controversial advert perceptions negatively influence attitude toward the advert. The study contributes to the limited knowledge on controversial advertising on SNS, yielding significant and relevant implications for academics and advertisers alike, in their effort to improve advertising effectiveness without offending or alienating target audiences

Disclination vortices in elastic media

The vortex-like solutions are studied in the framework of the gauge model of disclinations in elastic continuum. A complete set of model equations with disclination driven dislocations taken into account is considered. Within the linear approximation an exact solution for a low-angle wedge disclination is found to be independent from the coupling constants of the theory. As a result, no additional dimensional characteristics (like the core radius of the defect) are involved. The situation changes drastically for 2\pi vortices where two characteristic lengths, l_\phi and l_W, become of importance. The asymptotical behaviour of the solutions for both singular and nonsingular 2\pi vortices is studied. Forces between pairs of vortices are calculated.Comment: 13 pages, published versio

Business-to-business open innovation: COVID-19 lessons for small and medium-sized enterprises from emerging markets

Small and medium-sized enterprises (SMEs) from emerging markets are the most vulnerable types of firms, especially in times of crisis due to time and resource constraints. Thus, this paper aims to help SMEs from emerging markets in choosing the right business partners with whom to cooperate to develop relevant innovations in crisis periods in general, and during the COVID-19 pandemic in particular. To obtain relevant insights, qualitative data from SMEs in Bosnia and Herzegovina were collected in March-April 2020. The findings show that SMEs have embraced new collaborations with business customers and competitors, and developed a collaborative mindset opposed to the traditionally competitive way of doing business in emerging markets. Based on the findings, this paper presents a set of recommendations for managers, and suggests several future research opportunities around the management of openness in the context of SMEs from emerging markets

Photonic crystal carpet: Manipulating wave fronts in the near field at 1550 nm

Ground-plane cloaks, which transform a curved mirror into a flat one, and recently reported at wavelengths ranging from the optical to the visible spectrum, bring the realm of optical illusion a step closer to reality. However, all carpet-cloaking experiments have thus far been carried out in the far-field. Here, we demonstrate numerically and experimentally that a dielectric photonic crystal (PC) of a complex shape made of a honeycomb array of air holes can scatter waves in the near field like a PC with a at boundary at stop band frequencies. This mirage effect relies upon a specific arrangement of dielectric pillars placed at the nodes of a quasi-conformal grid dressing the PC. Our carpet is shown to work throughout the range of wavelengths 1500nm to 1650nm within the stop band extending from 1280 to 1940 nm. The device has been fabricated using a single- mask advanced nanoelectronics technique on III-V semiconductors and the near field measurements have been carried out in order to image the wave fronts's curvatures around the telecommunication wavelength 1550 nm.Comment: 6 page

Is it better to be both nice and nasty? Investigating the co-occurrence of sales manager aggressiveness and caring

Empirical research has largely neglected to investigate the issue of sales manager's problem resolution styles in handling conflicts. Building on the qualitative work of Lee and Cadogan (2009), we investigate how sales manager's problem resolution styles, as reflected in both caring and aggressive interpersonal interactions with their salespeople, impact important sales force outcomes. The results show that depending on the level of caring that manager exhibits during the problem resolution process, the curvilinear effects of aggressiveness on salespeople emotional exhaustion and sportsmanship are dramatically altered. Our findings are interesting, and suggest that the almost wholly negative picture painted in current academic literature regarding aggressive managerial style is at least somewhat simplistic, and perhaps rather overstated. Therefore aggressiveness and caring further should be considered together, rather than separatel

Business-to-business open innovation: COVID-19 lessons for small and medium-sized enterprises from emerging markets

This is the final version. Available on open access from Elsevier via the DOI in this recordSmall and medium-sized enterprises (SMEs) from emerging markets are the most vulnerable types of firms, especially in times of crisis due to time and resource constraints. Thus, this paper aims to help SMEs from emerging markets in choosing the right business partners with whom to cooperate to develop relevant innovations in crisis periods in general, and during the COVID-19 pandemic in particular. To obtain relevant insights, qualitative data from SMEs in Bosnia and Herzegovina were collected in March-April 2020. The findings show that SMEs have embraced new collaborations with business customers and competitors, and developed a collaborative mindset opposed to the traditionally competitive way of doing business in emerging markets. Based on the findings, this paper presents a set of recommendations for managers, and suggests several future research opportunities around the management of openness in the context of SMEs from emerging markets

Static non-reciprocity in mechanical metamaterials

Reciprocity is a fundamental principle governing various physical systems, which ensures that the transfer function between any two points in space is identical, regardless of geometrical or material asymmetries. Breaking this transmission symmetry offers enhanced control over signal transport, isolation and source protection. So far, devices that break reciprocity have been mostly considered in dynamic systems, for electromagnetic, acoustic and mechanical wave propagation associated with spatio-temporal variations. Here we show that it is possible to strongly break reciprocity in static systems, realizing mechanical metamaterials that, by combining large nonlinearities with suitable geometrical asymmetries, and possibly topological features, exhibit vastly different output displacements under excitation from different sides, as well as one-way displacement amplification. In addition to extending non-reciprocity and isolation to statics, our work sheds new light on the understanding of energy propagation in non-linear materials with asymmetric crystalline structures and topological properties, opening avenues for energy absorption, conversion and harvesting, soft robotics, prosthetics and optomechanics.Comment: 19 pages, 3 figures, Supplementary information (11 pages and 5 figures