The implications of gamma-ray photons from LHAASO on Lorentz symmetry

The Large High Altitude Air Shower Observatory (LHAASO) has reported the measurement of photons with high energy up to 1.42 PeV from 12 gamma-ray sources. We are concerned with the implications of LHAASO data on the fate of Lorenz symmetry at such high energy level, thus we consider the interaction of the gamma ray with those photons in cosmic microwave background (CMB), and compute the optical depth, the mean free path as well as the survival probability for photons from all these gamma-ray sources. Employing the threshold value predicted by the standard special relativity, it is found that the lowest survival probability for observed gamma ray photons is about 0.60, which is a fairly high value and implies that abundant photons with energy above the threshold value may reach the Earth without Lorentz symmetry violation. We conclude that it is still far to argue that the Lorentz symmetry would be violated due to the present observations from LHAASO. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Influence of Immunocastration and Diet on Meat and Fat Quality of Heavy Female and Male Pigs

Two experiments were carried out; one with female pigs and the other with male pigs destined for Teruel dry-cured ham production, to evaluate the effect of immunocastration (entire gilts-EG vs. immunocastrated gilts-IG and surgically castrated males vs. immunocastrated males-IM) and diet (control vs. high energy vs. low crude protein and amino acids) on meat quality and fat composition. Fifteen meat samples and eight fat samples of each treatment were analyzed in both experiments. In the case of males, six fat samples per treatment were analyzed to determine boar taint. Immunocastration is a good strategy in gilts intended for dry-cured ham production because improves meat composition; however, in males, immunocastration impairs the results of pork chemical composition compared with surgical castration. The IG presented a lower polyunsaturated/saturated fatty acids ratio than EG, improving fat technological quality. Diets had little effect on pork or fat quality in gilts, but a high-energy level using oilseeds and a low-crude-protein and -amino-acids diet from 80 to 137 kg of body weight could be interesting in IM to maintain or increase fat consistency, respectively. Moreover, in general, immunocastration is effective in avoiding boar taint in males.

Analysis of the propellers-airframe interaction of the light transport aircraft

In the design of multi-engine aircraft, one of the important issues is the interaction between the propellers and airframe configuration components, especially in take-off and go-around procedure modes. Modern propeller-driven aircraft concepts in the pulling configuration are characterized by a high disk loading and an increased number of propeller blades used to increase cruising speed and reduce excessive noise. The first problem arising due to high disk loading is the direct impact of forces by operating propellers (thrust, normal force) on fixed-wing stability, especially at angles of attack different from a zero value. The second one involves a high-energy level of the propeller slipstream, having a significant indirect impact on the aircraft’s aerodynamics, stability and controllability. This impact is primarily associated with the interaction of propellers slipstream with other aircraft’s configuration elements. The complexity of taking into account the slipstream-wing interaction and other airframe components stipulated the application of experimental methods to study the problems of propellers – airframe interaction while designing propeller-driven aircraft configurations. This article presents an analysis of the experimental studies results of the operating propellers- airframe interaction for a light twin-engine transport aircraft. The aerodynamic aircraft’s configuration is executed using the conventional pattern of a high-wing and the carrier-on deck type empennage. The high-lift wing device is a fixed-vane doubleslotted flap. The wind-tunnel tests of the model in the cruising, takeoff and landing configurations were carried out in TsAGI lowspeed wind-tunnel T-102. Measurement of forces and moments, acting on the model, was performed by means of an external sixcomponent wind-tunnel balance. Measurement of forces and moments, acting on the propeller, was conducted using strain gauge weighers installed inside the engine nacelles of power plant simulators. The simultaneous combined use of external and internal balances allowed researchers to determine the direct and indirect contribution of operating propellers to the model longitudinal aerodynamic characteristics under variation of loading factor B ranging from 0 to 2.

HIERARCHICAL ELECTROSPUN VEILS AS POTENTIAL TOUGHENING MATERIALS FOR STRUCTURAL COMPOSITE LAMINATES

The use of fiber reinforced polymers (FRPs) as a replacement of traditional homogeneous materials is still hindered by their brittle behavior and poor interlaminar resistance. Interleaving veils in polymer matrix, especially with fibers at the nanoscale dimension, is considered as one of the most promising toughening methods. By considering the hierarchical nature of the resulting laminated composites, their properties are intrinsically dependent on the interaction between the nanofibrous veils and the thermosetting resin and, in an attempt to tailor the interfacial adhesion between the electrospun fibers and matrix, surface modification of the fibers with the integration of inorganic nanostructures could be a solution. This work is an investigation on the use of commercially available electrospun nylon nanofibers decorated with ZnO nanorods obtained by three-step chemical synthesis. The modified veils were interleaved in carbon/epoxy prepreg composites and their mechanical properties were evaluated under Low Velocity Impact (LVI) tests at different energy levels (5 J and 7.5 J). Although the presence of ZnO nanorods did not limit the extension of the delaminated area in case of high energy level test (7.5 J), nanomaterials contributed positively to reduce the extent of the damaged area when a low energy impact was adopted (5 J). A beneficial effect of ZnO-functionalized commercial electrospun veils was observed in the flexural strength of laminated composites. After LVI tests at 5 J and 7.5 J, the flexural strength resulted higher compared to that observed in the same tests on specimens with non-decorated veils (NY4M), thus suggesting a positive role played by ZnO nanorods in hindering delamination propagation.

You as a Change Leader

The executive or other member of the organization who is in charge of the change initiative will need to engage in self-assessment to identify the need for personal development of any change leadership competencies and skills and then implement a plan for leader for development. Traits including a high energy level, emotional maturity, personal integrity, self-confidence, and an achievement orientation are valuable assets. Task, relationship, and change behaviors and the use of influence tactics are all essential. A change leader must develop self-awareness, including the understanding of one’s basic philosophies and preferences as well as strengths and areas to develop. Ethics issues are relevant in organizational change leadership. All of these dynamics of change leadership will affect how a change leader will design and implement an organizational change intervention.

Amorphization-induced surface electronic states modulation of cobaltous oxide nanosheets for lithium-sulfur batteries

Lithium-sulfur batteries show great potential to achieve high-energy-density storage, but their long-term stability is still limited due to the shuttle effect caused by the dissolution of polysulfides into electrolyte. Herein, we report a strategy of significantly improving the polysulfides adsorption capability of cobaltous oxide by amorphization-induced surface electronic states modulation. The amorphous cobaltous oxide nanosheets as the cathode additives for lithium-sulfur batteries demonstrates the rate capability and cycling stability with an initial capacity of 1248.2 mAh g-1 at 1 C and a substantial capacity retention of 1037.3 mAh g-1 after 500 cycles. X-ray absorption spectroscopy analysis reveal that the coordination structures and symmetry of ligand field around Co atoms of cobaltous oxide nanosheets are notably changed after amorphization. Moreover, DFT studies further indicate that amorphization-induced re-distribution of d orbital makes more electrons occupy high energy level, thereby resulting in a high binding energy with polysulfides for favorable adsorption.

Agility in the Events Sector A Case Study of a Business Event in Finland (Valentina Gorchakova and Ekaterina Berdysheva)

The events industry was estimated at $1,100 billion in 2018 and was expected to grow to reach $2,330 billion by 2026 (Allied Market Research, n.d.). Year 2020, however, turned out to be perhaps the most transformative year in the industry in the last decades. Numerous events, from smaller family occasions, like weddings, to major events of the likes of the Wimbledon tennis tournament, the UEFA EURO 2020, Glastonbury Festival and the Cannes Film festival, had to be cancelled due to the Covid-19 pandemic. The combined economic impact is not yet known but will be a loss in the hundreds of billions of US dollars (Gössling, Scott, & Hall, 2021). This shows the vulnerability of the events industry to major crises. Despite the negative impacts of crises on events, there is a paucity of research that explores organizational responses under unusual, unprecedented or critical circumstances in the events sector. This chapter applies the concept of agility in event organization within volatile, uncertain, complex, and ambiguous, so-called VUCA, environment (Bennett & Lemoine, 2014) that dominated year 2020 due to the unfolding pandemic. The agile approach is often seen as a stream of new ideas leading to elegantly simple solutions. It requires a high energy level of the team involved due to the tight constraints and deadlines. The authors introduce a case study of a business festival organized in Turku (Finland) and discuss the decision-making process, stakeholder involvement, introduction of a new modus operandi, and the new event format that was chosen.

Кинетика процесса накопления повреждений и разрушения в зонах концентраторов при испытаниях образцов на разрыв

The paper considers the effect of various stress concentrators on processes of damage accumulation, initiation and propagation of crack in steel (steel 3) samples during uniaxial tensile. In the middle of the samples there was a transverse welded joint or a hole with a diameter of 5 mm. The acoustic-emission testing results showed that weight content of location impulses (Wi) in the clusters of low, middle and high energy level and criteria parameters value Wi at the stages of the samples destruction have similar pattern of change despite the various types of concentrators, stress-strain material diagrams, pattern of damage accumulation, number of registered acoustic emission (AE) events and its registration activity.

Ultrafast capture of electrons ejected by photoionization leading to the formation of a charge-separated state at a high energy level

Photoionization-driven electron transfer realizes ultrafast formation of the charge-separated state at a high energy level beyond the traditional framework.

A Note on Tonelli Lagrangian Systems on $\mathbb{T}^2$ with Positive Topological Entropy on a High Energy Level

In this work we study the dynamical behavior of Tonelli Lagrangian systems defined on the tangent bundle of the torus $\mathbb{T}^2=\mathbb{R}^2/\mathbb{Z}^2$. We prove that the Lagrangian flow restricted to a high energy level $E_{L}^{-1}(c)$ (i.e., $c > c_0(L)$) has positive topological entropy if the flow satisfies the Kupka-Smale property in $E_{L}^{-1}(c)$ (i.e., all closed orbits with energy c are hyperbolic or elliptic and all heteroclinic intersections are transverse on $E_{L}^{-1}(c)$). The proof requires the use of well-known results from Aubry – Mather theory.