Sensitivity of the SHiP experiment to Heavy Neutral Leptons

Heavy Neutral Leptons (HNLs) are hypothetical particles predicted by many extensions of the Standard Model. These particles can, among other things, explain the origin of neutrino masses, generate the observed matter-antimatter asymmetry in the Universe and provide a dark matter candidate. The SHiP experiment will be able to search for HNLs produced in decays of heavy mesons and travelling distances ranging between $\mathcal{O}(50\text{ m})$ and tens of kilometers before decaying. We present the sensitivity of the SHiP experiment to a number of HNL's benchmark models and provide a way to calculate the SHiP's sensitivity to HNLs for arbitrary patterns of flavour mixings. The corresponding tools and data files are also made publicly available.Comment: journal versio

Experimental investigation of wave-induced motions of an obliquely moving ship

The lateral drift appears due to the effects of wind forces and/or wave drifting forces for a ship sailing in actual sea. The effects of wind forces and / or wave drifting forces in views of lateral drift for ship moving with certain forward speed have not been studied previously. Therefore, it is important to investigate experimentally the influence of the lateral drift to ship seakeeping performance. In this paper experimental results for the ship motions and drift forces on a container ship SR108 obliquely moving in waves are presented. An outline of the model test are also presented in this paper. It is shown that sway, yaw and roll motions are significantly occured even in head waves. In general it is also found that the ship motions and drift forces are influenced mostly by hull drift motion

Enhancement of Maritime Safety and Economic Benefits of Short Sea Shipping Ship Routing

The relevance of ship routing system is increasing according to the mitigation of carbon emissions and enhance the maritime safety. New generation of high-resolution meteo-oceanographic predictions provides useful tools for routing of ship. However, scientific efforts have been focused on inter-oceanic routes. This contribution investigates the economic benefits and improvement on maritime safety of ship routing of Short Sea Shipping (SSS) routes. The investigation is supported with the development of a ship routing system based on a path finding algorithm and meteo-oceanographic predications. Results show that the economic benefits using ship routing in SSS is estimated in percentage of the total cost during energetic wave episodes. The work establishes the basis of further developments in optimal route applied in relatively short-distances and its systematic use in the SSS maritime industry. In this work, the optimal ship routing analysis is investigated in a relative short distance maritime route between Barcelona and Palma de Mallorca (Spain). Dijkstra algorithm is implemented in order to obtain the optimal path under an energetic wave event. The methodology is based on the inclusion of the drag resistance due to waves. The results reveal how the wave direction has a relevant role in the optimum path due to the relative direction with the ship and the enhancement of the navigational safety.Postprint (published version

CFD investigation into seakeeping performance of a training ship

The numerous ship accidents at sea have usually resulted in tremendous loss and casualties. To prevent such disastrous accidents, a comprehensive investigation into reliable prediction of seakeeping performance of a ship is necessarily required. This paper presents computational fluid dynamics (CFD) analysis on seakeeping performance of a training ship (full scale model) quantified through a Response of Amplitude Operators (RAO) for heave and pitch motions. The effects of wavelengths, wave directions and ship forward velocities have been accordingly taken into account. In general, the results revealed that the shorter wavelengths (λ/L ≥ 1.0) have insignificant effect to the heave and pitch motions performance of the training ship, which means that the ship has good seakeeping behavior. However, the further increase of wavelength was proportional with the increase of RAO for her heave and pitch motions; whilst it may lead to degrade her seakeeping quality. In addition, the vertical motions behavior in the following-seas dealt with higher RAO as compared with case of the head-seas condition. Similarly, the subsequent increase of the ship forward velocity was prone to relatively increase of the RAO for her heave and pitch motions especially at λ/L ≥ 2.0. It was merely concluded that this seakeeping prediction using CFD approach provides useful outcomes in the preliminary design stage for safety assessment of the training ship navigation during sailing

Energy-efficient through-life smart design, manufacturing and operation of ships in an industry 4.0 environment

Energy efficiency is an important factor in the marine industry to help reduce manufacturing and operational costs as well as the impact on the environment. In the face of global competition and cost-effectiveness, ship builders and operators today require a major overhaul in the entire ship design, manufacturing and operation process to achieve these goals. This paper highlights smart design, manufacturing and operation as the way forward in an industry 4.0 (i4) era from designing for better energy efficiency to more intelligent ships and smart operation through-life. The paper (i) draws parallels between ship design, manufacturing and operation processes, (ii) identifies key challenges facing such a temporal (lifecycle) as opposed to spatial (mass) products, (iii) proposes a closed-loop ship lifecycle framework and (iv) outlines potential future directions in smart design, manufacturing and operation of ships in an industry 4.0 value chain so as to achieve more energy-efficient vessels. Through computational intelligence and cyber-physical integration, we envision that industry 4.0 can revolutionise ship design, manufacturing and operations in a smart product through-life process in the near future

Spectrograms of ship wakes: identifying linear and nonlinear wave signals

A spectrogram is a useful way of using short-time discrete Fourier transforms to visualise surface height measurements taken of ship wakes in real world conditions. For a steadily moving ship that leaves behind small-amplitude waves, the spectrogram is known to have two clear linear components, a sliding-frequency mode caused by the divergent waves and a constant-frequency mode for the transverse waves. However, recent observations of high speed ferry data have identified additional components of the spectrograms that are not yet explained. We use computer simulations of linear and nonlinear ship wave patterns and apply time-frequency analysis to generate spectrograms for an idealised ship. We clarify the role of the linear dispersion relation and ship speed on the two linear components. We use a simple weakly nonlinear theory to identify higher order effects in a spectrogram and, while the high speed ferry data is very noisy, we propose that certain additional features in the experimental data are caused by nonlinearity. Finally, we provide a possible explanation for a further discrepancy between the high speed ferry spectrograms and linear theory by accounting for ship acceleration.Comment: 21 pages, 10 figures, submitte

What is Godly Speech? (Chapter 7 of Redeeming How We Talk: Discover How Communication Fuels Our Growth, Shapes Our Relationships, and Changes Our Lives)

Excerpt: The Bible makes it clear that the tongue has tremendous power. James compares it to a rudder, which steers a whole ship. A rudder is only a fraction of the size of the boat it steers. While the rudder may have the power to steer an entire ship, someone is standing at the helm, responsible for the direction of the rudder and ultimately the ship and all the lives on it. We are in control of our tongues, and we are responsible for the direction we turn them