A Morse alphabet

A compact alphabetic form of the Morse code is constructed following some simple rules. It is mostly useful in learning the Morse code and using it in writing form

Quaternion Formalism for the Intrinsic Transfer Matrix

AbstractA quaternion formulation is applied to the intrinsic transfer matrix for longitudinal elastic wave propagation through a multilayer medium in order to find the spectral response of a sonic crystal. Resonance conditions and the band structure of the crystal are obtained. The presence of a defect is also analysed. The analysis is carried out theoretically and through simulations. A coupled oscillators model is used to validate the obtained results from a phenomenological point of view. Experimental measurements are carried out for some periodic multilayer arrangements and they are correlated with theory. The obtained spectral response and band structure are essential in characterising the sonic crystal and also in optimising its structure in order to obtain specific passbands and stopbands. The adaptedness of the quaternion formulation to periodic structures and to the inclusion of defects is considered

Requirements versus Knowledge in the Quality Management of the Global Engineering Process within an Organization in the Aerospace Industry

This paper presents original research on the identification and modeling of quality requirements for structural products in aircraft structures. As the main objective of this research, the authors focused on identifying the relationship between the previously mentioned requirements and the technical knowledge necessary to improve the quality of the processes involved. This scientific paper presents research in terms of defining a global engineering process addressing, as a starting point, the requirements necessary to be met in the manufacture of structural products for the structure of aircraft. The authors have identified directions for improvement in the global engineering process which will certainly lead to the creation of a sustainable, competitive advantage for the organization where the research was conducted. Based on the concept of intellectual capital and its components, the authors developed a model of knowledge analysis related to the requirements in order to later develop knowledge matrices at the subprocess level. This research presents a pragmatic evaluation based on the experience of those involved, but also on a study focused on pre-modeling the knowledge necessary to be considered and involved in the global engineering process. After this desideratum, the relationship between knowledge–requirements, but also the relationship between requirements–knowledge, was achieved, establishing a direct connection with the global quality of the analyzed products from the perspective of streamlining the global engineering process. This research is based on an entire procedure of analysis and modeling of the processes and subprocesses considered that could lead to favorable results from an economic point of view, but also from a technical point of view, the recommendation being to implement those presented to increase the competitive advantage in the profiled market

The Design and the Process Technology of a Rotational Mold

The present paper highlights a series of introduction aspects of the rotational system for slush plastic casting, which are the characteristic elements of this fabrication technology and which consistsof the rotational molding. Also, the structure of a rotational mold and the methods used to obtain themold, are presented. The purpose of this research is to describe the parametric design of a rotationalmold and its fabrication process. The research method used to accomplish this purpose consist of the CAD – Modelling specific software utilized to carry out the parametric design of the rotational mold. After the parametric design it was adopted the manufacturing technology of the mold, using a CAMspecific software. In the final part of the research a few important conclusions were drawn from the bibliographical study and from personal convictions

Requirements versus Knowledge in the Quality Management of the Global Engineering Process within an Organization in the Aerospace Industry

This paper presents original research on the identification and modeling of quality requirements for structural products in aircraft structures. As the main objective of this research, the authors focused on identifying the relationship between the previously mentioned requirements and the technical knowledge necessary to improve the quality of the processes involved. This scientific paper presents research in terms of defining a global engineering process addressing, as a starting point, the requirements necessary to be met in the manufacture of structural products for the structure of aircraft. The authors have identified directions for improvement in the global engineering process which will certainly lead to the creation of a sustainable, competitive advantage for the organization where the research was conducted. Based on the concept of intellectual capital and its components, the authors developed a model of knowledge analysis related to the requirements in order to later develop knowledge matrices at the subprocess level. This research presents a pragmatic evaluation based on the experience of those involved, but also on a study focused on pre-modeling the knowledge necessary to be considered and involved in the global engineering process. After this desideratum, the relationship between knowledge–requirements, but also the relationship between requirements–knowledge, was achieved, establishing a direct connection with the global quality of the analyzed products from the perspective of streamlining the global engineering process. This research is based on an entire procedure of analysis and modeling of the processes and subprocesses considered that could lead to favorable results from an economic point of view, but also from a technical point of view, the recommendation being to implement those presented to increase the competitive advantage in the profiled market

A New Thermal Conductivity Model and Two-Phase Mixed Convection of CuO–Water Nanofluids in a Novel I-Shaped Porous Cavity Heated by Oriented Triangular Hot Block

This paper investigates the cooling performance of nanofluid (NF) mixed convection in a porous I-shaped electronic chip with an internal triangular hot block using Buongiorno’s two-phase model. This type of cavity and hot block geometry has not been studied formerly. The NF was assumed to be a mixture of water and CuO nanoparticles (NP) up to 4% of volume concentration. As most published mathematical models for the thermal conductivity of NF give inaccurate predictions, a new predictive correlation for effective thermal conductivity was also developed with a high accuracy compared to the experimental data. The results showed that any increase in the NP volume concentration enhances the average Nusselt number (Nu¯) and the normalized entropy generation, and reduces the thermal performance of the cavity in all orientations of the hot block. The maximum enhancement in cooling performance was 17.75% and occurred in the right-oriented hot block in the sand-based porous cavity. Furthermore, adding the NP to the base fluid leads to a more capable cooling system and enhances the irreversibility of the process