Modelling of material cutting with a material microstructure-level (MML) model

In this research work a material microstructure-level cutting model (MML cutting model) is presented. The crystal plasticity theory is adopted for modeling the cutting of the titanium alloy Ti–6Al–4V in orthogonal case. In this model, the grains of the studied material are explicitly presented, and their orientation angles and slip system strength anisotropy are considered as the main source of the microstructure heterogeneity in the cutting material. To obtain the material degradation process, the continuum self-consistent intragranular damage model and discrete cohesive zone inter-granular damage model, were developed, wherein the zero thickness cohesive element is implemented to simulate the bond between grain interfaces. This model was validated by a comparison with compression tests from literature. Results demonstrate the possibility to capture the influence of the microstructure on the material removal in terms of chip formation. Particularly, it is demonstrated that the grain orientation angle plays an important role for the chip segmentation and its periodicity during the cutting process

Vibration harvesting integrated into vehicle suspension and bodywork

This work proposes a new piezoelectric transducer system with four freedoms of movement modelled and evaluated by mechatronic techniques. The proposed modelling techniques (finite element and bond graph) were performed in a 20-Sim framework attached to the ANSYS software. The established harvester system has the ability to increase the driver's comfort when travelling on several types of road surfaces. The piezoelectric harvester is designed to investigate and provide the health requirement and ride comfort of the vehicle's drives on random road surfaces. The simulation results affirm that the improved piezoelectric transducer arrangement is more productive for various aspects. The power recovery is significantly enhanced as well as the driving comfort on the three road categories. Finally, the harvestable power amount is highlighted and is graphically discussed for several specific applications

The Relationship Between Domain

The rights of Intellectual property are considered as moral rights. These rights, which come to non-material things, are the product of human thought and mind. They are developed and applied on the ground to become an intellectual product that may be material or moral. Among these ideas and innovations that has been emerged in recent years is Domain names. This term is often related to the domain of intellectual property in its branches. The reason for this is the novelty of this subject and its relevance to the field of information technology, in addition to the similarities that are associated with concepts of intellectual property such as trademarks and trade names. For example, more domain names in the field of intellectual property its disputes under the laws of similar elements such as the trademark. &nbsp

Entrepreneurship Study and Its Impact on Students’ Intention to Start Up: A Sample Case Study of Students Belonging to Two Universities of Tunisia

The present paper examines the impact of entrepreneurship education on students’ intention to start up business. Using a sample of young Tunisian students from both Sfax and Sousse (these are two tows in Tunisia) universities, we propose to determine the significant factors influencing their entrepreneurial intention. Our econometric results have revealed that the composite variables , i.e, the student’s internal and external socio-cultural background, the students’ profile in terms of their theoretical and practical knowledge in new business start-up and the students’ characteristics (age and, above all, educational level), are the most determining variables affecting students’ intention to engage in business start-ups. The gender variable has no significant effect on entrepreneurial behavior

Drift Tube Ion Mobility Measurements for Thermochemistry, Kinetics and Polymerization of Cluster Ions

In this work, the Drift Tube Ion Mobility technique is used to study the hydrophobic hydration and solvation of organic ions and measure the thermochemistry and kinetics of ion-molecule reactions. Furthermore, an exploratory study of the intracluster polymerization of isoprene will be presented and discussed. The ion hydration study is focused on the C3H3+ cation1 and Pyridine▪+ radical cation.2 The chemistry of the cyclic C3H3+ cation1 has received considerable attention and continues to be an active area of research.3-7 The binding energies of the first 5 H2O molecules to c-C3H3+ were determined by equilibrium measurements. The measured binding energies of the hydrated clusters of 9-12 kcal/mol are typical of carbon-based CH+X hydrogen bonds. The ion solvation with the more polar CH3CN molecules results in stronger bonds consistent with the increased ion-dipole interaction. Ab initio calculations show that the lowest energy isomer of the c-C3H3+(H2O)4 cluster consists of a cyclic water tetramer interacting with the c-C3H3+ ion, which suggests the presence of orientational restraint of the water molecules consistent with the observed large entropy loss. The c-C3H3+ ion is deprotonated by 3 or more H2O molecules, driven energetically by the association of the solvent molecules to form strongly hydrogen bonded (H2O)nH+ clusters. The kinetics of the associative proton transfer (APT) reaction C3H3+ + nH2O → (H2O)nH+ + C3H2 exhibits an unusually steep negative temperature coefficient of k = cT(sup\u3e63±4 (or activation energy of -32 ± 1 kcal mol-1). The behavior of the C3H3+/water system is exactly analogous to the benzene+ /water system8,9, suggesting that the mechanism, kinetics and large negative temperature coefficients may be general to multibody APT reactions. These reactions can become fast at low temperatures, allowing ionized polycyclic aromatics to initiate ice formation in cold astrochemical environments.The solvation energies of the pyridine+ radical cation by 1- 4 H2O molecules are determined by equilibrium measurements in the drift cell. The binding energies of the pyridine+(H2O)n clusters are similar to the binding energies of protonated pyridineH+(H2O)n clusters that involve NH+∙∙OH2 bonds, and different from those of the solvated radical benzene+(H2O)n ions that involve CHδ+∙∙OH2 bonds. These relations indicate that the observed pyridine+ ions have the distonic C5H4NH+ structure that can form NH+∙∙OH2 bonds. The observed thermochemistry and ab initio calculations show that these bonds are not affected significantly by an unpaired electron at another site of the ion. The distonic structure is also consistent with the reactivity of pyridine+ in H atom transfer, intra-cluster proton transfer and deprotonation reactions. The results present the first measured stepwise solvation energies of distonic ions, and demonstrate that cluster thermochemistry can identify distonic structures.The gas phase clustering of small molecules around the hydronium ion is of fundamental interest and is relevant to important atmospheric and astrophysical processes. In this work, the equilibrium constants for the formation of the H3O+(X)n clusters with X = H2, N2 and CO and n = 1-3 at different temperatures are measured using the drift tube technique10. The arrival time distributions (ATDs) of the injected H3O+ and the H3O+(X)n clusters formed inside the cell are measured under equilibrium conditions. The resulting binding energies for the addition of one and two hydrogen molecules are similar [3.4 and 3.5 kcal/mol, respectively). For the N2 clustering with n = 1-3, the measured binding energies are 7.9, 6.9 and 5.4 kcal/mol, respectively. The clustering of CO on the H3O+ ion exhibits a relatively strong binding energy (11.5 kcal/mol) consistent with the dipole moment and polarizability of the CO molecule. Theoretical calculations of the lowest energy structures are correlated to the experimental results. Finally, intracluster polymerization leading to the formation of covalent bonded oligomer ions has been investigated following the ionization of neutral isoprene clusters. The results indicate that isoprene dimer cation has a structure similar to that of the limonene radical cation. Mass-selected mobility and dissociation studies also indicate that the larger isoprene cluster ions have covalent bonded structures. The conversion of molecular clusters into size-selected oligomers is an important process not only for detailed understanding of the early stages of polymerization but also for practical applications such as the formation of new polymeric materials with controlled and unusual properties

Bearing capacity of a strip footing on a geosynthetic reinforced soil modular block walls after a seismic loading

Geosynthetic reinforced walls are widely used in public works. The aim of this paper is to study the bearing capacity of a strip rough footing on a geosynthetic reinforced soil modular block walls, after a seismic action. The numerical modelling was carried out by using the finite element method implemented in the Plaxis code. The influence of the eccentric vertical load on the bearing capacity of footing was examined considering different distances between the top of the wall and the edge of the footing. The results of this study confirm that the seismic loading does not affect the bearing capacity when the distance d/B is greater than 10

The first record of the invasive Chinese pond mussel Sinanodonta woodiana (Lea, 1834) (Bivalvia: Unionidae) in the African continent

The Chinese pond mussel Sinanodonta woodiana s.l., is a successful global invader. We report its first finding in Morocco, which represents the first record of the species in the African continent. Measures are needed to increase monitoring and management of its invasion process

The Contribution of Domestic Investment, Exports and Imports on Economic Growth: A Case Study of Peru

This article has examined the contribution of domestic investment, exports and imports on economic growth in Peru. To achieve this objective, annual data for the period between 1970 and 2017 were used and tested based on Johansen co integration analysis and the vector error correction model. According to the results of the analysis, it has been determined that domestic investment, exports and imports have not any effect on economic growth in the short run and in the long run. These outcomes manifest that trade openness and domestic investments are not beholden as a provenance of economic growth in Peru over this extended period and suffer from many issues and a miserable economic organization