Nano-confinement of biomolecules: Hydrophilic confinement promotes structural order and enhances mobility of water molecules

Molecular dynamics simulations have been used to investigate the confinement packing characteristics of small hydrophilic (N-acetyl-glycine-methylamide, Nagma) and hydrophobic (N-acetyl-leucine-methylamide, Nalma) biomolecules in large diameter single-wall carbon nanotubes (SWCNTs). We find that hydrophilic biomolecules easily fill the nanotube and self organize into a geometrical configuration which reminds the water structural organization under SWCNT confinement. The packing of hydrophilic biomolecules inside the cylinder confines all water molecules in its core, which enhances their mobility. Conversely, hydrophobic biomolecules accommodate into the nanotubes with a trend for homogeneous filling, which generate unstable small pockets of water and drive toward a state of dehydration. These results shed light on key parameters important for the encapsulation of biomolecules with direct relevance for long-term storage and prevention of degradation.

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The Biaxial Strain Dependence of Magnetic Order in Spin Frustrated Mn3NiN Thin Films

Multicomponent magnetic phase diagrams are a key property of functional materials for a variety of uses, such as manipulation of magnetization for energy efficient memory, data storage, and cooling applications. Strong spin‐lattice coupling extends this functionality further by allowing electric‐field‐control of magnetization via strain coupling with a piezoelectric. Here this work explores the magnetic phase diagram of piezomagnetic Mn₃NiN thin films, with a frustrated noncollinear antiferromagnetic (AFM) structure, as a function of the growth induced biaxial strain. Under compressive strain, the films support a canted AFM state with large coercivity of the transverse anomalous Hall resistivity, ρ_xy, at low temperature, that transforms at a well‐defined Néel transition temperature (T_N) into a soft ferrimagnetic‐like (FIM) state at high temperatures. In stark contrast, under tensile strain, the low temperature canted AFM phase transitions to a state where ρ_xy is an order of magnitude smaller and therefore consistent with a low magnetization phase. Neutron scattering confirms that the high temperature FIM‐like phase of compressively strained films is magnetically ordered and the transition at T_N is first‐order. The results open the field toward future exploration of electric‐field‐driven piezospintronic and thin film caloric cooling applications in both Mn₃NiN itself and the broader Mn₃AN family.     

Study of metamaterial surface wave antenna based on split ring resonator

Microsystem Technologies - In this paper, a new metamaterial-inspired high frequency surface wave antenna is designed. An artificial magnetic conductor surface is introduced into the near field...     

The <i>k</i> Nearest Neighbors Estimator of the M-Regression in Functional Statistics

It is well known that the nonparametric estimation of the regression function is highly sensitive to the presence of even a small proportion of outliers in the data. To solve the problem of typical observations when the covariates of the nonparametric component are functional, the robust estimates for the regression parameter and regression operator are introduced. The main propose of the paper is to consider data-driven methods of selecting the number of neighbors in order to make the proposed processes fully automatic. We use the     

Optimal parameters for performant heterojunction InGaP/GaAs solar cell

We demonstrated mainly some of the different parameters effects -as a function of temperature-as window layers, thickness, and doping of the various layers (emitter, base and BSF) on the performances of InGaP/GaAs solar cell. First, we have varied the molar fraction of different layers; their thickness and the doping of both emitters and bases. We have registered the result of each variation until obtaining optimal parameters. In a second stage, we have simulated the InGaP/GaAs cell without window layers which results in η = 12.47% and η = 22.14% for eliminating top and bottom windows respectively. Then, the elimination of layer BSFs(back surface field) on the back face of the considered cell causes a remarkable decrease in open circuit voltage Voc and output η which reached 1.57 V and 11.95% respectively. In a last stage, we optimized and simulated the performances of the InGaP/GaAs dual-junction solar cell for its optimal parameters while varying its operation temperature from 300 K to 375 K with an increment of 25 °C using a virtual wafer fabrication TCAD Silvaco. The optimization at 300 K led to the following results Icc = 15.19 mA/cm^?2, Voc = 2.53 V, FF = 91.32% and η = 25.43% which are close with those found in literature for In_(1?x)Ga_(x)P(x is molar fraction: x = 0.5). Therefore, we could determine the critical parameters of the cell and optimize its main parameters to obtain the highest performance for a dual junction solar cell. This work will pave the way with new prospects in the field of the photovoltaic. The structure simulation will simplify the manufacturing processes of solar cells; will thus reduce the costs while producing high outputs of photovoltaic conversion.     

Microstructural evolution and texture analysis of magnesium phosphate cement

Three-dimensional quantitative image analysis from synchrotron X-ray microcomputed tomography indicated a coarsening of the microstructure of magnesium potassium phosphate cements driven by crystallization of K-struvite from the first amorphous product. Porosity and pore surface area increased because of the progressive build-up of a network of elongated/tabular crystal domains, with density higher than the amorphous. The known increase in strength with time is thought to occur thanks to the overwhelming contribution of a developing interlocked lath-shaped microstructure. Combined X-ray and neutron diffraction texture analysis indicated that at least a fraction of K-struvite nucleates at the surface of MgO grains, suggesting the intervention of more than one crystallization mechanism. The detected weak texture, compatible with a nearly random orientation of crystallites, and the isotropic pore fabric, are beneficial with respect to crack propagation.     

Effect of thermomechanical loads on the propagation of crack near the interface brittle/ductile

The purpose of this paper is to understand the combined effect of thermal and mechanical loading on the initiation and behaviour of sub-interface crack in the ceramic. In this study a 2D finite element model has been used to simulated mixed mode crack propagation near the bimaterial interface. The assembly ceramometalic is subjected simultaneously to thermomechanical stress field. The extent of a plastic zone deformation in the vicinity of the crack-tip has a significant influence on the rate of its propagation. The crack growth at the joint specimen under four-point bending (4PB) loading and the influence of residual stresses was also evaluated by the maximum tensile stress criterion. The J-integral at the crack tip is generally expressed by the thermomechanical local stresses. The results obtained show the effect of the temperature gradient ΔT, the size of the crack and the applied stresses on the J-integral.     

Stress analysis in single molar tooth

The human tooth faces different stresses under environments of different loading conditions, these loading produces major factors in weakness of the tooth and bone structure. The need to save natural teeth has prompted the development of novel and complex techniques in endodontology, prosthodontics and periodontology. Despite a poor long-term prognosis and some prejudice to local bone, considerable efforts have been exerted for the realization of these techniques. Nowadays, the 3D finite element analysis (FEA) is one of the more recently used techniques for stress analysis in single human tooth under different loading cases. The von Mises stress distribution indicated that the greatest effort area of tooth lies at the base of crown up to the gingival line with varying intensities in the different loading cases. The highest stress in the cortical bone was predominantly found around the cervical region of the tooth and lowest in the cancellous bone and periodontal ligament (PDL). The PDL is a soft tissue, and it could function as an intermediate cushion element which absorbs the impact force and uniformly transfers the occlusal forces into the surrounding bone.     

Evolutionary computation approaches to the Curriculum Sequencing problem

Within the field of e-Learning, a learning path represents a match between a learner profile and his preferences from one side, and the learning content presentation and the pedagogical requirements from the other side. The Curriculum Sequencing problem (CS) concerns the dynamic generation of a personal optimal learning path for a learner. This problem has gained an increased research interest in the last decade, as it is not possible to have a single learning path that suits every learner in the widely heterogeneous e-Learning environment. Since this problem is NP-hard, heuristics and meta-heuristics are usually used to approximate its solutions, in particular Evolutionary Computation approaches (EC). In this paper, a review of recent developments in the application of EC approaches to the CS problem is presented. A classification of these approaches is provided with emphasis on the tools necessary for facilitating learning content reusability and automated sequencing.