Definite Shape Research Articles

Production of spin coated chromium oxide (CrO3) thin layers and application in the Al/p-Si metal semiconductor structures

A novel Al/CrO3/p-Si structure was built by help the spin coating technique. CrO3 thin layer has been characterized by the XRD, UV–vis, SEM and AFM measurements. It has been observed that the CrO3 layer has amorphous structure with optical band energy value of 3.96 eV. The surface analysis of CrO3 layer by using AFM and SEM methods has been found to be rather rough that is not observed grains of any definite shape or size. Furthermore, some electronic quantities of Al/CrO3/p-Si junction by help the thermionic charge transport mechanism have been extracted by utilizing current-voltage (I-V) and capacitance-voltage data. Moreover, it has been seen that interfacial state concentration for the Al/CrO3/p-Si contact varied in the range of 8.05 × 1012 eV−1 cm2 to 6.71 × 1011 eV−1 cm−2 in darkness, and 1.23 × 1013 eV−1 cm−2 to 3.82 × 1012 eV−1 cm−2 under the illumination condition. The photoelectric parameters of the Al/CrO3/p-Si contact under 100 mW cm−2 light illumination was studied by I-V measurement.

Systematic study on interfacial polymerization mechanism of toluene diisocyanate and water for the preparation of polyurea microspheres

• Droplets-based microfluidics is used to generate TDI droplets in aqueous phase. • Polyurea microspheres were prepared by interface polymerization of TDI with water. • Interface polymerization mechanism of TDI with water is studied in details. Polyureas (PU) are important materials in wide range of applications from protective coatings and catalyst supports to biomaterials for drug release and hydrogels. However, it has been a challenging task to prepare porous PU with definite form or shape limited by the nature of the PU synthesis, that is, precipitation polymerization. New chemical and physical techniques of PU synthesis have gained great attention in order to fabricate these materials with diverse morphologies and structural features. In this communication, droplet-based microfluidics approach is adopted to convert conventional precipitation polymerization of PU synthesis to interface polymerization and PU microspheres with porous morphology are prepared. In this process, first toluene diisocyanate (TDI) droplets were generated in flowing PVA aqueous solution inside a tube and then converted to uniform porous PU microspheres through interface polymerization. The interface polymerization mechanism is discussed in details by controlling the polymerization time. It was found that polymerization of TDI with water was started at the interface of TDI droplet and water, and PU shell was formed around the TDI droplets, leading to formation of microcapsules. After the formation of PU shell, polymerization was continued inside the microcapsule by the diffusion of water molecules through the PU shell until all the TDI was finished and PU microspheres with porous morphology were obtained. This communication provides therefore a systematic study on interfacial polymerization of TDI with water to get porous PU microspheres and enabling technical advantages for potential applications to get PU materials with specific shapes and textural modifications.

Influence of Shape Factor and Non-Linear Stretching of the Bullet-Shaped Object on the Mixed Convection Boundary Layer Flow and Heat Transfer with Viscous Dissipation and Internal Heat Generation

The two-dimensional incompressible axisymmetric mixed convection magnetohydrodynamic fluid flow and energy transfer over a bullet-shaped object with a non-linear stretching surface have been investigated. The main goal of this problem is to discuss the effect of the shape and size of the bullet-shaped object on the fluid velocity and temperature distributions. The present analysis has been performed in about two cases ε=0.0 and 2.0. Therefore, fluid velocity and temperature distributions have been investigated in two types of flow geometries such as the thicker surface (s ≥ 2) and the thinner surface (0 < s < 2) of the bullet-shaped object. The equations for momentum and heat transfer have been converted into ODEs by using suitable local similarity transformations. These equations have been performed with a recently developed spectral quasi-linearization method (SQLM). This method helps to identify the accuracy, validity, and convergence of the present solution. The novelty of the present work has been applying the recently developed numerical method to solve these highly nonlinear differential equations. The investigation shows that in the case of a thicker bullet-shaped object (s ≥ 2) the velocity and temperature profiles do not converse the far-field boundary condition asymptotically but cross the axis with an upright angle and the boundary layer structure has no definite shape whereas in the case of a thinner bullet-shaped object (0 < s < 2) the velocity profile converge the ambient condition asymptotically and the boundary layer structure has a definite shape. The innovation of this current work lies in the unification of relevant physical parameters into the governing equations and trying to explain how the flow properties are affected by these parameters.

Milk curd self-segmentation in cheesemaking tank

The purpose of this work is to describe and study the previously unknown phenomenon of self-segmentation of a milk curd in an open-type cheesemaking tank. Based on the analysis of the kinetics of gel formation, it has been determined that self-segmentation of the gel begins near the gel point, develops over several tens of seconds, and becomes stable as the gel condenses. The segments in the milk curd do not have a definite regular shape; their average size varies from 5 to 50 cm. The shape and size of the segments do not repeat and do not correlate with the type of cheese being produced. The displacement of the segments of the milk curd in the cheesemaking tank relative to each other in height is from 0.5 to 2 mm. The width of the boundary layer between the curd segments increases during the secondary phase of gelation from 3 to 10 mm. As a result of experimental studies, it has been shown that self-segmentation of milk gel is caused by thermogravitational convection, which forms Benard convection cells. A description of a possible mechanism of milk gel self-segmentation in open-type cheesemaking tanks is proposed. The effective role of fat globules in the mechanism of self-segmentation of the milk curd has been noted. It has been suggested that self-segmentation of the milk curd in the cheesemaking tank may cause some organoleptic defects in the finished cheese, in particular inhomogeneity of texture and color.

Traversable wormhole solutions in the f (R) theories of gravity under the Karmarkar condition* *The fourth author would like to express their gratitude to the Deanship of Scientific Research at King Khalid University, Saudi Arabia, for providing a funding research group under the research grant R.G.P2/130/43. The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project

This paper examines traversable wormhole models in the theories of gravity by applying the Karmarkar condition. For this purpose, we consider spherically symmetric space-time to examine the structure of wormholes. First, we investigate wormholes and their geometry using the redshift function under various conditions. Subsequently, we discuss the embedding diagram of the upper and lower universe using radial coordinates in two and three-dimensional Euclidean affine space. Three exclusive models are considered for the theories of gravity, and the radial and tangential pressures are observed. Furthermore, by taking a definite shape function, we observe the behavior of energy conditions. We determine that energy conditions are violated, and their violation is generic and represents the presence of exotic matter. According to Einstein's field theory, the existence of wormholes is predicated on the occurrence of rare material. Hence, we conclude that our study is more realistic and stable.

Trying an Alternative Ansatz to Quantum Physics

We report to which extent elementary particles and the nucleons can be described by an Ansatz that is alternative to the established standard model, and can still yield predicted results that reproduce the observed ones, without using the formalism of quantum mechanics. The different Ansatz is motivated by the attempt to explain known properties of elementary particles as a consequence of an inner structure, in contrast to the approach of the standard model, where the properties are ascribed to point-like particles. Based on the assumption of the existence of photons, the possibility of the creation of fermion and anti-fermion in an interaction of two photons of equal energy is shown. The properties of these created elementary material particles are found to agree with the ones observed. Also the possibility of the creation of a neutron by interaction of two photons of equal energy is shown. In this case, the newly formed neutron rests in the center of the collision system as a combined system of the localized two photons. The created neutron is shown to have the known properties of the neutron, and in addition, to have a definite shape of definite size. The proton is described as the particle formed by decay of the neutron, also owning the observed properties, and in addition a definite shape. For all particles described by the Ansatz, their properties are consequences of an inner structure. The merits of the alternative description as compared to the standard model and the application of quantum mechanics are discussed.

Shape-free theory for the self-assembly kinetics in macromolecular systems

Although temperature-dependent self-assembly kinetics is usually described by approaches which assume that the macromolecular aggregates have a definite shape, sometimes that assumption might be inappropriate, as in the case of several colloidal and biopolymeric systems. Here we consider a simple model for particle aggregation which displays a first-order phase transition in order to illustrate a rate theory based on microcanonical thermostatistics that allows one to obtain a shape-free description of its thermally induced self-assembly kinetics. Stochastic simulations are performed to validate our approach and demonstrate how the equilibrium thermostatistics properties of the system can be related to the temperature-dependent rate constants. As a model-independent kinetic approach, it may provide experimentalists with a reliable method to extract information about free-energy profiles and microcanonical entropies from kinetic data.

Closed-form solution for optimization of buckling column

The optimization problem for a column, loaded by compression forces is studied in this article. The direction of the applied forces coincides until buckling moment with the axis of the column. The critical values of buckling are equal among all competitive designs of the columns. The dimensional analysis eases the mathematical technique for the optimization problem. The dimensional analysis introduces two dimensionless factors, one for the total material volume and one for the total stiffness of the columns. With the method of dimensional analysis, the solution of the nonlinear algebraic equations for the Lagrange multiplier will be superfluous. The closed-form solutions for Sturm-Liouville and mixed types boundary conditions are derived. The solutions are expressed in terms of the higher transcendental functions. The principal results are the closed-form solution in terms of the hypergeometric and elliptic functions, the analysis of single- and bimodal regimes, and the exact bounds for the masses of the optimal columns. The isoperimetric inequality was formulated as the strict inequality sign, because the optimal solution could not be attained for any finite seting of the design parameter. The additional restriction on the minimal area of the cross-section regularizes the optimization problem and leads to the definite attainable shape of the optimal column.

An Experimental Study on the Soil Reinforced Blocks

Soil Reinforced Blocks are the new attempt in which a soil block of definite size and shape is produced by incorporating the Reinforcement into the Stabilized Soil by wrapping the Geomembrane around the soil block with the proposal of applying it as a Foundation Bed. Red soil is primarily stabilized by using Portland Cement and Steel bars are used as Reinforcement, by using these materials Soil reinforced blocks are constructed which is similar to the construction of Reinforced Concrete Columns in the form of solid blocks. The main objective of the work is to produce an Engineered Efficient Structure in the form of soil reinforced blocks to provide a Solid High Resistance Foundation Platform to the structure by placing these Soil Reinforced blocks in the ground where Foundation Soil has Low Bearing Capacity. After the construction of Soil Reinforced blocks, these are tested against Compression, Bending Tension, Triaxial Shear, UCS, CBR, and Water Absorption. To avoid the Saturation or Entry of Water into the Soil Reinforced blocks a Geo-Synthetic material named Geo-membrane is used. A Geo-membrane is a Synthetic material with the primary function of Obstructing Moisture and it will be wrapped around the Soil Reinforced blocks. A Geotechnical Structure possessing the Good Engineering properties are the Expected Possible Outcomes.

Numerical Analysis of Boundary Layer Flow and Heat Transfer over a Stretching and Non-Stretching Bullet-Shaped Object

The two-dimensional axisymmetric magnetohydrodynamic boundary layer flow with heat transfer of Newtonian fluid over a stretching and non-stretching bullet-shaped object has been investigated. Therefore, fluid flow and heat transfer have been investigated in two types of flow geometries such as the thicker surface and the thinner surface of the bullet-shaped object. The present analysis also focuses on the physical relevance and accurate trends of the boundary layer profiles which are adequate in the laminar boundary layer flow. The novelty of this current work is to discuss the effect of shape and size (surface thickness parameter s) and the stretching factor of the bullet-shaped object on the fluid velocity and temperature profiles within the boundary layer region also develop the relationship between the dependent and independent parameters by the correlation coefficient. The partial differential equations of momentum and energy have been reduced to a system of non-linear ordinary differential equations along with the transformed boundary conditions by applying the local similarity transformations. These coupled non‐linear ordinary differential equations’ governing the flow field has been solved by the Spectral Quasi-Linearization Method (SQLM). The numerical analysis of the SQLM has been carried out with MATLAB for investigating the effect of various controlling parameters on the flow fields. The residual error infinity norms have been analyzed to determine the speed of convergence and accuracy of the method. The numerical results have been displayed graphically and in tabular form and the physical behavior of the problem also discussed. The investigation shows that in the case of a thicker bullet-shaped object the velocity profile does not approach the ambient condition asymptotically but intersects the axis with a steep angle and the boundary layer structure has no definite shape whereas in the case of a thinner bullet-shaped object the velocity profile converge the ambient condition asymptotically and the boundary layer structure has a definite shape. It is also noticed that thinner bullet-shaped object acts as good cooling conductor compared to thicker bullet-shaped object and the wall friction can be reduced much when thinner bullet-shaped object is used rather than the thicker bullet-shaped object in both types of non-stretching or stretching bullet-shaped object . Keywords: forced convection, correlation coefficient, multiple regression, MHD, stretching

Populism in the political culture of Turkey: The foreign policy dimension

The paper analyses the phenomenon of populism and its impact on Turkish foreign policy in three dimensions: institutional, instrumental and ideological. The research scrutinizes a wide selection of party manifestos and public speeches of Turkish politicians with primarily focus on Recep Tayyip Erdoğan’s statements during his incumbency as the prime-minister and the president. The embeddedness of populism in political culture of Turkey provided it with ideological flexibility and made populism almost a universal instrument for engaging with electorate. Starting from Turkey’s transition to multiparty system the majority of political actors have resorted to populism in one or another way. Erdoğan has not only continued this tendency but mastered the populist rhetoric. The character and content of Erdoğan’s populism fluctuated following the changing domestic and international environment. In the 2000s it was hinged on the loose concept of conservative democracy. At the turn of the 2000s and 2010s the dreams for the EU membership gave way to ideas of ‘civilizational expansionism’ which had the concept of Islamic/Ottoman civilization as its core. From the mid-2010s ultra nationalism has come to the forefront of the populist rhetoric. Eventually, the populist binary opposition of ‘us’ and ‘they’ took a definite shape of global confrontation between Turkey as a defender of Islam and the ‘adverse’ West. Populist rhetoric helped Erdoğan to justify his almost two-decades-long incumbency and evade direct responsibility for economic hardships of the 2010s. Populism has become an effective instrument to monopolize the foreign policy in the hands of Erdoğan. Utilizing negative rhetoric against Turkish professional diplomats within the last decade Erdoğan has managed to cement his clout over the foreign-policy making. Institutionally the expansion of populism in the sphere of foreign policy led to its ‘domestication’ and ‘nationalization’ while its impact on the foreign policy discourse manifested itself in the spread of civilizationism. Making both domestic and foreign policy process more personalized Erdoğan has reinforced ‘personal authoritarianism’ at the expense of the state institutions. Thus their decline led to the ‘Erdoğanization of the Turkish politics’. The declarative pursuit of Turkey to get more independent and autonomous position in the international system resulted in the strategy of development with primarily focus on the bilateral relations with different states. Consequently Turkey, previously known as a consistent advocate of regional cooperation and integration, in many respects has become a regionally isolated state.

Mycofabrication of Silver Nanoparticles from Aspergillus Niger and Determination of its Anti-Fungal Potency Against Candida Species

Besides many synthetic approaches being used for the preparation of nanoparticles, bio-based synthesis of nano particles using nano factories such as microorganisms is a novel environmentally friendly approach for producing nanoparticles of definite size and shape with distinctive physical and chemical properties. This method is not only ecofriendly but provides a clean and nontoxic way for the fabrication and assembly of metallic nano sized particles. Therefore, mycosynthesis of colloidal silver nanoparticle from Aspergillus niger was achieved using fungal filtrate incubated with aqueous silver nitrate for a specific period of time as monitored by Ultraviolet-visible spectroscopy. Optimization studies of physioculture parameters such as time of incubation, pH, biomass, and substrate concentration was achieved to determine optimum conditions. It was observed that the optimum conditions were found to be 55 hours of incubation time at pH 9.0 and 6 mM of silver nitrate concentration using fungal biomass of 25g for method I and for method II were found to be after 40hours of incubation time at pH 8.0 and silver nitrate concentration of 2mM using fungal biomass of 15g. Furthermore, silver nanoparticles were found to be an effective antifungal agent against Candida species. Thus, mycofabrication of silver nanoparticles is the most reliable, inexpensive, and ecofriendly method. However, in future, identification of different eukaryotic fungal strains for the production of Silver nanoparticles is required to make this process commercially practicable.

Journey of Emancipation in R. K. Narayan’s Heroines

R.K. Narayan conforms to his times and during the period he wrote, there was a radical change in the status of women. Moreover, he maintains an objective detachment from his themes and characters. However detached he is from his characters, it is possible to draw out a conception that the portrayal of women characters takes a definite shape through his novels. As we read his novels, we can trace a gradual transition of his women characters from silence to speech. His pre-independence novels like Swami and Friends, The English Teacher, Dark Room have women who are submissive and docile even though they nurture the desire for liberation. But, R. K. Narayan was a genius to picturise the ordinary middle-class milieu. Narayan takes a different attitude in portraying his post-independence heroines. The middle-class is considered the citadel of tradition but has shown its heroines courageously negotiating their way out from stereotyped notions about women and their roles. His women who are presented as votaries of emancipation educate themselves, long for economic independence and do not hesitate in leaving their parents or dumping their husbands and lovers in their search for individual identity and desired happiness.

Fabrication of iron nanoparticles using Leptolyngbya valderiana and investigation of its Cr (VI) removal potential in the free and biomass associated forms

This study reported the ability of L. valderiana to fabricate iron nano particles of definite shape and size, as well as the enhanced effectiveness of the synthesized nanoparticle loaded biomass in removal of hexavalent chromium [Cr (VI)] from aqueous solution compared to free iron nano particles. Spindle-shaped nano scale zerovalent irons were synthesized by live biomass at intracellular and extracellular levels with the dimensions of 47.42 ± 3.86 × 7.7 ± 2.01 nm and 66.37 ± 3.09 × 12.49 ± 4.01 nm, respectively. The nanosorbents were prepared separately from intracellular particles (NI), extracellular particles (NE) and nano‑iron loaded biomass (BN). All the adsorbents were tested for chromium removal from Cr (VI) aqueous solutions with concentrations in the range of 5–20 mg L−1. The adsorption parameters were optimized. The removal rate and adsorption capacity, i.e., Langmuir constant (KL) of nano‑iron loaded biomass (BN) toward Cr (VI) reached the peak at 0.0439 L mg−1 of adsorbent, followed by intracellular particles (NI) (0.0162 L mg−1 of adsorbent) and extracellular particles (NE) (0.009 L mg−1 of adsorbent). The adsorption kinetics data of nano‑iron loaded biomass (BN) fitted well with the pseudo-second-order kinetic model and Freundlich isotherm model whereas, the other two nanosorbent-assisted removal processes followed the pseudo-first-order kinetic model and Langmuir isotherm model. Moreover, nano‑iron loaded biomass (BN) was the easiest to handle and showed maximum adsorption capacity; therefore, portraying it as a low-cost, environmentally benign potential nanosorbent for the removal of Cr (VI) from industrial waste.

Content or Context: Which is more important for publishing an article in high impact journals?

Sir/ Madam,
 To produce a high impact paper brings us to the question which matters more, a researcher’s oeuvre or the materials inside his/her article.Content is the total write-up and context is the theme or message behind the content. One can infer content from the context but not vice versa. In any article, context, includes the title as well as outcomes whereas content includes all, starting from introduction to conclusion part. Context provides a definite shape to the content and this idea or knowledge can be communicated by network of journals. During initial screening, the first thing an editor sees is the ‘title’ and then the content. If title is catchy, then only it attracts the reader/editor’s interest. So, here again the context comes first. However, when higher technologies were used to describe or justify the same context or idea, the paper is mostly accepted by high-tier journal basing upon the content but not context. Now people rarely think the motto or purpose of a journal. There is only a kind of competition between authors for their scientific credits /academic carrier or between editors for their journal publicity. Instead, we should remember that a journal, even high or low impact is only for a medium of communication where ideas from every corner of the world are reaching to every corner of the world. Lastly, there is a message “give priority to new idea/s because if idea is there then content will also come but without context or idea, content is meaningless”. Hence, the entire knowledge of ocean can only be filled by our drop by drop of collective contextual contributions.

A linear-elastic heuristic-molecular modelling for plane isotropic micropolar and auxetic materials

A discrete Lagrangian approach is the basis for modelling the macroscale elastic response of a solid material, which can be homogeneous as well as a periodic composite. The basic topology is a square “heuristic molecule” that is an assemblage of four rigid bodies with a definite shape bonded by elastic springs. This is the minimum unit cell, UC, that contains all the macroscopic mechanical properties of the solid material, object of study. The paper presents 4 unit cells, in progression from a basic molecule bonded by 2 types of central forces, to a refined “Cosserat-auxetic” molecule that is connected by 4 types of shear and central bond-springs. The emphasis is given to the isotropic response in relation to the value of the macroscopic Poisson ratio, and the four examples of UC topologies are presented showing their relationship to different materials at the macro-scale: from a “rari-constant” continuum, through a standard isotropic Cauchy continuum, up to an isotropic centre-symmetric auxetic Cosserat solid.

Synthesis of Pt-MWCNT Nano Composite in Trioctylmethyl Ammonium Hydrogen Phthalate (TOMAHP) Ionic Liquid Using Ultrasonic Cavitation

Background:Synthesis of nano composite materials is very important topic in recent times for its wide application as a catalyst in various chemical processes. Among various nano composite platinum-mutliwall Carbone Nano Tubes is of particular interest in recent past due to its unique application in methanol fuel cell as a catalyst. Now the challenge is to make a chemical process for definite size and shape selective platinum-mutliwall Carbone Nano Tubes catalyst/composite with well distribution and easy scale up.Methods:The aim of the present work is to develop a chemical process for synthesis of platinum- Mutliwall Carbone Nano Tubes nano catalyst/composite with very low size (1-3nm) using reduction of Pt4+and subsequently deposition to the Mutliwall Carbone Nano Tubes surface using ultrasound technique.Results:The platinum nano materials synthesized in trioctylmethyl ammonium hydrogen phthalate is characterized using TEM technique. The results show that the particle size of platinum nano are in the range of 1-3 nm. The platinum-mutliwall Carbone Nano Tubes catalyst/composite prepared using ultrasound technique does not change the particle size of the platinum nano particles. The distribution of platinum nano on Functionalized Mutliwall Carbone Nano Tubes surface is uniform compared to Non-functionalized Mutliwall Carbone Nano Tubes.Conclusion:The preparation of platinum-mutliwall Carbone Nano Tubes nano composite with very low size of platinum (1-3nm) is achieved in trioctylmethyl ammonium hydrogen phthalate as functionalized ionic liquid in presence of ultrasound.

Triaxial rigidity of Er166 and its Bohr-model realization

The triaxial nature of low-lying rotational bands of $^{166}\mathrm{Er}$ is presented from the viewpoint of the Bohr Hamiltonian and from that of many-fermion calculations by the Monte Carlo shell model and the constrained Hartree-Fock method with projections. A recently proposed novel picture of those bands suggests definite triaxial shapes of those bands, in contrast to the traditional view with the prolate ground-state band and the $\ensuremath{\gamma}$-vibrational excited band. Excitation level energies and $E2$ transitions can be described well by the Bohr Hamiltonian and by the many-fermion approaches, where rather rigid triaxiality plays vital roles, although certain fluctuations occur in shell-model wave functions. Based on the potential energy surfaces with the projections, we show how the triaxial rigidity appears and what the softness of the triaxiality implies. The excitation to the so-called double $\ensuremath{\gamma}$-phonon state is discussed briefly.

Shapes of large, static soap bubbles

Standard predictions induced by the balance of surface tension and pressure dictate that static soap bubbles must be spherical. However, definite non-spherical shapes appear in large bubbles, where noticeable oblate or prolate deformations occur. Gravity is the principal cause of such deformations, and multiple approaches for including its influence appear in recent literature. This paper derives a general surface-theoretic model by applying asymptotic and variational methods to a fully three-dimensional set-up where the soap bubble is a finite-thickness film. The procedure illuminates implicit assumptions, clarifying the discrepancies seen in previous models. Then the model is studied in four physical situations. In three of these situations, results show that there is a maximum stable span and volume of the soap bubbles, implying that their behaviour is qualitatively more similar to liquid drops than standard soap bubbles. Also, the model presented is directly analogous to the two-dimensional version of a hanging chain, and the derived predictions give practical insights into the construction of heavy containment vessels.

Disillusioned Trust – In an Ontogenesic and Historic Perspective

To be born means to be entrusted to others. On this basis, trust is first and foremost a mode of living with others (even anonymous others) which takes definite shape only when it appears to be weakened, doubtful, or even destroyed. In this case, mistrust raises the question how trust can get restored in order to stabilize social and political relations on which the state rests. In historical perspective, however, we are confronted with a radical desillusionment of trust that raises the question how the state can deserve our trust and how we are to avoid that mistrust reigns. The following considerations seek to make junctions plausible between the ontogenetic basis of trust on the one hand and the political precariousness of trust on the other hand.