Collapse of Double-Walled Carbon Nanotube Bundles under Hydrostatic Pressure

We use classical molecular dynamics simulations to study the collapse of single (SWNT) and double-walled (DWNT) carbon nanotube bundles under hydrostatic pressure. The collapse pressure (pc) varies as 1/R^3, where R is the SWNT radius or the DWNT effective radius. The bundles show ~ 30% hysteresis and the hexagonally close packed lattice is completely restored on decompression. The pc of DWNT is found to be close to the sum of its values for the inner and the outer tubes considered separately as SWNT, demonstrating that the inner tube supports the outer tube and that the effective bending stiffness of DWNT, D(DWNT) ~ 2D(SWNT) . We use an elastica formulation to derive the scaling and the collapse behavior of DWNT and multi-walled carbon nanotubes.Comment: This paper has been accepted for publication in Physical Review B. After publication, it will be available at http://prb.aps.org

THREAT TO SECULARISM- CONVERSIONS OR HOMECOMING.

The Constitution of India envisages India as a Sovereign Socialist Democratic Republic with emphasis on ensuring justice, liberty, equality and freedom. It is often visualized that India has been threatened by the invasion of diverse religious cultures which have disintegrated the secular character. The 42nd amendment to the Constitution added the word \"secular\" and emphasized that state has no religion nor does it propagate any religion. Each individual has freedom of choice to practice profess, and propagate any religion and it has been granted by Article 25 of the Constitution of India. The conflict since between religions and people practicing the faith continue in an attempt to allure people from other faiths into one\'s own religion by convincing them, forcing them, to convert. The moot/ core issue: 1. Weather conversion is valid, permissible within the purview of Article 25 of the Constitution of India 2. Weather conversion is anti- religious and amounts to excommunication from the society. The researchers have analyzed Article 25 of the Constitution of India and its various implications to evolve few conclusions in support of the statement that everyone has Freedom of religion

Coarse-Grained Model of SNARE-Mediated Docking

AbstractSynaptic transmission requires that vesicles filled with neurotransmitter molecules be docked to the plasma membrane by the SNARE protein complex. The SNARE complex applies attractive forces to overcome the long-range repulsion between the vesicle and membrane. To understand how the balance between the attractive and repulsive forces defines the equilibrium docked state we have developed a model that combines the mechanics of vesicle/membrane deformation with an apparently new coarse-grained model of the SNARE complex. The coarse-grained model of the SNARE complex is calibrated by comparison with all-atom molecular dynamics simulations as well as by force measurements in laser tweezer experiments. The model for vesicle/membrane interactions includes the forces produced by membrane deformation and hydration or electrostatic repulsion. Combining these two parts, the coarse-grained model of the SNARE complex with membrane mechanics, we study how the equilibrium docked state varies with the number of SNARE complexes. We find that a single SNARE complex is able to bring a typical synaptic vesicle to within a distance of ∼3 nm from the membrane. Further addition of SNARE complexes shortens this distance, but an overdocked state of >4–6 SNAREs actually increases the equilibrium distance

Indentation of a Rigid Sphere into an Elastic Substrate with Surface Tension and Adhesion

The surface tension of compliant materials such as gels provides resistance to deformation in addition to and sometimes surpassing that due to elasticity. This article studies how surface tension changes the contact mechanics of a small hard sphere indenting a soft elastic substrate. Previous studies have examined the special case where the external load is zero, so contact is driven by adhesion alone. Here, we tackle the much more complicated problem where, in addition to adhesion, deformation is driven by an indentation force. We present an exact solution based on small strain theory. The relation between indentation force (displacement) and contact radius is found to depend on a single dimensionless parameter: $\omega=\sigma(\mu R)^{-2/3}(9\pi W_{\textrm{ad}}/4)^{-1/3}$, where $\sigma$ and $\mu$ are the surface tension and shear modulus of the substrate, $R$ is the sphere radius, and $W_{\textrm{ad}}$ is the interfacial work of adhesion. Our theory reduces to the Johnson-Kendall-Roberts theory and Young-Dupr\'e equation in the limits of small and large $\omega$ respectively, and compares well with existing experimental data. Our results show that, although surface tension can significantly affect the indentation force, the magnitude of the pull-off load in the partial wetting liquid-like limit is reduced only by 1/3 compared with the JKR limit, and the pull-off behavior is completely determined by $\omega$

Impact of online dating on the adolescent population: a brief review of the literature with special reference to the Indian scenario

BACKGROUND: Online dating is becoming more and more popular not only among the adult population, but also among adolescents, which comes with its own advantages and disadvantages. Adolescents are more vulnerable to a number of issues connected with online dating, including online grooming, bullying, emotional abuse, revenge porn, harassment, and lack of social interaction. AIM: We aimed to briefly review the available literature exploring the impact of online dating on adolescents, with special reference to the current Indian Scenario. METHODS: A brief literature search was conducted in PubMed and Google Scholar in September 2022 with no date limits. Keywords included various combinations of terms such as online dating, dating applications, social media, mental illness, psychiatric disorders, adolescents, and mental health. Original studies and review articles exploring the impact of online dating on adolescents and published in English were reviewed in our work. A descriptive strategy was used to summarise the findings. RESULTS: The impact of online dating on adolescents is discussed in the light of (1) issues associated with online dating among adolescents, (2) the international context, and (3) Indian context. CONCLUSION: Since the beginning of the COVID-19 pandemic, online dating has grown in popularity among adolescents, which has led to a number of worrying situations, including increased risk of sexually transmitted infections, dating violence, and mental health issues. All of these issues are described in the literature in the context of unsupervised use of technology, peer pressure, and desire to fit into the society. Data from India remain scarce on this topic, highlighting the need for research exploring the influence of online dating on adolescents

An Analysis of Solution Properties of the Graph Coloring Problem

This paper concerns the analysis of solution properties of the Graph Coloring Problem. For this purpose, we introduce a property based on the notion of representative sets which are sets of vertices that are always colored the same in a set of solutions. Experimental results on well-studied DIMACS graphs show that many of them contain such sets and give interesting information about the diversity of the solutions. We also show how such an analysis may be used to improve a tabu search algorithm