Mg-MOF-74@SBA-15 hybrids: synthesis, characterization, and adsorption properties

Nanocrystals of Mg-MOF-74 have been immobilized into the mesopores of SBA-15 rods to fabricate Mg-MOF-74@SBA-15 hybrid materials. To furnish such composites, a relatively simple synthetic strategy has been adopted by direct dispersion of the metal-organic framework (MOF) precursors in SBA-15 matrix to prepare the hybrid materials in situ. The hybrid materials have been characterized using powder X-ray diffraction and several spectroscopic and microscopic techniques, which suggest growth of the MOF nanocrystals inside the SBA-15 mesopores and the composites exhibit characteristics of both the components. N2 adsorption isotherms at 77 K reveal that the composites contain additional mesopores, compared to only micropores of pristine MOF nanocrystals. In addition to such combination of both micro and mesoporosity, the composites also demonstrate significant CO2 adsorption at room temperature

Structural diversities in metal-organic coordination polymers based on flexibility in organic spacer

Metal-organic coordination polymers with their various novel structural motifs have drawn intense research interests over the last few decades. Interestingly, flexibility of the organic spacers in such metalorganic coordination polymers can direct various structural topology and intricate networks. A novel 1D coordination polymer and some other illustrative examples with different flexible ligands like 1,2-bis(4-pyridyl)ethane (bpe) and 1,3-bis(4-pyridyl)propane (bpp) have been discussed in this review. Both gauche and anti-conformations could be adopted by the bpe ligand, and hence diverse structures can be furnished. Further flexibility could be achieved by exploiting longer ligand like 1,3-bis(4-pyridyl) propane (bpp). Our group has been pursuing research to furnish such flexible compounds and study their different functionalities. An account of design of such diverse systems by employing judicious ligand design strategy and their different structural aspects will be presented in this review

Solution of Fractional Order Differential Equation Problems by Triangular Functions for Biomedical Applications

Abstract—Fractional Order Differential equations are used for modelling of a wide variety of biological systems but the solution process of such equations are quite complex. In this paper Orthogonal Triangular functions and their operational matrices have been used for finding an approximate solution of Fractional Order Differential Equations. This technique has been found to be more powerful in solving Fractional Order Differential Equations owing to the fact that the differential equations are reduced to systems of algebraic equations which are easy to solve numerically and the percentage error is lower compared to other methods of solutions (like: Laplace Transform Method). Also due to the recursive nature of this method, it can also be concluded that this method is less complex and more efficient in solving varieties of the Fractional Order Differential Equations

ANALYSIS OF TIME-DELAYED NON-LINEAR EQUATIONS USING HF FUNCTIONS

The paper deals with the analysis of non-linear time delayed differential equations solved using HF functions. The analysis is first performed on Mackey-Glass Equation, which is a standard model for quantitative characterization of chaotic dynamics. The procedure is then performed on a generalized Human respiratory control model, where for different simulation parameters the analysis of Cheyne-Stokes Breathing is done. Both models are simulated in MATLAB. The graphs thus generated are used to provide suitable conclusions

An Experimental Estimation Method of Diffusion Coefficients in Ternary and Multicomponent Systems from a Single Diffusion Couple Profile

Until recently, it was textbook knowledge that the diffusion coefficients could not be estimated in a multi-component system following the widely practised diffusion couple method. The recently proposed constrained diffusion couple methods need two intersecting diffusion paths in a multi-component space with very well-controlled compositions of the diffusion couple end members, which may be tricky depending on the complications of diffusion paths in certain systems. In this study, we have proposed a method for estimating all types of diffusion coefficients directly at the Kirkendall marker plane from a single diffusion couple. The estimation method and design strategy for producing diffusion couples are discussed in concentrated ternary Ni-Co-Fe, Fe-rich quaternary Fe-Ni-Co-Cr and Ni-rich Ni-Co-Fe-Cr-Al quinary alloys. As demonstrated further, one can even estimate the impurity diffusion coefficients utilizing the composition profiles at the ends of the diffusion couples, which has been rarely practised in multicomponent systems until now. We have further demonstrated the importance of estimating the tracer and intrinsic diffusion coefficients in a concentrated or multi-principal element alloy in which interdiffusion coefficients can be vague and misleading for understanding the elements' diffusional interactions and relative mobilities. We have also shown the importance of considering the vacancy wind effect in concentrated alloys. The method and design strategy of producing diffusion couples demonstrated in this study can be suitable for generating a mobility database in Ni-, Co-based (superalloys) and Fe-based (steel) multicomponent systems with relative ease, which was considered impossible until recently

Free-ranging dogs quickly learn to recognize a rewarding person

Individual human recognition is important for species that live in close proximity to humans. Numerous studies on domesticated species and urban-adapted birds have highlighted this ability. One such species which is heavily reliant on humans is the free-ranging dog. Very little knowledge exists on the amount of time taken by free-ranging dogs to learn and remember individual humans. Due to their territorial nature, they have a high probability of encountering the same people multiple times on the streets. Being able to distinguish individual humans might be helpful in making decisions regarding people from whom to beg for food or social reward. We investigated if free-ranging dogs are capable of identifying the person rewarding them and the amount of time required for them to learn it. We conducted field trials on randomly selected adult free-ranging dogs in West Bengal, India. On Day 1, a choice test was conducted. The experimenter chosen did not provide reward while the other experimenter provided a piece of boiled chicken followed by petting. The person giving reward on Day 1 served as the correct choice on four subsequent days of training. Day 6 was the test day when none of the experimenters had a reward. We analyzed the choice made by the dogs, the time taken to approach during the choice tests, and the socialization index, which was calculated based on the intensity of affiliative behaviour shown towards the experimenters. The dogs made correct choices at a significantly higher rate on the fifth and sixth days, as compared to Day 2, suggesting learning. This is the first study aiming to understand the time taken for individual human recognition in free-ranging dogs and can serve as the scaffold for future studies to understand the dog-human relationship in open environments, like urban ecosystems

The relationship among the age at menarche, anthropometric characteristics, and socio-economic factors in Bengali girls from Kolkata, India

Special Issue: Continuity and Change in Biocultural Anthropology.OBJECTIVES: The aim of the study was to measure the causal effect of selected socio-economic factors and anthropometrical characteristics on the menarche occurrence. METHODS: The sample consisted of 2195 Bengali girls (aged 7-21) from middle-class families, from Kolkata city, India. The age at menarche was recorded from the retrospective data and status quo method. The causal effect of anthropometric and socio-economic variables on menarche occurrence was estimated by the nonparametrical analysis of survival probability (survival random forest). RESULTS: In the examined cohort menarche occurred, on average, at 11.8 years of age. The probability of menarche occurrence amplified with the increasing values of factors such as body mass index, height-for-age z-scores, number of family members, household rooms, and toilets, but decreased when expenditures increased. The relation maintained a similar pattern of causal effect with girls' age. CONCLUSIONS: A complex pattern of relationship among sexual development, physique, and socio-economic characteristics was defined. The tendency toward early menarche, along with the observed causal relationships indicate that the analyzed sample is nearing the characteristics and standards of living noted in other middle and even high-income countries in the world.This study has been sponsored by the Neys van Hoogstraten Foundation, The Netherlands (ID158) and Indian Statistical Institute, Kolkata, India