Characterizing nutrient dynamics with relation to changes in partial pressure of CO2 in a tropical sewage‐fed aquaculture pond situated in a Ramsar wetland

The changes in nutrient dynamics (nitrate, ammonium, silicate, phosphate and iron concentration) vis‐à‐vis partial pressure of CO₂ in water [pCO₂(water)] from tropical sewage‐fed aquaculture ponds (East Kolkota Wetlands, India) were analysed by means of a microcosm. A significant relationship between these nutrient’s removal from the system and reduction in pCO₂(water) was observed (with few exceptions). These water bodies acted as significant sources of CO₂ in pre‐monsoon and monsoon seasons despite having substantial quantity of chlorophyll‐a to make it a net autotrophic system. The study revealed that if conditions favourable for optimum photosynthesis can be maintained in these ponds, the CO₂ source character of these ponds can be reversed. In the post‐monsoon season, when the pH of the water column was high, the system acted as sink for CO₂ which suggests the use of lime to prevent these systems from becoming hypereutrophic and carbon source at the same time.     

Synthesis of mesoporous geopolymeric powder from LD slag as superior adsorbent for Zinc (II) removal

Linz-Donawitz(LD) slag Geopolymer(LDSGP), a porous aluminosillicate geopolymeric adsorbent, has been synthesized from steel plant LD slag for efficient removal of Zinc(II) ions from wastewater, thus presenting a solution for converting industrial waste to adsorbent for wastewater treatment. The colloid paste of raw LD slag and the alkaline activator (10?M NaOH?+?sodium silicate (1:1 w/w)) has been cured for 3?days at low temperature to geopolymerize the calcium oxide rich LD slag. The BET surface area of LDSGP adsorbent (30.84?m²/g) has improved considerably compared to raw LDS (4.85?m²/g) and the FESEM and HRTEM images reveal the presence of micropetal and cauliflower like structures at outer surface of the adsorbent particles. The mesoporous nature of LDSGP adsorbent can be understood by analyzing N₂ adsorption-desorption and pore size distribution plot. The PXRD pattern of LDSGP adsorbent powder confirms the presence of Ca₂SiO₄ and Ca₃SiO₅ in the geopolymeric matrix. Langmuir isotherm model correlates the batch adsorption data of Zn²⁺ ions onto LDSGP particles at 298?K, 308?K and 318?K. The maximum Zn²⁺ ions adsorption capacity of LDSGP is 86?mg/g at 318?K. The adsorption kinetic data is correlated with pseudo-second-order model indicating chemisorption of Zn²⁺ ions onto LD slag geopolymeric powder adsorbent.     

Overview of the scientific production in the Pharmacy area in Brazil: profile and productivity of researchers granted with fellowships by the National Council for Scientific and Technological Development

In Brazil, the National Council for Scientific and Technological Development (CNPq) distributes productivity fellowships in research (RS) as a recognition to individuals with outstanding productivity levels in their areas. The aim of this study is to evaluate the scientific production of the Brazilian Pharmacy area, one division of the Health Sciences Great Area of CNPq, considering the profile and productivity levels of RS fellows. The results showed that most of the 156 active RS fellows in 2015 were female, with doctorate completed in the Southeast region (mainly in University of São Paulo) and with research activities developed in the South and Southeast regions. Most of their work was published in journals classified as B1 and B2 Qualis in Pharmacy by the Coordination for the Improvement of Higher Education Personnel (CAPES), with high prevalence of publications in local journals and/or specialized on medicinal plants. Besides, they featured much dependence on advising and productivity indexes related to the category and level of RS fellowship. The evolution of such data must be continually evaluated to determine the influence of CNPq productivity fellowships on performance and stratification of researchers in the Pharmacy area in Brazil.     

Structural and electrical properties of donor-doped NBT system synthesized by microwave-assisted solid-state reaction route

Journal of Materials Science: Materials in Electronics - A-site donor-doped NBT systems (Na0.5Bi0.5)1-xMxTi(1-x/4)O3 (M?=?La and Sm) were synthesized by microwave-assisted solid-state...     

A stabilized volume‐averaging finite element method for flow in porous media and binary alloy solidification processes

A stabilized equal‐order velocity–pressure finite element algorithm is presented for the analysis of flow in porous media and in the solidification of binary alloys. The adopted governing macroscopic conservation equations of momentum, energy and species transport are derived from their microscopic counterparts using the volume‐averaging method. The analysis is performed in a single domain with a fixed numerical grid. The fluid flow scheme developed includes SUPG (streamline‐upwind/Petrov–Galerkin), PSPG (pressure stabilizing/Petrov–Galerkin) and DSPG (Darcy stabilizing/Petrov–Galerkin) stabilization terms in a variable porosity medium. For the energy and species equations a classical SUPG‐based finite element method is employed. The developed algorithms were tested extensively with bilinear elements and were shown to perform stably and with nearly quadratic convergence in high Rayleigh number flows in varying porosity media. Examples are shown in natural and double diffusive convection in porous media and in the directional solidification of a binary‐alloy. Copyright © 2004 John Wiley & Sons, Ltd.     

Multi‐bit Boolean model for chemotactic drift of Escherichia coli

Dynamic biological systems can be modelled to an equivalent modular structure using Boolean networks (BNs) due to their simple construction and relative ease of integration. The chemotaxis network of the bacterium Escherichia coli (E. coli ) is one of the most investigated biological systems. In this study, the authors developed a multi‐bit Boolean approach to model the drifting behaviour of the E. coli chemotaxis system. Their approach, which is slightly different than the conventional BNs, is designed to provide finer resolution to mimic high‐level functional behaviour. Using this approach, they simulated the transient and steady‐state responses of the chemoreceptor sensory module. Furthermore, they estimated the drift velocity under conditions of the exponential nutrient gradient. Their predictions on chemotactic drifting are in good agreement with the experimental measurements under similar input conditions. Taken together, by simulating chemotactic drifting, they propose that multi‐bit Boolean methodology can be used for modelling complex biological networks. Application of the method towards designing bio‐inspired systems such as nano‐bots is discussed.Inspec keywords: cell motility, microorganisms, Boolean functionsOther keywords: multibit Boolean approach, conventional BNs, high‐level functional behaviour, steady‐state responses, chemoreceptor sensory module, drift velocity, chemotactic drifting, multibit Boolean methodology, complex biological networks, bio‐inspired systems, multibit Boolean model, chemotactic drift, dynamic biological systems, equivalent modular structure, Boolean networks, simple construction, chemotaxis network, bacterium Escherichia coli, biological systems     

Observation of ZBCP Above T C at Au/Y1Ba2Cu3O7−δ Heterostructure with a Nano Hole: A Possible Evidence for the Cooper Pairs above T C

Fabrication of a nanojunction by making a nano- hole on PMMA layer deposited in between Au and Y₁Ba₂Cu₃O_7?δ (YBCO) films is reported. We have measured the current-voltage characteristics across Au/YBCO nanojunction at different temperatures and studied Andreev Reflection (AR) phenomena. The presence of Zero Bias Conductance Peak (ZBCP) due to AR, which is considered to be the well-known feature of d-wave superconductors, has been noticed at temperatures below and above the transition temperature (T _C ～87 K) up to 130 K. The result obtained indicates the possible- existence of the phase-incoherent Cooper pairs above T _C for Au/YBCO.     

A perspective on functionalizing colloidal quantum dots with DNA

This perspective provides an overview of the techniques that have been developed for the conjugation of DNA to colloidal quantum dots (QDs), or semiconductor nanocrystals. Methods described include: ligand exchange at the QD surface, covalent conjugation of DNA to the QD surface ligands, and one-step DNA functionalization on core QDs or during core/shell QD synthesis in aqueous solution, with an emphasis on the most recent progress in our lab. We will also discuss emerging trends in DNA-functionalized QDs for potential applications.      

Numerical investigation of fatigue characteristics of concrete pavement

In concrete pavements, fatigue is one of the major causes of distress. Repeated loads result in the formation of cracks. The propagation of these cracks cause internal progressive damage within the structure, which ultimately leads to failure of the pavement due to fatigue. This paper presents a theoretical investigation of crack propagation within concrete pavement and its fatigue characteristics under cyclic loading. A numerical fatigue performance model has been developed for this purpose. The model is based on fictitious crack approach for the propagation of cracks and stress degradation approach for estimating the bridging stress under cyclic loading. Using the numerical model, a parametric study has been performed for a typical concrete pavement to evaluate its fatigue characteristics for different foundation strengths. The method can be used for prediction of crack propagation in concrete pavement under cyclic loading and gives an estimate of the incremental damage or the entire crack history of the pavement.