Vanadium in Borosilicate Glass

Understanding the role of V₂O₅ within borosilicate glass matrices is important for the development of novel matrices toward immobilization of sulfate containing high‐level nuclear wastes. Present investigation shows, within sodium barium borosilicate glass matrix V₂O₅ can be homogeneously added up to 5 mol% and beyond which it separates out into three phases, for example, (i) silica (ii) Barium (Ba) – Vanadium (V) oxide, and (iii) glass matrix. ²⁹Si MAS NMR (Nuclear Magnetic Resonance) studies of the samples show that below 5 mol% V₂O₅ addition, silicate network is dominantly constituted of Q² and Q³ structural units, whereas above this, the network gets more polymerized through formation of Q³ and Q⁴ units. In case of borate network, ¹¹B MAS NMR investigations revealed that the concentration of BO₄ [(0B, 4Si)] unit increases gradually up to 5 mol% and then it decreases at the cost of BO₄ [(1B, 3Si)], BO₃ (symmetric) and BO₃ (asymmetric) units. Micro‐Raman analyses of the samples showed that with additions of V₂O₅ in diluted concentrations, amorphous silicate network remained unaltered, whereas some amplification in signals corresponding to ring‐type metaborate and VO₅ units exists. It is therefore apparent from both MAS‐NMR and micro‐Raman studies that with V₂O₅ additions within the solubility limit (≤5 mol%), borate network gets depolymerized leading to decrease in hardness from an average value of 5.0–4.2 GPa.     

Characterisation of anthocyanins from Garcinia indica Choisy

The present study deals with isolation and characterisation of anthocyanins present in Garcinia indica Choisy (popularly known as kokum), which is a potential source of a natural food colourant. The kokum was found to contain a very high concentration of anthocyanins (2.4 g/100 g of kokum fruit), compared to other natural sources. Acid hydrolysis ascertained that this anthocyanin consisted of a single aglycone, i.e., cyanidin. A comparison of saponified and unsaponified fraction indicated that the pigment was not acylated. HPLC, mass and NMR spectroscopy analyses confirmed that the pigment essentially contains two anthocyanins, which were identified as cyanidin 3-glucoside and cyanidin 3-sambubioside.     

Optimization of solid–liquid extraction of phytochemicals from Garcinia indica Choisy by response surface methodology

A central composite rotatable design was employed to study the effect of ultrasound assisted extraction conditions namely sonication amplitude (10–90%), sonication cycle (0.1–1.0 s^?1), solid–liquid ratio (2–10) and extraction time (5–35 min) on the total anthocyanin extraction from Garcinia indica Choisy. Overall extractions of total anthocyanin, acidity and antioxidant activity were considered as response variables. The significant (p < 0.05) response surface models with high coefficients of determination values (R²) ranging from 0.91 to 0.93 were fitted for the experimental data, which indicated that the polynomial response models fitted well for describing the extraction efficiencies of anthocyanin, acidity and antioxidant activity. Based on the design, the optimal conditions for obtaining higher extraction were extraction time 35 min, cycle ranging from 0.44 to 0.48 s^?1, percentage amplitude ranging from 10 to 14%, and solid–liquid ratio 10. The graphical optimization of superimposed contour plots fulfilled the conditions to obtain total anthocyanin (Y₁) ≥ 135 mg/100 g DW, total titratable acidity (Y₂) ≤ 25 g/100 g DW and antioxidant activity (Y₃) ≥ 14.5 M Trolox/100 g DW. The study demonstrated that response surface methodology can be utilized for deriving the optimum conditions for extraction of anthocyanin from G. indica Choisy.     

Design,preparation, and evaluation of liposomal gel formulations for treatment of acne: in vitro and in vivo studies

The study highlights the significance of co-application of bioactive components into liposomal gel formulations and their comparison to azithromycin for treatment of Acne. A Design of Experiments (DoE) approach was utilized to obtain optimized liposomal formulation encapsulating curcumin, with size and zeta potential of ～100?nm and ～14?mV, respectively, characterized by DLS, HR-TEM, FESEM, and AFM. The curcumin liposomal dispersion depicted excellent stability over the period of 60?days, which was further converted in gel form using Carbopol. Pharmacokinetics of curcumin-loaded liposomal gel showed that T_max for curcumin was achieved within 1?h of post application in both stratum corneum and skin, indicating quick penetration of nano-sized liposomes. Stratum corneum depicted C_max of 688.3?ng/mL and AUC_0-t of 5857.5?h?×?ng/mL, while the skin samples displayed C_max of 203.3?ng/gm and AUC_0-t of 2938.1?h?×?ng/gm. Lauric acid and azithromycin liposomal gel formulations were prepared as per the optimum parameters obtained by DoE. In antibacterial activity using agar diffusion assay, lauric acid gel formulation revealed ～1.5 fold improved antibacterial effect than curcumin gel formulation. Interestingly, their co-application (1:1) exhibited significantly enhanced antibacterial effect against both macrolide-sensitive (1.81 versus 1.25 folds) and resistant strains of P. acnes (2.93 versus 1.22 folds) than their individual counterparts. The in vivo studies in rat ear model displayed a ～2 fold reduction in comedones count and cytokines (TNF-α and IL-1β) on co-application with curcumin and lauric acid liposomal gel compared to placebo treated group.     

Use of Multi-Media Courseware to Teach Real-World Decision Making Skills

We combined the case study approach and information technologies to create a multi-media courseware that brought real-world decision making from engineering industry into the classrooms. This paper describes the process of developing the CD-ROM courseware, details of classroom administration, and results of measuring the effectiveness of using the courseware in classes. This courseware was selected as the Premier Courseware of 1998 by NEEDS and John Wiley and Sons through a rigorous application and review process. Evaluation results of the use of the courseware in classrooms show that it enhanced classroom experience of students and helped them understand how decisions were made in the real-world. It also enhanced their higher-level cognitive skills. We expect that widespread use of multi-media courseware build on similar principles could lead to significant changes in the way students are educated.     

Coordination by design and the price of autonomy

We consider a multi-agent planning problem as a set of activities that has to be planned by several autonomous agents. In general, due to the possible dependencies between the agents’ activities or interactions during execution of those activities, allowing agents to plan individually may lead to a very inefficient or even infeasible solution to the multi-agent planning problem. This is exactly where plan coordination methods come into play. In this paper, we aim at the development of coordination by design techniques that (i) let each agent construct its plan completely independent of the others while (ii) guaranteeing that the joint combination of their plans always is coordinated. The contribution of this paper is twofold. Firstly, instead of focusing only on the feasibility of the resulting plans, we will investigate the additional costs incurred by the coordination by design method, that means, we propose to take into account the price of autonomy: the ratio of the costs of a solution obtained by coordinating selfish agents versus the costs of an optimal solution. Secondly, we will point out that in general there exist at least two ways to achieve coordination by design: one called concurrent decomposition and the other sequential decomposition. We will briefly discuss the applicability of these two methods, and then illustrate them with two specific coordination problems: coordinating tasks and coordinating resource usage. We also investigate some aspects of the price of autonomy of these two coordination methods.     

High Bulk Electron Mobility Diketopyrrolopyrrole Copolymers with Perfluorothiophene

The question of designing high electron mobility polymers by increasing the planarization using diffusive nonbonding heteroatom interactions in diketopyrrolopyrrole polymers is addressed in this. For this, three different diketopyrrolo[3,4‐c]pyrrole (DPP) derivatives with thienyl‐, 2‐pyridinyl‐, and phenyl‐flanked cores are copolymerized with an electron‐rich thiophene unit as well as an electron‐deficient 3,4‐difluorothiophene unit as comonomer to obtain diverse polymeric DPPs which vary systematically in their structures. The crystallinity differs significantly with clear trends on varying both flanking unit and comonomer. The optical gap and energy levels depend more on the nature of the flanking aryl units rather than on fluorination. Additionally, the charge transport properties are compared using different methods to differentiate between interface or orientation effects and bulk charge carrier transport. In organic field effect transistor devices with very high electron as well as hole mobilities (up to 0.6 cm² V^?1 s^?1) are obtained and fluorination leads to a more pronounced n‐type nature in all polymers, resulting in ambipolar behavior in otherwise p‐type materials. In contrast, space‐charge limited current measurements show a strong influence of the flanking units only on electron mobilities. Especially, the elegant synthetic strategy of combining pyridyl flanking units with difluorothiophene as the comonomer culminates in a record bulk electron mobility of 4.3 × 10^?3 cm² V^?1 s^?1 in polymers.     

Osmotic delivery of flurbiprofen through controlled porosity asymmetric membrane capsule

The release of poorly water-soluble drug, flurbiprofen, through asymmetric membrane capsule of cellulose acetate containing different pore forming agents like glycerol, polyethylene glycol 400, and dibutyl phthalate, in presence of sodium lauryl sulfate was investigated. The asymmetric membrane was fabricated in the shape of capsule body and cap by phase inversion technique. The type of pore forming agent incorporated had a marked influence on the porosity of the asymmetric membrane. However flurbiprofen due to its poor solubility was unable to create enough osmotic pressure and hence less than 10% of drug was released from all the systems with out SLS. However when the study was conducted with SLS, a maximum release of 72% was observed from the capsule with 70% glycerol. The release rates were found to increase with the increase in the concentration of pore forming agent and the amount of SLS encapsulated.     

Corrosion of Borosilicate Glasses Subjected to Aggressive Test Conditions: Structural Investigations

Sodium borosilicate (NBS) and barium sodium borosilicate (BBS) glasses, used for immobilization of high‐level nuclear waste with compositions (SiO₂)_0.477(B₂O₃)_0.239(Na₂O)_0.170(TiO₂)_0.023(CaO)_0.068(Al₂O₃)_0.023 and (SiO₂)_0.482(B₂O₃)_0.244(Na₂O)_0.220(BaO)_0.054 were subjected leaching experiments under hydrothermal conditions in an autoclave at 200°C for different time durations. Morphological and structural transformations associated with leaching, have been monitored with techniques like XRD, SEM, solid‐state nuclear magnetic resonance. XRD and SEM along with NMR studies have confirmed that, upon leaching, formation of an aluminosilicate phase, Zeolite‐P (Na₆Al₆Si₁₀O₃₂·12H₂O), occurs with NBS glass. BBS glass upon subjecting to the same conditions leads to formation of multiple amorphous phases having Q⁴ (silica rich phase) and Q³ structural units of Silicon along with structurally modified residual glass. Upon leaching BO₃ structural units preferentially get released from BBS glass. Comparison of results with international simple glass confirmed that, for the latter, mass loss rates are one order of magnitude lower.