A comprehensive investigation of copper pitting corrosion in a drinking water distribution system

Copper pitting is a complicated corrosion process for which exact causes and solutions are often uncertain. This paper presents the findings of a comprehensive investigation of a cold water copper pitting corrosion problem in a drinking water distribution system, including a refined process for preparing exhumed copper pipes for solids analysis. The investigation produced detailed structural, morphological and elemental details of copper pitting that strongly corroborated previous observations and theoretical models, and revealed new findings. For example, cross-sections revealed three components: the cap, characterized by two basic copper sulfate minerals; the cuprite membrane; and the pit containing cuprite crystals, and chloride.     

Status of Bioactive Compounds in Foods,with Focus on Fruits and Vegetables

Components of cereals, legumes, pulses, proteins, sea food, milk, carbohydrates and lipids are being evaluated for their influence on human health, as biofunctional compounds. However, references dealing with fruits and vegetables exceed any other food group and accordingly their focus. Fruits and vegetables abound in a spectacular range of such health influencing compounds and thus, study of their bioactivity, in lieu of their consumption in fresh or processed form. Anti-cancerous phenolics from Phyllanthus, radioprotective Litchi phenolics/flavonoids, hypoglycemic Sygium, quercitin and hydroxyl cinnamates of Sweet cherries, xanthones of Mangosteen, ellagitannins of Pomegranate, ursolic acid of Sea buckthorn, muscle relaxative watermelon, anti-cholesterolemic soluble fibre and sterols, cardioprotective saponins, ACE-inhibitory potato hydrolysates, anti-pancreatic cancerous ascorbic acid, carotenoids including pro-vitamin A are few examples unraveled. Thus, the imminent scope to obviate their structural chemistry, influence on storage and processing conditions, factors favoring their bio-accessibility/bio-availability in the food formulations, influencing human health. It is the meticulous combination of these compounds in daily consumption that determines their usefulness to human body. What is of paramount importance is the actual health benefits accrued from consumption of such functional- compound based fresh/processed fruits,vegetables or other foods.     

Flow of concentrated suspension through oblique bifurcating channels

Suspensions of solid particles in viscous fluid flowing through bifurcating channels are encountered in various industrial processes and biological applications. This work reports the detailed numerical simulations of shear‐induced particle migration in oblique bifurcating channels. The effect of particle concentration, bifurcation angle, and flow rate on the partitioning of bulk flow and particles in the downstream branches is studied. It was observed that the particle distribution in the downstream branches does not follow the flow distribution due to shear‐induced particle migration. The velocity and concentration profile for suspension flow were observed to be symmetric in the inlet branch but asymmetric in the daughter branches. The degree of asymmetry and bluntness of velocity profile was observed to depend on the bulk particle concentration and bifurcation angle. The reported results could be useful in the design of flow devices handling suspension transport in bifurcating channels. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2692–2704, 2014     

Multiple Linear Correlation Analysis of Daily Reference Evapotranspiration

An accurate estimation of reference evapotranspiration (ET₀) is of paramount importance for many studies such as hydrologic water balance, irrigation system design and management, crop yield simulation, and water resources planning and management. Simple regression techniques, may sometimes, provide adequate estimation of ET₀. Implementation of regression methods considering all the predictor variables may, however, lead to overfit and consequent reduction in the predictive capability. The regression models for ET₀ have been developed in the present study for Tirupati, Nellore, Rajahmundry, Anakapalli and Rajendranagar regions of Andhra Pradesh, India by following step-wise procedure, eliminating superfluous predictor variables based on statistical criteria. The sunshine hours, wind velocity, temperature and relative humidity influenced ET₀ in the study area. The linear regression models developed in terms of predictor variables may conveniently be applied in the regions selected for the present study and, in the regions with similar climatic conditions for satisfactory ET₀ estimation.     

Simultaneous optimal selection of design and manufacturing tolerances with different stack-up conditions using scatter search

The allocation of design and manufacturing tolerances directly influences the manufacturing cost and functionality of a product. Traditionally, it is carried out in two phases; CAD and CAPP, in a sequential manner. This approach has the drawbacks of more lead-time and sub-optimality. The present work reports on a procedure to simultaneously allocate both design and manufacturing tolerances based on minimum total manufacturing cost. The optimization model for tolerance design is a non-linear multivariable problem. Since such a problem may have a noisy surface, there is a need to apply an efficient global optimization technique. In the present work, scatter search, one of the recently emerged optimization techniques in the area of metaheuristics, is applied successfully to determine the optimal tolerances at the minimum manufacturing cost. An example is taken from the literature to explain the proposed methodology. The results exhibit the effectiveness of the proposed algorithm over other methods.     

Potential nutraceutical food beverage with antioxidant properties from banana plant bio-waste (pseudostem and rhizome)

Banana plant biomass waste, viz. pseudostem (BPS) and rhizome (BR), contribute 30.81 and 12.67 per cent respectively. A negligible percentage of these were used for fresh consumption, otherwise they are waste and incinerated. In order to utilize these bio-wastes in a bioactive perspective, nutritional and nutraceutical components were studied from the juices and its Ready-To-Serve (RTS) beverage. When compared to BPS juice, BR juice showed higher total phenolic content (TPC) and total flavonoid content (TFC) of 341.44 mgGAE and 87.60 mgCE/200 μL, respectively, and concomitantly exhibited high antioxidant activity (AOA) in all the assays tested, viz. DPPH radical scavenging activity (82.93%), superoxide radical scavenging activity (49.45%), metal chelation activity (48.32%) total reducing power (0.846 OD at 700 nm) and total antioxidant capacity (928 mmol ascorbic acid equivalents). High quantity of polyphenols present in BR juice resulted high AOA. Strong positive correlations were observed between TPC and TFC of BPS and BR juice with AOA assays. Among the different concentrations of RTS beverages prepared, 25% BPS juice and 20% BR juice with 15°brix TSS and 0.3% acidity were adjudged as best by sensory panelists. Thus, BPS and BR juice can be effectively used to produce new generation functional beverages.     

Microwave-assisted green synthesis of silver nanostructures

Over the past 25 years, microwave (MW) chemistry has moved from a laboratory curiosity to a well-established synthetic technique used in many academic and industrial laboratories around the world. Although the overwhelming number of MW-assisted applications today are still performed on a laboratory (mL) scale, we expect that this enabling technology may be used on a larger, perhaps even production, scale in conjunction with radio frequency or conventional heating. Microwave chemistry is based on two main principles, the dipolar mechanism and the electrical conductor mechanism. The dipolar mechanism occurs when, under a very high frequency electric field, a polar molecule attempts to follow the field in the same alignment. When this happens, the molecules release enough heat to drive the reaction forward. In the second mechanism, the irradiated sample is an electrical conductor and the charge carriers, ions and electrons, move through the material under the influence of the electric field and lead to polarization within the sample. These induced currents and any electrical resistance will heat the sample. This Account summarizes a microwave (MW)-assisted synthetic approach for producing silver nanostructures. MW heating has received considerable attention as a promising new method for the one-pot synthesis of metallic nanostructures in solutions. Researchers have successfully demonstrated the application of this method in the preparation of silver (Ag), gold (Au), platinum (Pt), and gold-palladium (Au-Pd) nanostructures. MW heating conditions allow not only for the preparation of spherical nanoparticles within a few minutes but also for the formation of single crystalline polygonal plates, sheets, rods, wires, tubes, and dendrites. The morphologies and sizes of the nanostructures can be controlled by changing various experimental parameters, such as the concentration of metallic salt precursors, the surfactant polymers, the chain length of the surfactant polymers, the solvents, and the operation reaction temperature. In general, nanostructures with smaller sizes, narrower size distributions, and a higher degree of crystallization have been obtained more consistently via MW heating than by heating with a conventional oil-bath. The use of microwaves to heat samples is a viable avenue for the greener synthesis of nanomaterials and provides several desirable features such as shorter reaction times, reduced energy consumption, and better product yields.     

Two-dimensional Darcy–Forchheimer flow of a dusty hybrid nanofluid over a stretching sheet with viscous dissipation

The main objective of the present examination is to design a stable mathematical model of a two-phase dusty hybrid nanofluid flow over a stretching sheet with heat transfer in a porous medium, and the Darcy–Forchheimer flow is taken into account with viscous dissipation and melting effect. The equations of motion are reduced to nonlinear ordinary differential equations by considering suitable similarity variables. These dimensionless expressions are solved by a well-known numerical technique known as Runge–Kutta–Fehlberg fourth–fifth order method. The behavioral study and analysis of the velocity and thermal profile in dual phases (fluid phase and dust phase) for diverse values of parameters are estimated using graphs and tables. The result outcome reveals that the velocity gradient declines in the fluid phase and increases in the dust phase for a rise in values of the velocity interaction parameter. Also, the velocity gradients of the both phases diminish for increasing values of the porosity parameter. Furthermore, it is determined that the increase in the value of melting parameter leads to a decline in the thermal gradient of both phases.     

PMMA‐based microgels for controlled release of an anticancer drug

Methyl methacrylate (MMA), methoxy poly(ethylene glycol) monomaleate (MPEG), and acrylamidoglycolic acid (AGA) terpolymeric microgels (MGs) have been synthesized by free‐radical surfactant‐free emulsion polymerization. MPEG was synthesized from maleic anhydride and methoxy poly(ethylene glycol). The MGs were crosslinked with ethylene glycol dimethacrylate, and the chemical crosslinking was confirmed by Fourier transform infrared spectroscopy. 5‐Fluorouracil (5‐FU), a model anticancer drug, has been loaded into the MGs by in situ and adsorption methods. Empty as well as drug‐loaded MGs were then characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). DSC and XRD studies indicated a molecular level dispersion of the drug in PMMA MGs during in situ loading. TEM images showed the formation of spherical MGs. In vitro release of 5‐FU from the crosslinked poly(MMA‐co‐AGA‐co‐MPEG) MGs were investigated at both pH 7.4 and 1.2 buffer medium that controlled release of the drug up to ～ 18 h. Both the encapsulation efficiency and the release patterns were dependent on the amount of crosslinking agent and the amount of drug loaded. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Near-infrared fluorescent probe for fast track of cyclooxygenase-2 in Golgi apparatus in cancer cells

Cyclooxygenase-2 (COX-2) has been used as an excellent traceable biomarker, and exists maximally in Golgi apparatus (Cancer cells). Celecoxib (CCB) is a selective inhibitor for COX-2, and has been used as one of non-steroidal anti-inflammatory drug. Herein we report the conjugation of nile blue (NB) with CCB via a six-carbon linkage to form a fluorescence probe NB-C6-CCB for the detection of COX-2. NB-C6-CCB displays strong fluorescence with the emission peak centered at near-infrared wavelength (700 nm) in tumor cells or tumor tissues with high expression of COX-2. Importantly, NB-C6-CCB can discriminate cancer cells (MCF-7) fluorescence intensity from normal ones (COS-7) in the co-culture medium under confocal microscope. Subcellular localization of the NB-C6-CCB preferentially points to the Golgi apparatus and increases the fluorescent intensity. The competitive analysis (with CCB) and Native-PAGE analysis confirmed that NB-C6-CCB shows selective binding affinity towards COX-2 enzyme. Competitive analysis with CCB (flow cytometry assay) revealed the fluorescence intensity fluctuation due to pretreatment of CCB with different concentrations, indicating that the NB-C6-CCB is a precise or sensitive probe for the COX-2. Tumor tissue (depth: 500 µm), organs and mice imaging tests show excellent near-infrared visualization, specific localization and identification of tumors.