Nanocrystalline diamond--an excellent platform for life science applications

Nanocrystalline diamond (NCD) has recently been successfully utilized in a variety of life science applications. NCD films are favorable and salubrious substrates for cells during cultivation. Therefore NCD has also been employed in tissue engineering strategies. NCD as reported in this contribution was grown by means of a modified hot-filament chemical vapor deposition technique, which results in less than 3% sp2-hybridization and yields grain sizes of 5-20 nm. After production the NCD surface was rather hydrophobic, however it could be efficiently refined to exhibit more hydrophilic properties. Changing of the surface structure was found to be an efficient means to influence growth and differentiation capacity of a variety of cells. The particular needs for any given cell type has to be proven empirically. Yet flexible features of NCD appear to be superior to plastic surfaces which can be hardly changed in quality. Besides its molecular properties, crystal structural peculiarities of NCD appear to influence cell growth as well. In our attempt to facilitate, highly specialized applications in biomedicine, we recently discovered that growth factors can be tightly bound to NCD by mere physisorption. Hence, combination of surface functionalization together with further options to coat NCD with any kind of three-dimensional structure opens up new avenues for many more applications. In fact, high through-put protein profiling of early disease stages may become possible from serum samples, because proteins bound to NCD can now be efficiently analyzed by MALDI/TOF-MS. Given these results, it is to be presumed that the physical properties and effective electrochemical characteristics of NCD will allow tailoring devices suitable for many more diagnostic as well as therapeutic applications.     

Experimental study of a micro-scale sloped solar chimney power plant

Journal of Mechanical Science and Technology - Solar chimney power plants (SCPP) are structures that have the potential to generate a significant amount of electrical energy without harming the...     

The fuzzy logic-based modeling of a micro-scale sloped solar chimney power plant

Journal of Mechanical Science and Technology - The energy demand of world is increasing worldwide because of increasing population and developing technology. The use of environmentally friendly...     

An approximate method for static and dynamic analyses of symmetric wall‐frame buildings

In this study an approximate method based on the continuum approach and transfer matrix method for static and dynamic analyses of symmetric wall‐frame buildings is presented. The whole structure is idealized as a sandwich beam in this method. Initially the differential equation of this equivalent sandwich beam is written; shape functions for each storey can then be obtained by the solution of differential equations. By using boundary conditions and storey transfer matrices obtained from these shape functions, system modes and periods can be calculated. The reliability of the study is shown using several examples. A computer program has been developed in MATLAB and numerical samples have been solved for demonstration of the reliability of this method. The results of the samples show the agreement between the present method and other methods given in the literature. Copyright © 2007 John Wiley & Sons, Ltd.     

Some geotechnical properties of soils in the Haditha area,W. Iraq

The present study is part of the regional engineering geological survey of the western deserts dealing with soil investigations attempting their classification and evaluation for engineering purposes. Field study has revealed that these soils are mainly of residual origin, partly they are colluvial and alluvial. Laboratory test results show that they composed of both coarse and fine fractions. The coarse-grained are mainly of SM-group, less frequently of SC-group. Fine-grained soils are of both CL-and ML groups in equal significance. These soils are seldom free from soluble salts, particularly sulphates in the form of secondary gypsum, some with a high content. Results are discussed in details. Important engineering properties with suitability for engineering use are also given.     

Silver Nanoflower Decorated Graphene Oxide Sponges for Highly Sensitive Variable Stiffness Stress Sensors

Soft conductive materials should enable large deformation while keeping high electrical conductivity and elasticity. The graphene oxide (GO)‐based sponge is a potential candidate to endow large deformation. However, it typically exhibits low conductivity and elasticity. Here, the highly conductive and elastic sponge composed of GO, flower‐shaped silver nanoparticles (AgNFs), and polyimide (GO‐AgNF‐PI sponge) are demonstrated. The average pore size and porosity are 114 µm and 94.7%, respectively. Ag NFs have thin petals (8–20 nm) protruding out of the surface of a spherical bud (300–350 nm) significantly enhancing the specific surface area (2.83 m² g^?1). The electrical conductivity (0.306 S m^?1 at 0% strain) of the GO‐AgNF‐PI sponge is increased by more than an order of magnitude with the addition of Ag NFs. A nearly perfect elasticity is obtained over a wide compressive strain range (0–90%). The strain‐dependent, nonlinear variation of Young's modulus of the sponge provides a unique opportunity as a variable stiffness stress sensor that operates over a wide stress range (0–10 kPa) with a high maximum sensitivity (0.572 kPa^?1). It allows grasping of a soft rose and a hard bottle, with the minimal object deformation, when attached on the finger of a robot gripper.     

Effects of spraying nano‐materials on the absorption of metal(loid)s in cucumber

This report investigates the spraying of nano‐silica and fullerene on cucumber leaves to expose their ability to reduce the toxicity and uptake of metal(loid)s. Cucumber seedlings were randomly divided into six treatment groups: 10 mg/L nano‐SiO₂, 20 mg/L nano‐SiO₂, 10 mg/L Fullerene, 20 mg/L Fullerene, 5 mg/L Fullerene + 5 mg/L nano‐SiO₂, and 10 mg/L Fullerene + 10 mg/L nano‐SiO₂. Nano‐silica‐treated plants exhibited evidence of the potential mitigation of metal(loid)s poisoning. Specifically, results showed that 20 mg/L of nano‐silica promoted Cd uptake by plants; comparatively, 10 mg/L of nano‐silica did not significantly increase the silicon content in plants. Both low‐concentration combined treatment and low‐concentration fullerene groups inhibited metal(loid)s uptake by plants. Scanning electron microscopy (SEM) was then used to observe the surface morphology of cucumber leaves. Significant differences were observed on disease resistance in plants across the different nano‐material conditions. Collectively, these findings suggest that both nano‐silica materials and fullerene have the potential to control metal(loid)s toxicity in plants.Inspec keywords: soil pollution, cadmium, silicon compounds, surface morphology, fullerenes, toxicology, fertilisers, scanning electron microscopy, crops, spraying, nanoparticles, sorption, plant diseases, agricultural safetyOther keywords: cucumber leaves, nanosilica materials, fullerene, spraying process, metalloids absorption, toxicity, scanning electron microscopy, surface morphology, disease resistance, soil pollution, SiO₂ , Cd     

UV curable lens production using molecular weight controlled PEEK based acrylic oligomer (Ac-PEEK)

We produced UV curable lenses with properties blocking short wave UV light. In the UV-curable formulations, we used an oligomer (Ac-PEEK) with another urethan oligomer (Mw = 2000). Radically active, molecular weight controlled Ac-PEEK was obtained by reacting 2-hydroxyl ethyl methacrylate with molecular- weight- controlled and isocyanate terminated PEEK (Mn = 4500). We characterized all synthesized monomer, oligomer and optical materials with UV/Vis spectrophotometer with interferogram, elemental analyser, mass spectrophotometer, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravimetric analyzer, differential scanning calorimeter, scanning electron microscopy and gas chromatography. Results suggested that newly synthesized oligomer with the structure of PEEK absorbs short wave UV-light. Ageing tests [ISO 11979-5, Ophthalmic implants—intraocular lenses (IOL)—Part 5: Biocompatibility] performed on the IOL materials were successful. High contact angle of the obtained lenses suggests that all lenses were hydrophobic and SEM results revealed that lenses are morphologically homogeneous. Based on all positive properties just mentioned, we safely conclude that the lenses produced in this study are very promising for IOL production.