Adsorption of lead(II) from aqueous solution by activated carbon prepared from Eichhornia

Activated carbon prepared from Eichhornia was used for the adsorptive removal of Pb(II) from aqueous solution. As the raw material for the preparation of the activated carbon is an aquatic weed, the production of this carbon is expected to be economically feasible. Parameters such as agitation time, metal ion concentration, adsorbent dose and pH were studied. Adsorption equilibrium was reached in 100 min for a solution containing 15 mgdm^?3 and 125 min for solutions containing 20 and 25 mgdm^?3 Pb(II), respectively. Adsorption parameters were determined using both Langmuir and Freundlich isotherm models. The adsorption capacity was 16.61 mgg^?1 at pH 3.0 for particle sizes of 125–180 µm. Pb(II) removal increased as the pH increased from 2 to 4 and remained constant up to pH 10.0. Desorption studies were also carried out with dilute hydrochloric acid to recover both carbon and Pb(II). Quantitative desorption of Pb(II) from carbon indicates that adsorption of metal ion is by ion exchange. © 2002 Society of Chemical Industry     

Optimization of Activated Carbon Preparation from Pomegranate Peel (Punica granatum Peel) Using RSM

This research involves the optimization of different variables of the operating conditions to prepare activated carbon from pomegranate peels (Punica granatum peel). For this purpose, a statistical method called Response Surface Methodology (RSM) has been adopted to economize the number of experiments and their meaningful interpretation. Activated carbon was produced by chemical activation (H₃PO₄). RSM was used to evaluate the variables considered in the preparation of activated carbon such as impregnation ratio (2–4?g H₃PO₄/g pomegranate peel), temperature (400–600°C), and activation time (30–90?min), experimented using a three-variable Box–Behnken Design (BBD) based on a quadratic model and an RSM tool provided by Design Expert 8.0.4 (STAT-EASE Inc., Minneapolis, USA). The responses analyzed for optimization were the methylene blue number and the iodine number. The factors that are significant influencing the activated carbon preparation have been identified by an analysis of variance (ANOVA). The optimum conditions established were impregnation ratio of 2.78, activation temperature of 575°C, and activation time of 73?min.     

Fabrication of Biogenic Silica Nanostructures from Sorghum bicolor Leaves for Food Industry Applications

Silicon - Due to the large production of sorghum, the generation of associated agricultural residues, which contain high contents of silica, is inevitable. Also, these agricultural residues are not...     

Shape engineering vs organic modification of inorganic nanoparticles as a tool for enhancing cellular internalization

ABSTRACT: In nanomedicine, physicochemical properties of the nanocarrier affect the nanoparticle's pharmacokinetics and biodistribution, which are also decisive for the passive targeting and nonspecific cellular uptake of nanoparticles. Size and surface charge are, consequently, two main determining factors in nanomedicine applications. Another important parameter which has received much less attention is the morphology (shape) of the nanocarrier. In order to investigate the morphology effect on the extent of cellular internalization, two similarly sized but differently shaped, rod-like and spherical, mesoporous silica nanoparticles were synthesized, characterized and functionalized to yield different surface charges. The uptake in two different cancer cell lines was investigated as a function of particle shape, coating (organic modification), surface charge and dose. According to the presented results, particle morphology is a decisive property regardless of both the different surface charges and doses tested, whereby rod-like particles internalized more efficiently in both cell lines. At lower doses, whereby the shape-induced advantage is less dominant, however, charge-induced effects can be used to fine-tune the cellular uptake as a prospectively "secondary" uptake regulator for tight dose-control in nanoparticle-based drug formulations.     

Developing Temperature–Time and Pressure–Time Diagrams for Diffusion Bonding AZ31B Magnesium and AA6061 Aluminium Alloys

Diffusion bonding is a suitable process for joining dissimilar materials without much difficulty. In this investigation, an attempt was made to develop temperature–time and pressure–time diagrams for effective diffusion bonding of AZ31B magnesium and AA6061 aluminium alloys. The bonding quality of the joints was checked by microstructure analysis, lap shear tensile testing and ram tensile testing. Based on the results, temperature–time and pressure–time diagrams were constructed and these diagrams will act as reference maps for selecting appropriate process parameters to get quality bonds.     

A review on conversion techniques of liquid fuel from waste plastic materials

The utilization of plastics has increased in packing sectors consistently, which lead indirectly to increased volumes of plastic wastes posing an environmental threat. Several utilization and recycling techniques of waste plastics are being practiced commercially around the world. In this article, recent conversion techniques of fuel oil from waste plastics and its utilization on a compression‐ignition engine are discussed. Recent statistics says most of the plastic wastes are generated from packing industries that contains polyethylene, polypropylene. In this connection, conversion techniques of polyethylene and polypropylene practiced frequently by researchers include catalytic processing, thermal degradation, and co‐processing. The effect of various parameters like catalysts, reaction temperature, and reaction time of the aforementioned conversion techniques are discussed in this review. Also, few research works about the utilization of waste plastic oil with a compression‐ignition engine along with engine performance and emissions in various blends of diesel with plastic oil are highlighted here. Copyright © 2017 John Wiley & Sons, Ltd.     

Evaluation of mechanical properties of hybrid Al7009 nanocomposite

ABSTRACT

Hybrid nanocomposites are prepared by Al7009 aluminum alloy as base material,graphite and nano magnesium oxide (MgO) as reinforcements. Stir casting processes are used for preparation of hybrid nanocomposite, the percentage of graphite is fixed at 1 wt.% and nano magnesium oxide is varied for 1%, 2%, and 3% by weight and the specimens are named as A (pure), B (1% graphite and 1% MgO), C (1% graphite and 2% MgO), and D (1% graphite and 3% MgO). Evaluation of mechanical properties such as compressive strength, hardness, density, and impact strength behavior of hybrid Al7009 nano aluminum composites are analyzed. From the experimental results, the compressive strength and hardness of hybrid nanocomposite increases up to 2% wt of nano MgO particles and then the value decreases for 3% wt of nano MgO particles. Density increases from the specimens A to C with an increase in percentage of reinforcement in the matrix phase and then it decreases for specimen D. With respect to toughness highest value of 4.4 Jis obtained for sample D and the increase in percentage was 62.9 when compared to sample A, it was 37.5% when compared to specimen B and 12.8% when compared to specimen C.     

Throughput analysis of IEEE 802.11 multirate WLANs with collision aware rate adaptation algorithm

This paper presents a mathematical model that analyzes the throughput of the IEEE 802.11b distributed coordination function (DCF) with the collision aware rate adaptation (CARA) algorithm. IEEE 802.11 WLANs provide multiple transmission rates to improve system throughput by adapting the transmission rate to the current channel conditions. The system throughput is determined by some stations using low transmission rates due to bad channel conditions. CARA algorithm does not disturb the existing IEEE 802.11b formats and it can be easily incorporated into the commercial wireless local area networks (WLAN) devices. Finally, we verify our findings with simulation.     

Optimization of spinning parameters influencing the hairiness properties of polyester/cotton vortex yarn

The influence of vortex spinning parameters on the hairiness properties of polyester/cotton vortex yarn has been studied. Polyester/cotton yarn of 50:50 blend ratio has been produced in two different counts (Ne 20s and Ne 40s) each with four different spinning parameters (delivery speed, spindle size, feed ratio and nozzle pressure). Experiments are designed with the aid of response surface method. Accordingly, different samples are produced with three levels of each parameter. The hairiness index H and zweigle hairiness have been evaluated from the samples produced with these combinations. It is found that the hairiness index H of both coarser and medium count vortex yarns are influenced by all the spinning parameters considered for this study. Also, zweigle S3 values of both coarser and medium count vortex yarns are influenced by all the four parameters. The interactions of some of the spinning parameters have significant influence on the hairiness index, H of both coarser and medium count vortex yarn. Also, few of the interactions have significant influence on zweigle S3 values of both coarser and medium count vortex yarns.