Synthesis of M–Nd doped Fe3O4 nanoparticles (M = Co, Ce, Cr, Ni) with tunable magnetic properties

Magnetic nanoparticles were prepared by the aqueous co-precipitation method. The magnetic nanoparticles obtained were characterized systematically through the use of an X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and a vibrating  sampling  magnetometer (VSM). The results revealed that the magnetic nanoparticles were spherical shaped with inverse spinel structure. The size of Fe3O4 and Nd-Co doped Fe3O4 magnetic nanoparticles were approximately 15 nm. Magnetic measurement revealed that the nanoparticles were super paramagnetic at room temperature. It was found that the magnetic response of the Fe3O4 increased when it was doped with Nd3+ and Co2+. However, the magnetic response of the Fe3O4 decreased when it was doped with Nd3+ or Ce3+ or Cr3+or Ni2+. KEYWORDS: Fe3O4, Magnetic nanoparticles, Superparamagnetic, Magnetite, Fe3O4 doped Bull. Chem. Soc. Ethiop. 2013, 27(1), 49-56.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

Safely dissolvable and healable active packaging films based on alginate and pectin

Extensive usage of long-lasting petroleum based plastics for short-lived application such as packaging has raised concerns regarding their role in environmental pollution. In this research, we have developed active, healable, and safely dissolvable alginate-pectin based biocomposites that have potential applications in food packaging. The morphological study revealed the rough surface of these biocomposite films. Tensile properties indicated that the fabricated samples have mechanical properties in the range of commercially available packaging films while possessing excellent healing effciency. Biocomposite films exhibited higher hydrophobicity properties compared to neat alginate films. Thermal analysis indicated that crosslinked biocomposite samples possess higher thermal stability in temperatures below 120 °C, while antibacterial analysis against E. coli and S. aureus revealed the antibacterial properties of the prepared samples against different bacteria. The fabricated biodegradable multi-functional biocomposite films possess various imperative properties, making them ideal for utilization as packaging material

Prevalence of prolonged QTcinterval in electrocardiograms of 1 -12 year-old seizure patients

Background: Children with long QT intervals are prone to life-threatening ventricular arrhythmias which may lead to seizure and syncope and may be misdiagnosed as seizure. Objective: This study aimed to assess the frequency of long QT intervals in children with and without convulsion. Method: This study is case-control. ECG tracings were requested for all children aged between one to twelve years who were hospitalized due to convulsion with no underlying etiology and simultaneously for children of the same age and gender who were admitted due to other than seizure as case group. Consequently, QT intervals were measured and compared in the two  groups. Results: If long QT interval was defined to be longer than 0.47 second, no significant difference was noted between two groups. On the other hand, if this interval was defined to be equal to or longer than 0.46 second, long QT intervals are more frequent in convulsive children. Conclusions: In this study, long QT interval, defined as QT interval 0.46 second, is found more frequently in children with seizure than non-convulsing ones. It is recommended that children with history of seizure without any identifiable causes and that is unresponsive to  anticonvulsive drugs should be investigated with ECG.Key words: Child, Diagnostic Errors, Long QT Syndrome, Seizur

SMOKE AND VAPOR PLUME MERGENCE

Observations at power plants have indicated that vapor plumes emitted from cooling towers frequently merge with smoke plumes released from stacks. Mergence of cooling tower and stack plume leads to formation of acidic compounds which have adverse effects on the en- vironment. Wind speed and direction play an important role in merging smoke and vapor plume. This paper lists some arguments to verify that studies have not sufficiently addressed stack and cooling tower plume mergence. In conclusion, the present authors hope to find more information in the future with regard to vapor and smoke plume mergence

Folate-conjugated nanoparticles as a potent therapeutic approach in targeted cancer therapy

The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy. © 2015, International Society of Oncology and BioMarkers (ISOBM)

Web Bearing Capacity of Cold-Formed Ferritic Stainless Steel Unlipped Channels with Web perforations under the End-Two-Flange (ETF) Loading

Laboratory and numerical evaluations on the web bearing capacity of unlipped cold-formed ferritic stainless steel channels are described in this paper. The channels considered have circular perforations in the web and are loaded under the end-two-flange (ETF) load case. A total of 387 results comprising 27 laboratory and 360 numerical results are presented. A nonlinear quasi-static finite element (FE) model was developed for the numerical investigation. An extensive parametric study is described to determine web bearing capacity reduction factors for different sizes of circular web perforations and cross-section dimensions; the circular web perforations are either centred or offset to the load and reaction plates. It is noted that no cold-formed stainless steel standard provides capacity reduction factors for any end-two-flange load case. The capacity reduction factor equations are first compared to reduction factors previously recommended for lipped cold-formed stainless steel channels. It is found that these existing equations are unreliable and unconservative for unlipped channels by as much as 11%. From both laboratory and finite element results, web bearing capacity design equations are proposed for both sections, with and without web perforations

Web Crippling Behavior of Cold-Formed Ferritic Stainless Steel Unlipped Channels under Interior-One-Flange And End-One-Flange Loadings

The web crippling strength of cold-formed ferritic stainless steel unlipped channels subject to interior-one-flange and end-one-flange loading is considered in this paper. A total of 144 results are presented, comprising 36 laboratory and 108 numerical results. These results cover the cases of both flanges restrained and unrestrained to the load and reaction plates. Unlike other work in the literature, the numerical analysis in this paper uses nonlinear quasi-static finite element analysis with an implicit integration scheme, which has advantages over static and quasi-static with an explicit integration scheme analyses, particularly for post buckling predictions of unlipped channels subject to web crippling. The laboratory and numerical investigations show current stainless steel design guidance to be too conservative. In terms of design standards, while no cold-formed stainless steel standard distinguishes between flanges restrained and unrestrained to the load and reaction plates, with each standard providing only one equation to cover both restrained and unrestrained, the web crippling strengths for the flanges unrestrained case were found to be higher than those predicted from SEI/ASCE-8 by as much as 24%. Also, the web crippling strengths for the flanges restrained case are shown to be higher than those predicted from equations found in the literature by as much as 48%. New web crippling design equations are proposed; the proposed equations are shown to be reliable when compared against laboratory and numerical results