A Method to Improve Gamma Energy Resolution of BC-420 Type Organic Scintillation Detector

Instruments and Experimental Techniques - Currently, plastic (organic) scintillators are using in new type positron emission tomography (PET) devices such as J-PET. But, these type scintillators...     

Synthesis and properties of starch-graft-acrylic acid/Na-montmorillonite superabsorbent nanocomposite hydrogels

The graft copolymerization of acrylic acid (AA) onto starch was carried out with monomer/starch weight ratio = 1.5. Cerium ammonium nitrate (CAN) and N,N′-methylenebis acrylamide (NMBA) were used as initiator and crosslink agent, respectively. Na-montmorillonite was used as nanoparticles. Starch-graft-acrylic acid/Na-MMT (S-g-AA/MMT) nanocomposite hydrogels were characterized by X-ray diffraction (XRD) and FTIR analysis. The effect of Na-MMT content in nanocomposite hydrogels on the swelling behavior was investigated. Increasing the Na-MMT/monomers ratio up to 1% causes an increment in water absorbency, which indicates that Na-MMT can improve the ability of water absorbency but further increase of Na-MMT causes a decrease in water absorbency. In addition, we describe the removal of safranine T from aqueous solutions using S-g-AA/MMT nanocomposite hydrogels. Effects of various parameters such as treatment time, initial dye concentration, and amount of the Na-MMT were investigated. The Freundlich equations were used to fit the equilibrium isotherms. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Growth of NBT template particles through topochemical microcrystal conversion and their structural characterization

In this study, uniform rectangular plate‐like perovskite Na_0.5Bi_0.5TiO₃ templates were obtained by molten salt synthesis method in three steps. Perovskite plate‐like Na_0.5Bi_0.5TiO₃ templates were synthesized from bismuth‐layered Na_0.5Bi_4.5Ti₄O₁₅ by topochemical microcrystal conversion method at the third and final step. The most important point was that the plate‐like morphology remained as desired, but templates were obtained in cubic perovskite structure. The Na₂CO₃ excess in the third step was the main controlling parameter. The crystalline orientation of the particles was investigated by electron backscatter diffraction analysis. The results indicated that the particles are single crystalline in nature. In the case of the 90 mol% excess of the stoichiometric Na₂CO₃ ratio, the NBT platelets had highly regular, rectangular prismatic morphology and single‐crystal nature. The structure was also confirmed through high‐resolution transmission electron microscope and selected area electron diffraction analysis.     

The Use of Microwave and K* Algorithm in Determination of Alcohol Concentration in Liquids

Russian Journal of Nondestructive Testing - Alcohol is widely used in various fields today. Alcohol overdose and its improper use can cause many health problems. Drinking liquids with high alcohol...     

Analysis and Optimization of Drying of Green Bricks in a Tunnel Dryer

One way to avoid the risk of condensation in a tunnel dryer for drying of green bricks is to use higher air flow rates. However, higher air flow rates accelerate the drying rate and thus cause damages. It is necessary to determine the optimal values of the hot and outdoor air mass flow rates and optimum stack temperature to avoid the condensation. Four different temperatures, (?5, 10, 20, and 30°C) and three different relative humidities (40, 60, and 80%) for the outdoor air were selected. Optimal operation parameters and the required stack temperature to avoid condensation for different cases were computed.     

The effect of transglutaminase on some physicochemical and sensory properties of the Turkish drinking yoghurt Ayran

This article presents research on the effect of microbial transglutaminase on the properties of Turkish drinking yoghurt Ayran. Transglutaminase (TGase) enzyme was added to Ayran milk at different production steps, after pasteurisation and together with starter culture addition, and two different incubation times (10 min and 1 h) were used. Three TGase‐treated Ayran samples and control sample were analysed on 1st, 10th and 20th days of storage. TGase addition did not cause significant changes on chemical properties of Ayran (P > 0.05). However, physical properties of Ayran were improved by TGase throughout the storage period. Compared to the untreated control sample, pretreatment of milk with enzyme increased the viscosity dramatically (P < 0.05) and prevented serum separation. Scanning electron microscopic studies revealed that transglutaminase treatment of milk led to more regular distribution of proteins in Ayran gel and decreased gel permeability. TGase treatment did not show any unfavourable effect on the sensory properties of the final product.     

Poly(3-hydroxyalkanoate)s: Diversification and biomedical applications: A state of the art review

Biomaterials have played an important role in the treatment of disease and the improvement of health care. Synthetic and naturally occurring biodegradable and biocompatible polymers have been used as biomaterials. Polyhydroxyalkanoates (PHAs) are promising materials for biomedical applications because they are biodegradable, non-toxic and biocompatible. We will shortly summarize the modification reactions, which include functionalization and grafting reactions, to improve the mechanical, thermal and hydrophilic properties of PHAs. The use of the modified PHAs in numerous biomedical applications, such as sutures, cardiovascular patches, wound dressings, scaffolds in tissue engineering, tissue repair/regeneration devices, drug carriers will be discussed in this review.     

Capacity Evaluation of a Severely Distressed and Deteriorated 50-Year-Old Box Beam with Limited Data

In 2005, 15 adjacent box-beam bridges were randomly selected and inspected to document their performance with consideration of the evolving design procedures. Longitudinal cracking along the soffit of several fascia beams was documented. After evaluating inspection data, the bridge engineer recommended the replacement of a severely distressed fascia beam from the Hawkins Road Bridge in Jackson County, Michigan. The beam was salvaged and the capacity was evaluated through load testing. The remaining prestress was 75% of the initial prestress, which is 5% less than the final prestress used for the design. Concrete modulus of elasticity was evaluated as 35.4?GPa and the nominal compressive strength as 54.4?MPa. Analysis of load test data indicated that a bridge with the beam in this distressed state is safe to operate. This is assuming that the transverse connectivity between the beams is sufficient for load distribution as envisioned in the design. The importance of identifying concealed corrosion, and quantifying material properties and load distribution is highlighted in this paper.     

Antibacterial activities of essential oils and extracts of Turkish Achillea,Satureja and Thymus species against plant pathogenic bacteria

BACKGROUND: The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC–MS, and to test antibacterial efficacy of essential oils and n‐hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS: Thymol, carvacrol, p‐cymene, thymol methyl ether and γ‐terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8‐cineole, δ‐cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n‐hexacosane, n‐tricosane and n‐heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed‐borne bacteria. CONCLUSION: Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright © 2009 Society of Chemical Industry