Changes in the Coastline and Water Level of the Akşehir and Eber Lakes Between 1975 and 2009

The Ak?ehir and Eber Lakes, relatively shallow, small freshwater lakes with an area of 361 km² and 150 km² and average depth of 7 m and 2 m (1998), respectively in southwestern Turkey, have experienced a severe decline in water levels in recent decades. This study aimed to investigate coastline and water level changes of lakes and identify the causes for the decline in lake levels. Nine Landsat images from different times, monthly temperature, precipitation, discharge, lake level records and population data were used to analyze these changes. From 1975 to 2009, the water surface areas of the Ak?ehir and Eber Lakes decreased from 356,929 to 126,482 km² and from 119,882 to 85,663 km², a loss of 64.5% and 28.4% over the 34-year period, respectively. From 1975 to 2004, the Ak?ehir Lake level declined by 2.67 m from 956.02 m to 953.35 and the Eber Lake level declined by 2.03 m from 966.75 m to 964.72 m from 1975 to 2004 based on ground lake level data (in situ). The results of the temperature and precipitation analysis showed that although the annual mean climatic factors vary substantially, they show small increasing trend over the record periods. Annual discharge records on the Akarçay River and its tributaries decreased over the basin during the same period. Irrigation systems, three dams and seven pounds built in recent decades for agricultural irrigation and domestic use, made the major impact on lowering the lake levels because they derive water from the river for human use upstream of the lakes’ catchments. Population growth, rising water consumption for agricultural and domestic purposes and building dams has led to lake levels declining. The change of lake levels might depend more on anthropogenic factors than on climatic factors.     

A robust color image watermarking with Singular Value Decomposition method

The performance of a watermarking method based on Singular Value Decomposition (SVD) has been improved for color image in this paper. One of the common methods used for hiding information on image files is Singular Value Decomposition method which used in the frequency domain. In Singular Value Decomposition based watermarking techniques; watermark embedding can usually be achieved by modifying the least significant bits of the singular value matrix. This paper gives application results which show the watermarking security of using this algorithm for the watermarking and demonstrate the accuracy of these methods. The performance comparison of the algorithms was also realized.     

Time–Temperature Management Along the Food Cold Chain: A Review of Recent Developments

The cold chain is responsible for the preservation and transportation of perishable foods in the proper temperature range to slow biological decay processes and deliver safe and high‐quality foods to consumers. Studies show that the efficiency of the cold chain is often less than ideal, as temperature abuses above or below the optimal product‐specific temperature range occur frequently, a situation that significantly increases food waste and endangers food safety. In this work, field studies on time–temperature conditions at each critical stage of the cold chain are reviewed to assess the current state of commercial cold chains. Precooling, ground operations during transportation, storage during display at retail and in domestic refrigerators, and commercial handling practices are identified and discussed as the major weaknesses in the modern cold chain. The improvement in efficiency achieved through the measurement, analysis, and management of time–temperature conditions is reviewed, along with the accompanying technical and practical challenges delaying the implementation of such methods. A combination of prospective experimental and modeling research on precooling uniformity, responsive food inventory management systems, and cold chains in developing countries is proposed for the improvement of the cold chain at the global scale.     

Daphne oleoides: An alternative source of important sesquiterpenes

This study was targeted to characterize the chemical composition and antibacterial properties of Daphne oleoides subsp. oleoides essential oil. The essential oil was analyzed and quantified by gas chromatography and gas chromatography/mass spectrometry. Additionally, the broth dilution method was used to evaluate its antibacterial activity against Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Streptococcus faecalis (ATTC 29212), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 25933), Proteus vulgaris (ATCC 13315), Pseudomonas aeruginosa (ATCC 27853), and Salmonella typhi Ty2 (ATCC 19430). Seventy-nine compounds were identified, representing 95.2% of the total oil. Nootkatone (18.5%), nootkatin (12.1%), and daphnauranol C (11.7%) were determined as the main constituents in the oil. Oxygenated sesquiterpenes were dominating in the oil (43.0%), followed by fatty acid derivatives (13.7%) and carbonylic compounds (9.6%). The minimal inhibitory/bactericidal concentrations of essential oils of D. oleoides were in the range from 25–100 μg/mL, which can be considered as high activity in comparison with the reference antibiotic which was active in the rangefrom 3.12–100 μg/mL. The greatest minimal inhibitory concentration value was determined as 25 µg/mL against both two Bacillus strains and S. epidermidis, B. cereus, B. subtilis, and S. aureus were the most sensitive strains against essential oils when compared with the minimal inhibitory concentrations of control antibiotic. Consequently, Daphne oleoides subsp. oleoides can be exploited as a source of natural antibacterial agents and nootkatone for the pharmaceutical, food, and agricultural industries.     

Active packaging of ground beef patties by edible zein films incorporated with partially purified lysozyme and Na2EDTA

In this study, antimicrobial activity of zein films incorporated with partially purified lysozyme and disodium ethylenediaminetetraacetic acid (Na₂EDTA) has been tested on selected pathogenic bacteria and refrigerated ground beef patties. The developed films containing 700 μg cm^?2 lysozyme and 300 μg cm^?2 Na₂EDTA showed antimicrobial activity on Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium. The application of lysozyme and Na₂EDTA incorporated zein films on beef patties significantly decreased total viable counts (TVC) and total coliform counts after 5 days of storage compared to those of control patties (P < 0.05). Zein films incorporated with lysozyme and Na₂EDTA or Na₂EDTA alone significantly slowed down the oxidative changes in patties during storage (P < 0.05). Redness indices of patties coated with zein films were significantly lower than those of uncoated control patties during storage (P < 0.05). This study demonstrated the potential usage of zein films containing lysozyme and Na₂EDTA for active packaging of refrigerated meat products.     

Effect of dowels and adhesive types on withdrawal strength in particleboard and MDF

Composite materials and wooden dowels are being used increasingly in the construction of furniture frames and inner decoration. However, there is little information available concerning the withdrawal strength of various fasteners and in particular, dowels in these materials. The aim of this study was to determine the withdrawal strengths of 6, 8, and 10?mm diameter dowels produced from different wood species bonded parallel or vertical to the surfaces of a medium-density fiberboard (MDF) or particleboard with poly vinylacetate or Desmodur (D-VTKA). According to TS 4539 standard, the effect of dowel species, direction of withdrawal, board type and the type of adhesive on the withdrawal strength were determined. The highest (8.35?N/mm²) withdrawal strength was obtained for oak dowels bonded with D-VTKA adhesive vertically to the surface of MDF. This value is higher than the predictive expression that allows designers to estimate the withdrawal strength of dowels.     

Maximum achievable diversity order for cascaded Rayleigh fading channels

In this Letter, we investigate the error rate performance of coherent M-ary phase shift keying (M-PSK) modulation over cascaded Rayleigh fading with receive antenna diversity. Through the derived symbol error rate (SER) expression, we present the maximum diversity order achievable over such channels and demonstrate the performance degradation in comparison to conventional Rayleigh channels.     

Impact of impregnation with boron compounds on the surface hardness and abrasion resistance of some varnished woods

This study was performed to determine the impact of impregnation with boron compounds on the surface hardness and abrasion resistance of some varnished woods. For this purpose, test specimens prepared from Oriental beech, White oak, Scotch pine, and Uludag fir, which met the requirements of ASTM D 358, were impregnated according to ASTM D 1413‐99 with boric acid (Ba), borax (Bx), and boric acid + borax (Ba+Bx) by the vacuum technique. After impregnation, the surfaces are coated with synthetic (Sn), water‐borne (Wb) and acid hardening (Ah) varnishes in accordance with ASTM D 3023. the surface hardness of specimens after the varnishing process was determined in accordance with ASTM D 4366. The abrasion resistance of specimens after the varnishing process was determined in accordance with TS 4755. According to the wood type, impregnation material and varnish type, the surface hardness was the highest for Oriental beech impregnated with borax + boric acid and acid hardening varnish and the lowest for Uludag fir impregnated with borax + boric acid and synthetic varnish. According to the wood type, impregnation material and varnish type, the abrasion resistance was the highest for Oriental beech impregnated with borax + boric acid and acid hardening varnish and the lowest for Scotch pine impregnated with borax + boric acid and synthetic varnish. Those results should be taken into account for applications like parquet, flooring etc., where the surface hardness and abrasion resistance values are very important. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Properties and behavior of self-compacting concrete produced with GBFS and FA additives subjected to high temperatures

This paper presents an experimental investigation on the performance of self-compacting concrete (SCC) subjected to high temperatures. For this purpose, Portland cement was replaced with fly ash (FA) and granulated blast furnace slag (GBFS) in various proportions with and without polypropylene (PP) fibers and the PP fiber content was 2 kg/m³ for the mixtures that contained fibers. When the specimens were 56 days old, they were heated to elevated temperatures (200, 400, 600 or 800 °C). Afterword, tests were conducted to determine the weight loss and the compressive strength. Moreover, the change in the ultrasonic pulse velocity (UPV) was determined, and observations for surface cracks were made after the specimens were exposed to elevated temperatures. A severe strength loss was observed for all of the concretes after 600 °C, particularly for the concretes that contained PP fibers; however, the fibers reduced and eliminated the risk of explosive spalling. Based on the test results, it can be concluded that the performance of FA concrete is better than that of the GBFS concrete.     

Comparative Antibacterial,Chemical and Morphological Study of Essential Oils of Thymbra spicata var. spicata Leaves by Solvent-Free Microwave Extraction and Hydro-Distillation

The essential oils of Thymbra spicata var. spicata were obtained by both hydrodistillation and solvent-free microwave extraction methods. Chemical composition and antibacterial activity of the essential oils were examined. The main constituents of both essential oils obtained by solvent-free microwave extraction and hydrodistillation from Thymbra spicata var. spicata were carvacrol (44.8–36.1%), γ-terpinene (23.8–26.1%), and p-cymene (7.3–9.6%), respectively. The essential oil obtained from solvent-free microwave extraction contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than hydrodistillation. The antibacterial activities of the essential oils from solvent-free microwave extraction and hydrodistillation were evaluated by the disc diffusion method against six bacterial strains. The essential oil extracted by solvent-free microwave extraction was more effective than the essential oil extracted by hydrodistillation against the tested bacteria except for E. coli ATCC 25922- and S. aureus ATCC 25923+. Especially, S. aureus ATCC 25923+ was more sensitive against the essential oils obtained from Thymbra spicata var. spicata. Scanning electron microscopy measurements show that glands (that are filled with essential oils) were subjected to more severe thermal stresses and localized high pressure by microwave heating, the pressure build up within the glands could have exceeded their capacity for expansion and break down of cell walls. Solvent-free microwave extraction resulted in more extract release more rapidly than in hydrodestillation.