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1.
This study investigated some of the important physical (thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond) properties of single-layer particleboard panels made from eucalyptus (Eucalyptus camaldulensis Dehn.), waste of grass clippings (Lolium perenne L.) and combinations of the two. The chemical properties (pH, holocelluse and alpha cellulose contents, and water, alcohol-benzene and 1% sodium hydroxide solubilities) of the raw materials were also determined. Panels with a 6:94 ratio of grass-to-eucalyptus particles had the required mechanical properties for interior fitments including furniture and general uses. Boards manufactured with 100% grass clippings exhibited the lowest quality. The overall panel properties improved with a lower percentage of grass clippings added. Based on initial results, it also appears that grass should compose no more than 13% to achieve acceptable panel properties for interior fitments and general uses.  相似文献   
2.
The purpose this study was to improve operational planning and management of national parks in Turkey to balance conservation use and sustainable management. Souksu National Park (SNP) was chosen as the study area. The data were obtained from interviews of 182 visitor groups (in total, 819 people) and analyzed using correlation, factor, discriminant, and regression analyses. It was found that the most important factors affecting operational planning and management of SNP are (1) travel cost, (2) visitor welfare level, (3) intensity of use, (4) size of visitor group, (5) type of recreational demand. The main source of visitors to SNP is from a zone within a 0–90-km radius. This region comprised 53.85% of total visitors to the park. The capital of Turkey (Ankara) is the most important source of visitors from within this zone. The optimum activity mix in SNP is also determined. Picnicking, viewing the scenery, and nature walks or trekking comprised the main uses of the park. It is anticipated that these findings will help to improve operational planning and sustainable management of the national park and the environment.  相似文献   
3.
In this study, we investigated the effects of Matricaria chamomilla L. extract (MCE) on lipid peroxidation, antioxidant enzyme systems, and several liver enzymes in carbon tetrachloride (CCl4)-treated rats. Rats were divided into five groups. The first group (control group) was fed on standard feed. The rats in the other groups (CCl4, MCE50, MCE100, and MCE200) were injected intraperitoneally with 0.8?mL?kg?1 CCl4. Moreover, rats in the MCE50, MCE100, and MCE200 groups were gavaged with 50?mg?kg?1, 100?mg?kg?1, and 200?mg?kg?1 MCE, respectively. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, whole blood malondialdehyde (MDA) and glutathione (GSH) levels, and erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity levels were measured after 14 days of exposure. ALT and AST in the CCl4 group increased significantly in comparison to the control group (p?4, MCE50, MCE100, and MCE200 groups at different significance levels. In conclusion, the findings suggest that, depending on the dose administered, MCE decreases CCl4-induced damage and consequent oxidative stress in rats; it affects the antioxidant system positively.  相似文献   
4.
A potentiometric titration technique has been used to determine the stability constants for the various complexes of Co(II) and Cu(II) with L‐asparagine and from DNA base, e.g. adenine. Stability constants of ternary systems have been evaluated by the method suggested by Irwing‐Rossotti. In addition, the conditional constants were calculated as a function of pH. The maximum values of the conditional formation constants were found to be in accordance with the mixed‐ligand complex formation constants in a determined pH region. Furthermore, the molar fractions of different species from mixed complexes were calculated by means of formation constants. The values of stability constants of mixed‐ligand complexes at 25°C are as follows: log K= 5.25 for Co(II)‐L‐asparagine‐adenine; log K= 9.30 for Cu(II)‐L‐asparagine‐adenine. The ionic strength was kept constant at I = 0.20 with NaClO4.  相似文献   
5.
The accumulations of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn in the exoskeleton, gills, hepatopancreas and abdominal muscles of crayfish Astacus leptodactylus (Eschscholtz, 1823) were determined. The strongest correlation observed was between Cr and Ni in the gills (r?=?0.904); moderate to strong correlations between Al, Cr, Fe, Ni and Cu were also observed in gill tissue. Disregarding the gills, the strongest correlation was found between Cu and Zn in the hepatopancreas (r?=?0.808); the correlation between these two metals might have been a result of metallothionein activity. The accumulation of Pb was found to correlate with that of Cd in the exoskeleton, Cd and Zn in the gills, Zn and Cu in the hepatopancreas and Cu in the abdominal muscle. None of these correlations were present in lakewater and sediment samples, suggesting that the crayfish metabolism may be responsible for the co-accumulation of metal–metal pairs. As all correlations in non-gill tissues are observed between divalent metals, a shared transporter such as divalent metal transporter 1 might be involved in the accumulation of these metals.  相似文献   
6.
The Balcova Geothermal Field (BGF) located in Izmir, Turkey is situated on an east-west directed graben plain within which the hot waters surface from a fault zone that cuts the Mesozoic aged Bornova Flysch. Due to the low permeability and porosity of the Bornova Flysch, the geothermal water cycles along the immediate vicinity of the Agamemnon fault and mixes with cold waters at different depths of this fractured zone. Within the scope of this study, the mixing patterns and the groundwater contamination mechanisms are analyzed by, hydrogeological and hydrogeochemical methods. Based on the results of this research, it has been found out that the hot geothermal water and the cold regional groundwater resources of the surficial aquifer mix within the fractured zone in Bornova Flysch and within the Quaternary alluvium aquifer due to natural and anthropogenic activities including (i) the natural upward movement of geothermal fluid along the fault line, (ii) the accelerated upward seepage of geothermal fluid from faulty constructed boreholes drilled in the area, (iii) the faulty reinjection applications; and, (iv) the uncontrolled discharge of waste geothermal fluid to the natural drainage network. As a result of these activities, the cold groundwater reserves of the alluvial aquifer are contaminated thermally and chemically in such a way that various toxic chemicals including arsenic, antimony and boron are introduced to the heavily used surficial aquifer waters hindering their use for human consumption and agricultural irrigation. Furthermore, the excessive pumping from the surficial aquifer as well as the reduced surface water inflow into BGF due to the dam constructed on Ilica Creek intensify the detrimental effects of this contamination. Based on the results of this study, it can be concluded that the groundwater pollution in BGF will expand and reach to the levels of no return unless a series of preventive measures is taken immediately.  相似文献   
7.

Introduction  

In this study, total petroleum hydrocarbon (TPH) contents and some aliphatic and aromatic hydrocarbon concentrations were analysed in coastal sediments of hot points collected from along the Southern Black Sea Shelf.  相似文献   
8.
For the past 60 years, Istanbul has been experiencing an accelerated urban expansion. This urban expansion is leading to the replacement of natural surfaces by various artificial materials. This situation has a critical impact on the environment due to the alteration of heat energy balance. In this study, the effect upon the urban heat island (UHI) of Istanbul was analyzed using 2009 dated Landsat 5 Thematic Mapper (TM) data. An Index Based Built-up Index (IBI) was used to derive artificial surfaces in the study area. To produce the IBI index, Soil-Adjusted Vegetation Index, Normalized Difference Built-up Index, and Modified Normalized Difference Water Index were calculated. Land surface temperature (LST) distribution was derived from Landsat 5 TM images using a mono-window algorithm. In addition, 24 transects were selected, and different regression models were applied to explore the correlation between LST and IBI index. The results show that artificial surfaces have a positive exponential relationship with LST rather than a simple linear one. An ecological evaluation index of the region was calculated to explore the impact of both the vegetated land and the artificial surfaces on the UHI. Therefore, the quantitative relationship of urban components (artificial surfaces, vegetation, and water) and LST was examined using multivariate statistical analysis, and the correlation coefficient was obtained as 0.829. This suggested that the areas with a high rate of urbanization will accelerate the rise of LST and UHI in Istanbul.  相似文献   
9.
The aim of this study was to determine the total metal accumulation (aluminium, copper, manganese, lead, cadmium and iron) in different organs and eggs of Astacus leptodactylus (Eschscholtz, 1823) and sediments total metal contents (aluminium, copper, manganese, lead, cadmium, iron, zinc, chromium, nickel) in Lake Terkos. Water and sediment samples were collected from two stations at two different depths (1 and 2 m) of Lake Terkos in May 2008. Crayfish samples were collected by trammel net at the same region. Primary hydrographic conditions, such as temperature (13.6–19.4°C), salinity (0.27–0.34‰), dissolved oxygen (7.04–12.30 mg l???1) and pH (7.42–8.51), were recorded for each sampling point. Moreover, the total organic carbon (1.65–5.44%) and the total calcium carbonate contents (19.44–41.16%) of sediment samples were determined. According to the Turkish Food Codex (J Zool 26:283–288, 2002), the maximum allowable Pb and Cd levels in crayfish are 0.5 mg/kg wet weight. Accordingly, the Pb and Cd levels determined in A. leptodactylus samples are below this limit. However, when compared with the acceptable metal limits defined by WHO, Australian National Health and Medical Research Council and Ministry of Agriculture in United Kingdom (UK), it is clear that the Cu level is at the limit and the Cd results exceed the limit. When the metal contents in sediment samples from Lake Terkos are examined, it is seen that the Al, Fe, Mn, Ni and Cu contents are lower while Zn, Cr, Cd and Pb contents are higher than the crustal average values. The high values draw attention to the land-based domestic and industrial inputs. Lake Terkos sediments have high enrichment factors (EF) of Zn, Cr, Cd and Pb metals which corroborate this result. The low EFs of Fe, Ni and Cu are due to the natural (terrigeneous) inputs. Additionally, there is no Al, Fe, Ni and Cu metal enrichment in these lake sediments because of the low contamination factor (CF) values. However, it is moderately contaminated by Zn, Cr and Pb, and heavily contaminated by Cd.  相似文献   
10.
First cross-border atmospheric pollution of 11 heavy metals and toxic elements assessed by Hypnum cupressiforme was reported for a part of Southeastern Europe (Southeastern Bulgaria and European Turkey). Moss monitoring technique followed the main requirements of European Moss Survey. Moss samples were collected in April 2006 both in Bulgaria and Turkey. Concentration of Al, As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, V, and Zn were determined by ICP-AES. Interlaboratory parallel calibration (exchanged four moss samples from each country), standard reference moss materials (M2 and M3) results ensured the study. ANOVA showed no differences between measured results in both laboratories at the 99% confidence level. Principle Component Analyze proved two factors: F1 group of Al, As, Cd, Cr, Fe, Ni, and V and F2 of Cu, Pb, and Zn as main atmospheric pollutants. Results obtained showed approximately Cu and Pb high concentrations around Istanbul and Burgas and Zn pollution in Istanbul district. Arsenic cross-border atmospheric pollution in the study area of Southeastern Europe was found.  相似文献   
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