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101.
Firstly, foam trays were produced from glyoxal cross-linked wheat, potato and corn starches and their mixtures. The most suitable starch type for starch-based foam tray production was selected according to the level of water absorption, density, surface and cross-section micrographs of the foam trays. It was decided that a wheat and potato starch blend was the most suitable starch source for producing the foam trays because they have the lowest water absorption percentage (25.5 ± 0.7%), low density (0.17 ± 0.01 g/cm3) and a smooth surface. Potato–wheat starch foam trays with fibres were produced by adding wheat and wood fibres. Unlike wood fibres addition, wheat fibres significantly decreased the percentage of water absorption (16.63 ± 1.2%) and density (0.115 ± 0.013 g/cm3) of the tray. Also, the trays including wheat fibre had a lighter colour than the wheat–potato starch tray. To further reduce water absorption of the tray, the trays were made by adding two different types of lipids (beeswax or shortening and three different types of filler materials—kaolin, montmorillonite or zinc oxide nanoparticles). According to the level of water absorption of the trays, it was decided that shortening and zinc oxide nanoparticles, in addition to kaolin, were respectively the most suitable lipid and filler materials. The foam trays were produced by adding these supplementary materials. The addition of shortening slightly, zinc oxide nanoparticles moderately and kaolin greatly increased the density of the wheat potato starch tray including fibre. However, the percent of water absorption of the trays containing wheat fibre + shortening or wheat fibre + shortening + zinc oxide nanoparticles decreased 6.4 ± 0.01 and 5.9 ± 0.3%, respectively.  相似文献   
102.
Classification of dimension stone wastes   总被引:1,自引:0,他引:1  

Purpose

For countries in which the stone industry is well developed, opposition to quarry and plant waste is gradually increasing. The primary step for waste control and environmental management is to define the problem of concern. In this study, natural building stone wastes were classified for the first time in the literature.

Methods

Following on-site physical observations and research at more than 50 quarries and 20 plants, stone wastes were classified as (1) solid, (2) dust and (3) semi-slurry, slurry and cake.

Conclusions

As a result of this study, the characteristics of wastes, their main environmental threats and the industries in which wastes could be used were defined for each group.  相似文献   
103.
Use of waste glass or glass cullet (GC) as concrete aggregate is becoming more widespread each day because of the increase in resource efficiency. Recycling of wastes is very important for sustainable development. When glass is used as aggregate in concrete or mortar, expansions and internal stresses occur due to an alkali-silica reaction (ASR). Furthermore, rapid loss in durability is generally observed due to extreme crack formation and an increase in permeability. It is necessary to use some kind of chemical or mineral admixture to reduce crack formation. In this study, mortar bars are produced by using three different colors of glass in four different quantities as fine aggregate by weight, and the effects of these glass aggregates on ASR are investigated, corresponding to ASTM C 1260. Additionally, in order to reduce the expansions of mortars, 10% and 20% fly ash (FA) as mineral admixture and 1% and 2% Li(2)CO(3) as chemical admixture are incorporated by weight in the cement and their effects on expansion are examined. It is observed that among white (WG), green (GG) and brown glass (BG) aggregates, WG aggregate causes the greatest expansion. In addition, expansion increases with an increase in amount of glass. According to the test results, it is seen that over 20% FA and 2% Li(2)CO(3) replacements are required to produce mortars which have expansion values below the 0.2% critical value when exposed to ASR. However, usages of these admixtures reduce expansions occurring because of ASR.  相似文献   
104.
105.
One of the most important hydrogeologic problems in and adjacent areas of evaporitic formations is severe quality degradation of groundwaters. These kinds of groundwaters contain high content of dissolved solids and generally have some limitations for use. Tatlicay basin (north-central Turkey) is an example to effects of the evaporites on groundwater quality in the adjacent alluvium aquifer. Gypsum and anhydrites in the two evaporite formations (Bayindir and Bozkir) effect of the groundwater quality in the alluvium adversely, by dissolution of the evaporites by surface drainage and infiltration into the alluvium aquifer (widespread effect) and by infiltration of low quality gypsum springs (local effect) into the aquifer. Evaporitic formations significantly increased EC, TDS, Ca and SO4 parameters in the alluvium aquifer in the central and downstream regions. EC has increased roughly from 500–800 to 1,700–2,000 μS/cm, Ca has roughly increased from 3–4 to 10 meq/l, SO4 has increased 0.5–1 to 11–12 meq/l. Consequently, three clusters were distinguished in the basin; (1) nonevaporitic waters in low TDS, Na, Ca, Mg, Cl and SO4, (2) diluted waters in high TDS and relatively high Cl, moderate-relatively high Na, Ca, Mg, SO4, (3) gypsum springs in highest TDS, Ca, SO4, but moderate Mg and low Na, Cl.  相似文献   
106.
107.
This paper was conducted in order to determine the groundwater and soil pollution within and around the landfill of Eskisehir, Turkey. In this paper, mud, leachate and groundwater samples were collected seasonally a year from near Eskisehir landfill-site to investigate the possible impact of leachate which affects soil and groundwater quality. Concentrations of various heavy metals (Fe, Cu, Zn, Mn, Co, Pb, Cr, Ni and Mo) were determined in mud, leachate and groundwater samples. In addition, the heavy metal transportation infiltrated from landfill through a porous medium into the groundwater was modelled in order to determine the potential groundwater pollution caused by the leachate of the landfill. The modelling of the contaminant transportation was carried out by using a multiflow computer programme which simulates the distribution of heavy metal concentrations. As a result of this study, the distribution of the contaminant concentration was modelled and determined with respect to time and distance. Hence, the contaminant concentrations were determined at any time interval according to distance. The heavy metal contamination in groundwater does not affect the wells found at far points from the source in a short time, e.g. 10, 20 and 30 days according to the obtained experimental results. When the time intervals extended more than 1 year, heavy metal concentrations decrease with distance but the concentration of the contamination increases when it gets closer to the pollution source. In this study, the potential contamination of groundwater was effectively estimated.  相似文献   
108.
Objectives. The purpose of this study was to collect data on self-reported sharps injuries to develop best practices to reduce them. Methods. Data on sharps injuries were collected for the period of January-October 2008 using Adverse Event Notification Forms already in use at Sema Hospital. Results. On average, 0.2% of all self-reported injuries were sharps injuries averaging one injury per month. Housekeeping staff sustained 64% of such injuries, nurses sustained 36% (5 incidents). Outpatient clinics experienced the most injuries at 28%, followed by the Internal Diseases Inpatient Unit with 21% and the Medical Waste Room with 14%. Injuries often occurred during contact with medical waste bags (28%) and while replacing full sharp-boxes (14%). Conclusion. In summary, reducing needle stick injuries is an important component of the occupational and patient safety program at Sema Hospital. The research described in this study allowed the hospital to provide targeted interventions to increase awareness of the risks of needle stick injuries and reduce such injuries. The steps used in the study can be used in any health care organization in the world to design a customized improvement plan to reduce risk and injury.  相似文献   
109.
Joubert syndrome is a rare, autosomal recessive condition, first described by Joubert in 1969. We present a case of Joubert syndrome from a consanguineous family in which, apart from the cerebellar vermis agenesis, ventriculomegaly, bilateral postaxial polydactyly of hands and right foot and micropenis, episodes of fetal breathing pattern with an increased respiratory rate were also demonstrated by prenatal ultrasound scan. At birth the infant showed an odd face and bilateral fleshy nodules of the tongue. He had an abnormal breathing pattern of alternating tachypnea and apnea. Cranial MRI showed molar tooth sign, hydrocephalus and Dandy–Walker malformation. He had nystagmus, and electroretinography showed retinal dystrophy. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
110.
In this study, the potential re-use of waste foundry sand in high-strength concrete production was investigated. The natural fine sand is replaced with waste foundry sand (0%, 5%, 10%, and 15%). The findings from a series of test program has shown reduction in compressive and tensile strengths, and the elasticity modulus which is directly related to waste foundry inclusion in concrete. Nevertheless the concrete with 10% waste foundry sand exhibits almost similar results to that of the control one. The slump and the workability of the fresh concrete decreases with the increase of the waste foundry sand ratio. Although the freezing and thawing significantly reduces the mechanical and physical properties of the concrete. The obtained results satisfies the acceptable limits set by the American Concrete Institute (ACI).  相似文献   
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