Chemical injection to prevent building damage induced by ground water drainage from shallow tunnels

Progressive developments in the application of chemical injection have been acquired through out the centuries, starting from the ancient Romans. The method of silica based injection has been employed for a long time and has replaced the polyurethane injection method since the 1970s as a remedy in difficult ground conditions including fractured rock. Currently, various applications of chemical injections are available in civil and mining engineering, including ground stabilization, support anchoring, strata sealing, reduction and diversion of ground water flow and water ingress and creation of a load-bearing ring in tunneling. Drainage of the ground water in the overburden during tunneling will result in an increase in ground settlement by the evacuation of water and closure of the pores in overburden. In this research, the ground water level was decreased to 3 m from the original level and the ground settlement was recorded to reach 25 mm, while the inner tunnel vertical convergence was 6.5 mm after the drainage of 3.5 l/s ground water from the tunnel. Subsequent field measurements and observations indicated that the ground water drainage in the tunnel was reduced to 0–0.5 l/s and the surface settlements were stopped after the chemical injection.     

The influence of gallium on the magnetocaloric properties of Gd5Si2Ge2

Gd₅Si₂Ge₂ was alloyed with varying amounts of Ga to study its influence on the giant magnetocaloric effect. Investigations on Gd₅(Si_2−xGe_2−x)Ga_2x with 2x = 0.03, 0.05 and 0.13 were carried out using X-ray powder diffraction, temperature and magnetic field dependent magnetization measurements, and differential scanning calorimetry. We observe that as the Ga content increases, the temperature stability range of the monoclinic phase narrows, and the orthorhombic structure gains stability. This is expected to be related to the decrease in the (Si/Ge)(Si/Ge) bond distance in the monoclinic phase. The maximum entropy change for the parent compound at 270 K was found to be 9.8 J kg⁻¹ K⁻¹ in an applied field of 5 T. For 2x = 0.03, this value reduces to 8.5 J kg⁻¹ K⁻¹, and the temperature corresponding to the maximum entropy change shifts marginally to 278 K. For other 2x values, the maximum entropy change further decreases.     

Characteristics of safflower seed oils of turkish origin

Technological characteristics of oils extracted from seventeen varieties of safflower seeds (Carthamus tinctorius L.) of Turkish origin were investigated for their utilization prospects in the food industry and in other industrial sectors. Standard procedures were applied to determine the technological characteristics of seventeen varieties of safflower seeds and the safflower seed oils; fatty acid compositions were determined by gas-liquid chromatography. Results show that safflower seed oils are suitable both for food and industrial purposes.     

Reducing the quantity of reworked parts in a robotic arc welding process

Today, the competitive environment of the knowledge age has been replaced with the competitive environment of the industrial age as the rules of the business world are changing completely. The focused issue is to reach to the knowledge as soon as possible, and to process and apply it rapidly. In this context, one of the important goals that the companies try to reach in order to achieve acceleration is the six sigma philosophy. Six sigma is a fundamental continuous improvement methodology aimed at reducing the variation and waste on processes by utilizing statistical methods and techniques efficiently. Global companies are making noteworthy profits by using this method in their processes. The six sigma methodology focuses on process excellence advantages for companies that apply it, to reach profit, to increase productivity and to have larger market share. In this paper, an application of six sigma methodology for reducing the quantity of rework parts for robotic arc welding process is given. The phases of six sigma and their results are indicated in detail. Furthermore, it is also shown how various techniques of six sigma methodology are applied to achieve financial benefits. Copyright © 2008 John Wiley & Sons, Ltd.     

Five-year survey of ochratoxin A in processed sultanas from Turkey

The results of surveillance for ochratoxin A (OTA) in 1885 samples of sultanas taken during five crop years between 1999 and 2003 are reported. The analytical method was based on extraction with methanol + sodium bicarbonate and clean-up by immunoaffinity column chromatography followed by high-performance liquid chromatography with fluorescence detection. The limit of detection for OTA was 0.3 µg kg^-1. The results show that 9.3% of the samples contained no detectable levels of OTA, whereas 0.6% had concentrations exceeding 10 µg kg^-1; the remaining 90.3% had levels within the range 0.3-10 µg kg^-1. The overall mean OTA concentration in the total number of 1885 samples taken was 1.36 ± 2.91 µg kg^-1; the overall median was calculated as 0.90 µg kg^-1.     

Soviet vacuum metallurgy

During a visit to the USSR, an intensive study by the author revealed the broad scope of Soviet research in and development of vacuum metallurgical techniques.     

Determination of immediate roof at mines of the Kutahya-Omerler coal basin, Turkey

The estimation of the relations between excavation height, longwall advance rate, convergence around a longwall in the roof-soil direction, and load distribution on support is reported, that are of specific importance for selecting support type. The principal attention is focused on determination of the immediate roof height that depends on the mobility characteristics of overlying rocks and governs mainly the stoping convergence and load intensity on the support. Numerical modeling, laboratory and field experiments are undertaken in this study, which included evaluation of composition and physicomechanical properties of rocks, assessment of stress-strain state of rock mass and of the immediate roof height, measurements of disintegration and bulking factor of overlying rocks, convergence of stoping floor and roof, and loads on hydraulic legs of supports. The study parameters obtained by different methods for the Omerler Mine are presented. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 67–80, March–April, 2006.