Assessment of high strength and light weight aggregate concrete properties using ultrasonic pulse velocity technique
In this study, the ultrasonic pulse velocity technique as a non-destructive testing of concrete was used to assess the effect of some criteria on high strength and light weight aggregate concrete. The study included several concrete mix design with ages of 7, 28 and 90 days. The effect of age, cement content, water ratio and slump on two concrete types was studied and discussed. The use of ultrasonic pulse velocity technique to assessconcrete strength and quality was a good choice for effects determination. 
 
   
 
 Key words: Non destructive testing (NDT), ultrasonic pulse velocity (UPV), compressive strength, regression analysis.
Research into the correlation between concrete strength and UPV values
In this study, a relationship is determined between concrete strength and UPV (Ultrasonic Pulse Velocity) by using the data obtained from many cores taken from different reinforced concrete structures having different ages and unknown ratios of concrete mixtures. Also, a correlation is set up so as to find concrete strength-UPV relationship between the data obtained from the earlier laboratory researches on the concrete specimens with various mixture ratios. By processing correlation between these data sets, the best fit formula for the concrete strength-UPV relationship is obtained. Therefore, with this study, a general concrete strength-UPV formula is developed without taking the concrete mixture ratios into consideration. This new formula enables to find concrete strengths practically in existing concrete structures that their records of concrete mixture ratios are not available or not present. It can also be used in conditions that the number of the st ructures is too many and the time of the examination of them is too restricted.
Magnetic properties of Lu2Fe17 crystals
Abstract We present the results of crystal structure and magnetization studies of three single crystals grown from melts of different nominal compositions in the vicinity of the Lu2Fe17 stoichiometry. The ferromagnetic state of the crystals is strongly dependent on the real sample composition and the local atomic ordering. A drastic difference is observed in the behaviour of the ferro–antiferromagnetic transition, even in crystals for which almost identical composition and crystal parameters were determined by microprobe and X-ray analysis.