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LABORATORY DETERMINATION OF ELECTRIC PROPERTIES OF ORNAMENTAL STONES IN GEORADAR HIGH FREQUENCY BAND

A new measurement system of dielectric permittivity and loss tangent of ornamental stones used for example on historical buildings has been developed. Complex permittivity has been measured in the frequency range 1.1 - 1.7 GHz on samples chosen between marbles, sandstones and limestones. The values of dielectric parameters were measured experimentally by placing the sample in a resonant cavity obtained from a waveguide. The research has been developed to define a laboratory testing method in order to improve GPR interpretation by creating a data base of electromagnetic properties of the analysed material

The diagnosis of benign uterine pathology using transvaginal endohysterosonography

Twenty-nine women believed to be affected with benign uterine pathologies underwent transvaginal hysterosonography insertion of a physiological solution into the cervical cavity by means of a catheter positioned in the cervical canal. This new technique, due to the acoustic window created by the fluid, made it possible to find: one cervical polyp, six endometrial polyps, one endometrial synechia, five submucosa myomas and one uterine malformation, the presence of which, with traditional ultrasonography can only be suspected. The subsequent hysteroscopic check-up confirmed the high diagnostic reliability of hysterosonography which is also easy to carry out, safe and costs little

[Fetal choroid plexus cysts: a real dilemma!]

The clinical significance of the fetal choroid plexus cysts, observed by prenatal sonographic examination, is now a days still discussed. A consequence of this situation is the discordance of opinions about the question of whether karyotype analysis is always necessary to evaluate chromosomal anomalies sometimes correlated, especially in the presence of (as some authors have reported) large (> 1 cm), bilateral, persistent cysts and of other structural abnormalities. We have effected a prospective study to estimate the incidence of fetal choroid plexus cysts and to establish the obstetrical behaviour to be adapted in these cases. During 834 routine ultrasonographic examinations at 18-21 weeks' gestational age, we have evaluated the presence of fetal choroid plexus cysts in 9 fetuses, with an incidence of 1.07%. Three of these cysts were larger than 1 cm, three were bilateral. Karyotype analysis, effected in all cases, diagnosed a case of Trisomy 18 in a fetus who ultrasonographically showed, in addition to a unilateral cyst of 1.2 cm, also a diaphragmatic hernia. Careful ultrasound follow-up revealed that all the cysts disappeared spontaneously, but two of them (whose dimensions were larger than 1 cm) were still visible at 24 weeks' gestation and probably this age will be too advanced to begin a chromosome analysis. In conclusion, we think that the presence of fetal choroid plexus cysts always imposes a careful ultrasonographic evaluation of fetal morphology and, since there is always the risk that other small fetal anomalies (evocative of abnormal fetal karyotypes) wight not be noted, we believe that it is better, in any case, to recommend to the patient a prenatal cytogenetical analysis

Laboratory determination of electric properties of ornamental stones in georadar high frequency band.

A new measurement system of dielectric permittivity and loss tangent of ornamental stones used for example on historical buildings has been developed. Complex permittivity has been measured in the frequency range 1.1 – 1.7 GHz on samples chosen between marbles, sandstones and limestones. The values of dielectric parameters were measured experimentally by placing the sample in a resonant cavity obtained from a waveguide. The research has been developed to define a laboratory testing method in order to improve GPR interpretation by creating a data base of electromagnetic properties of the analysed materials

LABORATORY DETERMINATION OF ELECTRIC PROPERTIES OF ORNAMENTAL STONES IN GEORADAR HIGH FREQUENCY BAND

A new measurement system of dielectric permittivity and loss tangent of ornamental stones used for example on historical buildings has been developed. Complex permittivity has been measured in the frequency range 1.1 – 1.7 GHz on samples chosen between marbles, sandstones and limestones. The values of dielectric parameters were measured experimentally by placing the sample in a resonant cavity obtained from a waveguide. The research has been developed to define a laboratory testing method in order to improve GPR interpretation by creating a data base of electromagnetic properties of the analysed materials