ALBERT

Description: A simultaneous two way clock synchronization experiment between three Earth stations, was performed and improvements over the technique earlier attempted in which transmit/receive roles of the two stations were alternated at regular intervals, were studied. Time signals via two modes high frequency and satellite were critically monitored and analyzed. This time format was modified to include the additional information about time of the day in year, month, day, hour, minute and second as well as DUT1 in BCD code and was disseminated via the satellite. These signals were decoded, displayed and studied. Some preliminary work on time transfer via TV using direct satellite broadcast, was also conducted.

Description: A recent clock synchronization experiment between the National Physical Laboratory (NPL), New Delhi and Space Applications Center (SAC), Ahemedabad, in India via geostationary satellite symphonie 2, stationed at 49 E longitude, is reported. A two-way transmission using a microwave transponder considered to provide the greatest precision in synchronization of two remote clocks is described.

Description: An approximate elastic analysis is made of the working load responses of single piles embedded in a soil of linearly increasing modulus with depth. The formulation employs, within a boundary element algorithm, the fundamental solution for point loads acting at the interface of a two-layer elastic half-space. This analysis is of comparable generality and computational efficiency to earlier elastic solutions of the corresponding homogeneous problem and has distinct advantages in practical applications over the simpler homogeneous soil model, namely, improved predictions of the response due to lateral loads and the rationalization of the selection of soil moduli. These advantages are highlighted in the comparisons made between reported observations on the behaviour of single piles from model and full scale field tests and those predicted by the theory. Comprehensive plots of the results of a parametric study are presented in non-dimensional form. Une analyse élastique approximative est faite à partir des réponses de pieux isolés charges et enfoncés dans un sol ayant un module croissant linéairement avec la profondeur. L'étude emploie, à l'intérieur d'un algorithme d'élément limite, la solution fondamentale pour des charges ponctuelles agissant sur la frontière d'un espace semi-infini élastique à deux couches. Cette analyse est d'une généralité et d'une possibilité de calcul comparables à celles des solutions élastiques precédentes du problème homogène correspondant et a des avantages distincts dans les applications pratiques sur le modèle de sol homogène plus simple, à savoir des prévisions améliorées de la réponse à des charges latérales et la rationalisation de la sélection des modules de sol. Ces avantages sont mis en lumière dans les comparaisons faites entre des observations rapportées sur le comportement de pieux isolés à partir d'essais de chantier sur modèle et en vraie grandeur, et les prévisions effectuées à l'aide de la théorie. Des tracés compréhensibles des résultats d'une étude paramétrique sont présentés dans une forme non-dimensionnelle.