The Technique of Single-Component Synchronous Grouting Allocation to Resist Floating in High Pressure Water-Rich Formation

In high pressure water-rich formation, the grout is diluted by groundwater, could not develop early strength as quickly as possible for the dissipation of cementing material, failed to fill effectively the space between the segment and formation, which is unhelpful to control segment floating. In this study, by adding a variety of organic and inorganic materials to reduce grout setting time, meanwhile ensure the low loss of fluidity, high anti-aqueous dispersions, low shrinkage, finally, to achieved better effect than Two-component grouting.

The Symmetry of GPS Orbit Ascending Nodes

Theoretical nominal GPS orbits are parallel and share six ascending nodes of orbital planes. However, due to the perturbations and continuous modernization of the system, this state does not occur. The configuration of satellite orbits is continuously monitored by the control segment and presented regularly in the form of a GPS almanac. Almanacs, however, do not contain a parameter defining the convergence of orbits. This work presents a novel method of assessment of the configuration of orbit ascending nodes compared with the nominal constellation state. The method is a tool for space segment monitoring and detection of anomalies. The source data were 7035 System Effectiveness Model almanacs published from the 847th to 2123rd GPS weeks (March 1996–September 2020). The algorithm uses the procedure of assigning satellites to orbital planes and both the robust estimation and the least-squares methods to determine the estimates of the angular separation of orbit ascending nodes. A long-term analysis of the symmetry and trend of changes in the position of the ascending nodes was conducted. The study showed the occurrence of significant anomalies. The research provides information on the trend of satellite orbit separations and deviations of orbital planes from the initial hexagonal GPS symmetry.

Priority Based Time-Division Multiple Access Algorithm for Medium Range Data Communication in Very High Frequency Radios

In this paper, A novel and efficient time division multiple access (TDMA) algorithm for military last-mile data communication is designed. A dynamic slot assignment method coupled with an out-of-band control mechanism is used for the proposed design. In out-of-band, there is a well-defined control segment along with the data segment. So, if a new node specifically a high priority node arrives at the network, it can signal its arrival by a response in the designated mini-slots and can also check the slot in the network, if no idle slots are available. Assigning priority to the nodes would also ensure the delivery of the important messages first. Query messages are broadcasted by the Central node in order to detect new nodes. This reduces nodes working time and also ensures that the nodes don’t interrupt any existing communication. Furthermore, we describe the feasibility and the reliability of this algorithm for military’s last-mile (end user) data communication.

The Role of the Leucocytosis Parameter in the Occurrence of Pregnancy Complications in Women with Periodontal Disease

For the present study, a total number of 109 pregnant patients in the second trimester of pregnancy were selected from the case studies of the Clinic of Obstetrics and Gynaecology of the Municipal Clinical Hospital Filantropia in Craiova. Among these, 56 patients had gingivitis, 26 had mild, moderate, or severe periodontitis, and 27 patients were used as a control segment. Each patient had her leukocytes values tested and they had their oral cavity examined. Leukocyte neutrophils are the primary cells of the body�s defence system as well as primary protective cells against periodontal disease. Based on the study, we can say that there is a significant difference between the average number of leukocytes found in the four groups, because the result of the ANOVA test was below the threshold p [0.001. By analyzing the involvement of the leucocytosis parameter in the occurrence or presence of pregnancy complications, we found it present in periodontal disease pregnant women who had complications, namely: premature birth, preeclampsia, or intrauterine growth restriction.

The Role of the Leucocytosis Parameter in the Occurrence of Pregnancy Complications in Women with Periodontal Disease

For the present study, a total number of 109 pregnant patients in the second trimester of pregnancy were selected from the case studies of the Clinic of Obstetrics and Gynaecology of the Municipal Clinical Hospital Filantropia in Craiova. Among these, 56 patients had gingivitis, 26 had mild, moderate, or severe periodontitis, and 27 patients were used as a control segment. Each patient had her leukocytes values tested and they had their oral cavity examined. Leukocyte neutrophils are the primary cells of the body’s defence system as well as primary protective cells against periodontal disease. Based on the study, we can say that there is a significant difference between the average number of leukocytes found in the four groups, because the result of the ANOVA test was below the threshold p <0.001. By analyzing the involvement of the leucocytosis parameter in the occurrence or presence of pregnancy complications, we found it present in periodontal disease pregnant women who had complications, namely: premature birth, preeclampsia, or intrauterine growth restriction. Keywords: periodontitis, leukocytes, pregnant, preterm birth

Modernization of time scale control unit for «Glonass-K» spacecrafts

Navigation spacecraft’s atomic clocks suffer from sudden small frequency jumps. These jumps lead to a decrease of user’s positioning accuracy and should be considered. Traditional method to detect these frequency jumps with the use of ground control segment does not ensure early user alert of increasing range error. A perspective way to improve global navigation satellite system’s signal integrity is the use of satellite on-board autonomous system for continuous control of board synchronization equipment time scale. This paper describes a novel diagram of frequency comparator – the main element of such system. The main difference of proposed solution is an application of time-to-digital converter for estimation of time error which allows to decrease mass, dimensions and power consumption. The paper deals with the particularities of direct frequency comparator implementation for on-board equipment of space vehicle and describes structure of implemented breadboard model.