Disturbance of the Electric Field in the Ionosphere by Sea Storms and Typhoons

The results of detecting quasi-stationary electric fields onboard the Kosmos-1809 satellite and observing sea storms and typhoons are analyzed jointly. We have detected an amplification of the electric field in the low-latitude ionosphere that is related to the preparatory stage and development of tropical storms and typhoons. In this case, the electric field strength can reach 20 mV/m, an anomalously high value for the low-latitude and near-equatorial ionosphere. High-accuracy estimates of the electric field strength are made on the basis of a model of its origination as a result of the generation of an extraneous electric current in the disturbed region of the lower atmosphere and the impact of these currents on the global atmosphere–ionosphere system of currents.     

Prevention of muscle fibers atrophy during gravitational unloading: The effect of l-arginine administration

Gravitational unloading results in pronounced atrophy of m.soleus. Probably, the output of NO is controlled by the muscle activity. We hypothesized that NO may be involved in the protein metabolism and increase of its concentration in muscle can prevent atrophic changes induced by gravitational unloading. In order to test the hypothesis we applied NO donor l-arginine during gravitational unloading. 2.5-month-old male Wistar rats weighing 220–230g were divided into sedentary control group (CTR, n=7), 14-day hindlimb suspension (HS, n=7), 14 days of hindlimb suspension+l-arginine (HSL, n=7) (with a daily supplementation of 500 mg/kg wt l-arginine) and 14 days of hindlimb suspension+l-NAME (HSN, n=7) (90 mg/kg wt during 14 days). Cross sectional area (CSA) of slow twitch (ST) and fast twitch (FT) soleus muscle fibers decreased by 45% and 28% in the HS group (p<0.05) and 40% and 25% in the HSN group, as compared to the CTR group (p<0.05), respectively. CSA of ST and FT muscle fibers were 25% and 16% larger in the HSL group in comparison with the HS group (p<0.05), respectively. The atrophy of FT muscle fibers in the HSL group was completely prevented since FT fiber CSA had no significant differences from the CTR group. In HS group, the percentage of fibers revealing either gaps/disruption of the dystrophin layer of the myofiber surface membrane increased by 27% and 17%, respectively, as compared to the controls (CTR group, p<0.05). The destructions in dystrophin layer integrity and reductions of desmin content were significantly prevented in HSL group. NO concentration decreased by 60% in the HS group (as well as HSN group) and at the same time no changes were detectable in the HSL group. This fact indicates the compensation of NO content in the unloaded muscle under l-arginine administration. The levels of atrogin-1 mRNA were considerably altered in suspended animals (HS group: plus 27%, HSL group: minus 13%) as compared to the control level. Conclusion: l-arginine administration allows maintaining NO concentration in m.soleus at the level of cage control group, prevents from dystrophin layer destruction, decreases the atrogin mRNA concentration in the muscle and atrophy level under gravitational unloading.     

Equatorial M(3000)F2 estimation of F2-layer models peak heights during low solar activity

M(3000)F2 estimation of h_mF2 based on four different formulated models viz: (1) Shimazaki (1955) (2) Bradley and Dudeney (1973), (3) Dudeney (1974) and (4) Bilitza et al. (1979) at an equatorial station in West Africa during low solar activity period (1995) are used to validate its conformity with observed and International Reference Ionosphere (IRI) model. Local time analyses of data from fifteen (15) selected days during the January and July solstices and April and October equinoxes are used. The results obtained show that the M(3000)F2 estimation of h_mF2 from the ionosonde-measured values using the Ionospheric Prediction Service (IPS-42) sounder compared to the observed values which were deduced using an algorithm from scaled virtual heights of quiet day ionograms are highly correlated with Bilitza model. International Reference Ionosphere (IRI 2007) model for the equatorial region also agrees with the formulation developed by Bilitza et al. (1979) for the four different seasons of the year. h_mF2 is highest (425 km) in summer (June solstice) season and lowest (386 km) in autumn (September equinox) season with daytimes peaks occurring at 1100–1200 LT during the solstices and at 1000 LT during the equinoxes respectively. Also, the post-sunset peaks are highest (362 km) at the spring (March equinox) and lowest (308 km) at the summer (June solstice) both occurring between 1800 and 2000 LT.     

Determination of crustal deformations based on GPS observing-session duration in Marmara region,Turkey

This paper reports on the estimation of changes of a GPS-based crustal deformation field as function of the observing session duration. This investigation was carried out on the Marmara Continuous GPS Network (Marmara region) by using GPS data collected on a set of 10 stations during the period 2002.50–2005.47 The GPS observations were processed in the ITRF 2005 reference frame using Bernese v5.0 software.     

声发射技术在复合材料结构无损检测中的应用

简述了复合材料AE技术的发展概况、AE特性和破坏类型;讨论了几种不同破坏机理的AE判据;着重介绍了AE技术在复合材料压力容器无损检测中的应用及压力容器水压试验时应注意的某些问题。     

固体火箭发动机无损检测和无损评价技术的现状

无损检测和评价技术在固体火箭发动机研制中起着重要的作用,该文介绍了国外固体发动机无损检测和评价技术的新进展,论述了无损检测和评价技术是保证固体发动机质量和可靠性的关键技术之一,并预示了未来的发展趋势。     

Virtual instruments used for LPG pipeline network monitoring

The paper presents a pipeline liquefied petroleum gas network (PLPGN) monitoring system based upon the virtual instrument architecture. Starting from the introduction of development requirements and environment for the monitoring system, the paper discusses its hardware configuration and software functionalities, in detail. Practical application has demonstrated that the virtual instrument-based structure is very effective and the obtained monitoring system is highly flexible.     

Developing a visual component library for a graphical programmingplatform using object orientation

The development of virtual instruments (VIs) is bringing a great revolution to the fields of automated testing and measurement. It is accelerating the integration of measurement systems and is promoting instrument standardization, modularization and generalization. A graphical programming platform for automated testing is one of the most important applications of VI technology, and it provides users with an intuitive and friendly programming environment. The visual component library (VCL) is the key part of such graphical programming platforms. The research reported in this paper makes full use of the advantages of the object-oriented methodology to develop the visual VI components for a graphical programming platform. By setting up two base classes for all the VI components, various VIs can be efficiently developed     

Geomagnetic transmission disturbances and heavy-ion fluences observed in low Earth orbit during the solar energetic particle events of October 1989.

The large solar energetic particle (SEP) events and simultaneous large geomagnetic disturbances observed during October 1989 posed a significant, rapidly evolving space radiation hazard. Using data from the GOES-7, NOAA-10, IMP-8 and LDEF satellites, we determined the geomagnetic transmission, heavy ion fluences, mean Fe ionic charge state, and effective radiation hazard observed in low Earth orbit (LEO) for these SEPs. We modeled the geomagnetic transmission by tracing particles through the combination of the internal International Geomagnetic Reference Field (IGRF) and the Tsyganenko (1989) magnetospheric field models, extending the modeling to large geomagnetic disturbances. We used our results to assess the radiation hazard such very large SEP events would pose in the anticipated 52 degrees inclination space station orbit.