Photoelectric observations of Krzeminski's star, the companion of Cen X-3

Centaurus X-3 was the first discovered X-ray source whose intensity is pulsed and eclipsed. Though the X-ray properties of the Cen X-3 system have been intensively studied, the optical properties remained unstudied until Krzeminski's identification of the optical counterpart of Cen X-3. Observations of the X-ray eclipse duration, pulsation frequency variation, and pulse arrival time variation have been used to place limits on the nature of the system and to predict the nature of the optical companion and X-ray sources. An observational determination is presented of the several system parameters based on a preliminary interpretation of the light curve of Krzeminski's star

A spectroscopic study of LMC X-4

The orbital radial velocity semi-amplitude of the binary star system LMC X-4 primary was determined to be 37.9 + or - 2.4 km/s from measurements of the hydrogen absorption lines. The semi-amplitude of the He I and He II absorption lines are consistent with this, namely 44.9 + or - 5.0 and 37.3 + or - 5.3 km/s. The phase and shape of the radial velocity curves of the three ions are consistent with a circular orbit and an ephemeris based upon X-ray measurements of the neutron star, with the exception that the He II absorption line radial velocity curve has detectable shape distortion. Measurements of the He II LAMBOA 4686 emission line velocity are consistent with a phase shifted sine wave of semi-amplitude 535 km/s, a square wave of semi-amplitude 407 km/s, or high order harmonic fits. The spectral type was found to be 08.5 IV-V during X-ray eclipse. Variations to types as early as 07 occur, but not as a function or orbital phase. Absorption line peculiarities were noted on 6 of 58 spectra

Capacity Assessment Of The System Of Gas Pipelines, Receiving And Transporting Gas Of Inland Production

Today, the majority of gas fields in Ukraine are in the final stages of development, which is characterized by a significant decrease in wellhead pressure, as well as an increased gas-water factor. As is well known, when lowering wellhead pressure arises the problem of ensuring the design capacity of the gas production system as a whole.The main function of the gas pipeline system of the gas producing company of Ukraine is collection of gas from deposits and transport natural gas to consumers.Taking into account the tasks of ensuring the energy independence of Ukraine, as well as the program to build up gas of its own production, the question of assessing the capacity of the gas pipeline system remains relevant, performing the function of collection and transportation.As part of the research, the current state of the gas collection and transportation system is analyzed. The workload of gas pipeline sections in the chain from the wellhead to the consumer is investigated. As a result, it is established that the initial sections of the gas production system are fully loaded. Areas that can be recharged are identified, as a result of which it will reduce the output pressure at the wellheads and stabilize hydrocarbon production.On the basis of the conducted research, it is revealed that one of the alternative methods of increasing the capacity of the gas production system at the initial sections is to increase the equivalent diameter and length of the system by building new gas pipelines. It is also found that the periodic cleaning of pipelines in existing parts of the system prevents the decrease in capacity.It has been established that reducing the backpressure of the system is possible only in conjunction with unloading the system by changing the flow directions, creating centralized gas collection points, as well as retrofitting existing booster compressor stations.The availability of data on the load on the gas transmission system will allow the gas producing company to plan the distribution of gas to areas with available free capacity, while ensuring an increase in the production of its own gas. As a result, when the gas is distributed to areas with partial load, it will prevent excessive pressure losses in the system, as well as provide optimal system operation conditions

Evaluating the effects of mountain beaver (\u3ci\u3eAplodontia rufa\u3c/i\u3e) management on conifer stocking in western Oregon

Mountain beaver (Aplodontia rufa) is the most primitive rodent species in North America and is endemic to the Pacific Northwest, USA. Within their range, mountain beaver cause more conflict with conifer forest regeneration than any other vertebrate species. Most damage occurs as a result of clipping and browsing new seedlings, which reduces stocking density and delays stand development. An integrated approach using trapping and a registered toxicant (baiting) has been suggested as the most efficacious means to reduce seedling loss during stand initiation. We evaluated this management strategy in intensively managed conifer stands across two mountain ranges in western Oregon. Harvest units were divided equally and management (trapping and baiting) was implemented on a randomly selected half of each unit; the remaining halves served as an experimental control. We conducted damage assessments in fixed 0.04 ha circular plots at approximate 1, 6, and 12 month intervals after planting and initiation of management activities. After 12 months, we observed mountain beaver damage in 100% of control plots and 95% of treatment plots; however, there was a 79% decrease in the estimated odds of damage for plots where trapping and baiting was implemented (95% CI 43–92). Mean seedling height was 10.6 cm taller in treated plots than control plots 1 year post-planting (95% CI 4.1–17.1). Reoccupation of vacant burrows began within 1 month; within 12 months, only 5% of trapped plots remained unoccupied. Reported costs and benefits varied among harvest units, but management was less expensive ($154.09/ha) than the cost of interplanting gaps created by mountain beaver damage ($182.13/ha). Although trapping and baiting may not offer a one-time solution to damage problems, it is an effective tool in reducing damage, saving management costs, and meeting compliance with forest regulations and certification requirements

NASA Facts: Edison Demonstration of Spacecraft Networks (EDSN) Mission

NASA's Edison Demonstration of Smallsat Networks (EDSN) mission will launch and deploy a swarm of 8 cubesats into a loose formation approximately 500 km above Earth. EDSN will develop technology to send multiple, advanced, yet affordable nanosatellites into space with cross-link communications to enable a wide array of scientific, commercial, and academic research. Other goals of the mission include lowering the cost and shortening the development time for future small spacecraft

Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30)

In this study we use recent image, spectral and topographic data to map the geology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-7]. The overall objective of this research is to constrain the geologic evolution of LQ-30 (60 -90 S, 0 - 180 ) with specific emphasis on evaluation of a) the regional effects of impact basin formation, and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Determining the geologic history of LQ-30 and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of potential resources (e.g., H, Fe, Th) and their relationships with surface materials

Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schroedinger Basin

In this study we use recent images and topographic data to map the geology and geomorphology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-4] in accordance with the Lunar Geologic Mapping Program. Mapping of LQ-30 began during Mest's postdoctoral appointment and has continued under the PG&G Program, from which funding became available in February 2009. Preliminary map-ping and analyses have been done using base materials compiled by Mest, but properly mosaicked and spatially registered base materials are being compiled by the USGS and should be received by the end of June 2009. The overall objective of this research is to constrain the geologic evolution of the lunar South Pole (LQ-30: 60deg -90deg S, 0deg - +/-180deg ) with specific emphasis on evaluation of a) the regional effects of basin formation on the structure and composition of the crust and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Constraining the geologic history of the lunar South Pole and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the vertical and lateral structure of the lunar regolith and crust, assessing the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of resources (e.g., H, Fe, Th) and their relationships with surface materials

Yield and quality of milk and udder health in Martina Franca ass: effects of daily interval and time of machine milking

Twenty asses of Martina Franca breed, machine milked twice a day, were used to assess the influence of milking interval (3-h, 5-h, and 8-h; N=5) and time (700, 1200 and 1900) on milk yield and udder health. Individual milk samples were taken to determine fat, protein and lactose con- tent. Sensory analysis profile was also assessed. Milk's total bacterial count (TBC), somatic cell con- tent (SCC) and udder's skin temperature were considered to assess udder health. Milk yield increases by 28.4% (P<0.01) with a milking interval from 3-h to 8-h and is higher (P<0.01) at morning milking. The maximum milk yield per milking corresponds to 700 milking (1416.9 mL) thus indicating a circa- dian rhythm in milk secretion processes. Milking intervals of 5 and 8 hours cause a decrease (P<0.01) in milk fat and lactose content. The 8-h interval leads to an increase (P<0.01) in SCC but without any significance for the health udder. No alterations about CBT, clinical evaluation and temperature of ud- der were observed. Milk organoleptic characteristics were better in the 3-h interval milking

A High-power Electric Propulsion Test Platform in Space

This paper will describe the results of the preliminary phase of a NASA design study for a facility to test high-power electric propulsion systems in space. The results of this design study are intended to provide a firm foundation for subsequent detailed design and development activities leading to the deployment of a valuable space facility. The NASA Exploration Systems Mission Directorate is sponsoring this design project. A team from the NASA Johnson Space Center, Glenn Research Center, the Marshall Space Flight Center and the International Space Station Program Office is conducting the project. The test facility is intended for a broad range of users including government, industry and universities. International participation is encouraged. The objectives for human and robotic exploration of space can be accomplished affordably, safely and effectively with high-power electric propulsion systems. But, as thruster power levels rise to the hundreds of kilowatts and up to megawatts, their testing will pose stringent and expensive demands on existing Earth-based vacuum facilities. These considerations and the human access to near-Earth space provided by the International Space Station (ISS) have led to a renewed interest in space testing. The ISS could provide an excellent platform for a space-based test facility with the continuous vacuum conditions of the natural space environment and no chamber walls to modify the open boundary conditions of the propulsion system exhaust. The test platform could take advantage of the continuous vacuum conditions of the natural space environment. Space testing would provide open boundary conditions without walls, micro-gravity and a realistic thermal environment. Testing on the ISS would allow for direct observation of the test unit, exhaust plume and space-plasma interactions. When necessary, intervention by on-board personnel and post-test inspection would be possible. The ISS can provide electrical power, a location for diagnostic instruments, data handling and thermal control. The platform will be designed to accommodate the side-by-side testing of multiple types of electric thrusters. It is intended to be a permanent facility in which different thrusters can be tested over time. ISS crews can provide maintenance for the platform and change out thruster test units as needed. The primary objective of this platform is to provide a test facility for electric propulsion devices of interest for future exploration missions. These thrusters are expected to operate in the range of hundreds of kilowatts and above. However, a platform with this capability could also accommodate testing of thrusters that require much lower power levels. Testing at the higher power levels would be accomplished by using power fiom storage devices on the platform, which would be gradually recharged by the ISS power generation system. This paper will summarize the results of the preliminary phase of the study with an explanation of the user requirements and the initial conceptual design. The concept for test operations will also be described. The NASA project team is defining the requirements but they will also reflect the inputs of the broader electric propulsion community including those at universities, commercial enterprises and other government laboratories. As a facility on the International Space Station, the design requirements are also intended to encompass the needs of international users. Testing of electric propulsion systems on the space station will help advance the development of systems needed for exploration and could also serve the needs of other customers. Propulsion systems being developed for commercial and military applications could be tested and certification testing of mature thrusters could be accomplished in the space environment