NGC1052 - A study of the pc-scale twin jet

We present results of a VLBA multi-frequency study of the pc-scale twin jet in NGC1052. We observed this object at epoch 1998.99 with the VLBA at 5, 8.4, 22 and 43 GHz both in total and linearly polarized intensity. The spectral analysis confirms the necessity of a free-free absorbing medium, obscuring the innermost part of both jets. At 5 GHz we found a compact linearly polarized emission region at the base of the eastern jet with a degree of polarization of 1.5%. At higher frequencies there is no evidence for polarization in our data. A core shift analysis constrains the position of the central engine to ~0.03 pc. The shift rates of the apparent core position with frequency confirm the strong influence of free-free absorption in conjunction with steep pressure gradients at the bases of both jets.Comment: Proceedings of the conference "SRT: the impact of large antennas on Radio Astronomy and Space Science", Cagliari, Italy, 7-10 November 2001, in press; 6 pages, 5 figures, needs srt_style.st

When and why do domestic respondents oppose AD petitions?

In the evolving global trade environment where traditional forms of protection have been falling as a result of multilateral trade agreements such as the Uruguay Round and NAFTA, antidumping policy has quickly become the protective policy instrument of choice. In the United States, there is evidence that domestic non-filing firms do not always support dumping investigations. In the absence of information asymmetries, domestic fims have an unambiguous incentive to support petitions filed by other domestic producers. We argue that in cases where the respondent is not a significant importer or exporter, the most plausible explanation is that non-support acts as a costly signal of private information

Liquid oxygen/liquid hydrogen boost/vane pump for the advanced orbit transfer vehicles auxiliary propulsion system

A rotating, positive displacement vane pump with an integral boost stage was designed to pump saturated liquid oxygen and liquid hydrogen for auxiliary propulsion system of orbit transfer vehicle. This unit is designed to ingest 10% vapor by volume, contamination free liquid oxygen and liquid hydrogen. The final pump configuration and the predicted performance are included

Power allocation for multiband coded OFDM systems with limited feedback

In this paper, we study the power allocation for multiband coded OFDM systems. With limited feedback, we propose an effective power allocation method across OFDM bands to maximize the throughput and achieve the quality of service target. To facilitate the proposed method, two optimization algorithms based on greedy and dynamic programming principles are discussed. The trade-off between performance and complexity is provided. Simulation results show that the proposed power allocation mechanism allows a signal to noise ratio gain of 2 dB at a goodput of 2.5 bit per second per Hz over the multiband OFDM systems with equal power allocation

Digital twin for 5G and beyond

Although many countries have started the initial phase of rolling out 5G, it is still in its infancy with researchers from both academia and industry facing the challenges of developing to its full potential. With the support of Artificial Intelligence, development of digital transformation through the notion of a ‘Digital Twin’ has been taking off in many industries such as smart manufacturing, oil & gas, constructions, bio-engineering, and automotive. However, Digital Twins remain relatively new for 5G networks, despite the obvious potential in helping develop and deploy the complex 5G environment. This paper looks into these topics and discusses how Digital Twin could be a powerful tool to fulfil the potentials of 5G networks and beyond

Serdexmethylphenidate/Dexmethylphenidate – A Promising Treatment Option for Childhood Attention Deficit Hyperactivity Disorder (ADHD)

To review the phase 2 and phase 3 clinical trials of Serdexmethylphenidate and dexmethylphenidate (SDX/d-MPH) in the treatment of Attention Deficit/Hyperactivity disorder (ADHD) in children

Assessment of Tourists Flow and Revenue Generation in Kainji Lake National Park, Nigeria

This study was carried out to assess tourists’ flow and revenue generation from 1999 to 2009 in Kainji Lake National Park (KLNP), north central Nigeria. Data were collected from both primary and secondary sources. Primary data collection was carried out through the use of structured questionnaire and oral interviews. Secondary data were collected from the park records and reports. Simple random sampling technique with 50% sampling intensity was used to draw representative samples from the staff population. In all, a total of 158 respondents were sampled. Data collected were subjected to descriptive and inferential statistics. Results showed that KLNP is well visited, with a total number of 39,138 tourists and ₦40,135,223.85 revenue generated within the period under review. Fluctuation in tourists flow was discernible, with the highest number of tourists (5,593) recorded in 2005, while the lowest (1,143) was in 2003. About 97.5% of the visitors were local tourists. The highest revenue generation (₦ 5,445,198.96) was in the year 2009, while the lowest (₦ 1,705,524.00) was in 1999. There was no significant correlation between revenue generation from ecotourism and tourists flow across the years (N = 11; Pearson Correlation = 0.526; P = 0.096). Proceeds from ecotourism contribute to conservation activities and park management, especially in times of inadequate funding from the federal government. The authorities of KLNP would have to explore the full range of income generation opportunities in ecotourism. There is need to improve upon the state of facilities in the park and orient these towards meeting visitors’ needs and wants for improved revenue generation.Key words: Kainji Lake National Park, Ecotourism, Tourist flow, Revenue generatio