Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System

A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m adaptive optics imaging in the $JHK$ near-infrared (NIR) in 2014 by Boyajian et al. (2016). The closeness of the star to KIC 8462852 suggested the two could constitute a binary, which might have implications for the cause of the brightness dips seen by {\it Kepler} (Boyajian et al. (2016) and in ground-based optical studies Boyajian et al. (2018). Here, NIR imaging in 2017 using the Mimir instrument resolved the pair and enabled measuring their separation. The faint star had moved $67 \pm 7$ milliarcsec (mas) relative to KIC 8462852 since 2014. The relative proper motion of the faint star is $23.9 \pm 2.6$ mas yr$^{-1}$, for a tangential velocity of $45 \pm 5$ km s$^{-1}$ if it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750 AU current projected separation is $1.5$ km s$^{-1}$, hence the star pair cannot be bound.Comment: 10 pages, 2 figure

Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity

Large-grain Nb has become a viable alternative to fine-grain Nb for the fabrication of superconducting radio-frequency cavities. In this contribution we report the results from a heat treatment study of a large-grain 1.5 GHz single-cell cavity made of "medium purity" Nb. The baseline surface preparation prior to heat treatment consisted of standard buffered chemical polishing. The heat treatment in the range 800 - 1400 C was done in a newly designed vacuum induction furnace. Q0 values of the order of 2x1010 at 2.0 K and peak surface magnetic field (Bp) of 90 mT were achieved reproducibly. A Q0-value of (5+-1)1010 at 2.0 K and Bp = 90 mT was obtained after heat treatment at 1400 C. This is the highest value ever reported at this temperature, frequency and field. Samples heat treated with the cavity at 1400 C were analyzed by secondary ion mass spectrometry, secondary electron microscopy, energy dispersive X-ray, point contact tunneling and X-ray diffraction and revealed a complex surface composition which includes titanium oxide, increased carbon and nitrogen content but reduced hydrogen concentration compared to a non heat-treated sample

Effectiveness of Shading Air-Cooled Condensers of Air-Conditioning Systems

In air-conditioning (A/C) systems with air-cooled condensers, the condensing unit has to be kept in the open for easy access to outdoor air in order to efficiently dissipate heat. During daytime, the solar radiation falling on the surfaces of the condenser and the high ambient temperatures can be detrimental for the energy performance. The effectiveness of shading the condensing unit to mitigate this adverse impact is investigated in this paper. A limiting analysis compares the performance of several A/C systems with ideal shade to those with ideal solar heat gain. The comparison is based on a theoretical model and data from equipment catalogs. The theoretical increase in the coefficient of performance (COP) due to shading is found to be within 2.5%. Furthermore, this small improvement in ideal efficiency decreases at higher ambient temperatures, when enhancements to efficiency are more needed. The actual efficiency improvement due to shading is not expected to exceed 1%, and the daily energy savings will be lower

Endophytic Mycoflora of Indian Medicinal Plant, Terminalia arjuna and their Biological Activities

Studies were undertaken to isolate, identify and evaluate the biological activities of endophytic mycoflora of Indian medicinal plant, Terminalia arjuna. A total of 20 isolates of endophytic fungi were obtained from the leaves, twigs and bark tissues of the Terminalia arjuna. Out of 20, six isolates exhibited promising antibacterial, antifungal and anti-inflammatory activities when cultivated at shake flask level. The selected isolates were identified on the basis of morphology and ITS gene sequencing. Three isolates, designated as TA BA 1, TA L1 and TA L2 were identified as Aspergillus flavus whereas; the remaining three endophytic fungi were identified as Diaporthe arengae (TA TW2), Alternaria Sp. (TA TW1) and Lasiodiplodia theobromae (TA BA2). Aspergillus flavus was found as the predominant endophyte in leaves and bark tissues of the plant. The crude extract of the test isolates showed considerable antimicrobial activity against common human bacterial (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella abony and Bacillus subtilis) and fungal (Candida albicans, Aspergillus niger and Penicilium sp.) pathogens. The extract of Diaporthe arengae (TA TW2) significantly reduced the concentration of DPPH free radical as percent DPPH scavenging activity was found to be highest (69.56%) in comparison with other isolates. The % inhibition of hemolysis of RBCs was found to be highest (82.85%) with Diaporthe arengae (TA TW2) in comparison (83.26%) with standard drug (Ibuprofen). Among all, the extract of the Diaporthe arengae (TA TW2) showed excellent biological activities and hence was subjected to further characterization. The phytochemical investigation of the extract revealed the presence of terpenoids as the major phytoconstituents which was supported by TLC and UV spectroscopic studies. The results indicate that the isolated endophytes could be the valuable source of these bioactive molecules with diverse biological activities. The bioactivities may be attributed to the terpenoids present in the endophytic extract

The Influence of Air-Conditioning Efficiency in the Peak Load Demand for Kuwait

A model co-relating the peak load demand of a utility with the allowable power rating (PR) of air-conditioning (AC) systems has been developed in this paper through a well defined methodology. The model is capable to predict the extent of allowable increase in the capital cost of the AC system for an improvement in PR from its base case as well. Furthermore, effectiveness of better PR of AC system for peak load management has been analyzed for Kuwait as a case study. It is found that up to 5,752 MW in reduction in peak load demand and savings of KD 2,301 million in capital expenditures are possible for the years between 2001 and 2025 if the PR of AC systems are improved to 1.2 kW/RT from its present level of 2.0 kW/RT. Also, it is estimated that extent of increase in capital cost of AC system by 106 % is justified for reducing the expenditure for new power plants. The paper will be useful for the energy planner and policy makers in the countries of Arabian Peninsula with huge demand for air-conditioning

Smart Operations of Air-Conditioning and Lighting Systems in a Government Buildings for Peak Power Reduction

This paper presents the achievements of implementing smart operations strategies for air-conditioning (A/C) and lighting systems in Justice Palace Complex (JPC), Kuwait during the summer 2007. The peak load of this building was 3700 kW. The achievements are summarized as direct savings between 13:00 and 22:00 h by closing supply and return air fans of 52 air-handling units with a connected load 400 kW, and an additional saving of 550 kW during the same period by optimizing the cooling production and distribution. Also an all time saving of 22 kW by de-lamping, and additional saving of 27 kW through TDC of lighting were achieved. In conclusion project achieved an overall reduction in power demand of around 20% between 13:00 to 17:00 h and reduction ranging from 7% to 15% between 17:00 to 20:00 h

Comparative Study Between Air-Cooled and Water-Cooled Condensers of the Air-Conditioning Systems

The weather in Kuwait is very dry where the dry-bulb temperature exceeds the wet-bulb temperature more than 20oC in most of the summer months. Thus, the air-conditioning (A/C) system with the water-cooled (WC) condensers is expected to perform more efficiently than with the air-cooled (AC) condensers. This fact was behind the idea of a field study conducted in one of the major hospital in Kuwait during a summer season to investigate the performance of WC and AC systems in terms of peak power and energy consumptions. The cooling capacities for WC and AC systems were 373 and 278 tons-of- refrigeration, respectively. It was found that for the same cooling production, the peak power demand and the daily energy consumption of the WC system were 45 and 32% less than that of the AC system, respectively. The maximum reduction in the power demand coincided with the peak power demand period of the utilities i.e. between 14:00 and 17:00 hr, thereby offering a maximum advantage of peak power saving

Cooling Tower Operation in the Hot and Humid Climates of Arid Zones

Air-conditioning (A/C) in Kuwait is a necessity for comfortable living as the summer is extremely hot. Dry weather for most of the summer months reflects the effectiveness of using water-cooled (WC) systems. Cooling towers (C/Ts) at a Ministry building in Kuwait were monitored and evaluated under actual operating conditions. Experimental results, weather data, and theoretical studies are used to demonstrate the effect of current operational practices on electrical power and water consumption. The performance of C/Ts has been evaluated under different operating conditions with different airflows through the C/T. It has been established that the use of a large flow of air, though helpful in providing cooler water temperatures, and thereby, improving the performance of the A/C system, increases the fan power and water consumption. The latter is of special concern to Kuwait and other countries in the region where the soft water is produced through seawater desalination