The TESS-Keck Survey. VIII. Confirmation of a Transiting Giant Planet on an Eccentric 261 Day Orbit with the Automated Planet Finder Telescope*

We report the discovery of TOI-2180 b, a 2.8 M J giant planet orbiting a slightly evolved G5 host star. This planet transited only once in Cycle 2 of the primary Transiting Exoplanet Survey Satellite (TESS) mission. Citizen scientists identified the 24 hr single-transit event shortly after the data were released, allowing a Doppler monitoring campaign with the Automated Planet Finder telescope at Lick Observatory to begin promptly. The radial velocity observations refined the orbital period of TOI-2180 b to be 260.8 ± 0.6 days, revealed an orbital eccentricity of 0.368 ± 0.007, and discovered long-term acceleration from a more distant massive companion. We conducted ground-based photometry from 14 sites spread around the globe in an attempt to detect another transit. Although we did not make a clear transit detection, the nondetections improved the precision of the orbital period. We predict that TESS will likely detect another transit of TOI-2180 b in Sector 48 of its extended mission. We use giant planet structure models to retrieve the bulk heavy-element content of TOI-2180 b. When considered alongside other giant planets with orbital periods over 100 days, we find tentative evidence that the correlation between planet mass and metal enrichment relative to stellar is dependent on orbital properties. Single-transit discoveries like TOI-2180 b highlight the exciting potential of the TESS mission to find planets with long orbital periods and low irradiation fluxes despite the selection biases associated with the transit method.

​Factors Affect to Stolon Formation and Tuberization in Potato: A Review

Potato tuber formation is a complex process that is induced by a mobile signal called tuberigen. It involves several genes such as AtBMI, St 14-3-3s, StBEL, StBELL11, StBELL29, StBMI1-1, StCDF1, StCEN, StCO, StFDL1, StFT, StGA2ox1, StGA3ox2, StMSI1, StSP6A. This article focuses on important factors such as genetic factors, low temperature, high irradiation, low nitrogen, abscisic acid, chlormequat chloride, auxin, Jasmonic acid, cytokinin and paclobutrazol that induce tuber formation while ethylene, drought, low irradiation, high-temperature that reduce or inhibit tuber initiation.

Green dielectric solids using PLA and luffa fiber modified by the medical linear accelerator

Biodegradable electronic devices are presently in command in various sectors mainly in the health care system. The present work comprehends the dielectric properties of biodegradable composites made from biodegradable polymer poly (lactic) acid (PLA) and natural fiber of luffa cylindrical (LC) fabricated using micro compounding and injection molding. LC fibers are agricultural waste, rich in cellulose.LC fibers were exposed to a 6 MeV electron beam of doses 0.5Gy, 1.0Gy, 2.0Gy, 4.0Gy, and 10.0 Gy generated from a medical linear accelerator(LINAC) in presence of air. Such low doses are normally used for the treatment of cancer patients and not for modifying polymers where doses in the range of 20-200KGy are used. The effect of such low irradiation dose on fiber and study if any significant changes taking place is the innovative aspect of the present work. The effects of irradiation dose on dielectric constant and ac conductivity were investigated at different temperatures 260C, 40oC, 60oC, and 80oC while keeping the frequency constant. The increase in dielectric constant from 57 in virgin PLA at 260C,500Hz to a maximum of 84 in the composite sample due to reinforcement of low dose irradiated LC fibers recording a 49% increase is an important result of the investigation.

Effects of gamma irradiation on structural, thermal and mechanical properties of polyamide-11/halloysite nanotubes nanocomposites

The effect of gamma irradiation on neat Polyamide-11 (PA11) and PA11 filled with 3 wt% of halloysite nanotubes (HNTs) was investigated at various doses up to 100 kGy in air and at room temperature. The irradiation test was conducted on sample films prepared by a twin-screw extruder in the first step then cast extrusion. The study showed the formation of a maximum of gel fraction up to 10 and 20 kGy for neat PA11 and PA11/HNTs, respectively. Furthermore, the results indicated the occurrence of crosslinking at low irradiation dose, whereas chain scission took place at higher ones. Additionally, the results revealed that the presence of HNTs limits the impacts of gamma irradiation through a barrier effect. An optimum irradiation dose was found for thermal and mechanical properties, corresponding to the dose for maximum gel formation. Moreover, experimental design was implemented to highlight the main incidences and interactions of both halloysite incorporation and radiation dose on some relevant effects of gamma irradiation.

Biodegradable dielectricmaterial using PLA and luffa fiber modified by medical linear accelerator

Biodegradable electronic devices are presently in command in various sectors mainly in health care system.The present work comprehends the dielectric properties of biodegradable composites made from biodegradable polymer poly (lactic) acid (PLA) and natural fiber of luffa cylindrica (LC) fabricated using microcompounding and injection molding. LC fibers are an agricultural waste, rich in cellulose.LC fibers were exposed to 6 MeV electron beam of doses 0.5Gy, 1.0Gy, 2.0Gy, 4.0Gy and 10.0 Gy generated from medical linear accelerator(LINAC) in presence of air. Such low doses are normally used for treatment of cancer patients and not for modifying polymers where doses in the range of 20-200KGy are used. The effect of such low irradiation dose on fiber and study if any significant changes taking place is the innovative aspect of the present work. The effects of irradiation dose on dielectric behavior such as dielectric constant and ac conductivity were investigated at different temperatures 260C, 40oC, 60oC and 80oC while keeping frequency constant. The increase in dielectric constant from 57 in virgin PLA at 260C,500Hz to a maximum of 84 in composite sample due to reinforcement of low dose irradiated LC fibers recording 49% increase is an important result of the investigation.

Comparison between classical ‘P&O’ algorithm and FLC of MPPT for GPV under partial shading

<p><span lang="EN-US">When the GPV is under partial shading, several peaks appear in the characteristic P-V, namely a GMP and one or more local maximums. The classical algorithm ‘P&amp;O’ MPPT cannot converge on the GMP for low irradiation values and is trapped by tracking down a LMP so making the algorithm ineffective making the algorithm ineffective, in this case under 200 W/m². An alternative objective function is developed to optimize the performance of the FLC by selecting the appropriate gains using PSO. In this simulation the GPV is composed of one hundred modules grouped parallel series (10x10) and subjected to partial shading. The proposed FLC provides better performance for GMP tracking for the chosen shade configuration selected.</span></p>

Colour–magnitude diagrams of transiting exoplanets – III. A public code, nine strange planets, and the role of phosphine

ABSTRACT Colour–magnitude diagrams provide a convenient way of comparing populations of similar objects. When well populated with precise measurements, they allow quick inferences to be made about the bulk properties of an astronomic object simply from its proximity on a diagram to other objects. We present here a python toolkit that allows a user to produce colour–magnitude diagrams of transiting exoplanets, comparing planets to populations of ultra-cool dwarfs, of directly imaged exoplanets, to theoretical models of planetary atmospheres, and to other transiting exoplanets. Using a selection of near- and mid-infrared colour–magnitude diagrams, we show how outliers can be identified for further investigation, and how emerging subpopulations can be identified. Additionally, we present evidence that observed differences in the Spitzer’s 4.5 μm flux, between irradiated Jupiters and field brown dwarfs, might be attributed to phosphine, which is susceptible to photolysis. The presence of phosphine in low-irradiation environments may negate the need for thermal inversions to explain eclipse measurements. We speculate that the anomalously low 4.5 μm flux of the nightside of HD 189733b and the daysides of GJ 436b and GJ 3470b might be caused by phosphine absorption. Finally, we use our toolkit to include Hubble Wide Field Camera 3 spectra, creating a new photometric band called the ‘Water band’ (WJH band) in the process. We show that the colour index [WJH − H] can be used to constrain the C/O ratio of exoplanets, showing that future observations with James Webb Space Telescope and Ariel will be able to distinguish these populations if they exist, and select members for future follow-up.

Dynamic Mechanical And Water Absorption Properties Of Microcrystalline Cellulose Reinforced Polypropylene Composites: The Effect Of Unconventional Irradiation Route

The unconventional electron beam (EB) irradiation route in preparing microcrystalline cellulose (MCC) fiber reinforced recycled polypropylene (rPP) composites was studied. In this route, the rPP was first subjected to EB irradiation at various doses (10-50kGy) and was then used as a compatibilizer. Unirradiated and irradiated rPPs were blended at two different ratios (90:10; 50:50) and added with MCC at contents of 5, 20 and 40wt%. Dynamic mechanical analysis (DMA) and water absorption tests were carried out. The DMA spectra exhibited high stiffness and damping behaviour. As the content of MCC increased, the water resistance of composites dropped slightly as compared to the controlled rPP. However, some compositions (50:50/40MCC-10kGy and 50:50/5MCC-50kGy) had shown opposite results. The improvement in the studied properties proved the existence of the compatibility effect that occurred at low irradiation doses, and also depended on the ratio (unirradiated and irradiated rPP) and MCC contents. ABSTRAK: Kaedah sinaran gelombang elektron secara bukan konvensional dalam penyediaan komposit polipropilena kitar semula (rPP) bersama serat selulosa mikrohablur (MCC) telah dikaji. Dalam kaedah ini, rPP telah didedahkan kepada sinaran gelombang elektron dengan dos yang berbeza (10-50kGy) dan kemudiannya digunakan sebagai penserasi. rPP tidak tersinar dan tersinar telah dicampur dengan nisbah (90:10; 50:50) dan ditambah dengan MCC pada kandungan 5, 20 and 40wt%. Analisis dinamik mekanikal (DMA) dan ujian penyerapan air telah dijalankan. Spektrum DMA menunjukkan sifat kekakuan dan pengenduran yang tinggi. Apabila kandungan MCC bertambah, kerintangan komposit terhadap air berkurang sedikit berbanding rPP terkawal. Bagaimanapun sebahagian komposisi (50:50/40MCC-10kGy and 50:50/5MCC-50kGy) telah menunjukkan keputusan sebaliknya. Penambahbaikan sifat bahan dalam kajian ini membuktikan kewujudan kesan keserasian yang berlaku pada dos sinaran rendah, dan juga bergantung kepada nisbah (rPP tidak tersinar dan tersinar) dan kandungan MCC.