Rotationally resolved spectroscopy of (20000) Varuna in the near-infrared

Models of the escape and retention of volatiles by minor icy objects exclude any presence of volatile ices on the surface of TNOs smaller than ~1000km in diameter at the typical temperature in this region of the solar system, whereas the same models show that water ice is stable on the surface of objects over a wide range of diameters. Collisions and cometary activity have been used to explain the process of surface refreshing of TNOs and Centaurs. These processes can produce surface heterogeneity that can be studied by collecting information at different rotational phases. The aims of this work are to study the surface composition of (20000)Varuna, a TNO with a diameter ~650km and to search for indications of rotational variability. We observed Varuna during two consecutive nights in January 2011 with NICS@TNG obtaining a set of spectra covering the whole rotation period of Varuna. After studying the spectra corresponding to different rotational phases, we did not find any indication of surface variability. In all the spectra, we detect an absorption at 2{\mu}m, suggesting the presence of water ice on the surface. We do not detect any other volatiles on the surface, although the S/N is not high enough to discard their presence. Based on scattering models, we present two possible compositions compatible with our set of data and discuss their implications in the frame of the collisional history of the Kuiper Belt. We find that the most probable composition for the surface of Varuna is a mixture of amorphous silicates, complex organics, and water ice. This composition is compatible with all the materials being primordial. However, our data can also be fitted by models containing up to a 10% of methane ice. For an object with the characteristics of Varuna, this volatile could not be primordial, so an event, such as an energetic impact, would be needed to explain its presence on the surface.Comment: 6 pages, 5 figures, to be published in A&

Connection between slow and fast dynamics of molecular liquids around the glass transition

The mean-square displacement (MSD) was measured by neutron scattering at various temperatures and pressures for a number of molecular glass-forming liquids. The MSD is invariant along the glass-transition line at the pressure studied, thus establishing an ``intrinsic'' Lindemann criterion for any given liquid. A one-to-one connection between the MSD's temperature dependence and the liquid's fragility is found when the MSD is evaluated on a time scale of approximately 4 nanoseconds, but does not hold when the MSD is evaluated at shorter times. The findings are discussed in terms of the elastic model and the role of relaxations, and the correlations between slow and fast dynamics are addressed.Comment: accepted by Phys Rev E (2010

Flight Mechanics of Ram-Scram Transition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106486/1/AIAA2013-4687.pd

Design Optimization of a Scramjet Vehicle for Ascent Using Surrogate Optimization

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140408/1/6.2014-0531.pd

Aurora 3d Presentation Dalam Pembelajaran Bangun Ruang Sisi Lengkung Di Kelas IX SMPN 24 Banjarmasin

Software Aurora 3D Presentation yang merupakan media pembelajaran interaktif yang diadaptasi dari software sebelumnya yaitu Microsoft Power Point. Hanya saja, Aurora 3D Presentation menyajikan kemudahan dalam penggunaan animasi presentasi baik dua atau tiga dimensi. Aurora 3D Presentation dipilih dikarenakan software yang berbasis presenatsi dan tidak terlalu mengurangi peranan guru dalam proses pembelajaran, selain itu software ini memiliki fitur-fitur tiga dimensi yang mudah digunakan serta mendukung materi yang akan diajarkan atau diteliti yaitu bangun ruang sisi lengkung. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil belajar antara pembelajaran dengan menggunakan media pembelajaran interaktif Aurora 3D Presentation dan model pembelajaran konvensional pada materi Bangun Ruang Sisi Lengkung di Kelas IX SMPN 24 Banjarmasin tahun pelajaran 2014/2015.Penelitian kali ini menggunakan metode eksperimen dengan jenis penelitian lapangan dan pendekatan kuantitatif. Populasi penelitian ini adalah kelas IX.A, IX.B, IX.C, IX.D, IX.E, dan IX.B SMPN 24 Banjarmasin yang dibagi menjadi dua kelompok atau dua kelas. Yaitu kelas eksperimen (kelompok uji coba) dan kelas kontrol (kelompok kendali) yang ditentukan melalui teknik Sample Random Sampling sehingga diperoleh kelas eksperimen adalah kelas IX.C dan kelas kontrol adalah kelas IX.A. Pada kedua kelas tersebut akan diberikan tes kemampuan awal, pre test, dan post test.Berdasarkan uji t pada hasil belajar siswa melalui post test, diperoleh harga thitung = 2.185dan ttabel = 2.000. Karena -ttabel ≤ thitung ≤ ttabel, maka Ha diterima dan H0 ditolak, kemudian disimpulkan bahwa terdapat perbedaan hasil belajar yang signifikan antara pembelajaran dengan menggunakan media pembelajaran interaktif Aurora 3D Presentation dan model pembelajaran konvensional pada materi bangun ruang sisi lengkung di kelas IX SMPN 24 Banjarmasin tahun pelajaran 2014/2015

Building Booster Separation Aerodynamic Databases for Artemis II

NASAs Artemis II mission will mark the return of humans to near-lunar space for the first time since Apollo. Shortly after launch on the Space Launch System (SLS), a critical phase of ascent occurs when 16 small rockets fire to push the boosters away from the core. Minimizing the risk of failure during separation requires the construction of multiple 13-dimensional databases, including perturbations in position, flight conditions, and engine thrust. The SLS Computational Fluid Dynamics team used NASAs FUN3D flow solver on the Pleiades and Electra supercomputers to run 5,780 simulations at nominal conditions and over 8,000 simulations with a core stage engine failure to generate the databases needed to verify the booster separation system for Artemis II

Decay accelerating factor (CD55) protects neuronal cells from chemical hypoxia-induced injury

Background: Activated complement system is known to mediate neuroinflammation and neurodegeneration following exposure to hypoxic-ischemic insults. Therefore, inhibition of the complement activation cascade may represent a potential therapeutic strategy for the management of ischemic brain injury. Decay-accelerating factor (DAF, also known as CD55) inhibits complement activation by suppressing the function of C3/C5 convertases, thereby limiting local generation or deposition of C3a/C5a and membrane attack complex (MAC or C5b-9) production. The present study investigates the ability of DAF to protect primary cultured neuronal cells subjected to sodium cyanide (NaCN)-induced hypoxia from degeneration and apoptosis. Methods: Cultured primary cortical neurons from embryonic Sprague-Dawley rats were assigned one of four groups: control, DAF treatment alone, hypoxic, or hypoxic treated with DAF. Hypoxic cultures were exposed to NaCN for 1 hour, rinsed, followed by 24 hour exposure to 200 ng/ml of recombinant human DAF in normal medium. Human DAF was used in the present study and it has been shown to effectively regulate complement activation in rats. Neuronal cell function, morphology and viability were investigated by measuring plateau depolarization potential, counting the number dendritic spines, and observing TUNEL and MTT assays. Complement C3, C3a, C3a receptor (R) production, C3a-C3aR interaction and MAC formation were assessed along with the generation of activated caspase-9, activated caspase-3, and activated Src. Results: When compared to controls, hypoxic cells had fewer dendritic spines, reduced plateau depolarization accompanied by increased apoptotic activity and accumulation of MAC, as well as up-regulation of C3, C3a and C3aR, enhancement of C3a-C3aR engagement, and elevated caspase and Src activity. Treatment of hypoxic cells with 200 ng/ml of recombinant human DAF resulted in attenuation of neuronal apoptosis and exerted significant protection against neuronal dendritic spine loss and plateau depolarization reduction. Furthermore, treatment with DAF resulted in decreased accumulation of C3a, MAC, C3a-C3aR interaction, caspase-9, activated caspase-3, and pTyr416-Src (activated Src) tyrosine kinase. Conclusion: DAF was found to reduce neuronal cell death and apoptosis in NaCN induced hypoxia. This effect is attributed to the ability of DAF to limit complement activation and inhibit the activity of Src and caspases 9 and 3. This study supports the inhibiting of complement as a neuroprotective strategy against CNS ischemia/reperfusion injury

Effect of Including Fermented Feather Meal as Substitution of Concentrate in the Basal Diet With Different Levels on the Performance of Landrace Crossbred Pigs

The study aimed to evaluate the effect of adding fermented feather mael (FFM) on pigs' performance, intake, and digestibility. There were 16 landrace crossbred pigs 2-3 months old with 6-19 kg (average 13.59 kg; CV= 29.59%) initial body weights used in the study. Trial method using complete block design 4 treatments with 4 replicates procedure was applied in the study. The 4 treatment feeds were formulated as: R0: basal diet with 100% concentrate without TBAT (control); R1: basal diet with 90% concentrate + 10% FFM; R2: basal diet with 80% concentrate + 20% FFM; and R3: basal diet with 70% concentrate + 30% FFM. Variables evaluated were feed intake, daily weight gain and feed conversion (performance) landrace crossbred pigs. Statistical analysis shows no significant (P>0.05) on feed intake, daily weight gain and feed conversion. The conclusion were that that including FFM into basal diet gave relative the same results in the feed intake, daily weight gain and feed conversion

Ascent Trajectories of Hypersonic Aircraft: Operability Limits Due to Engine Unstart

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140638/1/1.c032801.pd