Depth of Cracking beneath Impact Craters: New Constraint for Impact Velocity

Both small-scale impact craters in the laboratory and less than 5 km in diameter bowl-shaped craters on the Earth are strength (of rock) controlled. In the strength regime, crater volumes are nearly proportional to impactor kinetic energy. The depth of the cracked rock zone beneath such craters depends on both impactor energy and velocity. Thus determination of the maximum zone of cracking constrains impact velocity. We show this dependency for small-scale laboratory craters where the cracked zone is delineated via ultrasonic methods. The 1 km-deep cracked zone beneath Meteor Crater is found to be consistent with the crater scaling of Schmidt (1) and previous shock attenuation calculations

Theoretical Study of the Pseudomonic and Monic Acids

The drug Mupirocin has shown positive effects against both Gram-negative and Gram-positive bacteria with varying levels of success. It has been shown to be effective against Methicillin-Resistant Staphylococcus Aureas (MRSA) as a topical treatment in high concentrations. Mupirocin is comprised of pseudomonic acids. The monic acids are structurally similar to the pseudomonic acids and thus function as a good model to better understand the chemical characteristics of the drug. This work presents results of DFT (B3LYP) calculations with an accurate basis set on monic acid A and related species with focus on internal rotation barriers, optimal geometries, IR and Raman spectra, and electrostatic potentials to identify the differences between the monic and pseudomonic acids with an eye towards potential antibacterial treatments

Secondary-School Principals\u27 Perceptions of their Role in the Retention of the Novice Teacher

ABSTRACT SECONDARY-SCHOOL PRINCIPALS’ PERCEPTIONS OF THEIR ROLE IN THE RETENTION OF NOVICE TEACHERS Theresa J. Coker Secondary schools in the U.S. face instructional challenges due in part to novice teacher turnover. Research indicates that new teachers remain in the profession due to: supportive principal leadership, an orderly school environment, classroom autonomy, and significant professional development (Grissom, 2008). The purpose of this study was to understand how secondary-school principals perceived their role in novice teachers’ professional development and retention. Qualitative research using in-depth, semi-structured interviews included 15 secondary-school administrators from an urban district in the southeast United States. Data analysis used Eisner’s (1998) four-part approach to educational criticism—description, interpretation, evaluation, and thematics—supported by Hatch’s (2002) typological analysis. Four typologies organized description and interpretation: principals’ early experiences as educators; principals’ perceptions of the recruitment process; principals’ view of the process of professional development; and life and duties of principals. The thematics dimension of educational criticism indicated that principals’ lack of time led to their delegating leadership tasks to other staff regarding novice teachers’ professional development. Their descriptions of their interactions with novice teachers reflected a transactional leadership style and an approach of “leading from the middle” (Bolman & Gallos, 2011) to respond to both demands from above and needs at the school level. Further, these principals perceived all teachers new to their schools as novice, whether experienced or inexperienced. Implications include considering transformational leadership when working with novice teachers and clarifying hiring and retention responsibilities regarding novice teachers. Such communication among all parties would support novice teachers’ development and commitment to the profession. Further research might focus on observing the interactions of both administrators and faculty with novice teachers to understand the complexity of the process of their professional development

Suborbital Payload Testing Aboard Level 3 Rocket Research Platform

Embry-Riddle Aeronautical University (ERAU) has launched several suborbital scientific payloads aboard Blue Origin’s New Shepard in 2017 and 2019. Students continue gaining hands-on experience in rocket design and construction, and payload integration and testing of future and more mature payloads to be launched into space. A Level 3 Rocket is being designed and developed at ERAU to serve as a scaled-down model research platform for launching and testing of payloads that will be later flown in commercial suborbital platforms such as Blue Origin’s New Shepard and PLD space Miura 1 rockets. Computer simulations were conducted to calculate the key parameters such as flight trajectory profiles, stability and flight velocities for different rocket motors configurations. A preliminary design of the rocket was developed using Computer-Aided Design (CAD) software. The rocket will accommodate multiple payloads (Cubesats, NanoLabs, TubeSats) designed and developed in the Payload Applied, Technology and Operations (PATO) laboratory. The rocket will be primarily constructed of carbon fiber composite as it has a high strength to weight ratio. These simulations are used to select a suitable motor for the rocket according to the flight requirements and landing restrictions. This prospective Level 3 Rocket is referred to as Suborbital Technology Experimental Vehicle for Exploration (STEVE). Rocket procedures and results from the design, simulation, construction and assembly will be presented

Baseline design of the filters for the LAD detector on board LOFT

The Large Observatory for X-ray Timing (LOFT) was one of the M3 missions selected for the phase A study in the ESA's Cosmic Vision program. LOFT is designed to perform high-time-resolution X-ray observations of black holes and neutron stars. The main instrument on the LOFT payload is the Large Area Detector (LAD), a collimated experiment with a nominal effective area of ~10 m 2 @ 8 keV, and a spectral resolution of ~240 eV in the energy band 2-30 keV. These performances are achieved covering a large collecting area with more than 2000 large-area Silicon Drift Detectors (SDDs) each one coupled to a collimator based on lead-glass micro-channel plates. In order to reduce the thermal load onto the detectors, which are open to Sky, and to protect them from out of band radiation, optical-thermal filter will be mounted in front of the SDDs. Different options have been considered for the LAD filters for best compromise between high quantum efficiency and high mechanical robustness. We present the baseline design of the optical-thermal filters, show the nominal performances, and present preliminary test results performed during the phase A study.Comment: Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 91446

Design and construction of an inverter using solar cell as a source of charger

The present study is basically on electricity generation in which solar cell or module is used to power an inverter. This can also be called photovoltaic system, because it consists of solar modules, solar charge controller, 24V.d.c battery and an inverter. Solar modules serve as source of charger through solar charge controller to the battery and inverter are used in converting the direct current into an alternating current for the domestic appliance. This study is very useful in electricity generation especially in a developing country such as Nigeria where there is epileptic power supply. It-’s use is far better than generating set because it needs less maintenance, it does not use fuel, it is not heavy, it is rugged, it does not need an alternating current for its charging and it is noiseless

Ultrasonic method of Biodiesel production from Palm kernel

Biodiesel is a clean burning alternative fuel derived from chemical reactors produced from palm kernel oil, is currently spreading like a wind dust in the air. It is considered as the fuel for the future without rise in global warming. It has advantages over the fossil fuel diesel as sustainability (renewable resources), ease of production, and availability of raw materials. The study examines the biodiesel produced through transesterification of palm kernel oil (1% fatty acid) with methanol using granulated sodium hydroxide as catalyst through ultrasonic method. The palm kernel oil biodiesel produced was characterized as alternative diesel fuel through standard tests (ASTM) for basic fuel properties such as viscosity, cloud point, pour point, flash point and specific gravity as well as economical feasibility for Nigeria. The result showed that 875g of palm kernel oil (1% fatty acid) with 175g of methanol using 13g of sodium hydroxide (granulated) subjected to ultrasonic method for 1 hour through transesterification process produced 96.23% of biodiesel and 16.89% of glycerol plus high excess methanol wasallowed to settle for 6 hours. Two layers were observed containing unwashed biodiesel at the top and darker layers of glycerin. After washing the biodiesel with warm water, the cleaned, biodiesel was dried by heat to remove the moisture from and allowed to settle down. A bright colour biodiesel was obtained which was within the international standard for biodiesel fuel