61 research outputs found
Films CdS Grown on Porous Si Substrate
In this work, CdS films were obtained on the technology of chemical surface deposition on porous semiconductor substrates. The morphology and chemical composition of the obtained structures were studied.
The possibility of using CdS/porous-Si/p-Si heterostructures as photovoltaic solar energy converters is considere
Growth of SiC films by the method of substitution of atoms on porous Si (100) and (111) substrates
The mechanisms of growth of silicon carbide (SiC) films by the method of substitution of atoms on macro- and mesoporous silicon substrates (Si) of p- and n-type conduction are investigated. Significant dependence of the rate and the mechanism of nucleation of SiC layers on Si on the type of Si doping and its crystallographic orientation is
experimentally found. Comparison of the experimental data with the theoretical results obtained earlier is performed. It is shown that the presence of the system of pores on the surface allows one to significantly increase the thickness of silicon transformed into SiC during the process of synthesis by the method of substitution of atoms, which was equal to 115 microns in our experiments. The obtained samples are studied by methods of scanning electron microscopy, micro-Raman spectroscopy, and X-ray diffraction analysis. Numerical simulation of the distribution of elastic stresses caused by the difference in thermal expansion coefficients (TEC) in the heterostructures of GaN/SiC/porous Si/Si is conducted. It is revealed that the presence of pores in the near-surface layers of Si leads to considerable relaxation of
elastic stresses in GaN films caused by differences in the TEC between GaN and Si
Room Temperature High-Field Spin Dynamics of NV Defects in Sintered Diamonds
Sintered oriented nanodiamond arrays with the extremely high concentrations of the nitrogen-vacancy (NV) centers (up to 103 ppm) were investigated by the W-band (94 GHz) electron spin echo electron paramagnetic resonance techniques. The NV centers were fabricated by the high-pressure high-temperature sintering of detonation nanodiamonds (DND) without the post or prior irradiation of the samples. The processes of polarization and recovery of the equilibrium population of the spin sublevels by optical and microwave pulses have been examined at room temperature in high magnetic fields corresponding to the fine-structure transitions for the NV defects at 94 GHz (3,250-3,450 mT). A long spin coherence time of 1.6 μs and spin-lattice relaxation time of 1.7 ms were measured. The results were compared with those obtained on the NV centers fabricated by the irradiation and subsequent annealing of the commercially available bulk diamonds. It was shown that the relaxation characteristics of the NV defects were similar in the both types of the samples despite the extremely high concentrations of NV defects and isolated nitrogen donors in the sintered DND. © 2013 Springer-Verlag Wien
Defects in Nanodiamonds: Application of High-Frequency cw and Pulse EPR, ODMR
© 2014, Springer-Verlag Wien. Different aspects of applications of electron paramagnetic resonance (EPR) based techniques including high frequency (HF) electron spin echo (ESE), electron-nuclear double resonance (ENDOR) and optically detected magnetic resonance (ODMR) approaches to study diamond nanostructures are examined
Small Business Contracting in the United States and Europe: A Comparative Assessment
On Jul 27, 2009 the European Commission (EC) issued its annual report, United States Barriers to
Trade and Investment Report for 2008, where it once again republished its complaint that "small business setaside
schemes, exemplified by the Small Business Act of 1953," are discriminatory measures that "limit bidding
opportunities for EU (or European Union) contractors" in the US procurement market. As this Article
demonstrates, small business has long held a special place in the Western public procurement systems both in
Europe and in the US. Public authorities on both sides of the Atlantic use the demand created by government
contracts to stimulate competitive private entrepreneurship and greater economic development within their
borders. In 2003, both the US and the combined European economies had gross domestic products roughly
equal to $11 trillion. With admission of twelve new members since 2003, the EU now includes twenty-seven
countries
Increasing the U.S. Department of the Navy
Naval Postgraduate School Acquisition Research Progra
U.S. and E.U. SME Subcontracting Policy and Practice Trends: Towards a Transatlantic Accountability Consensus
U.S. and E.U. public and defense procurement rules require large
prime contractors to promote subcontracts to small businesses, a.k.a. small
and medium enterprises (SMEs). Under the U.S. Small Business Act, large
firms encourage subcontracting through publicity, subcontracting plans, and
“good faith” efforts to achieve subcontracting goals. However, process-oriented
measures failed to guarantee definitive results. In contrast, E.U.
and member governments can hold large firms accountable to stricter
subcontracting standards (often sweetened by incentives). With the Small
Business Jobs Act of 2010, the U.S. is trying accountability measures now.
Therefore, large contractors must plan for definitive subcontracting
commitments in both markets.George Washington University, U.S.A.U.S. GovernmentGeorge Washington University, U.S.A.U.S. Governmen
Increasing the Department of the Navy’s Opportunities for Small Business and Non-Traditional Suppliers through Simplified Acquisitions Contracting and NAICS Targeting
This is a revised version.The Department of the Navy’s (DON’s) total acquisition workforce, including the 1105 Purchasing Agent series and the 1102 Contract Specialist series, is directed to maximize contract awards to small and nontraditional suppliers by the terms of the Small Business Act and the Federal Acquisition Regulation (FAR), as well as Presidential, Department of Defense (DOD), and DON initiatives such as Better Buying Power (BBP). This direction is particularly strong with regards to low-dollar awards.
The Federal Acquisitions Regulation (FAR) Part 13 Simplified Acquisitions Procedures (SAP) was designed to be a highly effective tool that can overcome contracting barriers for non-traditional and small business suppliers. Through the Small Business Reservation (SBR), Congress directed agencies to automatically attempt small business set-asides of contract awards below the Simplified Acquisitions Threshold (SAT) of $150,000.00. The Small Business Jobs Act of 2010 recently authorized discretionary set-asides on task and delivery orders under FAR Subparts 8.4 and 16.5. However, there are concerns that SAT contracts are often benefitting large firms across various North American Industrial Category System (NAICS) categories. The DOD’s preferred MAXPRAC model is unsuitable for solving this apparent problem.
This Report examines barriers, tools, structure, and best practices of small business SAT contracting based on a test case study of the Naval Postgraduate School (NPS) SAT level contracting authority and a survey of relevant regional agencies. The Report develops three alternative NAICS Access Visualization (NAV) models with emphasis on targeting requirements and industries for award to small and non-traditional suppliers: NAVUSA (Understanding Subsector Availability), NAVBID (Barriers Intelligence Dashboards), and NAVBOSS (Business Opportunities Solutions Sequence). The Report recommends these models for further testing at NPS and their eventual adoption DON-wide.Director, Small Business Programs, Office of the Secretary of the Navy.Approved for public release; distribution is unlimited
An open door and a leg up: increasing service-disabled veteran-owned small business (SDVOSB) participation in defense, Navy, and Marine Corps contracting through simplified acquisitions
Contracting with service-disabled veteran-owned small businesses (SDVOSBs) is widely promoted as an important benefit for veterans, particularly at the Department of Defense (DOD) and its component the Department of the Navy (DOD). In FY2014, DOD finally met its three (3) percent SDVOSB statutory contact spending goal, while DON made significant strides towards meeting it. This real progress came despite five (5) academic assessments which persistently suggested that the SDVOSB Procurement Program’s design contain inherent conceptual flaws that sow confusion among disabled veterans and Contracting Officers about scope of discretion to assist SDVOSBs, generate widespread disillusionment among veterans, promote entrenchment by a few already successful firms instead of helping veterans at large to obtain self-employment, and thereby impede goal achievement. This study tests the academic criticisms by examining the SDVOSB Program design and operation trends through the prism of the generally accepted Cohen-Eimicke Contract Management Performance Model. Finally, this study proposes veteran-centric performance management realignments of the SDVOSB Program at DOD and DON through the use of targeted set-asides and Simplified Acquisition Procedures (SAP) in order to match the Program with its original intent of broad-based SDVOSB business development.Director, Small Business Programs, Office of the Secretary of the Navy, 720 Kennon Street, SE, Bldg. 36, Room 207, Washington Navy Yard, DC 20374-5079Director, Secretary of the Navy’s Office of Small Business Programs (SECNAV OSBP).Approved for public release; distribution is unlimited
Increasing the U.S. Department of the Navy's Opportunities for Small Business and Non-Traditional Suppliers through Simplified Acquisitions Contracting and NAIC Targeting
A Symposium PresentationFocus: The challenge of small and nontraditional business
participation in small-dollar “simplified” contracts awarded by the
U.S. Department of the Navy (DON)Naval Postgraduate School Acquisition Research Progra
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