Dicarboxylic acid anhydride condensation with compounds containing active methylene groups. 4: Some 4-nitrophthalic anhydride condensation reactions

By 4-nitrophthalic anhydride condensation with acetoacetate in acetic anhydride and triethylamine solution with subsequent breakdown of the intermediate condensation product, 5-nitroindanedione-1,3 was obtained. A 4-nitrophthalic anhydride with acetic anhydride, according to reaction conditions, may yield two products: in the presence of potassium acetate and at high temperatures 4-(or 5-)-nitro-2-acetylbenzoic acid is formed: in the presence of triethylamine and at room temperature 5-( or 6-)-nitrophthalic acetic acid is isolated. A 4-nitrophthalic anhydride and malonic acid in pyridine solution according to temperature yield either 5-( or 6-)-nitrophthalic acetic acid or 4-(or 5-)-nitro-2-acetylbenzoic acid

Surface analysis for students in Nuclear Engineering and Radiological Sciences

Students in Nuclear Engineering and Radiological Sciences at the University of Michigan are required to learn about the various applications of radiation. Because of the broad applicability of accelerators to surface analysis, one of these courses includes a laboratory session on surface analysis techniques such as Rutherford Backscattering Analysis (RBS) and Nuclear Reaction Analysis (NRA). In this laboratory session, the students determine the concentration of nitrogen atoms in various targets using RBS and NRA by way of the 14N(d,α)12C reaction. The laboratory is conducted in a hands‐on format in which the students conduct the experiment and take the data. This paper describes the approach to teaching the theory and experimental methods behind the techniques, the conduct of the experiment and the analysis of the data. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87310/2/856_1.pd

Origins of luminescence from nitrogen-ion-implanted epitaxial GaAsGaAs

We have examined the origins of luminescence in N-ion-implanted epitaxial GaAsGaAs, using a combination of cross-sectional transmission electron microscopy and low-energy electron-excited nanoscale-luminescence spectroscopy. A comparison of reference, as-implanted, and implanted-plus-annealed samples reveals a variety of emissions. In all samples, we observe the GaAsGaAs fundamental band-gap emission, as well as several emissions related to GaAsGaAs native defects. In the as-implanted and implanted-plus-annealed samples, an emission related to the implantation-induced defects, is also observed. Interestingly, in the implanted-plus-annealed samples, we identify a near-infrared emission associated with GaAsNGaAsN nanocrystallites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69942/2/APPLAB-85-14-2774-1.pd

Matrix-seeded growth of nitride semiconductor nanostructures using ion beams

We have examined the matrix-seeded growth of narrow-gap nitride nanostructures in nitrogen ion implanted GaAs and InAs. Low-energy implantation followed by rapid thermal annealing (RTA) results in the formation of 2–3 nm sized amorphous precipitates in a crystalline matrix. On the other hand, high-energy implantation results in an amorphous layer, with or without crystalline remnants. When the ion-beam-synthesized amorphous matrix is a continuous amorphous layer, subsequent RTA leads to the formation of 4–5 nm zinc blende (ZB)-GaN-rich crystallites in an amorphous matrix. When this matrix contains crystalline remnants, subsequent RTA leads to the formation of 2–4 nm ZB-GaN-rich crystallites within the amorphous regions. These results suggest that the matrix plays an important role in the nucleation and growth of narrow-gap nitride nanostructures, and that matrix-seeded growth may provide an opportunity to control the structure and properties of the nanostructures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87633/2/064301_1.pd

Evolution of structural and optical properties of ion-beam synthesized GaAsN nanostructures

We have investigated the evolution of structural and optical properties of GaAsN nanostructures synthesized by N ion implantation into epitaxial GaAs, followed by rapid thermal annealing. Transmission electron microscopy and x-ray diffraction indicate the formation of nanometer-sized crystallites with lattice parameters close to those of pure zincblende GaN. The average crystallite size increases with annealing temperature while the size distribution is self-similar and the volume fraction remains constant, suggesting a coarsening process governed by Ostwald ripening. These GaAsN nanostructures exhibit significant photoluminescence in the near infrared range. The apparent lowering of the fundamental band gap is likely due to the incorporation of a small amount of As in GaN. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70225/2/JAPIAU-92-7-4012-1.pd

Corrosion and mechanical behavior of ion implanted bearing steels for improved fretting behavior

Ion implantation of AISI 52100 and 1070 steels was conducted in order to improve the corrosion, wear and ultimately the fretting behavior of the steels. Implantations consisted of 1 x 1017 Ta+ cm-2, 3 x 1017 Ti+ cm-2 + 1.5 x 1017 C+ cm-2, and 3.1 x 1017 Ti+ cm-2 + 1.55 x 1017 N+2 cm-2. All implantations were successful in improving the corrosion resistance. On average, the peak anodic current was reduced by over 300 mV, the passivation potential was reduced, and the pitting potential was increased by over 1000 mV in 0.01 M NaCl. Ti + C and Ti + N implantations increased the load-carrying capacity in lubricated scuffing tests by 60% and 40% respectively. Ta produced no improvement in scuffing resistance. Ti + N implantation increased the hardness by 25% over the unimplanted steel and both Ti + C and Ta implantation reduced the surface hardness. Fretting wear was reduced only slightly in the Ta implanted sample and increased in both the Ti + C and Ti + N implanted samples with the latter showing 4-5 times the weight loss as the unimplanted sample. The correlation between fretting and hardness supports a mechanism in which the hard surface layer breaks into fine particles which act as an abrasive under the intense load of the balls.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31416/1/0000333.pd

Analysis of TiN by charged particle beams: Nuclear reaction analysis, nuclear reaction broadening and Rutherford backscattering

Charged particle beams have been used to extract data both on the composition and also on the thickness of two series of TiNx films (about 5 and 2 [mu]m thick respectively), where x varied from 0.3 to 1.0. The technique used were nuclear reaction analysis (NRA), resonance nuclear reaction broadening (NRB) and Rutherford backscattering, together with Auger electron spectroscopy (AES). The data from the NRB depth profiles scale remarkably well with the results from AES. The NRA results have the greatest experimental uncertainty and also indicate a systematic error which is not understood. Both NRA and NRB can return reliable film thickness data. It is also demonstrated that TiC should not be used as a reference standard when analyzing TiN films by AES.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27028/1/0000016.pd

Kinstate intervention in ethnic conflicts : Albania and Turkey compared

Albania and Turkey did not act in overtly irredentist ways towards their ethnic brethren in neighboring states after the end of communism. Why, nonetheless, did Albania facilitate the increase of ethnic conflict in Kosovo and Macedonia, while Turkey did not, with respect to the Turks of Bulgaria? I argue that kin-states undergoing transition are more prone to intervene in external conflicts than states that are not, regardless of the salience of minority demands in the host-state. The transition weakens the institutions of the kin-state. Experiencing limited institutional constraints, self-seeking state officials create alliances with secessionist and autonomist movements across borders alongside their own ideological, clan-based and particularistic interests. Such alliances are often utilized to advance radical domestic agendas. Unlike in Albania's transition environment, in Turkey there were no emerging elites that could potentially form alliances and use external movements to legitimize their own domestic existence or claims

How ready is China for a China-style world order? China's state media discourse under construction

What exactly is the China-style world order that Chinese officials and intellectual elites have recently been talking about, and how ready is China for it? An examination and analysis of discourses on ‘Africa Live’ on CCTV Africa, the first overseas news center of China Central Television (CCTV), yields some highly noticeable features and significant themes, confirming that although China has shifted from a low-profile approach to a more assertive one, in an attempt to change the global order, its verbal challenge and sometimes harsh criticism of the American-led international system is accompanied by an obvious absence of a clear vision of what the new world order should be like. This lack of a clear vision may be due to the fact that the Chinese discourse on world order is still a work in progress, constrained by internal practices, and Africa is its testing ground for the construction of a discourse that China envisages as an alternative

Everyday legitimacy and international administration: global governance and local legitimacy in Kosovo

International administrations are a very specific form of statebuilding. This paper examines the limits illustrated by the experience in Kosovo. Here, the international administration faced the same requirements of any legitimate, Liberal government, but without the checks and balances normally associated with Liberal governance. Thus, the international administration was granted full authority and the power thereby associated, but without the legitimacy upon which the Liberal social contract rests. The state-building agenda put forth came to be seen as more exogenous, reinforcing the delegitimization process. This paper will specifically address the influence of the Weberian approach to legitimacy on the statebuilding literature, as well as its limits. It will then propose other possible avenues for statebuilding, more in line with a wider understanding of legitimacy and intervention