Explicit formulae for Chern–Simons invariants of the hyperbolic orbifolds of the knot with Conway’s notation <Emphasis Type="Italic">C</Emphasis>(2<Emphasis Type="Italic">n</Emphasis>, 3)

We calculate the Chern–Simons invariants of the hyperbolic orbifolds of the knot with Conway’s notation C(2n, 3) using the Schläfli formula for the generalized Chern–Simons function on the family of C(2n, 3) cone-manifold structures. We present the concrete and explicit formula of them. We apply the general instructions of Hilden, Lozano, and Montesinos-Amilibia and extend the Ham and Lee’s methods. As an application, we calculate the Chern–Simons invariants of cyclic coverings of the hyperbolic C(2n, 3) orbifolds.     

MFM and Raman studies in PEMBE-grown (Ga,Mn)N thin films showing room-temperature ferromagnetism

We present the room-temperature ferromagnetism in the (Ga,Mn)N films grown on n-type GaN templates by plasma-enhanced molecular beam epitaxy for semiconductor spintronic device applications. Despite of the possible interface effects between the (Ga,Mn)N layers and n-type GaN templates, the (Ga,Mn)N films were found to exhibit the ferromagnetic ordering above room temperature. The magnetic force microscopy identified the magnetic domains with the different magnetic orientations at room temperature, indicating the existence of the ferromagnetic long-range ordering. In Raman spectra, an additional peak at 578 cm⁻¹ was observed, which is attributed to the local vibration of substitutional Mn in the (Ga,Mn)N lattice. Therefore, it is believed that the ferromagnetic ordering in (Ga,Mn)N is due to the carrier-mediated Ruderman-Kittle-Kasuya-Yosida interaction.     

Inhibition of methane formation from municipal refuse in laboratory scale lysimeters

Changes in chemical composition and population development of key groups of bacteria (hydrolytic, acetogenic, and methanogenic) were measured in a laboratory scale simulation of refuse decomposition from the time of initial incubation through the methane production phase. Inhibition of methane production appeared to be characteristic of refuse decomposition. It was observed in 20 of 32 leachate recycle containers and all 19 control containers. Inhibition was not owing to an absence of indigenous microorganisms, toxic concentrations of carboxylic acids or cations, or insufficient ammonia. Characteristics of inhibited and successful containers are compared.     

Temperature dependence of the stress-induced polarization of F center luminescence

The temperature dependence of the stress-induced polarization of F center luminescence is calculated for the simplest vibronic model for the relaxed excited state, in which 2s and 2p electronic states interact in cubic symmetry via a triply degenerate odd-parity vibrational model. The 2s state is assumed lower in energy than 2p by |E_sp|. A lower bound for |E_sp| can be determined for those alkali halides for which this polarization has been found experimentally to be independent of temperature.     

Polylactones derived from polymethacrolein and styrene–methacrolein copolymerizations

Emulsion polymerization of methacrolein produces a polyacetal which can be converted through the action of sodium hydroxide to an alternating copolymer of methallyl alcohol and sodium methacrylate. Support for the alternating structure was gained primarily through a study of the polylactone formed through subsequent acidification of the sodium salt. Thus, the poly(methallyl alcohol–sodium methacrylate) copolymer was acidified under selected conditions to give a soluble polylactone containing 14.2 mole-% of residual acid and hydroxyl groups. This number agrees quite closely with the value of 13.5 mole-% which one would predict from the random cyclization of a true alternating copolymer. Cyclization of a random copolymer of poly(methallyl alcohol–sodium methacrylate) in a random fashion would have resulted in a value of about 36.8 mole-%. The results also support both the 1,2 vinyl polymerization of methacrolein and a nonrandom attack of the polymethacrolein by base. In a completely separate set of experiments, the value of r₁ and r₂ for the copolymerization of styrene (M₁) and methacrolein (M₂) were determined to be 0.22 ± 0.02 and 0.88 ± 0.02, respectively.     

Application of Pd(0)-catalyzed intramolecular oxazine formation to the efficient total synthesis of (-)-anisomycin

The enantioselective total synthesis of (-)-anisomycin, a potent antibiotic agent, has been achieved. The key steps are a Pd(0)-catalyzed stereoselective intramolecular oxazine formation from d-tyrosine and pyrrolidine formation by catalytic hydrogenation of the oxazine.     

Preparation and wittig reactions of organotrifluoroborato phosphonium ylides

[reaction: see text] Potassium [(trifluoroboratophenyl)methyl]triphenylphosphonium chlorides have been prepared from the corresponding benzyl chlorides and PPh3. In the presence of 1.2 equiv of K2CO3 and various aldehydes, these mixed salts are easily converted to the corresponding unsaturated organotrifluoroborates via the intermediate phosphorus ylides. A protocol for a one-pot transformation has also been developed.     

Integrated cell manipulation system--CMOS/microfluidic hybrid

Manipulation of biological cells using a CMOS/microfluidic hybrid system is demonstrated. The hybrid system starts with a custom-designed CMOS (complementary metal-oxide semiconductor) chip fabricated in a semiconductor foundry. A microfluidic channel is post-fabricated on top of the CMOS chip to provide biocompatible environments. The motion of individual biological cells that are tagged with magnetic beads is directly controlled by the CMOS chip that generates microscopic magnetic field patterns using an on-chip array of micro-electromagnets. Furthermore, the CMOS chip allows high-speed and programmable reconfiguration of the magnetic fields, substantially increasing the manipulation capability of the hybrid system. Extending from previous work that verified the concept of the hybrid system, this paper reports a set of manipulation experiments with biological cells, which further confirms the advantage of the hybrid approach. To enhance the biocompatibility of the system, the microfluidic channel is redesigned and the temperature of the device is monitored by on-chip sensors. Combining microelectronics and microfluidics, the CMOS/microfluidic hybrid system presents a new model for a cell manipulation platform in biological and biomedical applications.