Surface/Thickness Translated: Design-Build as Vehicle

The Building-Design Workshop at the Taubman College of Architecture and Urban Planning pursues the integration of teaching, design research, and the design-build process. The program brings University-sponsored projects into the teaching context, offering a unique forum for testing pedagogies about making. Collaborating with faculty on both architectural and constructional aspects of a project, students are given a valuable occasion to realize a design in built form. The project shown here is a renovation of the College's Faculty Resource Room (FRR), a support facility for the research and teaching of the Architecture and Planning faculty.     

Entirely VPE-grown 1-5?m DFB lasers with low threshold currents

Entirely hydride VPE-grown 1.5?m DFB lasers have been obtained by means of high controllability in film thickness and alloy composition for the GalnAsP/InP system. A low threshold current of 13 mA was achieved by improving the growth method for the layer burying the grating. High uniformity in threshold current and lasing wavelength (Ith = 27.3 ± 9.7 mA, ? = 15571 ± 12?) was obtained.     

Analysis of chirp power penalty in 1.55-µm DFB-LD high-speed optical fiber transmission systems

In a 1.55-μm high-speed transmission system using a DFB-LD, the chirp effect in the LD is a factor limiting transmission span length. In order to evaluate the chirp effect, we derive expressions for the chirp power penalty for two cases: the cases of the chirp occurring in both edges of the pulse and in the whole time of the pulse. The calculations based on the results of the LD chirp measurement predict that the chirp effect will be significant above 2 Gbit/s even if the zero dispersion wavelength of fiber is shifted to the 1.55-μm band. Transmission experiments performed at 1.2 Gbit/s and 2.4 Gbit/s verify this prediction.     

Penetration and stainability of modified Sato's lead staining solution.

The penetration and stainability of modified Sato's lead staining solution containing calcined lead citrate were studied. Modified Sato's lead solution was preserved for 1 week and for 2 years, each at room temperature and at 4 degrees C. Specimens were stained with these solutions to measure the stainability. After 2-min staining, specimens were stained to the depth of 1.0-1.2 microns even when there had been 2-year preservation of the staining solution. This modified solution could be preserved for a long time and good penetration and stainability could still be obtained. This solution is also suitable for the observation of semithin sections.     

Interfacial microstructure and strength of steel/aluminum alloy joints welded by resistance spot welding with cover plate

We joined aluminum alloy A5052 to cold-rolled steel SPCC (Steel Plate Cold Commercial) and austenitic stainless steel SUS304 using resistance spot welding with a cover plate. The interfacial microstructure was observed using transmission electron microscopy. A thick two-layered reaction layer contains Fe₂Al₅ and FeAl₃ and a thin serration reaction layer contains Fe₂Al₅ and FeAl₃ were observed at the A5052/SPCC and A5052/SUS304 interface, respectively. Mechanical property analysis suggested that the reaction layer has no effect on the tensile shear strength of the A5052/SUS304 joint and that the tensile shear strength of the A5052/SPCC joint is influenced by the reaction layer formed at its interface.     

Hierarchical state estimation using a fast rectangular-coordinatemethod [power system analysis computing]

A hierarchical computing scheme for power system state estimation is developed by carefully considering mismatches arising from the system decomposition. The method makes use of an extension of a fast second-order load-flow method that allows a fixed Jacobian matrix to be used in the hierarchical algorithm. In the problem formulation, the power network is decomposed into two or more subsystems; the interaction among them is taken into account through the tie-line bus voltages. The hierarchical structure of the method consists of two levels: the upper level, where the optimal tie-line bus voltages are evaluated; and the lower level, where the optimal states of each subsystem are determined by minimizing a cost function that involves the entire system. Three test cases using the method are reported here and the test results are compared with those obtained by another hierarchical power system state estimation method     

Polymer-derived β-SiAlON:Eu2+ phosphors

A series of β-SiAlON:Eu²⁺ phosphors were synthesized from single-source precursors, perhydropolysilazane chemically modified with Al(OCH(CH₃)₂)₃, AlCl₃, and EuCl₂. The single-source precursors were converted to β-SiAlON:Eu²⁺ phosphors by pyrolysis under flowing N₂ or NH₃ at 1000°C, followed by heat treatment at 1800°C under an N₂ gas pressure at 980 kPa. By varying the molar ratio of the chemical modifiers, β-SiAlON:Eu²⁺ with the compositions close to the theoretical ones expressed as Si_6−zAl_zO_z−2yN_8−z+2y:yEu²⁺ were synthesized, where the z values and Eu²⁺ contents were controlled in the ranges of .44–.78 and .35–1.48 mol%, respectively. The polymer-derived β-SiAlON:Eu²⁺ phosphors exhibited green emission under excitation at 460 nm attributed to the 4f⁷–4f⁶(7f³)5d¹ transition of dopant Eu²⁺. High-angle annular dark-field-scanning transmission microscopy analysis confirmed that the doped-Eu²⁺ existed interstitially within the channels along the c axis of host β-SiAlON. Compared with the conventional powder metallurgy route, the polymer-derived ceramic route in this study offers some advantages in the grain growth of host β-SiAlON and photoluminescence properties in terms of green emission intensity under excitation at 460 nm, and the highest intensity was achieved for the polymer-derived β-SiAlON:Eu²⁺ with z = .64 and .37 mol% Eu²⁺.     

Relationship among collagen amount, distribution and architecture in the M. longissimus thoracis and M. pectoralis profundus from pigs

The relative distribution of types I and III collagens and collagen fibre architecture in the perimysium and endomysium were compared to the longissimus thoracis (LT) and pectoralis profundus (PP) muscles in pigs. The LT muscle was composed of type I myofibres 16.8%, IIA 12.9% and IIB 70.2%, and the PP muscle was 25.4, 23.1 and 51.5%, respectively. The total collagen amount differed significantly between the LT (2.66 mg/g) and PP (4.13 mg/g) muscle (P<0.001). On image analysis of the immunohistochemical preparations for types I and III collagens, the percentage area of the perimysium to the total collagen area showed significant differences between the muscles, where perimysial type I collagen occupied 25.4% of the total area in the LT muscle and 45.7% in the PP and perimysial type III 37.6 and 54.5%, respectively (P<0.001). In scanning electron microscopic photographs of the macerated preparation, very thick collagen layers composed of several fibre bands were observed in the perimysia of the PP muscle and appeared differently from the thinner perimysia with a few bands in the LT. Similar architecture of endomysial collagen fibres were observed around every myofibre type in the PP muscle and also in the LT. The fine surface cover of reticular collagen fibres around an adipocyte was shown as a global cast. These results suggested that the total collagen amount of the PP muscle was related mainly to the well developed perimysia composed of several collagen bands, indicating tougher meat compared with the LT muscle.     

Solid polymerization and supramolecular chirality formation of azobenzene substituted diacetylene Langmuir–Blodgett films

An azobenzene mesogen-substituted diacetylene (NADA) monolayer has been transferred onto the solid substrate by the traditional Langmuir–Blodgett (LB) method. Solid-state polymerization of NADA LB films can be sensitized in visible light region. In situ UV–vis absorption measurement enables us to study polymerization kinetics of NADA LB films. The polymerization process can be described as a first order rate equation and polymerization rate constants are characterized in detail. Furthermore, achiral NADA molecules can form chiral LB films through overcrowded packing of the azobenzene moiety.     

Intravesical BCG therapy for superficial bladder cancer

Intravesical instillation of Tokyo 172 strain bacillus Calmette-Guerin (BCG) after transurethral resection of bladder tumor (TUR-Bt) was applied to 35 patients with superficial bladder cancer. The patients received 80 mg of BCG in 40 ml saline infused into the bladder once a week for 6 weeks. Actuarial non-recurrence rates for all 35 patients were 81.7% and 58.4% at one and two years after the BCG therapy, respectively. The recurrence of the bladder cancer after the BCG therapy was observed in 12 patients 3-27 months later. Seven patients received an additional course of BCG instillation, and 6 (86%) showed no further recurrence. Thus, the overall success rate of 2 cycles of BCG instillation was 83% (29 of 35 patients). Moreover, in some cases intravesical BCG instillation was effective for recurrent superficial bladder cancer after intravesical instillation of anti-cancer agents and prolonged the period until recurrence. The progression rate was only 5% (2 of 35 patients). These results suggest that intravesical BCG therapy for superficial bladder cancer helps prevent disease progression.