Determination of Young’s modulus and residual stress of electroless nickel using test structures fabricated in a new surface micromachining process

This paper reportsin situ measurement of Young’s modulus and residual stress of electroless nickel films through the use of microfabricated nickel test structures, including electrostatic microactuators and passive devices. Th test structures are fabricated in a new surface micromachining process, termed “nickel surface micromachining”, using electroless plated nickel as the structural layer and polysilicon as the sacrificial layer. Subsequent to fabrication, lateral resonant-type electrostatic microactuators of different geometries are resonated by electrical excitation. Using the measured resonant frequencies and knowledge of the device geometry, the Young’s modulus of the film is determined. The passive electroless nickel microstructures deform upon completion of the fabrication process due to residual stress in the film Measurement of this deformation in conjunction with an appropriate mechanical model is used to determine the residual stress in the films.     

Ultrastructural localization of DNA in leukemic cells using osmium ammine B

In order to determine whether there were any differences in distribution of nuclear DNA between acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), the localization of DNA in blasts from the bone marrow or buffy coat of 30 patients with ALL and 30 patients with AML was examined ultrastructurally by staining with osmium ammine B. By the ultrastructural cytochemistry, DNA in ALL cells was clumped in the nuclei, while in AML cells, it was dispersed. DNA had accumulated around the nucleoli of some blasts, and flecks of DNA were observed in nucleoli of a majority of blasts. The perinucleolar and intranucleolar DNA distribution could be classified into four types. The types with abundant perinucleolar DNA were frequently observed in ALL blasts, while the majority of AML blasts showed scant perinucleolar DNA. The types with intranucleolar flecks of DNA were more prominent in leukemic cells than in normal immature leukocytes. In conclusion, the pattern of distribution of DNA in the nuclei of leukemic cells differs between ALL and AML.     

A case of lymphoid interstitial pneumonia in a 3-month-old boy not associated with HIV infection: immunohistochemistry of lung biopsy specimens and serum transforming growth factor-beta 1 assay

Women have a higher stress fracture rate than men in military studies, although the exact cause of this is not clear. Hyperpronation has been implicated as a potential risk factor for injury. In this prospective observational study, we measured subtalar joint range of motion in 101 women (ages 20-27 years) enrolled in Marine Corps Officer Candidate School in June 1994. The purpose of this study was to identify risk factors for injury in female Marine Corps officer candidates. The primary area of interest was the association between the amount of subtalar joint range of motion and stress reactions. Questionnaires were administered that explored previous physical activities, sports participation, and menstrual history. Anthropometric measurements were performed, including subtalar joint range of motion. During the 10 weeks of physical training, 11.5% of the women (N = 12) had stress reactions compared with 7% of the men (N = 10). There was no statistically significant difference in the means of subtalar joint range of motion in the stress reaction group compared with the non-stress reaction group. Differences in stress reaction rate across quartiles of subtalar joint range of motion were not significant. Those women who ran fewer miles (< or = 2.8 miles per session) before training had a higher rate of stress reactions (p < 0.04). Younger individuals (< 23 years) had a higher rate of stress reactions (p < 0.01). Women with fewer menstrual periods (< 10 per year) had a higher rate of stress reactions (p < 0.02). A narrow pelvis (< or = 26 cm) was associated with a higher rate of stress reactions (p < 0.09). We conclude that an increased subtalar joint range of motion is not a risk factor for stress reactions in women. However, further studies with a larger study population should be performed to confirm these findings.     

A/O摇动床石化废水生物脱氮

摇动床反应器是由日本NET株式会社研发的一种新型的附着生长污水处理工艺,本文将A/O法应用到摇动床反应器中,研究了A/O摇动床对石化废水的生物脱氮效果,考察了硝化液回流比和进水负荷对脱氮效果的影响.实验结果表明,A/O摇动床对石化废水具有较好的脱氮效果,在进水COD浓度、NH⁺₄-N浓度、硝化液回流比和水力停留时间分别为400～600 mg&#8226;L^-1、20～40 mg&#8226;L^-1、2.5和26.1 h时,出水COD、NH⁺₄-N和TN浓度小于40 mg&#8226;L^-1、1.0 mg&#8226;L^-1、7.0 mg&#8226;L^-1,COD去除率、硝化率和反硝化率分别达到90%、95%和70%.     

Dielectric Properties of (Pb1–xXx) (Zr0.7Ti0.3)O3 (X = Ca, Sr, Ba) Ceramics

The dielectric properties of (Pb_{1– x} X_x) (Zr_0.7Ti_0.3)O₃ (X = Ca, Sr, Ba) ceramics (abbreviated PXZT) were investigated for applications to multilayer ceramic capacitors (MLCs) with dielectric layers thinner than 10 μm. The dissipation factors for MLCs with 5-μm-thick dielectric layers were estimated from those for 100-μm-thick disk specimens measured at an oscillation voltage of 20 V_rms. Those for PCZT and PSZT were less than 1.0% when the oscillation voltage was 20 V_rms, while those for conventional BaTiO₃-based dielectric ceramics were greater than 2.5% at 20 V_rms. According to polarization–electric field hysteresis measurements, PCZT and PSZT revealed linear and double hysteresis loops, respectively, while PBZT and BaTiO₃ indicated typical ferroelectric hysteresis loops. The differences in the dissipation factors for the dielectric compositions are attributed to hysteresis in the polarization–electric field loops. These results suggest that PCZT and PSZT are promising dielectric ceramics for MLCs with dielectric layers thinner than 10 μm.