Hydration of propylene oxide using ion-exchange resin catalyst in a slurry reactor

Kinetics of hydration of propylene oxide using an ion-exchange resin catalyst in a slurry reactor was studied. The kinetics of homogeneous, uncatalyzed reaction was studied separately and used to obtain heterogeneous reaction kinetics. The homogeneous reaction was found to be 0.43 order with respect to propylene oxide concentration. The heterogeneous reaction was found to have intraparticle diffusional resistance under certain conditions. The intrinsic kinetic parameters and effective diffusivity were obtained from these data. The heterogeneous reaction was found to be 0.55 order with respect to propylene oxide concentration. The activation energies obtained for homogeneous and heterogeneous reactions were 51.5 and 53.4 kJ/mol, respectively. A theoretical model incorporating all the mass transfer resistances has been proposed.     

The design, analysis, and development of highly manufacturable 6-T SRAM bitcells for SoC applications

We present here an extensive static random access memory (SRAM) bitcell development methodology that has led to the qualification and production of the smallest 6-T SRAM bitcell reported in 0.13-/spl mu/m CMOS technology. No additional processing steps were employed in accomplishing this result. Such a methodology is being extended also to subsequent technology generations. The development efforts included the electrical evaluation of several candidate 6-T SRAM bitcell architectures for both high-density and high-speed applications. Based on the electrical evaluations, the chosen cell architectures were incorporated in silicon and verified for their robustness with respect to critical design rules, yields and reliability. The methodology for optical proximity correction for bitcell development has been described here. Minor process enhancements to ensure compatibility of the overall process flow with the SRAM bitcells are described. The use of SRAM-specific electrical test structures serves an important role in validating the electrical performance and confirming the robustness of the bitcells in a manufacturing environment. The monitoring of V/sub ddmin/, the minimum voltage at which the memory is functional was used to drive overall process improvements and reliability. Lastly, measurements of soft error rates demonstrated excellent immunity of the bitcells to single event upsets.     

The Cr−Po (Chromium-polonium) system

This work was supported in part by ASM INTERNATIONAL under Grant No. FG-104-1A and in part by the National Science Foundation through the Joint Program on Critical Compilation of Physical and Chemical Data coordinated through the Office of Standard Reference Data, National Bureau of Standards. Literature searched through 1985. Professor Neumann is the ASM/NBS Data Program Category Editor for binary chromium alloys, and Dr. Peterson is the ASM/NBS Data Program Category Editor for binary actinide alloys.     

Protic Ionic Liquid Assisted Synthesis and Characterization of Ferromagnetic Cobalt Oxide Nanocatalyst

Cobalt oxide (Co₃O₄) nanocatalyst was synthesized by sol-gel method using the protic ionic liquid namely 1-butylimidazolium glycolate as solvent and stabilizer. The obtained Co₃O₄ nanocatalyst was characterized by powder X-ray diffraction (XRD), Fourier transform infrared, High resolution scanning electron microscopy (HR-SEM), Energy dispersive X-ray (EDX), High resolution transmission electron microscopy (HR-TEM), Selected area electron diffraction, UV–Visible diffuse reflectance spectroscopy, Photoluminescence spectroscopy, Brunauer–Emmett–Teller surface area and Vibrating sample magnetometer (VSM). Powder XRD results showed the well-crystalline cubic structure of synthesized Co₃O₄ with size of 19.29 nm. Also, the sphere-like morphology of Co₃O₄ nanocatalyst was confirmed by HR-SEM and HR-TEM images. Furthermore, the synthesized Co₃O₄ nanocatalyst possessed optical band gap values of 1.75 and 2.46 eV and hence acted as a semiconducting material. In addition, the presence of small hysteresis loop in Magnetic measurement (VSM) confirmed the ferromagnetic nature of Co₃O₄ nanoparticles. Moreover, the synthesized Co₃O₄ nanocatalyst found to be used in photo-catalytic degradation of methylene blue and exhibited 94.61% efficiency.     

Influence of genotype on diet-induced changes in membrane phosphatidylcholine and phosphatidylethanolamine composition of splenocytes,liver nuclear envelope and liver mitochondria

Inbred congenic mice of strains MRL/Mp-lpr/lpr (lpr/lpr) and MRL/Mp-+/+ (+/+) were fed nutritionally adequate semipurified diets containing 20% (w/w) fat and differing in linoleic acid content. Levels of linoleic acid (18∶2n−6) and arachidonic acid (20∶4n−6) in phospholipids of splenocytes, liver mitochondria and liver nuclear envelopes were determined. Membranes of lpr/lpr mice exhibited significantly lower levels of 18∶2n−6 and 20∶4n−6 in phospholipids compared with the +/+ strain. The high linoleic acid diet increased incorporation of 18∶2n−6 and 20∶4n−6 in most phospholipid fractions of these membranes. These observations indicate that genotype as well as dietary 18∶2n−6 content significantly influenced incorporation of 18∶2n−6 and 20∶4n−6 into membrane phospholipids. The results also suggest that membrane compositional abnormalities found in the lpr/lpr mice, which develop lymphoma and age faster than +/+ mice, are not restricted to the immune system but also extend to other organs. Differences observed in phospholipid fatty acid composition in splenocytes and liver subcellular membranes for mice fed diets differing in linoleic acid content suggest that the early expression of the lpr gene resulting in progression of autoimmunity may be delayed through dietary manipulation.     

Effects of n−3 and n−6 fatty acids on the activities and expression of hepatic antioxidant enzymes in autoimmune-prone NZB×NZW F1 mice

Menhaden fish oil (FO) containing n−3 fatty acids dramatically extends the life span and delays the onset and progression of autoimmune disease in (NZB×NZW)F₁ (B/W) female mice as compared to those fed corn oil (CO) rich in n−6 lipids. As an inefficient antioxidant defense system has been linked to autoimmune diseases, the present study was undertaken to determine whether the protective action of n−3 lipids is mediated through their antioxidant defense system. Weanling B/W mice were fed a nutritionally adequate, semipurified diet containing CO or krill oil (KO) or FO at 10% level (w/w)ad libitum until the mice were 6.5 months old. All diets contained the same level of vitamin E (21.5 mg/100 g diet). We compared the effects of feeding n−6 and n−3 lipids on survival, kidney disease, hepatic microsomal lipid composition, peroxidation, and on the activity and mRNA expression of the antioxidant enzymes catalase, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in 6.5-month-old B/W mice. The results showed that when compared to livers from CO-fed mice, livers from KO- and FO-fed mice showed: (i) significantly higher (P<0.001) activities and expression of CAT, GSH-Px and SOD; (ii) significantly lower (P<0.001) arachidonic acid (20∶4n−6) and linoleic acid (18∶2n−6) and higher (P<0.001) eicosapentaenoic acid (20∶5n−3) and docosahexaenoic acid (22∶6n−3) levels in hepatic microsomes; and (iii) significantly lower (P<0.001) estimated peroxidation indices and thiobarbituric acid reactive substances generation. The data indicate that one of the mechanisms through which the n−3 lipids delay the onset of autoimmune diseases in B/W mice may be through maintenance of higher activities and expression of hepatic antioxidant enzymes.     

Structure-Optical Property Correlation of Epitaxial Potassium Niobate Thin Films Deposited on Magnesium Oxide (100) Substrates Using a Strontium Titanate Transition Layer

Epitaxial thin films of orthorhombic KNbO₃ (100)/(010) were deposited on MgO (100) single-crystal substrates by pulsed laser ablation using an ε120 Å SrTiO₃ (110) transition layer in between. From X-ray diffraction, the orientation relationships were determined as (010) [100] or (100) [010] KNb0₃∥ (110) [110] SrTiO₃∥ (100) [011] MgO and (010) [001] or (100) [001] KNbO₃∥ (110) [001] SrTiO₃∥ (100) [011] MgO. The measured film refractive indices at 632.8 nm were 2.213 ± 0.003, 2.278 ± 0.003, and 2.285 ± 0.003, respectively, along MgO [100], [011], and [011] directions. A model was developed to correlate the measured effective refractive indices of the film to area fractions of domain variants in the film. Using the model, the area fraction of domains with their polarization axis normal to the substrate was estimated to be 60.0 ± 2.7%.     

Sizing up models of heart failure: Proteomics from flies to humans

Cardiovascular disease is the leading cause of death in the western world. Heart failure is a heterogeneous and complex syndrome, arising from various etiologies, which result in cellular phenotypes that vary from patient to patient. The ability to utilize genetic manipulation and biochemical experimentation in animal models has made them indispensable in the study of this chronic condition. Similarly, proteomics has been helpful for elucidating complicated cellular and molecular phenotypes and has the potential to identify circulating biomarkers and drug targets for therapeutic intervention. In this review, the use of human samples and animal model systems (pig, dog, rat, mouse, zebrafish, and fruit fly) in cardiac research is discussed. Additionally, the protein sequence homology between these species and the extent of conservation at the level of the phospho-proteome in major kinase signaling cascades involved in heart failure are investigated.