Some Effects of Stator Cone Angle and Blade-tip Leakage on 40 Percent Reaction Turbine Having Rotor-blade Caps

An investigation of the effects of stator cone angle and tip leakage on turbine performance

(OC-6-35)-(2,2′-Bipyridine-κ2 N,N′)dimeth­yl(3-sulfido­propionato-κ2 S,O)platinum(IV)

The title complex, [Pt(CH3)2(SCH2CH2CO2)(C10H8N2)], is formed by the unusual oxidative addition of the disulfide, R 2S2 (R = CH2CH2CO2H), to (2,2′-bipyridine)­dimethyl­platin­um(II) with elimination of RSH. The product contains an unusual six-membered thiol­ate–carboxyl­ate chelate ring. This slightly distorted octa­hedral complex exhibits cis angles ranging from 77.55 (11) to 97.30 (8)° due to the presence of the thiol­ate–carboxyl­ate chelate ring and the constrained bipyridine group. The crystal packing appears to be controlled by a combination of π-stacking [centroid–centroid distance = 3.611 (2) Å] and C—H⋯O inter­actions

Experimental and Modeling Improvements to a Co-Fluid Cycle Utilizing Ionic Liquids and Carbon Dioxide

Carbon dioxide is undergoing a renaissance as an alternative to synthetic refrigerants due to its environmental advantages in addition to a high density and excellent transport properties. A weakness of carbon dioxide is having a critical point which occurs at a lower temperature and higher pressure than most other fluids used as refrigerants. This combination leads to high operating pressures, especially on the heat rejection side of the thermodynamic cycle. Ionic liquids, which are salts which remain in their liquid phase at room temperatures, have been shown to strongly absorb carbon dioxide. Due to recent advances in ionic liquids, the cation and anion groups are able to be formulated to tailor a variety of fluid properties including liquid-vapor equilibrium characteristics. By selecting appropriate ionic liquids, it is possible to reduce the operating pressure of an air-conditioning system utilizing carbon dioxide to be in the range of conventional refrigerants. Not only are ionic liquids able to physically absorb volatile refrigerants as in other co-fluid cycles, but ionic liquids also offer the possibility of chemical absorption thereby giving the opportunity for greater enthalpy changes. Conceptually, the ionic co-fluid cycle is similar to a traditional vapor compression cycle. In the high pressure heat exchanger, heat is rejected to lower the enthalpy and to absorb carbon dioxide into the ionic liquid. The enthalpy is further reduced in an internal heat exchanger before the high pressure liquid is passed through a valve to decrease the pressure which causes the fluid mixture to cool. Heat is absorbed by the mixture from the environment, thus boiling additional carbon dioxide. After passing through an internal heat exchanger, the fluid is mechanically compressed and the cycle is repeated. System modeling work was utilized to identify important thermodynamic characteristics for achieving good performance. These characteristics included heats of mixing, solubility, entropy of mixing, and viscosity. Using experimentally and numerically determined IL-CO2 mixture properties, system models were able to predicatively select anion and cation pairs for optimizing performance. The ionic liquids selected from the modeling exercises were subsequently synthesized for demonstration in a laboratory. An air conditioning system was built from components designed for use with conventional refrigerants. The system was installed in a facility which was instrumented to measure air and refrigerant pressures and temperatures. Air flow rate and temperature information allowed the cooling capacity to be measured. The power consumption of the pump and compressor used to circulate the working fluids was measured so that COP could be determined. Modeling results were validated with experimental findings. The emphasis of modeling and experiments was to determine the effect of operational parameters on system performance. The loading of ionic liquid and carbon dioxide, along with valve opening and compressor speed, was found to dramatically alter the operating pressures. The difference and ratio between high and low side pressures directly affected the specific cooling capacity and COP, respectively. While the model had strong agreement with the experimental results, non-idealities to be incorporated in more sophisticated models are identified

The rad18 Gene of Schizosaccharomyces pombe Defines a New Subgroup of the SMC Superfamily Involved in DNA Repair

The rad18 mutant of Schizosaccharomyces pombe is very sensitive to killing by both UV and ¿ radiation. We have cloned and sequenced the rad18 gene and isolated and sequenced its homolog from Saccharomyces cerevisiae, designated RHC18. The predicted Rad18 protein has all the structural properties characteristic of the SMC family of proteins, suggesting a motor function- the first implicated in DNA repair. Gene deletion shows that both rad18 and RHC18 are essential for proliferation. Genetic and biochemical analyses suggest that the product of the rad18 gene acts in a DNA repair pathway for removal of UV-induced DNA damage that is distinct from classical nucleotide excision repair. This second repair pathway involves the products of the rhp51 gene (the homolog of the RAD51 gene of S. cerevisiae) and the rad2 gene

Mapping genomic and transcriptomic alterations spatially in epithelial cells adjacent to human breast carcinoma.

Almost all genomic studies of breast cancer have focused on well-established tumours because it is technically challenging to study the earliest mutational events occurring in human breast epithelial cells. To address this we created a unique dataset of epithelial samples ductoscopically obtained from ducts leading to breast carcinomas and matched samples from ducts on the opposite side of the nipple. Here, we demonstrate that perturbations in mRNA abundance, with increasing proximity to tumour, cannot be explained by copy number aberrations. Rather, we find a possibility of field cancerization surrounding the primary tumour by constructing a classifier that evaluates where epithelial samples were obtained relative to a tumour (cross-validated micro-averaged AUC = 0.74). We implement a spectral co-clustering algorithm to define biclusters. Relating to over-represented bicluster pathways, we further validate two genes with tissue microarrays and in vitro experiments. We highlight evidence suggesting that bicluster perturbation occurs early in tumour development

The 74MHz System on the Very Large Array

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and resolution (~25 arcsec) for low-frequency observations. We review the hardware, the calibration and imaging strategies, comparing them to those at higher frequencies, including aspects of interference excision and wide-field imaging. Ionospheric phase fluctuations pose the major difficulty in calibrating the array. Over restricted fields of view or at times of extremely quiescent ionospheric ``weather'', an angle-invariant calibration strategy can be used. In this approach a single phase correction is devised for each antenna, typically via self-calibration. Over larger fields of view or at times of more normal ionospheric ``weather'' when the ionospheric isoplanatic patch size is smaller than the field of view, we adopt a field-based strategy in which the phase correction depends upon location within the field of view. This second calibration strategy was implemented by modeling the ionosphere above the array using Zernike polynomials. Images of 3C sources of moderate strength are provided as examples of routine, angle-invariant calibration and imaging. Flux density measurements indicate that the 74 MHz flux scale at the VLA is stable to a few percent, and tied to the Baars et al. value of Cygnus A at the 5 percent level. We also present an example of a wide-field image, devoid of bright objects and containing hundreds of weaker sources, constructed from the field-based calibration. We close with a summary of lessons the 74 MHz system offers as a model for new and developing low-frequency telescopes. (Abridged)Comment: 73 pages, 46 jpeg figures, to appear in ApJ

Probing Cation Antisite Disorder in Gd2Ti2O7 Pyrochlore by Site-specific NEXAFS and XPS

Disorder in Gd2Ti2O7 is investigated by near-edge x-ray-absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS). NEXAFS shows Ti4+ ions occupy octahedral sites with a tetragonal distortion induced by vacant oxygen sites. O 1s XPS spectra obtained with a charge neutralization system from Gd2Ti2O7(100) and the Gd2Ti2O7 pyrochlore used by Chen et al. [Phys. Rev. Lett. 88, 105901 (2002)], both yielded a single peak, unlike the previous result on the latter that found two peaks. The current results give no evidence for an anisotropic distribution of Ti and O. The extra features reported in the aforementioned communication resulted from charging effects and incomplete surface cleaning. Thus, a result confirming the direct observation of simultaneous cation-anion antisite disordering and lending credence to the split vacancy model has been clarified

OCTANE (ontario-wide cancer targeted nucleic acid evaluation): A platform for intraprovincial, national, and international clinical data-sharing

Cancer is a genetic disease resulting from germline or somatic genetic aberrations. Rapid progress in the field of genomics in recent years is allowing for increased characterization and understanding of the various forms of the disease. The Ontario-wide Cancer Targeted Nucleic Acid Evaluation (octane) clinical trial, open at cancer centres across Ontario, aims to increase access to genomic sequencing of tumours and to facilitate the collection of clinical data related to enrolled patients and their clinical outcomes. The study is designed to assess the clinical utility of next-generation sequencing (ngs) in cancer patient care, including enhancement of treatment options available to patients. A core aim of the study is to encourage collaboration between cancer hospitals within Ontario while also increasing international collaboration in terms of sharing the newly generated data. The single-payer provincial health care system in Ontario provides a unique opportunity to develop a province-wide registry of ngs testing and a repository of genomically characterized, clinically annotated samples. It also provides an important opportunity to use province-wide real-world data to evaluate outcomes and the cost of ngs for patients with advanced cancer. The octane study is attempting to translate knowledge to help deliver precision oncology in a Canadian environment. In this article, we discuss the background to the study and its implementation, current status, and future directions