Unsteadiness in a ramjet model

The process of combustion of a hydrocarbon fuel in a pulsed mode is discussed on the basis of results of ramjet testing in an external flow modeling a Mach 5 flight.     

Purification of an Inducible DNase from a Thermophilic Fungus

The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 μm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the presence of DNA and/or deoxyribose. Static growth of the organism resulted in significantly higher DNase production than agitated growth. The DNase was purified 145-fold using a novel affinity membrane purification system with 25% of the initial enzyme activity remaining. Electrophoresis of the purified enzyme resulted in a single protein band, indicating DNase homogeneity.     

Continuous logic in problems of finite automata dynamics

A technique for ordering, classification, and unification of fuzzy (continuous) logic formulas describing dynamical processes in finite automata is proposed. On the example of the class of automata without memory and with simplest input action, it is shown that the technique makes it possible to significantly (in several times) reduce the number of necessary formulas.     

Creative heritage of Vyacheslav Sergeevich Tanaev: Seventieth anniversary

The main stages of life and scientific activity of V.S. Tanaev, as well as his basic scientific findings in the scheduling theory, decomposition of the optimization problems, and other fields of the applied mathematics are outlined in brief.     

Rate design for a decarbonizing grid

The Western U.S. electric grid has undergone vast changes since the pre-renewables era. For example, renewables now comprise nearly 30% of California’s electric supply portfolio, and recent CA legislation mandates 50% renewables by 2030. As a consequence, intra-day variation in hourly net loads is rapidly steepening, as shown by the California Independent System Operator (CAISO)’s now famous ‘Duck Curve”. In 2015, CAISO recommended a four-season TOU pricing period design, with peak hours between 4?PM and 9?PM on summer weekdays, and a “super-off-peak” period in spring mid-day hours. We present an aggressive four-season time-of-use (TOU) rate design based on CAISO’s recommended TOU periods, and some illustrative impacts of implementing such TOU rates.In Western U.S. energy markets, high wholesale prices generally correspond to high marginal carbon emissions, and conversely. Properly designed TOU rates can help reduce GHG emissions by discouraging energy use during times of high marginal carbon emissions. However, demand charges, a feature of many commercial rate designs, can negate the benefits of TOU rates if applied during off-peak hours. We show that overuse of non-coincident demand charges can discourage customer investments that would benefit both the customer and the grid if rates were correctly aligned with cost. We recommend the following pricing strategies to support long-term efforts toward decarbonization of the electric grid: (1) More widespread use of aggressive 3- or 4-season TOU rates (or RTP where feasible); and (2) Reduced dependence on demand charges that apply during off-peak hours. Widespread utilization of retail rates that are aligned with temporal variation in carbon intensity, by both residential and nonresidential customers, is essential, for achievement of decarbonization goals.

Phosphoproteomic Analysis of Subcutaneous and Omental Adipose Tissue Reveals Increased Lipid Turnover in Dairy Cows Supplemented with Conjugated Linoleic Acid

Phosphoproteomics is a cutting-edge technique that can be utilized to explore adipose tissue (AT) metabolism by quantifying the repertoire of phospho-peptides (PP) in AT. Dairy cows were supplemented with conjugated linoleic acid (CLA, n = 5) or a control diet (CON, n = 5) from 63 d prepartum to 63 d postpartum; cows were slaughtered at 63 d postpartum and AT was collected. We performed a quantitative phosphoproteomics analysis of subcutaneous (SC) and omental (OM) AT using nanoUPLC-MS/MS and examined the effects of CLA supplementation on the change in the phosphoproteome. A total of 5919 PP were detected in AT, and the abundance of 854 (14.4%) were differential between CON and CLA AT (p ≤ 0.05 and fold change ± 1.5). The abundance of 470 PP (7.9%) differed between OM and SC AT, and the interaction treatment vs. AT depot was significant for 205 PP (3.5% of total PP). The integrated phosphoproteome demonstrated the up- and downregulation of PP from proteins related to lipolysis and lipogenesis, and phosphorylation events in multiple pathways, including the regulation of lipolysis in adipocytes, mTOR signaling, insulin signaling, AMPK signaling, and glycolysis. The differential regulation of phosphosite on a serine residue (S777) of fatty acid synthase (FASN) in AT of CLA-supplemented cows was related to lipogenesis and with more phosphorylation sites compared to acetyl-coenzyme A synthetase (ACSS2). Increased protein phosphorylation was seen in acetyl-CoA carboxylase 1 (ACACA;8 PP), FASN (9 PP), hormone sensitive lipase (LIPE;6 PP), perilipin (PLIN;3 PP), and diacylglycerol lipase alpha (DAGLA;1 PP) in CLA vs. CON AT. The relative gene expression in the SC and OM AT revealed an increase in LIPE and FASN in CLA compared to CON AT. In addition, the expression of DAGLA, which is a lipid metabolism enzyme related to the endocannabinoid system, was 1.6-fold higher in CLA vs. CON AT, and the expression of the cannabinoid receptor CNR1 was reduced in CLA vs. CON AT. Immunoblots of SC and OM AT showed an increased abundance of FASN and a lower abundance of CB1 in CLA vs. CON. This study presents a complete map of the SC and the OM AT phosphoproteome in dairy cows following CLA supplementation and discloses many unknown phosphorylation sites, suggestive of increased lipid turnover in AT, for further functional investigation.     

A New Method to Determine the Number Concentrations of Refractory Black Carbon Ice Nucleating Particles

Ice nucleating particles (INP) initiate heterogeneous ice nucleation in mixed-phase clouds, influencing cloud phase and onset temperatures for ice formation. Determination of particle types contributing to atmospheric INP populations requires isolation of the relatively rare INP from a total particle sample, typically followed by time-consuming single-particle characterization. We propose a method to estimate the contributions of light-absorbing, primarily refractory black carbon (rBC), particles to INP populations by selectively removing them prior to determination of INP concentrations. Absorbing particles are heated to their vaporization temperature using laser induced incandescence in a single particle soot photometer (SP2) and the change in INP number concentrations, compared to unheated samples, is assessed downstream in the CSU Continuous Flow Diffusion Chamber (CFDC). We tested this approach in the laboratory using strongly-absorbing and nonabsorbing aerosol types to confirm effective removal of rBC INP and to explore the impact of the processing on non-light-absorbing INP. An INP-active rBC particle type was efficiently removed, while nonabsorbing kaolinite and a soil-based INP were not affected by laser exposure. Results for the products of wiregrass combustion indicated that absorbing particles, primarily rBC, accounted for about 40% of all INP, consistent with electron microscopy of INP emitted during prescribed burns of this fuel type. However, kaolinite internally mixed with rBC exhibited reduced activity after passing through the SP2, suggesting that the validity of the method for realistic internal mixtures needs additional research. The sensitivity of the CFDC presently limits applicability of the method to relatively high INP number concentration samples.

Copyright 2014 American Association for Aerosol Research