Thermodynamic and heat transfer analysis of heat recovery from engine test cell by Organic Rankine Cycle

During manufacture of engines, evaluation of engine performance is essential. This is accomplished in test cells. During the test, a significant portion of heat energy released by the fuel is wasted. In this study, in order to recover these heat losses, Organic Rankine Cycle (ORC) is recommended. The study has been conducted assuming the diesel oil to be composed of a single hydrocarbon such as C₁₂H₂₆. The composition of exhaust gases (products of combustion) have been computed (and not determined experimentally) from the stoichiometric equation representing the combustion reaction. The test cell heat losses are recovered in three separate heat exchangers (preheater, evaporator and superheater). These heat exchangers are separately designed, and the whole system is analyzed from energy and exergy viewpoints. Finally, a parametric study is performed to investigate the effect of different variables on the system performance characteristics such as the ORC net power, heat exchangers effectiveness, the first law efficiency, exergy destruction and heat transfer surfaces. The results of the study show that by utilizing ORC, heat recovery equivalent to 8.85 % of the engine power is possible. The evaporator has the highest exergy destruction rate, while the pump has the lowest among the system components. Heat transfer surfaces are calculated to be 173.6, 58.7, and 11.87 m² for the preheater, evaporator and superheater, respectively.     

Laser excited fluorescence of I2

The fluorescence spectrum of iodine was investigated from 200 to 520 nm in the presence and absence of buffer gases following excitation of I₂ with 193 nm photons. The pressure dependence of the fluorescence and tentative transition assignments for one new and several less well-known I₂ emission bands are discussed.     

High‐Throughput Measurement of Binding Kinetics by mRNA Display and Next‐Generation Sequencing

There is great demand for high‐throughput methods to characterize ligand affinity. By combining mRNA display with next‐generation sequencing, we determined the kinetic on‐ and off‐rates for over twenty thousand ligands without the need for synthesis or purification of individual members. Our results are reproducible and as accurate as those obtained with other methods of affinity measurement.     

Tempered Fractional Stable Motion

Tempered fractional stable motion adds an exponential tempering to the power-law kernel in a linear fractional stable motion, or a shift to the power-law filter in a harmonizable fractional stable motion. Increments from a stationary time series that can exhibit semi-long-range dependence. This paper develops the basic theory of tempered fractional stable processes, including dependence structure, sample path behavior, local times, and local nondeterminism.     

Borate,lithium borate,and borophosphate powders by sol–gel precipitation

Borate, lithium borate and borophosphate powders were synthesized by the sol–gel method. Triethyl borate, lithium methoxide, and orthophosphoric acid were used as precursors for B₂O_3, Li₂O, and P₂O₅, respectively. Powders were characterized by FTIR, DTA, XRD and SEM techniques. Powders from the Li₂O–B₂O₃ system exhibited glassy features while borate and borophosphate powders contained mainly crystalline B₂O₃ according to XRD analysis. However, a 500 °C heat treatment transformed these crystalline powders into glass powders. Conversely, heat treatment of Li₂O–B₂O₃ powders transformed their structure from glassy to crystalline (Li₂B₄O₇). Chemical durability studies conducted in water at 60 °C showed that minor additions of P₂O₅ into borate and lithium borate powders improved their chemical durability significantly. Furthermore, Li₂O and P₂O₅ acted synergistically on the chemical durability when added simultaneously to borate compositions.