Should Reversible Convective Inhibition be Used when Determining the Inflow Layer of a Convective Storm?

Convective inhibition (CIN) is one of the parameters used by forecasters to determine the inflow layer of a convective storm, but little work has examined the best way to compute CIN. One decision that must be made is whether to lift parcels following a pseudoadiabat (removing hydrometeors as the parcel ascends) or reversible moist adiabat (retaining hydrometeors). To determine which option is best, idealized simulations of ordinary convection are examined using a variety of base states with different reversible CIN values for parcels originating in the lowest 500 m. Parcel trajectories suggest that ascent over the lowest few kilometers, where CIN is typically accumulated, is best conceptualized as a reversible moist adiabatic process instead of a pseudoadiabatic process. Most inflow layers do not contain parcels with substantial reversible CIN, despite these parcels possessing ample convective available potential energy and minimal pseudoadiabatic CIN. If a stronger initiation method is used, or hydrometeor loading is ignored, simulations can ingest more parcels with large amounts of reversible CIN. These results suggest that reversible CIN, not pseudoadiabatic CIN, is the physically relevant way to compute CIN and that forecasters may benefit from examining reversible CIN instead of pseudoadiabatic CIN when determining the inflow layer.

Experimental implementation of precisely tailored light-matter interaction via inverse engineering

Accurate and efficient quantum control in the presence of constraints and decoherence is a requirement and a challenge in quantum information processing. Shortcuts to adiabaticity, originally proposed to speed up the slow adiabatic process, have nowadays become versatile toolboxes for preparing states or controlling the quantum dynamics. Unique shortcut designs are required for each quantum system with intrinsic physical constraints, imperfections, and noise. Here, we implement fast and robust control for the state preparation and state engineering in a rare-earth ions system. Specifically, the interacting pulses are inversely engineered and further optimized with respect to inhomogeneities of the ensemble and the unwanted interaction with other qubits. We demonstrate that our protocols surpass the conventional adiabatic schemes, by reducing the decoherence from the excited-state decay and inhomogeneous broadening. The results presented here are applicable to other noisy intermediate-scale quantum systems.

Structure, thermoelectric and electrical properties of bismuth-manganese oxide prepared by mechanochemical method

Production of nanomaterials by mechanochemical synthesis is one of the important modern methods in new technology. Mechanochemical technique followed by heat treatment has been used to produce bismuth-manganese oxide from bismuth oxide and manganese dioxide. X-Ray Diffraction (XRD) analysis is conducted evaluate the structure changes during the mechanochemical process. Structure transformation from crystalline to complete amorphous phase was observed after short time of milling. The amorphization mechanism and reaction kinetics are examined in the light of the processing parameters and materials composition. Interdiffusion and distraction of the long rang order structure are the proposed mechanisms for amorphization. Bismuth manganese oxide phase with chemical formula Bi2Mn4O10 was formed after heat treatment at 1073 K. Bi2Mn4O10 partially decomposed to γ-Bi12.8O19.2 and α-Mn2O3. Crystallite size (47.6–102.4 nm) of the formed phases after heat treatment is significantly affecting the electrical properties. Thermoelectric power (S) of present samples was reported and the fraction C of reduced transition metal ions was calculated. The manganese ions concentration N were calculated and found to be increasing from 1.11 X1022 cm− 3 to 1.38 X1022 cm− 3, while the average distance between manganese ions R increased from 0.623nm to 0.647nm. The hopping carrier mobility (µ) of the prepared samples was also calculated at fixed temperature. From studying the conduction mechanism, the present work was found to agree with non-adiabatic process of small polaron hopping.

Efficiency at maximum power of quantum-mechanical Carnot engine enhanced by energy quantization

In an adiabatic process, the change in energies of select states may be inhomogenously scaled due to energy quantization. To illustrate this, we introduce a [Formula: see text] barrier turning up (turning down) in an adiabatic expansion (compression). We consider a quantum-mechanical Carnot engine employing a single particle confined in an infinite potential, assuming only the lowest two energy levels to be occupied. This cyclic engine model consists of two isoenergetic strokes where the system is alternatively coupled to two energy baths, and two adiabatic processes where the potential is adiabatically deformed with turning up or down a [Formula: see text] barrier. Having obtained the work output and efficiency, we analyze the efficiency at maximum power under the assumption that the potential moves at a very slow speed. We show that the efficiency at maximum power can be enhanced by energy quantization.

Experimental Investigation of Thermal Performance of Aluminum Foil Coated with Polyester in a Direct Evaporative Cooling System

An experimental study was carried out for an evaporative cooling system in order to investigate the effect of using an aluminum pad coated with fabric polyester. In the present work, it was considered to use a new different type of cooling medium and test its performance during the change in the wet-bulb temperature and dry-bulb temperature of the supply air outside of the pad, the relative humidity of the supply air, the amount of air supplied (300-600) CFM and also the change of the amount of circulated water (1.75, 2.5, 4.5) liter per minute. A decrease in the WBT of the air was obtained, whereas the WBT of the air entering the pad was 26.5 . In contrast, the WBT of the outside air had reached 23 even though evaporative cooling is an adiabatic process which makes the WBT of the air that comes out of the pad is equal to the entering air WBT. The decrease in DBT is by changing the amount of air and water passing through the aluminum pad, whereas the DBT of the air entering the pad was 45 , while the DBT of the outside air had reached 29 . Also, an essential thing was obtained as this rise in the relative humidity of the air is very small 57%RH compared to the conventional pads, and this gives a positive impression as the air supplied from this pad has less moisture and its ability to carry moisture is much higher than that of air supplied from other pads. This gives a positive impression because the air supplied from this pad has lower humidity and its ability to hold moisture much higher than the air supplied from other traditional pads.

Analysis of the adiabatic process by using the thermodynamic property diagram of water vapor

In the steam power plant, the working medium used for energy transformation is water vapor. The thermodynamic properties of water vapor are usually obtained by using water vapor tables and charts. Adiabatic process of water vapor is widespread in engineering applications. The adiabatic process is realized without heat addition or rejection and the entropy of the working medium during a reversible adiabatic process remains constant. During an adiabatic expansion process, superheated steam turns into saturated vapor , and further into wet vapor, the pressure and the temperature of the steam decreases. The entropy during a irreversible adiabatic process increases. In general, when analyzing the thermodynamic process of water vapor, we first determine the state parameters by using charts and tables, and then make relevant calculations according to the first law of thermodynamics.

A theoretical analysis of temperature rise of hydrogen in high-pressure storage cylinder during fast filling process

During the fast filing process, thermal stress is generated due to the increase in the pressure and temperature of hydrogen in the hydrogen storage tank. For its safety purpose, it is necessary to predict and control the temperature change in the tank. The aim of this study is quantitative analysis of the final temperature and the mass of the hydrogen in the tank through experimental and theoretical methods. In this paper; Theoretical model for adiabatic and non-adiabatic real filling processes of high pressure hydrogen cylinder has been proposed. The cycle of filling process from the initial vacuum state is called the “First cycle.” After the first cycle is completed, there is a certain residual pressure in the tank. Then the second filling process called “Second cycle” begins. The final temperature in fast filling of hydrogen storage cylinders depends on targeted pressure, initial pressure and temperature, and mass filling rate. The final temperature of hydrogen in the tank was calculated from the real gas equation of state, mass and energy conservation equations. As a result of the analysis, based on the first cycle analysis of high pressure tank, the final temperatures were calculated to be 442.11 K for the adiabatic filling process, and 422.37 K for the non-adiabatic process. Based on the second cycle analysis of high pressure tank, the final temperature were obtained as 397.12 K and 380.8 K for the adiabatic and non-adiabatic processes, respectively. The temperatures calculated from the theoretical non-adiabatic condition were lower than those from the adiabatic condition by 5%. The results of this study can provide a reference basis in terms of how to control the temperature in the actual hydrogen storage tank during the fast filling process and how to improve safety.