Rooting Responses of Female and Male Cuttings of Leucadendron elimense E. Phillips subsp. elimense on the Type and Concentration of Auxin

Female and male plants of difficult-to-root species Leucadendron elimense subsp. elimense were investigated for rooting potential with three rooting hormones: indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA) at three different concentrations (2000 ppm, 4000 ppm, and 6000 ppm). The experiment was made under essential misting, bottom heat, and a naturally ventilated greenhouse. After 18 weeks the experiment terminated and callusing and rooting percentage, root number, and root length were determined. Female cuttings rooted in the highest percentage (80%), root number (>30), and root length (close to 100 mm) after treatment with IAA at 4000 ppm. Under the above treatment male cuttings rooted in 70%, with a mean root number of 24 and root length of 90 mm. The efficient rooting results could aid in saving the species in its natural habitat and supporting restoration ecology, as well as introducing this species into the flower market.

Development of an Experimental Apparatus for Studying High-Temperature Heat and Mass Transfer in Soils

The objective of this study was to design and build an experimental apparatus for studying heat and moisture transport phenomena in soils at temperatures greater than 40°C up to 90°C. An experimental soil cell was designed and constructed for experimental studies of one-dimensional heat and moisture transfer within a vertical soil column. The interference effect between two proximate TDR probes was examined for three types of soils and it was found that parallel TDR probes can interfere with each other if the distance between them is around 1 cm. Also, for the samples with higher water contents, the effect of interference on the electromagnetic waveform signals is more prominent, which can result in 15% uncertainty in the measurement of water content. Through the numerical study, four stages of design analysis were carried out to eventually reach a satisfactory design which was deemed to meet the research objective, i.e. less than 5% variation of heat fluxes in the radial direction along the soil cell. The experimental assessment of the final soil cell was first performed using dry Matilda soil. The temperature profile along the soil cell deviated from the linear temperature profile by 18.6% when the temperature level and gradient was high at 82.6°C and 90°C/m, respectively. At this condition, the difference of heat fluxes between the top and bottom heat flux meters was recorded to be 34%. This case is the worst case due to the low thermal conductivity of the dry soil. The experimental assessment of the final soil cell was also done for a wet Matilda soil at a degree of saturation of about 65%. The temperature profile along the soil cell had a maximum deviation of 7.7% from the linear temperature profile even when the temperature level of the soil cell was high at 82.1°C. At this condition, the difference of heat fluxes between the top and bottom heat flux meters was recorded to be 4.2%. After the reliability of the apparatus was assessed, nine cases of the wet soil were studied. The results show that the temperature gradient is the main driving force to cause moisture migration.

Development of an Experimental Apparatus for Studying High-Temperature Heat and Mass Transfer in Soils

The objective of this study was to design and build an experimental apparatus for studying heat and moisture transport phenomena in soils at temperatures greater than 40°C up to 90°C. An experimental soil cell was designed and constructed for experimental studies of one-dimensional heat and moisture transfer within a vertical soil column. The interference effect between two proximate TDR probes was examined for three types of soils and it was found that parallel TDR probes can interfere with each other if the distance between them is around 1 cm. Also, for the samples with higher water contents, the effect of interference on the electromagnetic waveform signals is more prominent, which can result in 15% uncertainty in the measurement of water content. Through the numerical study, four stages of design analysis were carried out to eventually reach a satisfactory design which was deemed to meet the research objective, i.e. less than 5% variation of heat fluxes in the radial direction along the soil cell. The experimental assessment of the final soil cell was first performed using dry Matilda soil. The temperature profile along the soil cell deviated from the linear temperature profile by 18.6% when the temperature level and gradient was high at 82.6°C and 90°C/m, respectively. At this condition, the difference of heat fluxes between the top and bottom heat flux meters was recorded to be 34%. This case is the worst case due to the low thermal conductivity of the dry soil. The experimental assessment of the final soil cell was also done for a wet Matilda soil at a degree of saturation of about 65%. The temperature profile along the soil cell had a maximum deviation of 7.7% from the linear temperature profile even when the temperature level of the soil cell was high at 82.1°C. At this condition, the difference of heat fluxes between the top and bottom heat flux meters was recorded to be 4.2%. After the reliability of the apparatus was assessed, nine cases of the wet soil were studied. The results show that the temperature gradient is the main driving force to cause moisture migration.

Nitric Oxide Emission Reduction in Reheating Furnaces through Burner and Furnace Air-Staged Combustions

In this study, a series of experiments were conducted on a testing facility and a real-scale furnace, for analyzing the nitric oxide (NO) emission reduction. The effects of the temperature, oxygen concentration, and amount of secondary combustion air were investigated in a single-burner combustion system. Additionally, the NO-reduction rate before and after combustion modifications in both the burner and furnace air-staged combustion were evaluated for a real-scale reheating furnace. The air-to-fuel equivalence ratio (λ) of individual combustion zones for the furnace was optimized for NO reduction without any incomplete combustion. The results indicated that the NO emission for controlling the λ of a single-zone decreased linearly with a decrease in the λ values in the individual firing tests (top-heat, bottom-heat, and bottom-soak zones). Moreover, the multi-zone control of the λ values for individual combustion zones was optimized at 1.13 (top-preheat), 1.0 (bottom-preheat), 1.0 (top-heat), 0.97 (bottom-heat), 1.0 (top-soak), and 0.97 (bottom-soak). In this firing condition, the modifications reduced the NO emissions by approximately 23%, as indicated by a comparison of the data obtained before and after the modifications. Thus, the combined application of burner and furnace air-staged combustions facilitated NO-emission reduction.

Modified coke breeze distribution in iron ore sintering - a novel technique of reducing energy consumption and improving quality

In normal sintering of iron ore, there is a wide difference in temperature of the sinter bed between top and bottom; i.e. the flame front temperature of the sinter bed gradually increases towards the bottom because the lower part gets longer time for drying and preheating by exit gas. Therefore, the top part may have insufficient fusion and the bottom is excessively fused. Thus, sinter quality may become inhomogeneous and the coke breeze requirement becomes higher than the actual thermal requirement. If it is charged in multiple layers; e.g. higher amount of coke at the top and a lower amount of coke at the bottom, heat will be homogeneously distributed and the actual coke requirement would be lower than the existing. However, no study has been done so far on this. Therefore, the current study explores the possibility of reducing energy consumption in iron ore sintering by reducing the coke ratio from top to bottom without deteriorating the sinter property. 12% reduction in coke breeze rate has been found and the sinter quality has been improved by the use of a triple layer of sinter mix with a lower coke rate towards the bottom. Further, when 5-vol% of oxygen has been enriched in suction gas along with using a triple layer of sinter mix, up to an 18-wt% reduction in coke breeze has been found.

Modeling of irreversible two-stage combined thermal Brownian refrigerators and their optimal performance

This paper establishes a model of an irreversible two-stage combined thermal Brownian refrigerator with an intermediate heat reservoir by combining finite time thermodynamics with non-equilibrium thermodynamics. The model is composed of two irreversible thermal Brownian refrigerators working in series. The combined thermal Brownian refrigerator works among three constant temperature heat reservoirs. There exist finite rate heat transfer processes among heat reservoirs and refrigerators. Considering heat leakage, heat transfer losses, and heat flows via kinetic energy change of particles, expressions of cooling load and the coefficient of performance (COP) are derived. The effects of design parameters on system performance are studied. The optimal performance of the irreversible combined thermal Brownian refrigerator is studied. The cooling load and COP are higher when the temperature of the intermediate heat reservoir is close to that of the bottom heat reservoir. Compared with the single-stage thermal Brownian refrigerator, which works between the heat source and sink with the same temperatures, the cooling load of the combined thermal Brownian refrigerator is greater, whereas the COP is smaller.

Multi-Objective Optimization of Activation Time and Discharge Time of Thermal Battery Using a Genetic Algorithm Approach

Activation time and discharge time are important criteria for the performance of thermal batteries. In this work a heat transfer analysis is carried out on the working process of thermal batteries. The effects of the thicknesses of heat pellets which are divided into three groups and that of the thickness of insulation layers on activation time and discharge time of thermal batteries are numerically studied using Fluent 15.0 when the sum of the thickness of heating plates and insulation layers remain unchanged. According to the numerical results, the optimal geometric parameters are obtained by using multi-objective genetic algorithm. The results show that the activation time is mainly determined by the thickness of the bottom heat pellet, while the discharge time is determined by the thickness of the heat pellets and that of the insulation layers. The discharge time of the optimized thermal battery is increased by 4.08%, and the activation time is increased by 1.23%.

Qualifying the TIG orbital welding technology of titanium pipes with a perforated bottom

The article presents the method of qualifying orbital welding technology using the TIG (142) method of the perforated bottom heat exchanger made of steel A516M (Grade 485) explosively clad with titanium B265 (Grade 1) with titanium pipes B338 (Grade 2) with a diameter of 34.93 mm and thickness 0.7 mm. Based on preliminary tests, welding technologies have been developed that meet the acceptance criteria for acceptance requirements. Qualification of the developed technology and welding parameters that were used during welding was carried out in accordance with PN-EN ISO 15614 Specification and qualification of metal welding technology, welding technology testing, Part 8: Welding of tubes with perforated bottom. This standard specifies the requirements for the qualification of automatic arc welding technology, metal pipe joints with perforated bottom by means of technology testing.

Effect of Working Fluid on Thermal Performance of Closed Loop Pulsating Heat Pipe

The pulsing heat pipe (PHP) is an technology that is increasingly capable of applying many manufacturing areas, but a thorough knowledge of its thermo-hydrodynamic There's far from enough system. This research explored the features of oscillation and the heat transfer efficiency of a closed-loop PHP using an internal and external diameter copper tube with 2.0 and 3.0 mm respectively. For all experimentation, filling ratio (FR) was 40%, five turns and different heat inputs of 20 to 80 W was supplied to PHP. The position of the PHP was vertical bottom heat type. 52 mm, 170 mm,60 mm was retained for the duration of the evaporator, adiabatic and condenser section. Water, Ethanol are chosen as working liquids. To understand, thermal resistance features and median evaporator pressures for multiple operating liquids at distinct heat inputs. An significant consideration for the results of PHPs is the research on PHP stated operating fluid. The result demonstrates that, with the rise of the heating output from 20 to 80 W, where as steadily increases above 80W, the thermal resistance reduces faster. By comparing Water , Ethanol working fluids, Ethanol provides the highest heat performance . The simulation is performed in Mat lab and the results have been contrasted