Understanding the Effect of Operating Conditions on UO2 Reduction Efficiency in Molten LiCl-Li2O Salts

2020 ◽  
Author(s):  
M. Morrow ◽  
M. Williamson ◽  
N. Smith ◽  
K. Hawthorne
Keyword(s):  
Operating Conditions ◽  
Reduction Efficiency

scholarly journals Experimental analysis on the synergistic effect of combined use of ozone and UV radiation for the treatment of dairy industry wastewater

2020 ◽  
Vol 26 (5) ◽  
pp. 200375-0
Author(s):  
Ramya Suresh ◽  
Baskar Rajoo ◽  
Maheswari Chenniappan ◽  
Manikandan Palanichamy
Keyword(s):  
Uv Radiation ◽  
Dairy Industry ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Circulation Rate ◽  
Combined Use ◽  
Reduction Efficiency ◽  
Cylindrical Reactor ◽  
Ozone Injection ◽  
Industry Wastewater

The present study focused on the various advanced oxidation processes; Ozone, UV radiation, O<sub>3</sub>/H<sub>2</sub>O<sub>2</sub>, O<sub>3</sub>/UV, UV/H<sub>2</sub>O<sub>2</sub> and O<sub>3</sub>/UV/H<sub>2</sub>O<sub>2</sub> for treatability of dairy industry wastewater. With this aim, the trials were carried out in cylindrical reactor fortified with UV radiation and Ozone injection. Efficiency of the treatment process was evaluated considering Chemical Oxygen Demand (COD), lactose reduction and process parameters were determined to be reaction time, pH, circulation rate, and H<sub>2</sub>O<sub>2</sub> dosage. 32.5%, 35.2% , 25%, 83% COD and 40.6%, 43.6%, 38.2%, 80% lactose reduction efficiency were obtained under the operating conditions for O<sub>3</sub>/H<sub>2</sub>O<sub>2</sub>, O<sub>3</sub>/UV, UV/H<sub>2</sub>O<sub>2</sub> and O<sub>3</sub>/UV/H<sub>2</sub>O<sub>2</sub> processes, respectively. As per this outcome, UV/H<sub>2</sub>O<sub>2</sub>/O<sub>3</sub> process gave more than 65% of COD and 52.36% of lactose reduction efficiency than other hybrid processes. Optimum conditions for UV/H<sub>2</sub>O<sub>2</sub>/O<sub>3</sub> process (pH = 5, time = 180 mins, circulation rate = 50 mL/h and H<sub>2</sub>O<sub>2</sub> dosage of 0.5 mL) resulted in 88% of COD and 93.4% lactose reduction.

scholarly journals The Utilization of Laundry Wastewater as Liquid Fertilizer for Rice Plants

2021 ◽  
Author(s):  
Sadono Mulyo ◽  
Suwarno Hadisusanto ◽  
Prabang Setiono
Keyword(s):  
Aquatic Ecosystems ◽  
Waste Treatment ◽  
Quality Standard ◽  
Operating Conditions ◽  
Treatment Model ◽  
Liquid Fertilizer ◽  
Effluent Quality ◽  
Rice Plants ◽  
Variable Quantity ◽  
Reduction Efficiency

Abstract The laundry liquid wastewater contains detergents and phosphates which are nutrients for plant which can also causepollution, explosive growth of aquatic biota, and aquatic ecosystems eutrophication. The great potential of laundrywaste requires an efficient and inexpensive waste treatment model to reduce the phosphate content. This study aimsto examine the effect of wetlands on laundry wastewater, straw soaking water, and the use of effluent as a liquidfertilizer for rice plants. As well as analyzing the fate of toxic detergents (ABS) in rice grains on a laboratory scale.The results showed the wetland was able to reduce the pollutants level in laundry wastewater and toxic organic bondswith the BOD, COD, TSS, TDS, Detergent, Phosphate reduction efficiency between 49% - 95%; has met the PERDADIY no. 7 of 2016 about Quality Standard. The operating conditions that provided the optimum results in this studywere the laundry wastewater treatment model and the utilization of effluent as liquid fertilizer for rice plants withstraw soaking water neutralization with minimum discharge variations resulting in effluent quality and quantity ofharvested products of 75 gr/0.4 m2 and there is a detergent residue content of 24.80 mg/kg; without straw soaking,yields 155 gr/0.4 m2 with detergent residue content of 32.65 mg/kg. Iconic and diagrammatic models of laundrywastewater treatment were obtained based on the quality variable, quantity variable, and the effluent pre-treatmentcapacity variable thus it can be used as liquid fertilizer for rice plants to describe the behavior of the real system. Thefactor that has a high influence on system performance, but the dependence between factors is low, namely the effluent flow discharge into the wetland.

scholarly journals RESEARCH ON THE MANUFACTURING MAGNESIUM FROM THANHHOA DOLOMITE BY PIDGEON PROCESS

2020 ◽  
pp. 97-107
Author(s):  
Quyen Vu Viet ◽  
Trang Vu Thi Thu ◽  
Nam Nguyen Duong ◽  
Binh Duong Ngoc ◽  
Huy Tran Duc
Keyword(s):  
Magnesium Alloys ◽  
Raw Materials ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Current Time ◽  
Reduction Efficiency ◽  
Set Up ◽  
The One ◽  
Pidgeon Process ◽  
The Ideal

The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietnam

Modeling Competitive Adsorption in Urea-SCR Catalysts for Effective Low Temperature NOx Control

2010 ◽  
Author(s):  
Maruthi Devarakonda ◽  
Russell Tonkyn ◽  
Diana Tran ◽  
Jong H. Lee ◽  
Darrell Herling
Keyword(s):  
Low Temperature ◽  
Kinetic Model ◽  
Competitive Adsorption ◽  
Nox Reduction ◽  
Operating Conditions ◽  
Adsorption Model ◽  
Kinetics Of Adsorption ◽  
Lean Nox Reduction ◽  
Scr Catalysts ◽  
Reduction Efficiency

Although the SCR technology exhibits higher NOx reduction efficiency over a wider range of temperatures among the lean NOx reduction technologies, further improvement in low-temperature performance is required to meet the future emission standards and to lower the system cost. In order to improve the catalyst technologies and optimize the system performance, it is critical to understand the reaction mechanisms and catalyst behaviors with respect to operating conditions. For example, it is well known that the ammonia coverage on catalyst surface is critical for NOx reduction efficiency. However, the level of ammonia storage is influenced by competitive adsorption by other species, such as H2O and NO2. Moreover, hydrocarbon species that slip through the upstream DOC during the cold-start period can also inhibit the SCR performance, especially at low temperatures. Therefore, a one-dimensional kinetic model that can account for the effects of such competitive adsorption has been developed based on steady state surface isotherm tests on a commercial Fe-zeolite catalyst. The model is developed as a C language S-function and implemented in Matlab/Simulink environment. Rate kinetics of adsorption and desorption of each of the adsorbents are determined from individual adsorption tests and validated for a set of test conditions that had all the adsorbents in the feed gas. Using the competitive adsorption model, a kinetic model for standard-SCR reaction involving NH3 and H2O is developed and validated.

scholarly journals Application of Response Surface Methodology (RSM) for optimizing removal of Cr(VI) wastewater using Cr(VI)-reducing biofilm systems

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Nurfadilah Mohammed ◽  
Wan Azlina Ahmad
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Operating Conditions ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Nutrient Supplementation ◽  
Dependent Variables ◽  
Reduction Efficiency ◽  
Central Composite ◽  
Experimental Runs

Response surface methodology (RSM) involving central composite design (CCD) was employed to obtain optimal conditions for Cr(VI) wastewater treatment by Cr (VI) reducing biofilm systems. On the basis of a CCD, RSM was used to determine the effect of initialmetal concentrations (40-100 mgL-1), nutrient supplementations (10-20%) and flowrate (3-6 mLmin-1) on the levels of response, i.e. Cr(VI) reduction efficiency. A set of 20 experimental runs were needed for optimizing of the operating conditions. Quadratic regressionmodels with estimated coefficients were developed to describe the Cr (VI) reduction. Analysis of variance (ANOVA) showed a highcoefficient of determination (R2) value of 0.9941, thus ensuring a satisfactory adjustment of the second-order regression model with theexperimental data. Cr (VI) reduction had significant effect on all the three dependent variables. The experimental results show that Cr(VI)-reducing biofilm systems could effectively reduce Cr (VI), 100% at the optimum conditions of initial metal concentration of 100mgL-1, nutrient supplementation of 20% and flowrate of 3 mLmin-1. The experimental observations were in reasonable agreement withthe modelled values.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Slow-scan CCD cameras and low-dose High-Resolution Electron Microscopy: Direct and quantitative

1994 ◽  
Vol 52 ◽  
pp. 412-413
Author(s):  
M. Pan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Damage ◽  
Low Dose ◽  
Dynamic Range ◽  
High Resolution Electron Microscopy ◽  
Operating Conditions ◽  
Digital Data ◽  
Ccd Cameras ◽  
Resolution Electron

It has been known for many years that materials such as zeolites, polymers, and biological specimens have crystalline structures that are vulnerable to electron beam irradiation. This radiation damage severely restrains the use of high resolution electron microscopy (HREM). As a result, structural characterization of these materials using HREM techniques becomes difficult and challenging. The emergence of slow-scan CCD cameras in recent years has made it possible to record high resolution (∽2Å) structural images with low beam intensity before any apparent structural damage occurs. Among the many ideal properties of slow-scan CCD cameras, the low readout noise and digital recording allow for low-dose HREM to be carried out in an efficient and quantitative way. For example, the image quality (or resolution) can be readily evaluated on-line at the microscope and this information can then be used to optimize the operating conditions, thus ensuring that high quality images are recorded. Since slow-scan CCD cameras output (undistorted) digital data within the large dynamic range (103-104), they are ideal for quantitative electron diffraction and microscopy.

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

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