Characteristics of the Supersonic Combustion Coherent Jet for Electric Arc Furnace Steelmaking

Herein, a supersonic combustion coherent jet is proposed based on current coherent jet technology to improve the impact capacity of a coherent jet and increase the stirring intensity of the electric arc furnace (EAF) bath. Further, numerical simulations and an experimental analysis are combined to study the supersonic combustion coherent jet characteristics, including the Mach number, dynamic pressure, static temperature, vorticity, and turbulence intensity, in the EAF steelmaking environment. The results show that the supersonic combustion coherent jet exhibits stable combustion in a high-temperature EAF steelmaking environment. The supersonic combustion flame generated by the supersonic shrouding fuel gas can envelop the main oxygen jet more effectively than current coherent jets. Furthermore, the velocity attenuation, vorticity, and turbulence intensity performances of the supersonic combustion coherent jet are better when compared with those of the current coherent jet. The velocity core length of the main oxygen jet for the supersonic combustion coherent jet is 30% longer than that of the current coherent jet, resulting in an improved impact capacity and stirring intensity of the molten bath.

Effective Utilization of Algae Biomass from Wastewater for Biodiesel Production by Direct Transesterification: A Promising Approach for Sustainable Bioenergy Production

Currently, biodiesel produced from algae is receiving a positive response as a substitute for conventional base diesel. To cope up from the costs of expensive downstream stages in the production of biodiesel from algae, present investigation is conducted using algae growing in wastewater as lipid source for biodiesel production. The in situ transesterification using algae was carried to optimize the effect of reaction parameters on the biodiesel yield. The parameters studied were: temperature (35-75 ºC), algae biomass (wt.) to methanol (vol.) ratio (1:1-1:6), catalyst concentration (25-100 wt. %) and stirring intensity (150-750 rpm). The optimum conditions for maximum biodiesel yield achieved were: catalyst concentration and algae biomass to methanol ratio were 60 % and 1:4, respectively with stirring intensity of 450 rpm at 55 ºC. The gas chromatographic studies and fuel properties of biodiesel also establish its potential to be used as fuel in existing engines in accordance to American and European standards.

Calcined sodium silicate as an efficient and benign heterogeneous catalyst for the transesterification of natural lecithin to L-α-glycerophosphocholine

Calcined sodium silicate could serve as an efficient and benign heterogeneous catalyst for the production of L-α-glycerophosphocholine from natural lecithin. The catalytic transesterification of natural lecithin by calcined sodium silicate proceeded to almost 100% conversion under the following conditions: sodium silicate amount of 6 wt%, reaction temperature of 65°C, lecithin concentration of 10.5 mmol/l, stirring intensity of 300 rpm, reaction time of 120 min. In addition, this catalyst could be separated completely by simple centrifugation and retained high activity after three re-uses. Compared to the previously reported catalysts, calcined sodium silicate, with the significantly important characteristics of non-toxicity and easy excretion from the human body, was beneficial to the benign production of L-α-glycerophosphocholine and its security as well as application in food and medicine fields.

Simple Protocol for immunoglobulin G Purification from Camel “Camelus dromedarius” Serum

The present study aimed to describe and standardize a simple and efficient protocol for purification of camel IgG from serum, which can be applied for Camilidae antibody production in research laboratories, the preindustrial stage. Camel serum IgG was separated with caprylic acid and ammonium sulfate, then the effect of four variables studied: caprylic acid concentration, pH, stirring time, and stirring intensity. Camel IgG prepared by standardized caprylic acid fractionation method for camel serum was compared with commercial anti-sera products. Camel IgG purification from undiluted sera using caprylic acid at concentration of 8% v/v gave the best results. Purification at different pH values using caprylic acid at 8% v/v revealed that pH 5.5 was optimal. Investigating purification at different stirring time intervals using 8% v/v caprylic acid at pH 5.5 demonstrated that stirring for 90 min gave the optimum results. Finally, studying purification at different stirring intensities using 8% v/v caprylic acid at pH 5.5 for 90 min, the best stirring intensity was at 450 rpm. Overall, the results suggest that caprylic acid purification of camel serum IgG is more effective and safe than ammonium sulfate method in simplicity, purity, and lower non-IgG proteins in the final preparation with lower protein aggregates.

Characterization and Application Process Optimization of CuO/γ-Al2O3 Catalyst in CWAO Technology

CuO/γ-Al2O3 catalyst was used to deal with the waste leachate in CWAO technology of, and the SEM and TEM characterization showed: active component in the surface of the carrier distribution is uniform; In CWAO process, six factors, based on the CODCr removal rate and turbidity removal rate, the biggest impact factor is reaction temperature, and the influence factors of the top three were reaction temperature, catalyst dosage and reaction time. The influence factors of those in the bottom three are influent water pH, oxygen partial pressure, stirring intensity, and three factors of influence on the strength is close. Optimizing operation process, in order: reaction temperature of 200 °C, catalyst dosage of 1.5 g, oxygen partial pressure of 2.0 MPa, stirring intensity 800 rpm, influent water pH of 7.0, the reaction time of 70 min.

Study on the High Speed Jet-Electrode Position Ni-P Alloy

The high speed jet-electrodepositing equipment was used to prepare Ni-P alloy in substrate of 45 steel. The influences of current density on depositing rate, hardness of deposit and microstructure of Ni-P alloy were studied, and the comparation with that of conventional electroplating were studied. The results show that with the increase of stirring intensity of the electrolyte, the thickness of diffused layer decreases, the critical current density increases, and then the depositing rates increase to 69.82/min. A linear increasing of the depositing rate with the increase of current density is observed, and it refines grain size obviously. Deposit hardness up to 679HV.

Optimization of Operating Conditions on Ceramic Printing Wastewater Treatment with Coagulation and Sedimentation Method

The ceramic printing wastewater was treated with coagulation sedimentation method by adopted AlCl3 polymerization (PAC) as a coagulant. In order to optimize the wastewater treatment of operating conditions, with absorbance, turbidity and conductivity for testing index, the PAC dosing quantity, stirring time, stirring intensity and influx water pH value on the influence of the wastewater treatment. The results show that the wastewater absorbance and turbidity with PAC dosing quantity increase, mixing time extension and stirring intensity increase present reduced trend, with the water pH increases present first decreases trend of increase; Proper operating conditions of wastewater treatment: PAC dosing quantity 90 mg/L, mixing time 15 min, mixing strength medium speed and influx water pH value is about seven. On this condition, ceramic printing wastewater treatment of effluent decolorization rate reached 86.9%, turbidity removal rate reached 92.5%, conductivity is 2.05 x 103 s/cm.

Measurement of activated sludge particle diameters using laser diffraction method / Pomiary średnicy cząstek osadu czynnego za pomocą metody dyfrakcji laserowej

The paper presents a study on the possibility of using the laser diffraction method for measuring the size of the activated sludge particles. Susceptibility of the particles to mechanical disintegration, dependent on the programmed value of stirring intensity, was observed (stirring was caused by required dynamic flow of analysed suspension through the measurement unit). According to the conclusions presented in this paper, it may be assumed that the laser diffraction method can be applied for measurement of activated sludge particle diameters under the following conditions: 1) the size of activated sludge particles measured by the laser diffraction method is not a real value, but after standardisation of measurement conditions can be treated as a parameter describing the sludge; 2) the particle diameters of activated sludge should be stabilised before the measurement, eg by mixing in the measurement unit or by ultrasound waves application.