scholarly journals Separation and Rectification of Chloroacetyl Chloride from TiCl4

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 287
Author(s):  
Fuxing Zhu ◽  
Liang Li ◽  
Dafu Zhang ◽  
Shangrun Ma ◽  
Zhanshan Ma ◽  
...  
Keyword(s):  
Removal Rate ◽  
Standard Addition ◽  
Heating Power ◽  
Test Method ◽  
Detection Methods ◽  
Effective Control ◽  
Orthogonal Experimental Design ◽  
Chloroacetyl Chloride ◽  
Imperfect Detection ◽  
Continuous Rectification

Titanium tetrachloride (TiCl4) is an important intermediate material for the preparation of titanium products. The organic impurities in TiCl4 are easily accumulated during the production of titanium sponges due to the problems of imperfect detection methods and the lack of effective control methods, resulting in a poor quality of sponge titanium. Among all impurities, chloroacetyl chloride (CAC) is the most important in TiCl4. Herein, the determination of the CAC content in TiCl4 solution, with a low detection limit of 0.633 ppm, was established by the standard addition method using Fourier transform infrared (FTIR) spectrometry. This test method presented good repeatability, excellent accuracy, and moderate precision. Furthermore, the influencing factors of CAC separation in the continuous rectification process, including the heating power (the ratio of total heating power to feed rate), reflux temperature, top tower pressure, and feed temperature were optimized based on an orthogonal experimental design. The experimental data demonstrated that the average CAC removal rate reached 78.94% ± 1.00% under the optimal distillation conditions, with 72.21% of the CAC removed via the off-gas system. Therefore, excellent control of the negative pressure of the tail gas is highly desirable for the removal of CAC impurities.

scholarly journals Performance Evaluation and Comparison between Direct and Chemical-Assisted Picosecond Laser Micro-Trepanning of Single Crystalline Silicon

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 41 ◽  
Author(s):  
Hao Zhu ◽  
Zhaoyang Zhang ◽  
Kun Xu ◽  
Jinlei Xu ◽  
Shuaijie Zhu ◽  
...  
Keyword(s):  
Material Removal ◽  
Crystalline Silicon ◽  
Removal Rate ◽  
Picosecond Laser ◽  
Orthogonal Experimental Design ◽  
Single Crystalline Silicon ◽  
Machining Performance ◽  
Single Crystalline ◽  
Direct Laser ◽  
Micro Holes

The fabrication of micro-holes in silicon substrates that have a proper taper, higher depth-to-diameter ratio, and better surface quality has been attracting intense interest for a long time due to its importance in the semiconductor and MEMS (Micro-Electro-Mechanical System) industry. In this paper, an experimental investigation of the machining performance of the direct and chemical-assisted picosecond laser trepanning of single crystalline silicon is conducted, with a view to assess the two machining methods. The relevant parameters affecting the trepanning process are considered, employing the orthogonal experimental design scheme. It is found that the direct laser trepanning results are associated with evident thermal defects, while the chemical-assisted method is capable of machining micro-holes with negligible thermal damage. Range analysis is then carried out, and the effects of the processing parameters on the hole characteristics are amply discussed to obtain the recommended parameters. Finally, the material removal mechanisms that are involved in the two machining methods are adequately analyzed. For the chemical-assisted trepanning case, the enhanced material removal rate may be attributed to the serious mechanical effects caused by the liquid-confined plasma and cavitation bubbles, and the chemical etching effect provided by NaOH solution.

Influence of Heating Area and Heating Power on Lithium Ion Battery Thermal Runaway Test

2021 ◽  
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Heating Time ◽  
Thermal Runaway ◽  
Heating Power ◽  
Test Method ◽  
Battery System ◽  
Important Method ◽  
A Cell ◽  
Time Required

Thermal propagation test of lithium-ion battery is an important method to verify the safety of battery system, and how to effectively trigger the thermal runaway of a cell and minimize the energy introduced into the system become the key of test method design. In this work, the influence of different heating area and different heating power on thermal runaway of prismatic cells and pouch cells is studied. The results show that when the heating area is fixed, the heating power increases, the heating time required to trigger the thermal runaway of the cells becomes shorter. The energy needed to be introduced becomes smaller, but there will be a minimum value of the introduced energy. On the other hand, the thermal runaway results of prismatic cells are more sensitive to the change of heating area, and the thermal runaway results of pouch cells are more sensitive to heating power.

scholarly journals Development and Application of a Quantitative PCR Detection Method to Quantify Venturia oleaginea in Asymptomatic Olive (Olea europaea) Leaves

2020 ◽  
Vol 110 (3) ◽  
pp. 547-555
Author(s):  
Silvia Scibetta ◽  
Giovanni E. Agosteo ◽  
Ahmed Abdelfattah ◽  
Maria G. Li Destri Nicosia ◽  
Santa O. Cacciola ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
High Throughput Sequencing ◽  
Current Knowledge ◽  
Leaf Growth ◽  
Its Region ◽  
Qpcr Assay ◽  
Detection Methods ◽  
Effective Control ◽  
Its2 Region

Olive leaf spot (OLS), caused by Venturia oleaginea, is one of the most common and serious diseases of olive trees in the Mediterranean region. Understanding the pathogen life cycle is important for the development of effective control strategies. Current knowledge is incomplete owing to a lack of effective detection methods. It is extremely difficult to culture V. oleaginea in vitro, so primers were designed to amplify and sequence the internal transcribed spacer ITS1-5.8S-ITS2 region of the fungus directly from infected olive leaves. Sanger sequencing indicated a unique ITS region present in the European strains screened, confirming the appropriateness of the target region for developing a quantitative PCR (qPCR) assay. Furthermore, high-throughput sequencing of the same region excluded the presence of other Venturia species in the olive phyllosphere. The qPCR assay proved very specific and sensitive, enabling the detection of approximately 26 copies of target DNA. The analysis of symptomless leaves during early stages of the epidemic from the end of winter through spring revealed a similar quantity of pathogen DNA regardless of the leaf growth stage. In contrast, the pathogen titer changed significantly during the season. Data indicated that leaf infections start earlier than expected over the season and very young leaves are as susceptible as adult leaves. These findings have important practical implications and suggest the need for improved scheduling of fungicide treatments. The qPCR assay represents a valuable tool providing quantitative results and enables detection of V. oleaginea in all olive organs, including those in which OLS cannot be studied using previously available methods.

scholarly journals Application of Remote Sensing Technology in Macro-Ecological Environment Monitoring

2020 ◽  
Vol 9 (1) ◽  
pp. 26
Author(s):  
Miaocai Guo
Keyword(s):  
Remote Sensing ◽  
Environmental Monitoring ◽  
Environmental Pollution ◽  
Global Economy ◽  
Relevant Information ◽  
Detection Methods ◽  
Effective Control ◽  
Industrial Enterprises ◽  
Remote Sensing Technology ◽  
Sensing Technology

<p>At present, all countries in the world attach great importance to the development and application of remote sensing technology, which is widely used in many fields. By means of detection methods, this technology combines physics knowledge and modern network technology to provide relevant information for human exploration of geology, atmosphere, ocean and weather. In recent years, the global economy has developed rapidly. However, the environmental pollution has become increasingly serious at the same time. Industrial enterprises have discharged a large number of pollutants, resulting in air pollution, water pollution, soil pollution and so on, which seriously endanger human health and life safety. Environmental monitoring is the basis of effective control of environmental pollution. Remote sensing technology can be applied to carry out environmental monitoring and improve the monitoring effect of environmental monitoring.</p>

Novel Sample Pretreatment to Determine Iron Counts in Sour Glycol Streams by Spectrophotometer

2021 ◽  
Author(s):  
Mohamed Mahmoud ◽  
Ahmed Alsalman ◽  
Hassan Almalki
Keyword(s):  
Inductively Coupled Plasma ◽  
Oil And Gas ◽  
Iron Concentration ◽  
Sample Pretreatment ◽  
Standard Addition ◽  
Test Method ◽  
Icp Oes ◽  
Important Indicator ◽  
Main Challenge ◽  
Amine Additives

Abstract Determination of Iron Content in Triethylene glycol (TEG) samples is a very important indicator in measuring the system corrosion rate in oil and gas facilities. This study employed the application of an alternative/easy and reliable test method, which involved the use of a spectrophotometer for quantification of Iron concentration in tri ethylene glycol samples, that are used in sour gas dehydration units, rather than the sophisticated technique of Inductively Coupled Plasma Optical Emission Spectroscopy, ICP-OES. The main challenge was how to eliminate/minimize the significant interference from the carryover condensate hydrocarbons, BTEX, H2S and amine additives, which cause either precipitation with spectrophotometer reagents or turbid samples. The sample pretreatment process included: 1 - Sample digestion with dilution to eliminate the dissolved acid gases and the dissolved BTEX from the sample in acidic medium; 2 - pH adjustment from 9 – 10.5 to eliminate the amine additives interference with spectrophotometer reagents and 3 – Application of standard addition technique with certified reference material for iron with dilution, to reach the spectrophotometer detection limit and give intense color with more UV absorbance. The method was validated against ICP-OES and the results variance were within 10% acceptance criteria.

Effects of the DO of Nitrification Return Flow on the Nitrogen Removal of A/A-MBR Combined Process

2012 ◽  
Vol 174-177 ◽  
pp. 58-63 ◽  
Author(s):  
Xiao Ying Zheng ◽  
Wei Chen ◽  
Ji Li ◽  
Yu Jie He ◽  
Xi Huang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Denitrification Rate ◽  
Effective Control ◽  
Return Flow ◽  
Stable Operation ◽  
Combined Process

In this study, the traditional A/A/O process was combined with MBR to create the A/A-MBR combined process. A 2.0 m3/h pilot scale study on the combined process was carried out. The influence mechanism of dissolved oxygen (DO) in the return flow on the A/A-MBR combined process was analyzed and the suitable dissolved oxygen concentration in MBR was further optimized. The results show that the combined process has the characteristics of rapid start and stable operation. Its COD, NH4+-N, TN and TP removals were 82.1%~92.4%, 93.0~98.3%, 48.4~70.7% and 93.8~97.9%, respectively. The return flow with high concentration of DO in MBR seriously affected the denitrification rate. The DO concentration of return flow increased gradually from 2.0 mg/L to 5.0 mg/L, the denitrification rate continuously decreased, the denitrification rate in the first stage decreased from 2.52 mg NO3--N/(gVSS•h) to 0.34mg NO3--N/(gVSS•h). When the DO of nitrification return liquid ascended to 5 mg/L, the denitrification ability of activated sludge was severely inhibited, and its denitrification activity was even lost. DO were controlled between 4.0±0.5 mg/L by adjusting the aeration rate in the MBR, effluent TN could be stably maintained between 10.82-13.94 mg/L with 62.6% average removal rate. The effluent COD, NH4+-N, TN and TP stably qualified to t criteria of the first level A of China’ s "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant" (GB18918-2002). If the effective control of membrane fouling could be ensured, the DO in the MBR was controlled as much as possible fewer than 4.0 mg/L. This could decrease the inhibition of denitrification by high DO from the return flow and insure that effluent TN achieved the discharge standard.

scholarly journals Construction summary of karst grouting treatment for Railway Subgrade

2018 ◽  
Author(s):  
Lincheng Wang
Keyword(s):  
Treatment Plan ◽  
Test Method ◽  
Detection Methods ◽  
Electrical Method ◽  
Drilling Method ◽  
Water Test ◽  
Pressure Water ◽  
Scheme Selection ◽  
Surface Wave Method ◽  
Targeted Detection

The karst is one of the main bad geological problems, which determines the design of the subgrade treatment plan and the safety of the engineering construction.This paper summarizes the key technology of grouting in karst roadbed regulation, and the following factors should be considered in grouting scheme selection: grouting method, technology, material, equipment, grouting control and detection means and standard of grouting effect.Through the use of high density electrical method, transient surface wave method, core drilling method, pressure water test method and so on, study the targeted detection methods for different coverage karst types and different remediation methods.

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