Chemical Basis of the Carbamidodiacetyl Micromethod for Estimation of Urea, Citrulline, and Carbamyl Derivatives

1970 ◽  
Vol 16 (1) ◽  
pp. 3-6 ◽  
Author(s):  
Michael P Veniamin ◽  
Catherine Vakirtzi-Lemonias
Keyword(s):  
Reaction Temperature ◽  
Colorimetric Assay ◽  
Mineral Acid ◽  
Heating Time ◽  
Acid Mixture ◽  
Chemical Basis ◽  
Temperature Heating

Abstract The chemical pathway of the carbamidodiacetyl colorimetric assay was investigated. The experimental variables that were studied include reaction temperature, heating time, and the ratio of the mineral acid mixture to the reactants. Evidence is presented establishing the involvement of either 7- or 8-methyl, or 7,8-dimethyltetrahydroimidazo(4,5-d)imidazole-2,5-diones as chromogens, all three being equally acceptable.

Numerical Simulation and Process Optimization of Automotive Friction Materials in Warm Pressing Forming

2013 ◽  
Vol 788 ◽  
pp. 57-60
Author(s):  
Chun Cao ◽  
Chun Dong Zhu ◽  
Chen Fu
Keyword(s):  
Process Optimization ◽  
Heating Temperature ◽  
Maximum Energy ◽  
Heating Time ◽  
Product Performance ◽  
Forming Process ◽  
Friction Materials ◽  
Forming Technology ◽  
The Relationship ◽  
Temperature Heating

Warm pressing forming technology has been gradually applied to the forming of automotive friction materials. How to ensure product performance to achieve the target at the same time achieve the maximum energy saving is the research focus of this study. In this paper, by using finite element method, the field of automotive friction materials in warm pressing forming was analyzed, reveals the relationship between the temperature field and the heating temperature/heating time. Furthermore, the energy consumption was analyzed and compared it with hot pressing forming process. The results will have significant guiding to the process optimization in warm pressing forming.

scholarly journals Study on the Thermal Treatment of Nano-Ag/TiO2 Thin Film

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Peng Bing ◽  
Wang Jia ◽  
Chai Li-yuan ◽  
Wang Yun-yan ◽  
Mao Ai-li
Keyword(s):  
Thin Film ◽  
Methyl Orange ◽  
Thermal Treatment ◽  
Photocatalytic Degradation ◽  
Tio2 Thin Film ◽  
Heating Temperature ◽  
Antibacterial Properties ◽  
Heating Time ◽  
Degradation Rates ◽  
Temperature Heating

The photocatalytic degradation rates of methyl orange and antibacterial properties of nano-Ag/TiO2 thin film on ceramics were investigated in this study. XRD was used to detect the structure of film to clarify the impacts on the rates and properties. The effect of film layers, heating temperature, heating time, and embedding of Ag+ on the degradation rates and antibacterial properties were ascertained. The nano-Ag/TiO2 film of 3 layers with AgNO3 3% embedded and treated at 350°C for 2 h would exhibit good performance.

Study on the NaOH Modified Bagasse as Briquette Binder

2013 ◽  
Vol 724-725 ◽  
pp. 310-312
Author(s):  
Yu Niu ◽  
Ren Zhang Wang ◽  
Fu Ying Li
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Heating Temperature ◽  
Heating Time

This The study is focused on the influence of NaOH ratio, reaction time, reaction temperature to strength of briquette binder. The results show that the NaOH ratio is 3 %, the heating time is 2 h, the heating temperature is 85°C had a great effect on the binder preparation.

scholarly journals Experimental Measurement of Vacuum Evaporation of Aluminum in Ti-Al, V-Al, Ti6Al4V Alloys by Electron Beam

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1688
Author(s):  
Dawei Wang ◽  
Zhiguo Liu ◽  
Wenrui Liu
Keyword(s):  
Additive Manufacturing ◽  
Weight Ratio ◽  
Difficult Problem ◽  
Heating Time ◽  
Vacuum Evaporation ◽  
Al Alloy ◽  
Composition Control ◽  
Tc4 Alloy ◽  
And Performance ◽  
Temperature Heating

Titanium alloys have been widely used in aerospace engineering due to their excellent mechanical properties, especially their strength-to-weight ratio. In addition, Ti6Al4V (TC4) alloy is the most widely used among α+β alloys. The main three elements of TC4 alloy are titanium (Ti), aluminum (Al) and vanadium (V). Since the boiling point of aluminum is much lower than the melting point of the other two elements, the consistency of TC4 alloy during smelting, additive manufacturing and surface treatment is difficult to control. Therefore, in order to study the difficult problem of composition control in TC4 alloy production, we measured the vacuum evaporation of Al, Ti and V in Ti-Al, V-Al and TC4 alloys, and tracked the changes of molten pool temperature, heating time and weight. According to the results, the Al started to evaporate near 1300 ± 10 °C in vacuum and totally evaporated after 225 s heating to 1484 °C at 10−2 Pa. However, V and Ti barely evaporated below 2000 °C. The Al in Ti-Al alloy started to evaporate at 1753 ± 10 °C and lost 20.6 wt.% aluminum during 500 s at 1750~1957 °C. The Al in V-Al alloy started to evaporate at 1913 ± 10 °C and lost 26.4 wt.% aluminum during 543s at 1893~2050 °C. The Al in TC4 alloy started to evaporate at 1879 ± 10 °C and lost 79.6 wt. % aluminum after 113 s at 1879~1989 °C. The results indicate that smelting TC4 alloy with Ti-Al and V-Al alloys by EBM below 1900 °C improves the consistency and performance. Additionally, the lowest loss of Al occurred in the additive manufacturing of TC4 alloy below 1900 °C.

Studies on changes in the temperature field and recrystallization properties of glass fiber reinforced polypropylene composite strip winding process

2020 ◽  
pp. 095440622097059
Author(s):  
Jiazhong Xu ◽  
Tianyu Fu ◽  
Zhao Hui
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Heating Temperature ◽  
Heating Time ◽  
Temperature Fields ◽  
Fiber Reinforced ◽  
Composite Ring ◽  
Glass Fiber Reinforced ◽  
The Press ◽  
Temperature Heating

The glass fiber reinforced polypropylene (GF/PP) composite ring specimens were fabricated based on the composites prepreg tape winding process. The heated winding process was simulated by ANSYS software to obtain the temperature distribution of the wound layer of the specimen. At the same time, the temperature of the wound layer was collected and stored using a temperature-controlled recorder. The temperature fields between the wound layers were found to be different significantly, and the temperature measured through experiments was generally below the simulation results, where it is especially noticeable in the fusion zone. After the recrystallization of GF/PP specimen, the maximum shear strength that the specimen can withstand was improved. The response surface method was used to test and analyze the influence of recrystallization on the mechanical properties of the specimen, Obtain optimized process parameters, heating temperature of 91 °C, pressure of the press roller is 106 N, heating time of 13 min, the highest sample obtained is 28.67Mpa. The experimental results show that the influence of recrystallization parameters on the mechanical properties of the composite specimens (from large to small) are: heating temperature, heating time, and the roller pressure.

Investigation of the Influences of Reaction Temperature and Time on the Chemical Reduction of Graphene Oxide by Conventional Method Using Vitamin C as a Reducing Agent

2017 ◽  
Vol 909 ◽  
pp. 225-230
Author(s):  
Chaval Sriwong ◽  
Kittisak Choojun ◽  
Samart Kongtaweelert
Keyword(s):  
Graphene Oxide ◽  
Vitamin C ◽  
Reaction Temperature ◽  
Chemical Reduction ◽  
Aqueous Suspension ◽  
Heating Time ◽  
Reducing Agent ◽  
Conventional Heating ◽  
Vis Spectroscopy ◽  
Ft Ir

The aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman and UV-Vis spectroscopy. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications.

Impacts of Hydrothermal Process on the Perfomance Parameters of Restaurant Garbage

2014 ◽  
Vol 955-959 ◽  
pp. 2794-2802
Author(s):  
Ren Lian Hai
Keyword(s):  
Process Parameters ◽  
Uniform Design ◽  
Hydrothermal Process ◽  
Physicochemical Characteristics ◽  
Heating Time ◽  
Optimal Conditions ◽  
Water Addition ◽  
Nutrient Value ◽  
Oil Performance ◽  
Temperature Heating

First, through implementing a U24(63) uniform design trial with 3 factors at 6 levels on temperature, heating time and water addition ratio as the main influencing factors of hydrothermal process and analyzing the physicochemical characteristics, the process parameters were optimized in this research. Then, the impacts of the hydrothermal process on the performance of sterilization, de-oiling and dewaterability were studied. It showed that the highest nutrient value of the product appears on condition that the temperature, heating time and water addition ratio were 120 °C, 80 minutes and 30% respectively. Additionally, hydrothermal treatment can kill bacteria thoroughly and affect the dewaterablity of the garbage markedly. Furthermore, hydrothermal process improved the de-oil performance of the garbage, and the optimal conditions for de-oil was the temperature 160 °C and heating time 80 minutes.

scholarly journals Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates

2008 ◽  
Vol 6 (3) ◽  
pp. 456-464 ◽  
Author(s):  
Sigute Cizauskaite ◽  
Aivaras Kareiva
Keyword(s):  
Sol Gel ◽  
Structural Features ◽  
Synthesis Temperature ◽  
Heating Time ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Gel Preparation ◽  
Temperature Heating

AbstractThis paper reports on the results concerning the sol-gel preparation and characterization of Sr-substituted perovskite lanthanum cobaltates La1−xSrxCoO3−δ (x = 0.0, 0.25, 0.5 and 0.75). The metal ions, generated by dissolving starting materials in diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the non-substituted and Sr-substituted LaCoO3. The influence of the synthesis temperature, heating time and the amount of substituent on the phase purity of La1−xSrxCoO3−δ were investigated. The phase transformations, composition and micro-structural features in the gels and polycrystalline samples were studied by thermal analysis (TG/DTA), infrared spectroscopy (IR), powder X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM).

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