Optimisation of welding parameters in pulsed MIG/MAG welding with width-controlled sine-wave current pulses. Part 2: Determination of an optimum material transfer through the arc and a control method

2007 ◽  
Vol 29 (1/2/3/4) ◽  
pp. 255
Author(s):  
Danijel Langus ◽  
Viljem Kralj ◽  
Janez Grum
Keyword(s):  
Control Method ◽  
Sine Wave ◽  
Mag Welding ◽  
Welding Parameters ◽  
Material Transfer ◽  
Current Pulses ◽  
Optimum Material

Fast Method for the Determination of Residual Solvents in Radiopharmaceutical Products

2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric
Keyword(s):  
Gas Chromatography ◽  
Control Method ◽  
Limit Of Detection ◽  
The Body ◽  
Biologically Active ◽  
Injection Technique ◽  
Fast Method ◽  
Residual Solvent ◽  
Residual Solvents

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.

scholarly journals Development and Validation of a GMP-Compliant High-Pressure Liquid Chromatography Method for the Determination of the Chemical and Radiochemical Purity of [18F]PSMA-1007, a PET Tracer for the Imaging of Prostate Cancer

2021 ◽  
Vol 14 (3) ◽  
pp. 188
Author(s):  
Ines Katzschmann ◽  
Heike Marx ◽  
Klaus Kopka ◽  
Ute Hennrich
Keyword(s):  
Prostate Cancer ◽  
Quality Control ◽  
Radiochemical Purity ◽  
Control Method ◽  
Solid Phase ◽  
Hplc Method ◽  
Attractive Alternative ◽  
Chromatography Method ◽  
Pet Tracer

For the PET imaging of prostate cancer, radiotracers targeting the prostate-specific membrane antigen (PSMA) are nowadays used in clinical practice. [18F]PSMA-1007, a radiopharmaceutical labeled with fluorine-18, has excellent properties for the detection of prostate cancer. Essential for the human use of a radiotracer is its production and quality control under GMP-compliance. For this purpose, all analytical methods have to be validated. [18F]PSMA-1007 is easily radiosynthesized in a one-step procedure and isolated using solid phase extraction (SPE) cartridges followed by formulation of a buffered injection solution and for the determination of its chemical and radiochemical purity a robust, fast and reliable quality control method using radio-HPLC is necessary. After development and optimizations overcoming problems in reproducibility, the here described radio-HPLC method fulfills all acceptance criteria—for e.g., specificity, linearity, and accuracy—and is therefore well suited for the routine quality control of [18F]PSMA-1007 before release of the radiopharmaceutical. Recently a European Pharmacopeia monograph for [18F]PSMA-1007 was published suggesting a different radio-HPLC method for the determination of its chemical and radiochemical purity. Since the here described method has certain advantages, not least of all easier technical implementation, it can be an attractive alternative to the monograph method. The here described method was successfully validated on several radio-HPLC systems in our lab and used for the analysis of more than 60 batches of [18F]PSMA-1007. Using this method, the chemical and radiochemical purity of [18F]PSMA-1007 can routinely be evaluated assuring patient safety.

Determination of Ultrasonic Welding Optimal Parameters for Thermoplastic Material of Manufacturing Products

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Rashiqah Rashli ◽  
Elmi Abu Bakar ◽  
Shahrul Kamaruddin
Keyword(s):  
Electronic Device ◽  
Low Cost ◽  
Near Field ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Field Configuration ◽  
Welding Parameters ◽  
Optimal Parameters ◽  
Thermoplastic Material

Ultrasonic welding had been widely used in various manufacturing industries such as aviation, medical, electronic device and many more. It offers a continued safe operation, faster and also low cost as it able to join weld part less than one second and also simple to maintain the tooling devices. Though ultrasonic welding brings a lot of advantages in assembly especially in thermoplastic material of manufacturing product, it also has a dominant problem to be deal with. The problem in ultrasonic welding is poor weld quality due to improper selection of ultrasonic welding parameters especially in near field configuration. Thus, an optimal combination of parameters is crucial in order to produce good quality weld assembly for this configuration. In this paper, ultrasonic welding process, ultrasonic weld joint defects and determination of optimal parameters for thermoplastic material had been discussed thoroughly. 

scholarly journals Evolution Regularity Mining and Gating Control Method of Urban Recurrent Traffic Congestion: A Literature Review

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Changxi Ma ◽  
Jibiao Zhou ◽  
Xuecai (Daniel) Xu ◽  
Jin Xu
Keyword(s):  
Traffic Congestion ◽  
Quantitative Research ◽  
Control Method ◽  
Time Correlation ◽  
Small Scale ◽  
Trend Prediction ◽  
Quantitative Research Methods ◽  
The Status ◽  
Evolution Trend

To understand the status quo of urban recurrent traffic congestion, the current results of recurrent traffic congestion, and gating control are reviewed from three aspects: traffic congestion identification, evolution trend prediction, and urban road network gating control. Three aspects of current research are highlighted: (a) The majority of current studies are based on statistical analyses of historical data, while congestion identification is performed by acquiring small-scale traffic parameters. Thus, congestion studies on the urban global roadway network are lacking. Situation identification and the failure to effectively warn or even avoid traffic congestion before congestion forms are not addressed; (b) correlation studies on urban roadway network congestion are inadequate, especially regarding deep learning, and considering the space-time correlation for congestion evolution trend prediction; and (c) quantitative research methods, dynamic determination of gating control areas, and effective countermeasures to eliminate traffic congestion are lacking. Regarding the shortcomings of current studies, six research directions that can be further explored in the future are presented.

scholarly journals Quality-control method for the determination of biological activity of engineered calcineurin subunit B

2016 ◽  
Vol 59 (6) ◽  
pp. 584-588
Author(s):  
Xinchang Shi ◽  
Huan Yang ◽  
Li Xu ◽  
Xiang Li ◽  
Zongwen Huang ◽  
...  
Keyword(s):  
Quality Control ◽  
Biological Activity ◽  
Control Method ◽  
Quality Control Method ◽  
Subunit B
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