Quality Control of CSG with P-Wave Speed Measurement

2014 ◽  
Vol 1049-1050 ◽  
pp. 497-504 ◽  
Author(s):  
Xiao Bin Lu ◽  
Jin Sheng Jia ◽  
Feng Ling Ma ◽  
Wei Feng ◽  
Li Juan Meng
Keyword(s):  
Quality Control ◽  
Wave Speed ◽  
Control Method ◽  
Control Measure ◽  
P Wave ◽  
Experimental Program ◽  
Compression Tests ◽  
Cemented Sand ◽  
Speed Measurement ◽  
Sand And Gravel

This paper first introduces the basic concept of the CSG (cemented sand and gravel) dam construction. It then puts forward a new quality control method by inspecting the in-situ P-wave speed of CSG as an alternative to the conventional specimen compression tests. Through an extensive experimental program, it is found that there is a good correlation between the compressive strength and P-wave speed of CSG, which makes the P-wave speed measurement potentially an effective and efficient quality control measure to evaluate the CSG strength on site.

scholarly journals Study of Static and Dynamic Properties of Sand under Low Stress Compression

2021 ◽  
Vol 11 (8) ◽  
pp. 3311
Author(s):  
Vladimir Frid ◽  
Stelios M. Potirakis ◽  
Semen Shulov
Keyword(s):  
Uniaxial Compression ◽  
Wave Speed ◽  
Dynamic Properties ◽  
P Wave ◽  
Compression Tests ◽  
P Wave Velocity ◽  
Wide Range ◽  
The Us ◽  
Natural Dune ◽  
Maximum Compression Stress

The aim of this work was to investigate a wide range of grain sizes of sand in the pre-yield regime during compression through the combined study of ultrasound (US) wave speed and acoustic emission (AE). The specific study was performed using modified oedometer and uniaxial compression experimental set-ups. The studied samples were natural dune sand (poorly graded on the poorly graded sand (SP) index) as well as its three extracted fractions as follows: 2.36–0.6 mm, 0.6–0.3 mm and 0.3–0.075 mm. The maximum compression stress during the modified oedometer experiments was <150 kPa, while during the modified uniaxial compression experiments, it was <400 kPa. Each sample was loaded while measuring the US pressure (P) wave speed and AE at each loading stage. The results show that the stiffer the soil is, the higher the value of the P wave speed measured, resulting in similar P wave velocity values achieved at a much lower applied stress during the oedometer experiments in comparison with the uniaxial compression tests. Regarding the AE results, it is seen that the higher the stress level is, causing more friction between the sand particles, the more AE events there are during their movement. The following parameters of AE were shown to be the most sensitive to the stress increase: the number of AE hits and the signals’ energy.

Perencanaan Pengendalian Kualitas Produk Pakaian Bayi dengan Metode Six Sigma Pada CV. AGP

JEMAP ◽  
2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Albertus Reynaldo Kurniawan ◽  
Bayu Prestianto
Keyword(s):  
Quality Control ◽  
Continuous Improvement ◽  
Six Sigma ◽  
Screen Printing ◽  
Control Method ◽  
Operational Performance ◽  
Machine Maintenance ◽  
Quality Product ◽  
Break Time ◽  
And Control

Quality control becomes an important key for companies in suppressing the number of defective produced products. Six Sigma is a quality control method that aims to minimize defective products to the lowest point or achieve operational performance with a sigma value of 6 with only yielding 3.4 defective products of 1 million product. Stages of Six Sigma method starts from the DMAIC (Define, Measure, Analyze, Improve and Control) stages that help the company in improving quality and continuous improvement. Based on the results of research on baby clothes products, data in March 2018 the percentage of defective products produced reached 1.4% exceeding 1% tolerance limit, with a Sigma value of 4.14 meaning a possible defect product of 4033.39 opportunities per million products. In the pareto diagram there were 5 types of CTQ (Critical to Quality) such as oblique obras, blobor screen printing, there is a fabric / head cloth code on the final product, hollow fabric / thin fabric fiber, and dirty cloth. The factors caused quality problems such as Manpower, Materials, Environtment, and Machine. Suggestion for consideration of company improvement was continuous improvement on every existing quality problem like in Manpower factor namely improving comprehension, awareness of employees in producing quality product and improve employee's accuracy, Strength Quality Control and give break time. Materials by making the method of cutting the fabric head, the Machine by scheduling machine maintenance and the provision of needle containers at each employees desk sewing and better environtment by installing exhaust fan and renovating the production room.

Chemical Fingerprint Analysis and Simultaneous Determination of Nucleosides and Amino Acids in Kang Fu Xin Liquid by High Performance Liquid Chromatography with Diode Array Detector

2020 ◽  
Vol 16 (7) ◽  
pp. 831-843
Author(s):  
Yuwen Wang ◽  
Shuping Li ◽  
Liuhong Zhang ◽  
Shenglan Qi ◽  
Huida Guan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Quality Control ◽  
Uric Acid ◽  
Control Method ◽  
Principal Component ◽  
Gradient Elution ◽  
Hplc Method ◽  
Array Detector ◽  
Fingerprint Analysis ◽  
Wavelength Switching

Background and Objective: Kang Fu Xin liquid (KFX) is an official preparation made from the ethanol extract product from P. Americana. The present quality control method cannot control the quality of the preparation well. The aim of the present study is to establish a convenient HPLC method for multicomponents determination combined with fingerprint analysis for quality control of KFX. Methods: An HPLC-DAD method with gradient elution and detective wavelength switching program was developed to establish HPLC fingerprints of KFX, and 38 batches of KFX were compared and evaluated by similarity analysis (SA), hierarchical clustering analysis (HCA), and principal component analysis (PCA). Meanwhile, six nucleosides and three amino acids, including uracil, hypoxanthine, uric acid, adenosine, xanthine, inosine, tyrosine, phenylalanine and tryptophan in KFX were determined based on the HPLC fingerprints. Results: An HPLC method assisted with gradient elution and wavelength switching program was established and validated for multicomponents determination combined with fingerprint analysis of KFX. The results demonstrated that the similarity values of the KFX samples were more than 0.845. PCA indicated that peaks 4 (hypoxanthine), 7 (xanthine), 9 (tyrosine), 11, 13 and 17 might be the characteristic contributed components. The nine constituents in KFX, uracil, hypoxanthine, uric acid, adenosine, xanthine, inosine, tyrosine, phenylalanine and tryptophan, showed good regression (R2 > 0.9997) within test ranges and the recoveries of the method for all analytes were in the range from 96.74 to 104.24%. The limits of detections and quantifications for nine constituents in DAD were less than 0.22 and 0.43 μg•mL-1, respectively. Conclusion: The qualitative analysis of chemical fingerprints and the quantitative analysis of multiple indicators provide a powerful and rational way to control the KFX quality for pharmaceutical companies.

scholarly journals Statistical Law and Predictive Analysis of Compressive Strength of Cemented Sand and Gravel

2020 ◽  
Vol 27 (1) ◽  
pp. 291-298
Author(s):  
Shoukai Chen ◽  
Yongqiwen Fu ◽  
Lei Guo ◽  
Shifeng Yang ◽  
Yajing Bie
Keyword(s):  
Compressive Strength ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Predictive Analysis ◽  
Distribution Law ◽  
Data Set ◽  
Cemented Sand ◽  
Mix Proportion ◽  
Kolmogorov Smirnov ◽  
Sand And Gravel

AbstractA data set of cemented sand and gravel (CSG) mix proportion and 28-day compressive strength was established, with outliers determined and removed based on the Boxplot. Then, the distribution law of compressive strength of CSG was analyzed using the skewness kurtosis and single-sample Kolmogorov-Smirnov tests. And with the help of Python software, a model based on Back Propagation neural network was built to predict the compressive strength of CSG according to its mix proportion. The results showed that the compressive strength follows the normal distribution law, the expected value and variance were 5.471 MPa and 3.962 MPa respectively, and the average relative error was 7.16%, indicating the predictability of compressive strength of CSG and its correlation with the mix proportion.

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.

scholarly journals A Reliable, Label Free Quality Control Method for the Production of DNA Microarrays with Clinical Applications

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 340
Author(s):  
Elisa Chiodi ◽  
Francesco Damin ◽  
Laura Sola ◽  
Lucia Ferraro ◽  
Dario Brambilla ◽  
...  
Keyword(s):  
Quality Control ◽  
Dna Microarrays ◽  
Control Method ◽  
False Negative ◽  
Label Free ◽  
Negative Results ◽  
System A ◽  
Quality Control Method ◽  
False Negative Results ◽  
Imaging Sensor

The manufacture of a very high-quality microarray support is essential for the adoption of this assay format in clinical routine. In fact, poorly surface-bound probes can affect the diagnostic sensitivity or, in worst cases, lead to false negative results. Here we report on a reliable and easy quality control method for the evaluation of spotted probe properties in a microarray test, based on the Interferometric Reflectance Imaging Sensor (IRIS) system, a high-resolution label free technique able to evaluate the variation of the mass bound to a surface. In particular, we demonstrated that the IRIS analysis of microarray chips immediately after probe immobilization can detect the absence of probes, which recognizably causes a lack of signal when performing a test, with clinical relevance, using fluorescence detection. Moreover, the use of the IRIS technique allowed also to determine the optimal concentration of the probe, that has to be immobilized on the surface, to maximize the target recognition, thus the signal, but to avoid crowding effects. Finally, through this preliminary quality inspection it is possible to highlight differences in the immobilization chemistries. In particular, we have compared NHS ester versus click chemistry reactions using two different surface coatings, demonstrating that, in the diagnostic case used as an example (colorectal cancer) a higher probe density does not reflect a higher binding signal, probably because of a crowding effect.

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