Understanding the Quality of Chemical Data from the Urban Environment - Part 1: Quality Control Procedures

Author(s):  
Christopher C. Johnson
2005 ◽  
Vol 22 (11) ◽  
pp. 1691-1705 ◽  
Author(s):  
Kenneth E. Kunkel ◽  
David R. Easterling ◽  
Kenneth Hubbard ◽  
Kelly Redmond ◽  
Karen Andsager ◽  
...  

Abstract A recent comprehensive effort to digitize U.S. daily temperature and precipitation data observed prior to 1948 has resulted in a major enhancement in the computer database of the records of the National Weather Service’s cooperative observer network. Previous digitization efforts had been selective, concentrating on state or regional areas. Special quality control procedures were applied to these data to enhance their value for climatological analysis. The procedures involved a two-step process. In the first step, each individual temperature and precipitation data value was evaluated against a set of objective screening criteria to flag outliers. These criteria included extreme limits and spatial comparisons with nearby stations. The following data were automatically flagged: 1) all precipitation values exceeding 254 mm (10 in.) and 2) all temperature values whose anomaly from the monthly mean for that station exceeded five standard deviations. Additional values were flagged based on differences with nearby stations; in this case, metrics were used to rank outliers so that the limited resources were concentrated on those values most likely to be invalid. In the second step, each outlier was manually assessed by climatologists and assigned one of the four following flags: valid, plausible, questionable, or invalid. In excess of 22 400 values were manually assessed, of which about 48% were judged to be invalid. Although additional manual assessment of outliers might further improve the quality of the database, the procedures applied in this study appear to have been successful in identifying the most flagrant errors.


Author(s):  
Carl-Henric de Verdier ◽  
Torgny Groth ◽  
James O. Westgard

Author(s):  
Tuan Anh Tran

There is a gap between 3D Printing’s fast pace of development and the acceptance of 3D Printing technologies by other industries and applications. This hesitation comes mostly from unanswered questions about the consistency, reproducibility, and quality of 3D printed products. Although the list of excellent examples demonstrating its potential keeps expanding, a wide and thorough adoption of the technology requires crucial, yet currently missing elements including consensus standards, quality control procedures, and measuring methodologies. Progress in developing these elements, however, has been rather limited.


2001 ◽  
Vol 7 (S2) ◽  
pp. 470-471
Author(s):  
Robin H Cross

The economic importance of animal hides and skins as the source material for the natural leather industry is significant world-wide, and in some countries of the developing world the livelihood of a large proportion of the population depends upon it. Consequently, it is understandable that anything affecting the quality of the source material and the finished product has major economic, industrial and sociological significance. It is also inevitable that a product that is so widely-used in many ways by most of the population will become an important source of evidence in forensic investigations.Quality control procedures in the leather industry involve monitoring the progress of the hides and skins from the growth stages of the animal, through the slaughter, storage, transportation, curing, tanning and finishing processes, to the sale and distribution of the finished product. There are many factors during these stages that can affect quality of finished leather, amongst the most important of which are mechanical and parasite damage during growth, biodeterioration and mechanical damage between slaughter and curing, mechanical, heat and chemical damage during curing, tanning and finishing.


Radiocarbon ◽  
2020 ◽  
pp. 1-16
Author(s):  
Christophe Moreau ◽  
Cyrielle Messager ◽  
Bernard Berthier ◽  
Stéphane Hain ◽  
Bruno Thellier ◽  
...  

ABSTRACT Quality control procedures have been developed at the Laboratoire de Mesure du Carbone 14 (LMC14) national laboratory throughout the years of operation. Routine procedures are applied to sample preparation depending on their composition and their size. The tuning of the ARTEMIS AMS facility, hosted by the LMC14 laboratory, uses an accurate procedure. A batch of unknown samples is measured with accompanying samples (primary and secondary standards and blanks), which give a powerful set of data to control the quality of each measurement. A homemade database has been created to store the sample information and study the evolution of the accompanying samples. The LMC14 laboratory participated in the Sixth International Radiocarbon Intercomparison, SIRI. The results are presented here, with statistical tests to assess the quality of the preparations and measurements done at the LMC14 national laboratory. To obtain a reliable radiocarbon (14C) age by AMS, 1 mg of sample is required in routine analysis. Recently, the LMC14 developed a new procedure dedicated to microsamples, allowing the size of samples to be reduced and contributing to opening 14C dating to materials that were previously unreachable. This new procedure has been successfully tested on valuable Cultural Heritage samples: lead white mural paintings.


2021 ◽  
Vol 10 (2) ◽  
pp. 85
Author(s):  
Winona Valeria Siregar ◽  
M. Nur Ghoyatul Amin

Red snappers are fishery commodities which have high market values. Raw materials of red snappers are important elements which determine the quality of the final products. Therefore, an enhancement of raw materials quality should be conducted through quality supervision and examination when the raw materials are retrieved, stored, and about to enter production process. The aim of this fieldwork practice is to find out the raw materials quality control on red snapper freezing process in PT. Tridaya Jaya Manunggal Pasuruan, East Java. The data taken consists of primary and secondary data which are processed descriptively. Data collection techniques through observation, interviews, active participation and literature review. PT. Tridaya Jaya Manunggal has implemented quality control on production process, starting from raw materials retrieval until these raw materials become final products. The quality control of raw red snappers were done in accordance with the quality control procedures which are plan, do, check, and action. The results of implementing quality control which were executed with organoleptic examination, temperature, Total Volatile Base (TVB), microbiology, and heavy metals on raw red snappers. Raw materials which didn’t meet the required standard were rejected, and then they were processed to be second grade products.


2013 ◽  
Vol 3 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Justine Rayner ◽  
Brian Skinner ◽  
Daniele Lantagne

Locally produced ceramic pot filters have been shown to improve the microbiological quality of household drinking water and reduce the burden of diarrheal disease in users. They are considered one of the most promising household water treatment methods. However, overarching manufacturing and quality control guidelines do not exist for the 35 decentralized filter factories in 18 countries that currently produce filters. In this study, we conducted manufacturing process surveys with 25 filter factories worldwide to document production methods and identify areas where manufacturing and quality control guidelines are needed. Our results show that manufacturing processes vary widely both between and within factories, including the consistency of materials, manufacturing methods, and quality control practices. These variations pose concerns about the consistency and quality of locally produced filters in the absence of standardized quality control procedures. We propose areas where manufacturing guidelines are needed to assist factories in producing consistently high quality filters, and identify topics where further research is needed to refine manufacturing recommendations. These results guided the development of a best practice manual that described consensus-based recommendations to advance consistent, quality-controlled filter production world-wide.


Doklady BGUIR ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 13-20
Author(s):  
D. I. Kazlouski ◽  
Y. V. Titovich ◽  
Y. I. Kazlouskaya

A study of the technical and dosimetry characteristics of brachytherapy afterloaders and applicators was carried out. Ring applicator has been taken as an example, the correctness of positioning of a radiation source (RS) inside the applicators was tested as part of the comissioning and quality control procedure of the brachytherapy applicators. The magnitudes of inconsistencies in the position of RS were established when planning and implementing treatment plans for radiation therapy. The identification of the values of the discrepancy was carried out using the obtained X-ray images of the applicator at the time of the implementation of the irradiation plans. The treatment plan was a sequential positioning of RS in the body of the applicator in each active position with a minimum step from the tip to the vaginal part of the applicator. The X-ray image was obtained by locating the source sequentially at each active position of the applicator. When carrying out dosimetric planning, 3 methods of applicator reconstruction were used. The analysis revealed that the applicator reconstruction method affects the magnitude of the discrepancy in determining the position of the source in the lumen of the applicator ring. Using the methods of statistical analysis, the mean, median, maximum and minimum values of the detected deviations were calculated. The results are presented in the form of tables and graphs for all investigated stop positions of IRS. Based on the results of the study, we consider it expedient to carry out quality control procedures when putting applicators into clinical operation. Based on the results obtained, we consider it acceptable to conduct a quality control procedure for the positioning accuracy of radiation sources in the applicators at least 1 time per month. Taking into account the results of the study when carrying out dosimetric planning will improve the quality of the irradiation sessions using the brachytherapy method, thereby improving the quality of oncological care for the population.


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