Results Of Quality Control Tests Research Articles

Testes de controle de qualidade de materiais frescos à base de cimento para impressão 3D

Abstract Three-dimensional concrete printing (3DCP) has emerged as a promising solution for the modernization of the construction sector. Additionally, design optimization allows for material reduction, promoting sustainable construction. Despite these advancements, there is still no standard for the assessment of the fresh state and quality control of 3DCP. This work discusses the results of quality control tests for fresh 3DCP. Specifically, seven samples with different mix designs were produced and subjected to rotational rheometry, slug tests, flow table tests, and buildability tests (i.e., the height supported prior to collapse). The results showed that the yield stress obtained from rheometry and the slug test did not match but fell within the same order of magnitude. The yield stress values obtained from rheometry were the closest to the gravity-induced stress in the buildability test. Regarding buildability prediction, the slug test exhibited the strongest correlation with the number of layers supported in buildability (R2 = 0.92); rotational rheometry also demonstrated a good correlation with that parameter (R2 = 0.80). In contrast, the results of the flow table test neither correlated with the yield stress obtained from any other tests nor proved efficient in predicting buildability. Finally, the paper presented a discussion on testing and printing challenges.

Evaluating the Creep Deformation and Elastic Recovery of Different Polymer-Modified Bitumens Using a New Bitumen Quality Control Test

Abstract To quickly and accurately evaluate the creep deformation and elastic recovery performance of polymer-modified bitumen, a new bitumen quality control test (QCT) was carried out to analyze the creep deformation and recovery properties of styrene-butadiene-styrene (SBS)-modified bitumen and rubber powder–modified bitumen with different modifier dosage at 15°C, 20°C, 25°C, and 30°C. At the same time, the creep deformation speed of different polymer-modified bitumens was also investigated based on the QCT results. Then, the penetration and dynamic shear rheological tests were implemented on these binders to establish the relationship between QCT indexes (maximum creep deformation and deformation recovery rate) and physical–rheological indexes (penetration and complex viscosity). Results show that the creep deformation resistance and elastic recovery ability of bitumen enhance gradually with the increase of both SBS and rubber powder. Between SBS and rubber powder, SBS exhibits a more significant influence on the creep deformation resistance and elastic recovery properties of bitumen than rubber powder under the same temperature and modifier dosage. A polymer-modified bitumen with smaller penetration and bigger complex viscosity is prone to better creep deformation resistance and elastic recovery performance.

Pharma Software - A Complete Overview

With the recent advancements in Pharmaceutical Industry, there comes an increased complexity in data and products. In a Pharmaceutical Industry, various aspects are considered simultaneously. So, nowadays various advanced softwares are used to handle these parameters. A Software is a set of programs that tells a computer what tasks it should perform. It consists of a series of code written by a programming language, which is then interpreted by a computer. This process is known as compilation. Thus, it makes our work easier by maintaining all the records and performing necessary calculation and much more. In a pharmaceutical industry variety of software are used as the tasks that needs to be performed are also of various types. For example, Record keeping of a Batch of Tablet in a manufacturing section, Quality Control Test Results, Regulatory Management, Marketing And Sales Data Handling, Clinical Trial Data Management, etc. Sometimes, a single software is used and sometimes a combination of two or more are used. There are roughly 19 types of software used in the whole Pharmaceutical Industry, and among them various companies have their wide range of products. Currently, after the implementation of GMP, GLP and GCP, the use of the software has marginally increased. Keywords: Pharmaceutical, Software, Industry, Recent software, Pharma- Industry

Determining the Optimum Sample Size for Quality Assurance (QA) of Asphalt Mixtures: A Case Study

Acceptance plans for asphalt mixtures use a certain sample size that is often established based on the purpose of sampling, population size, risk, and allowable error for evaluation. The rate of quality control (QC) sample size is often higher than the quality assurance (QA) sample size. The test results obtained from the QA samples are commonly used to validate the QC test results and to assist the state department of transportation (DOT) with payment decisions. However, if the QA sample size is insufficient to make accurate judgments, the probability of making incorrect decisions regarding acceptance increases. On the other hand, oversampling needlessly consumes both time and cost. To identify the appropriate sample size for QA testing, a balance must be struck between a number of variables. In this case study, two models were developed using the Oregon Department of Transportation (ODOT) data to determine the appropriate QA sample size. The need for this work was realized when a review of ODOT paving projects revealed a large variability in lot size. These ranged from 3000 to more than 100 000 tons with commensurate QA sample size rates. The typical standard deviation (STDEV) values of asphalt content (AC) and in-place density were determined. The developed models show that using the STDEV values that represented more than 90 percent of the projects, ODOT needed to increase QA sample size for both AC and density in lots of less than 22 000 tons. The results also show that sample can be decreased for AC and remain as is for density in projects of more than 22 000 tons of asphalt mixtures. The proposed models can be used to determine the optimum sample size for different lots sizes.

Critical Quality Control on Determination of Boron Using ICP-OES with Gravimetric Method

Critical quality control on the determination of boron using ICP-EOS with gravimetric method is carried out. This study was conducted to examine the critical aspects which include linearity, LOD, LOQ, precision, and accuracy. Based on the results of the study showed that the determination of boron with the ICP-OES method was following the critical aspects of quality control test results. The linearity of the calibration curve with a concentration range of 0 - 10 mg/L has linearity with a correlation coefficient of 0.9998 and a determination coefficient of 0.9996. The standard solution calibration curve follows the linear regression equation y = 2567.5 x + 23.043. This method has a LOD of 1.24 mg/L and a LOQ of 4.13 mg/L. The ICP-OES method has high precision and accuracy at low, medium, and high concentration levels. The testing precision of low, medium and high concentration levels is 0.44, 0.54, and 0.14%. The accuracy obtained for the three concentration levels was 98.03, 95.05, and 98.61%. Based on the ANOVA test, it was shown that the precision and accuracy at all concentration levels were not significantly different.

Study of the automated synthesis of the radiopharmaceutical fluoroestradiol-18F

Approximately 75% of breast cancer cells express estrogen receptor positive, being the second leading cause of cancer death among women worldwide with an incidence of 25% per year. 16α-[18F]-fluoro-17β-estradiol, FES-18F, is a radiopharmaceutical that binds to estrogen receptors enabling the acquisition of molecular images for non-invasive diagnosis of primary and metastatic breast cancer using PET-CT. The objective of this work was to study the synthesis of FES-18F in the GE TRACERlab® MXFDG module, using the chemical kit and the ABX® disposable cassette, and to determine the process yield and the analytical parameters to be used in the routine production of this radiopharmaceutical. Automated synthesis occurs in 75 minutes and includes percolation of [18F-] fluoride into an anion exchange cartridge, cartridge elution, 3-step azeotropic drying, labeling using precursor 3-methoxymethyl-16β,17β-epiestriol-O-cyclic sulfone (MMSE) and a hydrolysis step. Product purification is done in the module using solid phase extraction (SPE) cartridges. The radiochemical yield was reproductive, regardless of fluor-18 activity at entry into the module, and the results of quality control tests suggest that the radiopharmaceutical meets the criteria established for other fluor-18-labelled radiopharmaceuticals that have monographs in official compendiums. In vivo biodistribution studies in healthy animals and with a tumor model developed with MCF-7 cells, demonstrated radiopharmaceutical uptake in excretory organs and specificity for breast tumor cells.

Analysis of quality control test results of medical electron linear accelerators in Guangxi Province 2017—2019

Objective To understand the level of quality control in medical linear accelerator in Guangxi, and to provide technical support for the health administrative department to make related standards. Methods To select medical linear accelerators in Guangxi by random sampling method. Results A total of 118 accelerators were checked in 2017—2019, the initial inspection pass rates of medical linear accelerators were 56.8% and re-inspect pass rate were 96.6%. Conclusion The quality control level of the radiology institutions needs to be improved. The health administrative department should strengthen routine management, it is necessary to implement quality control in medical linear accelerator. 摘要： 目的 了解广西省医用电子直线加速器设备性能的质量控制水平, 为卫生行政部门研宄制定医用电子直线加 速器卫生标准和质量控制检测规范提供技术支持。 方法 采用随机抽样方法, 对广西省部分医用电子直线加速器进 行质控检测。 结果 2017—2019 年累计检测 118 台次加速器, 加速器质控检测(包括 X 射线和电子束)总初检合格率 为 56.8%, 总复检合格率为 96.6%; 二级、三级医院加速器质控检测初检合格率分别为 32.0%、62.2%, 差异有统计学意 义 ( P < 0.05), 初检合格率最低的指标是辐射剂量示值误差, 其次是辐射野均整度。 结论 广西省医用电子直线加速器 质量控制水平有待提高;卫生行政部门应进一步加强对加速器质控检测的监督, 定期开展加速器质控检测。

Health and safety control measures and MR quality control results in the MRI units of two public hospitals within the Mangaung metropolitan

This study aimed to identify risks and hazards in the magnetic resonance imaging (MRI) units, and assess the quality compliance of the scanners within two public hospitals in Mangaung. This is a follow-up study from a previously published study that measured static magnetic fields and radiofrequency magnetic fields in the MRI units included here. An observational checklist was used to identify risks and hazards which were later fed into a baseline risk assessment to classify and review existing control measures in the MRI units of hospitals A and B. The availability of MRI Health and Safety measures were benchmarked against the latest American College of Radiology (ACR) MRI safety requirements. The probability of risk occurrence and severity of hazards were assigned a score ranging from improbable (1) to very likely (5) and minimal (1) to irreversible effect (5). The weekly quality control test results obtained from both units were measured against the ACR quality control acceptable criteria. Similar risks were observed in both MRI units but the multiplication of probability and consequence in all risk categories resulted in a moderate risk-rating score of 12.3 for hospital A and 13.1 for hospital B. Lack of demarcation of four MRI safety zones, ferromagnetic detectors, 5-gauss line, and access control in both units scored above 15 and were classified as high risk. The defective air-cooling systems influenced the temperature of the scanner room, which affected the apparent diffusion coefficient (ADC) measurements performed from 1.5 T Siemens. On a 3.0 T Philips, a low contrast object detectability had 29 spokes for ACR T2, while the percent integral uniformity for image intensity uniformity was 78.2 %. High and moderate risks observed in both units could be reduced by the implementation of an effective health and safety programme. The ambient temperature within the scanner room should be maintained at 21 °C to attain well-performing ADC measurements and RF subsystems should be visually inspected and maintained regularly to obtain optimal image quality.

Establishment of 2nd National Reference Standard for Purified Vi Polysaccharide Typhoid vaccine

This study aimed to establish a national reference standard for the purified Vi typhoid vaccine. The first national standard for the typhoid vaccine established in 2009 is currently outdated; hence, Boryung Biopharma Co. produced 4,070 vials of a candidate vaccine as per the second standard outlined in 2018. The large-scale manufacture of the standard candidate was guaranteed through quality tests and accelerated and long-term stability tests. Reference standards ensure the accuracy and reliability of the results of quality control tests for vaccines. Thus, a collaborative study was conducted to estimate the potency of the candidate material as per the second national standard using the test methods of HPAEC-PAD (High Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection) and rocket immunoelectrophoresis. The HPAEC-PAD result was 51.5 μg/vial (95% confidence interval [CI]: 50.70-52.29 μg/vial). On the other hand, the rocket assay result was 63.4 μg/vial (95% CI: 61.08-65.89 μg/vial). In addition, the precision and proficiency of the institutes was confirmed by the CV and robust Z-score, respectively. The candidate will be registered for use as the second national standard for the purified Vi typhoid vaccine after evaluating its long-term stability. After registration, it will contribute to securing the reliability and consistency of the quality control test results for typhoid vaccines by being used in the national release system and quality control of the manufacturer.

Quality Control Assessment of Diagnostic X-Ray Units in Zanzibar, Tanzania

Regular execution of quality control (QC) tests in medical diagnostic X-ray units is primarily important to provide high-quality images and proper diagnoses with least hazard. The performance criteria in diagnostic radiology in Zanzibar Islands, Tanzania were followed in accordance with the QC guidelines, and the values of the measured parameters were compared with the tolerance limits. The study was designed to perform QC tests on the diagnostic X-ray units in governmental and private hospitals. In this study six QC tests (beam alignment, beam collimation, kV reproducibility, half-value layer (HVL), mAs linearity and kV accuracy) were carried out by using beam alignment tool and Unfors non-invasive X-ray test device (Xi R/F&amp;MAM detector). The measured parameters were conducted in two periods, from 2017 to 2018 (14 X-ray units were considered) and from 2019 to 2020 (16 X-ray units were considered). In both periods, the QC test results indicated that 100% of the X-ray units had acceptable HVL≥ 2.3 mm Al at 80 kVp. In the first period (2017−2018), the QC results showed that 78.57% and 85.71% had acceptable beam alignment (≤3% of the focus to image distance) and beam collimation (≤ ± 2 cm). Of the X-ray units evaluated, 85.71% had tolerable kV reproducibility of 5%, and 71.43% had mAs linearity within the tolerance limit of 10%, whereas 85.71% had acceptable kV accuracy within the tolerance limit of 5%. In the second period (2019−2020), the tolerance limits of X-ray units exceeded by 8.04% for kV reproducibility, 8.04% for kV accuracy, 16.07% for mAs linearity, 8.93% for beam alignment and 8.04% for beam collimation. The exceeded tolerance limits could be attributed to the new X-ray units which have full support of service agreements signed during the second period and increase of the compliances with the Tanzania Atomic Energy Act. No 7 of 2003 and its regulations. Results obtained highlight the need to regularly carry out comprehensive QC tests together with routine equipment maintenance.

Does a change in quality control results influence the sensitivity of an anti-HCV test?

Background Laboratories use quality control (QC) testing to monitor the extent of normal variation. Assay lot number changes contribute the greatest amount of variation in infectious disease serology testing. An unexpected change in six lots of an anti-HCV assay allowed the determination of the effect these lot changes made to the assay's clinical sensitivity. Methods Two sets of seroconversion samples comprising of 44 individual samples and 9 external quality assessment scheme (EQAS) samples, all positive to anti-HCV, were tested in affected and unaffected assay lots, and the difference in the quantitative and qualitative results of the samples was analyzed. Results Of 44 low-positive seroconversion samples tested in affected and unaffected assay lots, only three samples had results reported below the assay cutoff when tested on two of the six affected assay lot. A further sample had results below the cutoff for only one affected lot. None of the EQAS samples reported false-negative results. Samples having a signal to cutoff value of less than 6.0 generally had lower results in the affected lots compared with the unaffected lots. Conclusions Unexpected changes in QC reactivity related to variation, in particular assay lot changes, may affect patient results. This study demonstrated that QConnect Limits facilitated the detection of an unexpectedly large variation in QC test results, allowed for the identification of the root cause of the change, and showed that the risk associated with the change was low but credible. The use of evidence-based QC program is essential to detect changes in test systems.

SPECT – BT ’nin Kalite Kontrolleri

The one of the aim of nuclear medicine is diagnosis of an abnormal metabolic activities in target organs. In a routine nuclear medicine imaging procedure, a radiopharmaceutical is used. Radiopharmaceutical’s radionuclide part emits gamma radiation. This radiation is dedected by Gamma Camera or Single Photon Emission Computed Tomography (SPECT). A computed tomography (CT) device was added to the SPECT(SPECT- CT). To combine anatomical images. Image quality of this device is important for accurate diagnosis and treatment of diseases. By means of quality control tests, performance changes of device are dedected. A various quality control parameters such as uniformity, sensivity, resolution, linearity have been developed for Gamma cameras, SPECT. Quality control test results are should be verify by comparing acceptable results. In this study, quality control tests of SPECT-CT are performed as proposed by the National Electrical Manufacturers Association ( NEMA) and it was aimed to investigate some correction methods.

Predicting VMAT patient-specific QA results using a support vector classifier trained on treatment plan characteristics and linac QC metrics

The use of treatment plan characteristics to predict patient-specific quality assurance (QA) measurement results has recently been reported as a strategy to help facilitate automated pre-treatment verification workflows or to provide a virtual assessment of delivery quality. The goal of this work is to investigate the potential of using treatment plan characteristics and linac performance metrics (i.e. quality control test results) in combination with machine learning techniques to predict the results of VMAT patient-specific QA measurements.Using features that describe treatment plan complexity and linac performance metrics, we trained a linear support vector classifier (SVC) to classify the results of VMAT patient-specific QA measurements. The ‘targets’ in this model were simple classes representing median dose difference between measured and expected dose distributions—‘hot’ if the median dose deviation was >1%, ‘cold’ if it was <−1%, and ‘normal’ if it was within ±1%. A total of 1620 unique patient-specific QA measurements were available for model development and testing. 75% of the data were used to develop and cross-validate the model, and the remaining 25% were used for an independent assessment of model performance. For the model development phase, a recursive feature elimination (RFE) cross-validation technique was used to eliminate unimportant features. Model performance was assessed using receiver operator characteristic (ROC) curve metrics.Of the ten features found to be most predictive of patient-specific QA measurement results, half were derived from treatment plan characteristics and half from quality control (QC) metrics characterizing linac performance. The model achieved a micro-averaged area under the ROC curve of 0.93, and a macro-averaged area under the ROC curve of 0.88.This work demonstrates the potential of using both treatment plan characteristics and routine linac QC results in the development of machine learning models for VMAT patient-specific QA measurements.

Optimization of solid-phase extraction (SPE) in the preparation of [18F]D3FSP: A new PET imaging agent for mapping Aβ plaques

IntroductionAlzheimer's disease is a common neurodegenerative disease that is characterized by the presence of Aβ plaques in the brain. The FDA has approved the use of Amyvid (florbetapir f18, AV-45) as a PET imaging agent for detecting Aβ plaques in the living human brain. In an attempt to reduce N-demethylation in vivo by taking advantage of more stable C-D bonds, an analog of AV-45, [18F]D3FSP ([18F]7), was synthesized to improve image contrast for detecting and monitoring the Aβ plaques. A convenient and improved preparation of [18F]D3FSP ([18F]7) is needed for widespread clinical application. We report herein the optimization of the radiosynthesis and solid-phase extraction (SPE) procedure. MethodsRadiosyntheses of [18F]D3FSP ([18F]7) under different fluorination conditions were evaluated, and the intermediate, containing an N-Boc protecting group, was deprotected using different acids. One of the major objectives was to simplify the final purification step via SPE to avoid the commonly employed HPLC purification and maximize the radiochemical yields of [18F]D3FSP ([18F]7) while simultaneously removing several chemical impurities (pseudocarriers). Washing various solid-phase cartridges with different combinations of ethanol/water and acetonitrile/water was explored to optimize the purification step. To evaluate the potential interference in Aβ plaques imaging from the presence of pseudocarriers, each chemical was identified and quantified by LC/MS and HPLC. An in vitro binding assay was employed to evaluate the binding affinities of [18F]D3FSP ([18F]7) and the pseudocarriers to Aβ plaques using postmortem AD brain tissue. ResultsUsing the optimized radiosynthesis method and SPE purification, the final dose of [18F]D3FSP ([18F]7) was obtained in 50 min with a very low content of pseudocarriers (21.7 ± 5.5 μg). The radiochemical yield was 44.4 ± 5.7% (decay corrected), and the radiochemical purity was >95%. SPE-purified doses of [18F]D3FSP ([18F]7) displayed excellent binding affinity and specificity for Aβ plaques as measured in an in vitro binding assay using AD brain homogenates, and the OH-pseudocarrier, 8 (Ki = 19.5 ± 0.5 nM), and the Cl-pseudocarrier, 10 (Ki = 18.6 ± 3.9 nM), showed lower binding affinities for Aβ plaques than those of AV-45 (Ki = 8.6 ± 0.5 nM) and D3FSP, 7 (Ki = 9.8 ± 0.5 nM). ConclusionsAn optimized radiosynthesis and fast SPE purification method suitable for the preparation of clinical doses of [18F]D3FSP ([18F]7) was accomplished. The results of quality control tests and binding studies suggested that the SPE-purified doses of [18F]D3FSP ([18F]7) are appropriate for imaging Aβ plaques in the human brain.

IMPLEMENTATION OF QUALITY ASSURANCE PROGRAM IN RADIOGRAPHY-2-YEAR EXPERIENCE OF COLLABORATION WITH PUBLIC HEALTH INSTITUTIONS IN WEST REGION OF CROATIA.

Quality Assurance program on using ionizing radiation is mandatory in all EU member states but this is still not implemented in most facilities in Croatia mostly because of a lack of medical physicists in diagnostic radiology. Since public health institutions in Croatia do not employ medical physicists in diagnostic radiology, collaboration between these institutions in west region of Croatia with Clinical Hospital Center Rijeka (CHC) was initiated during the year 2015. Physicists from CHC Rijeka performed periodical Quality Control (QC) tests and were included in optimization process. Results of QC tests during the period of 2 years showed a lot of improvements-equipment is maintained more frequently, some old units were replaced with new ones and all institutions acquired QC equipment so radiographers could perform daily and monthly QC tests. All these activities showed that medical physics support in radiology departments is necessary and can improve clinical practice.

Characterization and Evaluation of Carboxymethyl Starch of Cajanus Cajan Seeds as Tablet Binder

The aim of this study was to characterize carboxymethyl cajanus cajan starch (CMCCS) and evaluate its capacity as binder, using metronidazole as model drug. Wet granulation method was adopted in preparation of metronidazole tablets containing CMCCS. Native cajanus cajan starch (NCCS) was carboxymethylated using monochloroacetic acid (MCA) and sodium hydroxide. Also the effect of CMCCS concentration and wet massing time on the physical properties of metronidazole (200 mg) tablet formulations was tested in a 22 full factorial design. The degree of substitution, amylose content, moisture content, pH and moisture uptake of CMCCS were found to be 0.252, 20.92%, 8.86 %, 6.9 and 48.5 respectively. Also CMCCS dissolved in cold water forming viscous solution. Similarly amylose content, moisture content, pH and moisture uptake of NCCS were 32.9%, 9.6 %, 6.12 and 17.34% respectively. in terms of bulk density, NCCS gave higher values compared to CMCCS. The values of Hausner ratio were 1.42 and 1.46 for NCCS and CMCCS respectively. The results of angle of repose revealed that the CMCCS had good flow characteristics, while the NCCS had passable flow characteristics. FT-IR analysis of the CMCCS sample showed peak shifting compared to the NCCS sample indicating carboxymethylation. CMCCS with degree of substitution (DS) of 0.252 was synthesized and it was further evaluated as tablet excipient in metronidazole based tablets. The results of quality control tests which performed for metronidazole formulations that prepared by CMCCS as binder, showed that the increase of CMCCS concentration from 12.5 % to 17.5 % led to increase in hardness and decrease in % friability values significantly, but no significant effect on DT was observed when wet massing time was kept at 6 min but when wet massing time was increased to 12 min, DT was significantly increased. Also the increase of wet massing time from 6 to 12 min led to slight increase in tablets hardness. The % friability was decreased due to increasing in wet massing time only in formulations containing CMCCS at 17.5%. Also all the batches showed more 90 % drug release within 15 min. Generally, the physicochemical and functional properties of CMCCS and NCCS showing that both NCCS and CMCCS can be used as tablet excipient in pharmaceutical industries. With CMCCS having superior properties compared to unmodified cajanus cajan starch.

Quality control of apheresis platelets: a multicentre study to evaluate factors that can influence pH measurement.

Blood operators routinely monitor the pH of apheresis platelets as a marker of the so-called storage lesion, which can result from manufacturing problems. It is also suspected that some donor characteristics can increase the risk of poor platelet storage. To explore this hypothesis, we analysed a large, multinational data set of quality control (QC) pH test results on apheresis platelets. For the period between September 2011 and August 2014, seven blood operators in Canada, the USA, the Netherlands, the United Kingdom, France and Australia provided pH QC test results and donor characteristics on a total of 21,671 apheresis platelets. Some variations in pH distribution between blood operators were in part explained by differences in collection, processing and testing methods. Younger age and female gender were significantly associated with a pH value below the 10th percentile. Among donors who had two or more pH measurements (n = 3672), there was a strong correlation between pH results (r = 0·726; P < 0·0001). The strong intradonor correlation of pH measurements and the association between donor characteristics and pH results suggest that donor factors play a role in the quality of platelets.

Quality Control Assessment of Conventional Radiology Devices in Iran

Introduction Quality control (QC) techniques are used in monitoring and maintenance of the components of an x-ray system. QC of radiology devices plays a significant role in reduction of medication dose and optimization of image quality. This study aimed to conduct QC tests on randomly selected radiology devices, installed in diagnostic imaging departments of Iran. Materials and Methods In total, quality control tests were conducted on 51 conventional radiology devices installed in 20 cities of Iran in order to assess the accuracy of peak kilovoltage (kVp), exposure time, exposure linearity and reciprocity, reproducibility of exposure and determination of half-value layer (HVL) using a calibrated Mult-O-Meter. Results In this study, 38.6% of devices had intolerable variance of kVp accuracy. The results of 34.5% of devices were out of the acceptable limits in exposure time accuracy test. In 46.7% and 53.1% of devices, variance was greater than the acceptable range for exposure linearity and exposure reciprocity, respectively. In terms of reproducibility of exposure test, the reproducibility variance and percentage of tube output variations in 19.4% of devices exceeded the limits. Moreover, the thickness of first HVL was lower than the acceptable limit in 14.7% of devices. Conclusion According to the results of this study, there were wide variations in QC test results, perhaps mainly due to the fact that it is not an obligation to implement QC programs in Iran. The most important problems were non-reciprocity of exposure, nonlinearity of exposure with milliampere-second (mAs), kVp and timer inaccuracy. Involvement of medical physicists, radiologists and radiographers in the implementation of QC programs at various stages of development, installation and use of equipment should enable the gradual improvement in equipment performance.

Wisconsin Department of Transportation Hot-Mix Asphalt Round Robin Laboratory Qualification Testing Program

The Wisconsin Department of Transportation (DOT), Madison, uses a quality management program (QMP) specification for acceptance and payment of hot-mix asphalt (HMA) pavement. The QMP allows for product acceptance on the basis of contractor quality control (QC) testing when verified by the Wisconsin DOT quality verification (QV) tests. The contractor is required to do daily QC testing of mix properties in a department-certified, qualified laboratory located at the plant site. The Wisconsin DOT maintains a QV program (QVP) and conducts QV tests to determine the quality of the final product. QV and QC test results are compared, and a mix is considered acceptably verified if the two results are within specified limits. When test results do not meet these limits, the Wisconsin DOT performs referee tests to determine mixture conformance, acceptability, and payment. In 2011, the Wisconsin DOT began to see significant increases in the number of requests for referee testing as a result of wide disparities between QC and QV laboratory test results. To investigate this disparity, the department initiated a round robin laboratory test program. Results from the investigation proved to be insightful. The program was expanded and is now a key component of the Wisconsin DOT annual laboratory qualification certification program. This paper describes the program, how it is administered, how tests results are analyzed, and how nonconforming laboratories are identified. Test results obtained from the program are presented and recommendations developed for program improvements. The program details should be useful to other state highway agencies that use contractor QC tests for acceptance.

Assessment of the direct cyclotron production of 99mTc: An approach to crisis management of 99mTc shortage

Nowadays, the cyclotron production of technetium-99m (99mTc) has been increased, due to the worldwide 99mTc generator shortage. In the present work, an improved strategy for the production of 99mTc, using the proton irradiation of the enriched 100Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA−1h−1. A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of 99mTc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the 99mTc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced 99mTc is suitable for preparation of USP-compliant.