Absolute Standardization Research Articles

The calibration of transfer standards for the measurement of 222Rn at NIM

A high-purity germanium (HPGe) gamma-ray spectrometer and an Alpha-GUARD radon monitor are the activity and activity concentration transfer standards of 222Rn, respectively. The gaseous 222Rn standard source traceable to the NIM's absolute standardization apparatus of 222Rn was developed for calibrating these transfer standards. The calibration results of HPGe detector at three different distances show that the uncertainties of experimental efficiency are less than 0.77% (k = 1). Meanwhile, the Monte Carlo (MC) simulation was carried out at wider distances range for the HPGe calibration as well, and the deviation at same three distances between experiments and simulations results is within ±3.0%. The advantage of calibration using MC simulation and the possible reasons for the deviation were discussed in detail in this article. In addition, a reference activity concentration environment based on the gaseous 222Rn standard source was also developed to calibrate the radon monitor, and the typical uncertainty for calibration factor of Alpha-GUARD radon monitor could be reduced to 1.9% (k = 1).

Visual Extraction of Refined Operation Mode of New Power System Based on IPSO-Kmeans

Due to the influence of the high proportion of renewable energy penetration, the time-varying and complex operation mode of the new power system is gradually increasing, leading to a lack of fineness and practicality of traditional operation modes. To this end, a new visual extraction method for fine operation mode of power system is proposed. Specifically, aiming at the dimensional problem between high-dimensional electrical characteristic variables, a power grid operation data preprocessing method based on maximum absolute standardization (MaxAbs) is designed. Then, in order to reduce the impact of redundant features on the accuracy of the operation mode extraction results, the Pearson correlation coefficient is introduced to optimize the feature space relationship matrix, constructing a screening model of operating mode characteristic variables based on pearson kernel principal component analysis (P_KPCA). Then, with the clustering elbow index as the constraint condition, a K-means algorithm based on improved particle swarm optimization (IPSO-Kmeans) was proposed to realize fine operation mode extraction. Finally, the experimental analysis is carried out with the actual operation data of the power grid for one year and based on uniform manifold approximation and projection (UMAP) to visualize the extraction results of the operation mode. The validity and accuracy of the proposed method are verified.

Alternative mechanisms of managing the education’s development in the social investment model of Russia’s economic growth: standardization versus deregulation

Regression analysis is used to determine the contribution of the factors of managing the development of higher education – share of university branches – to increase the population’s quality of life. To determine the optimal approach to managing education’s development in the social investment model of Russia’s economic growth with alternative mechanisms of standardization and deregulation. The results of the research show that absolute standardization, as well as absolute deregulation of higher education, does not allow achieving significant results in the sphere of increase in quality of life in Russia. The determined and substantiated optimal scenario of managing the development of higher education in Russia to increase the quality of life envisages a foundation on a flexible approach, which envisages the combination of standardization and deregulation. It is recommended to entirely refuse branches in favor of main universities, refuse government financing in favor of fee-based education and refuse diversification of education forms in favor of the intramural form of study. This allows raising the quality of life by 13.26% (up to 70.87 points). For practical implementation of this approach, it is offered to allow each region to form their own programs of development of higher education with the foundation of the main federal principles.

Host Galaxy Mass Combined with Local Stellar Age Improve Type Ia Supernovae Distances

Abstract Type Ia supernovae (SNe Ia) are standardizable candles, but for over a decade there has been a debate on how to properly account for their correlations with host galaxy properties. Using the Bayesian hierarchical model UNITY, we simultaneously fit for the SN Ia light curve and host galaxy standardization parameters on a set of 103 Sloan Digital Sky Survey II SNe Ia. We investigate the influences of host stellar mass, along with both localized (r <3 kpc) and host-integrated average stellar ages, derived from stellar population synthesis modeling. We find that the standardization for the light-curve shape (α) is correlated with host galaxy standardization terms (γ i ) requiring simultaneous fitting. In addition, we find that these correlations themselves are dependent on host galaxy stellar mass that includes a shift in the color term (β) of 0.8 mag, only significant at 1.2σ due to the small sample. We find a linear host mass standardization term at the 3.7σ level, that by itself does not significantly improve the precision of an individual SN Ia distance. However, a standardization that uses both stellar mass and average local stellar age is found to be significant at >3σ in the two-dimensional posterior space. In addition, the unexplained scatter of SNe Ia absolute magnitude post standardization, is reduced from to 0.109 ± 0.017 mag, or ∼10%. We do not see similar improvements when using global ages. This combination is consistent with either metallicity or line-of-sight dust affecting the observed luminosity of SNe Ia.

Characteristics of Moslem Families Economy Based on Maqashid Sharia Perspective

Modern lifestyle has interfered principles of moslem families. This era tries to define attitude, wealth value, and social position of individuals in society. It might become a doctrine, patent product, challenge or threat. The objective of this research is to elaborate the Islamic characteristics within the economy of moslem families and also implementation of Maqashid Sharia in the economy of moslem families. This research exerts case-study, by determining selected informants from the community of moslem small entrepreneurs in Malang. The findings show that the moslem families consider faith (iman) as basic foundation of economy. They also hold on to character perfection that is based on akhlaqul karimah, lawfulness and wholesomeness, priority scale as expenditure reference, moderation as absolute standardization and responsibility of woman’s wealth proprietary. Internalization of Islamic economy principles in the moslem families economy includes the statement that working as a form of ikhtiar and worship, expenditure as material and spiritual distribution of wealth, savings as urgent post in the future, and wealth as instrument to serve to Allah. Finally, it is important to regard Maqashid Sharia as a standard of Muslim action in economy

Absolute standardisation and determination of the half-life and gamma emission intensities of 89Zr

An absolute standardisation of 89Zr was performed alongside determination of gamma emission intensities and half-life. The collected data were evaluated alongside complementary works from previous publications and new recommended nuclear data values are presented including a new evaluated T1/2 = 78.361(25) h and new absolute intensities for gamma transitions resulting from its decay to 89Y. Dial settings for commercially available radionuclide calibrators are also presented and show a relative difference of approximately 3% compared to previously published values.

Fiducial reference systems for time and coordinates in satellite altimetry

Time is the fundamental measurement in satellite altimetry and the key parameter in building and keeping up a long-term, consistent, and reliable record for monitoring changes in sea level. Over the years, different time scales, although interconnected, have been used in altimetry and also in satellite positioning. This sometimes leads to inexplicit descriptions and ambiguous use of time and orbit coordinates as well as of their transformations between various reference and measuring systems. Altimetry satellites, like Sentinel-3, CryoSat-2, Jason-3, HY-2A/-2B, IceSat-2, etc., observe and practically realize ranges by measuring time differences between the transmission and reception of an electromagnetic wave (either radar or laser at present). Similar principles apply for global navigation satellite systems and for their terrestrial reference systems upon which altimetry is linked and tied together. Yet, the “meter” of any terrestrial reference systems is also defined by time. This work seeks to establish a standard reference system for “time” and “coordinates” in an effort to reach uniform and absolute standardization for satellite altimetry. It describes various errors generated from differences, discontinuities and interactions in time, frequency, range, time tagging, and reference coordinate frames. A new approach, called “fiducial reference measurements for altimetry”, is here given to examine ways to connect errors with metrology standards in order to improve the estimation of uncertainty budgets in ocean and water level observation by altimetry. Finally, the geocentric inertial reference system and the international atomic time are proposed in this paper for satellite altimetry observations and products.

An Action Plan Towards Fiducial Reference Measurements for Satellite Altimetry

Satellite altimeters have been producing, as of 1992, an amazing and historic record of sea level changes. As Europe moves into full operational altimetry, it has become imperative that the quality of these monitoring signals with their uncertainties should be controlled, fully and properly descripted, but also traced and connected to undisputable standards and units. Excellent quality is the foundation of these operational services of Europe in altimetry. In line with the above, the strategy of the Fiducial Reference Measurements for Altimetry (FRM4ALT) has been introduced to address and to achieve reliable, long-term, consistent, and undisputable satellite altimetry products for Earth observation and for sea-level change monitoring. FRM4ALT has been introduced and implemented by the European Space Agency in an effort to reach a uniform and absolute standardization for calibrating satellite altimeters. This paper examines the problem and the need behind the FRM4ALT principle to achieve an objective Earth observation. Secondly, it describes the expected FRM products and services which are to come into being out of this new observational strategy. Thirdly, it outlines the technology and the services required for reaching this goal. And finally, it elaborates upon the necessary resources, skills, partnerships, and facilities for establishing FRM standardization for altimetry.

Standardization of the emerging medical positron emitter 89Zr

89Zr is a beta plus and electron capture decaying radionuclide. This paper presents: (1) Absolute standardization by the 4πβ(PC)-γ coincidence method: a new equivalent decay scheme, the mathematical formalism applied to it and the choice of the optimal measurement conditions. (2) Measurements by HPGe gamma-ray spectrometry, to determine the possible impurities, to measure the activity and the relative intensities of the emitted gamma rays. (3) Calibration of the CENTRONIC IG12/20A ionization chamber, by two methods: direct measurement using the absolutely standardized solution and linear least square modelling, as well as their comparison. (4) Comparisons of results of all measurement methods.

Determination of activity meter settings for the PET nuclides 44Sc and 89Zr

Radionuclide activity meters depend on “calibration setting numbers” that are specific for a certain combination of radionuclide, volume and geometry. This work describes their determination for two PET emerging nuclides (44Sc and 89Zr), three commercial activity meters (CAPINTEC CRC15 BETA, ATOMLAB BIODEX 500 and VEENSTRA VDC 405) and two geometries: 1 mL plastic syringes and 5 mL glass vials. For 44Sc, only values for the dial setting for 5 mL ampoules were reported previously and its use for the assayed geometries would lead to significant differences. For 89Zr more data were available in the literature, and results are provided for new geometries. All results rely on the absolute standardisation in activity of solutions of both radionuclides.

Embracing standardisation and contextualisation in medical education.

The tensions that emerge between the universal and the local in a global world require continuous negotiation. However, in medical education, standardization and contextual diversity tend to operate as separate philosophies, with little attention to the interplay between them. The authors synthesise the literature related to the intersections and resulting tensions between standardization and contextual diversity in medical education. In doing so, the authors analyze the interplay between these competing concepts in two domains of medical education (admissions and competency-based medical education), and provide concrete examples drawn from the literature. Standardization offers many rewards: its common articulations and assumptions promote patient safety, foster continuous quality improvement, and enable the spread of best practices. Standardization may also contribute to greater fairness, equity, reliability and validity in high stakes processes, and can provide stakeholders, including the public, with tangible reassurance and a sense of the stable and timeless. At the same time, contextual variation in medical education can afford myriad learning opportunities, and it can improve alignment between training and local workforce needs. The inevitable diversity of contexts for learning and practice renders any absolute standardization of programs, experiences, or outcomes an impossibility. The authors propose a number of ways to examine the interplay of contextual diversity and standardization and suggest three ways to move beyond an either/or stance. In reconciling the laudable goals of standardization and the realities of the innumerable contexts in which we train and deliver care, we are better positioned to design and deliver a medical education system that is globally responsible and locally engaged.

Production and standardization of an on-demand protactinium-233 tracer

Protactinium-233 (233Pa) was generated by neutron activation of thorium and isolated by column chromatography using an octanol-impregnated resin. Absolute activity standardization was performed on 233Pa using three independent methods, the results of which agreed within their associated uncertainties. The standardized 233Pa was used to calibrate a secondary standard ionization chamber and high purity germanium detectors to enable a rapid and traceable method for the production and quantification of this radiotracer.

Absolute standardization of 57Co and analysis of the results obtained in two international comparisons

The absolute standardization of Co-57 by the 4π(PC)-γ coincidence method, in efficiency extrapolation variant, is presented. An original, improved method, based on the use of the equivalent decay scheme, was applied; apart from the enhancement of efficiency, a diminution of extrapolation slope was obtained, lowering the extrapolation uncertainty. The results obtained in the participation at the supplementary comparison CCRI(II)-S6.Co-57 and at the key comparison code BIPM.RI(II)-K1.Co-57 are presented. The method allows to simplify the treatment of 56Co and 58Co impurities’ correction, which influences significantly the measurements in a CENTRONIC type ionization chamber. An example of treatment of this mixture, where the influence of impurities on results was analyzed, will be presented.

Absolute standardization of the 133Ba by sum-peak method and comparison with other methods

This paper presents the absolute standardization of 133Ba by sum-peak method. 133Ba owns a complex decay and was used the sum coincidences between the average energy of characteristic X-rays (kα1 and kα2) and gamma-rays. The activity results presented uncertainty values below 0.3 % and were compared with those of other absolute activity measurement techniques. The results obtained are compared with other methods and confirm that this is an alternative, fast and efficient method for 133Ba standardization.

Motion Correction and Its Impact on Absolute Myocardial Blood Flow Measures with PET.

Motion artifacts, due to cardiac and respiratory cycles, myocardial cardiac creep, or gross patient movements, have been extensively investigated in the context of relative myocardial perfusion imaging with SPECT and PET. These movements have been identified as a major source of errors in image quantification and diagnosis. Recently, as dynamic PET quantification for myocardial blood flow assessment has entered clinical practice, similar questions have arisen on the impact of motion on final blood flow values. While preliminary investigations have underlined the potential impact of these motions on MBF quantification, their correction on dynamic acquisition remains challenging and limited to research studies. Gross patient's body movements occur in a consistent number of cases, particularly during stress acquisition, typically involving a limited number of image frames. If undetected, these movements can lead to great differences in flow values and consequently misdiagnosis. Quality control routines can be applied to automatically inspect the shape of time activity curves and to help identify motion artifacts. Cyclic cardiac and respiratory motion may have a considerable impact on final flow values. Correction of gross body motion represents a priority in the context of optimizing absolute flow clinical routine utilization and protocol standardization.

Deconvolution method to split up X-ray peaks emitted by 223Ra

The Radium-223 ( 223 Ra) has being used as a medicine for localized treatment of patients with osteoblastic metastasis originated by prostate cancer resistant of castration or hormone refractory. For a better treatment with this radionuclide, clinical images are one path to turn achievable organ's dosimetry for each patient. The X-rays emitted by 223 Ra demonstrated as the main way to turn the image acquiring feasible. In order to study this X-ray area, deconvolution is necessary to split up the mains X-ray peaks that are measured by a high-purity germanium detector as doublet peaks in a complex region of the spectrum below 100 keV. For this, the Colegram® code was applied using the Low Energy X Voigt fitting curve on raw data source from Maestro® software. Results of activity using the deconvolution data from this work were in agreement with values obtained at absolute standardization live-time anticoincidence counting. The Colegram® code demonstrates a powerful tool to aid Maestro to split up the mains overlapped X-rays emitted by 223 Ra.

Standardization of 67Cu and calibration of the ionization chamber. Impurities and decay scheme problems

This paper describes the standardization of 67Cu by the 4πβ(PC)-γ coincidence method, and the calibration of ionization chamber. The difficulties were. (i) One of the excited levels of 67Zn has a half life of 9.10μs. (ii) A recent publication reconsiders the decay scheme parameters. (iii) The solution had a significant content of impurities. The conclusions were that the result of absolute standardization is less influenced by the decay scheme parameters and impurities than the measurements by ionization chamber.

Investigation of γ-γ coincidence counting using the National Nuclear Array (NANA) as a primary standard

The National Physical Laboratory has recently been in the process of commissioning a multi-detector γ ray array - the National Nuclear Array (NANA). In this study we have sought to exploit the NANA and the excellent timing characteristics of its intrinsic LaBr3(Ce) scintillation detectors for use as a primary standardisation system. For this initial investigation, the absolute standardisation of 60Co has been performed by the γ-γ coincidence technique using NANA and the result compared to the established 4π(LS)-γ Digital Coincidence Counting (DCC) system. The effect of the angular correlation of the stretched E2 transitions emitted from the 4+→2+→0 states of 60Ni on the activity determined by NANA was observed between the pairs of detectors. Corrections for these angular correlations were derived through Monte Carlo simulations. An activity per unit mass by NANA of 330.8 (10) kBqg−1 for the 60Co solution was determined. There was no significant statistical difference between the results of NANA and the 4π(LS)-γ DCC, with a relative difference of 0.04% observed. This study shows that NANA can be used as a primary standard.

Development of the absolute standardization apparatus for radon-222 activity

A defined solid angle counting apparatus for radon-222 activity absolute measurement is presented. Two home-made vacuum sealed radium-226 sources with radioactivity of 500kBq and 3MBq are used to minimize the impact from gas impurities. The defined solid angle is calculated using precisely measured geometrical parameters by several algorithms. The result from Monte Carlo simulation agrees with results obtained by other methods within the estimated uncertainty limit. Alpha particle's scattering behavior in the measurement chamber and collimator is simulated by the geant4 code and a total scattering alpha particle ratio of 0.23% as well as a relative uncertainty contribution to activity measurement of 0.02% to 0.09% are estimated. A typical total combined standard uncertainty of 0.28% is evaluated for the radon activity primary measurement.

Absolute standardizations of 99mTc and 57Co by 4π electron-gamma liquid scintillation coincidence counting for SIRTI and SIR comparisons

The radionuclides 99mTc and 57Co were standardized via absolute liquid scintillation counting techniques. We provide the first technical report on the absolute standardization of 99mTc using 4π(LS)e-γ coincidence counting. The low detection efficiency of low-energy conversion electrons translates into a large efficiency extrapolation range. A simulation indicated that the γ-ray interacting with the liquid scintillator introduces curvature to the count rate vs. efficiency relationship, the approximation of the functional form used for extrapolation providing the main measurement uncertainty for 99mTc. A detection efficiency analysis for both radionuclides is presented. Results from the standardizations, and SIRTI and SIR comparison exercises are reported.