Bilateral Comparison Research Articles

A comparison in conventional mass measurements SIM.M.M-S6

Main textThe present document reports the results of a bilateral comparison in the calibration of mass standards that was carried out between CESMEC (Chile) and CENAMEP AIP (Panamá). This comparison was carried out in the following nominal values: 200 mg, 1 g, 50 g, 200 g, 1 kg, 2 kg, and 10 kg.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A bilateral comparison of particle number concentration standards via calibration of an optical particle counter for number concentration up to ∼1000 cm−3

The first bilateral comparison of particle number concentration (PNC) standards via calibrating the counting efficiency (CE) of an optical particle counter (OPC) at high concentration of 1000 cm−3 is reported. An OPC (GRIMM 11-D) has been used as the transfer standard between NMC and NMIJ, with its CE being calibrated using monodisperse polystyrene latex (PSL) particles around 0.3 µm by the Faraday Cup Aerosol Electrometers (FCAE) of both metrology institutes. The CE of the OPC has been evaluated for a series of increasing concentrations to determine the highest concentration level which is free from coincidence loss. The OPC was also calibrated at 0.5 µm using an inkjet aerosol generator (IAG) and FCAE to compare its CE at different concentration levels. We have analysed the CE’s stability at decreasing concentration levels from 1228 to 0.5 cm−3 to derive the evidence for the equivalence of CE at different concentration levels. The CE values of the OPC around 0.3 and 0.5 µm measured by two institutes have agreement within 1.5% (normalizederror En < 1), which can serve as evidence of the equivalence of the PNC standards of both metrology institutes for concentrations up to 1000 cm−3. The measurement setup, comparison results and uncertainty analysis for the OPC calibration have been presented.

Bilateral Comparison of Radiation Temperature Measurements from − 20 to 1600 °C Between TUBITAK-UME (Turkey) and SASO-NMCC (Kingdom of Saudi Arabia)

Bilateral Comparison of Radiation Temperature Measurements from − 20 to 1600 °C Between TUBITAK-UME (Turkey) and SASO-NMCC (Kingdom of Saudi Arabia)

Interlaboratory Comparison of Solar Cell Measurements Under Low Indoor Lighting Conditions

In recent years, industrial demand for energy harvesting from the indoor environment using photovoltaic (PV) solar cells has grown substantially. Much of this demand is focused on powering Internet of Things devices such as remote sensors and actuators because their power requirements can be easily met by indoor PV cells that convert, otherwise, wasted indoor light energy into low power electricity. However, accurate measurement of PV cells’ indoor performance is challenging because there are currently no broad consensus approaches or standards for doing such measurements. Here, we have taken the first steps toward establishing such a consensus by performing an interlaboratory comparison (ILC) of measurements of a PV solar cell under three distinct low illumination reporting conditions. In this bilateral comparison, each laboratory uses a different technique for reporting the performance parameters of the cell under a fixed set of agreed upon illumination conditions. Our results demonstrate good agreements under some reporting conditions and divergent results under another. Yet, first steps have been taken toward understanding the challenges of establishing a universally acceptable method of measurement.

Interlaboratory Comparison on the Quantification of Total and Accessible Amine Groups on Silica Nanoparticles with qNMR and Optical Assays.

Risk assessment of nanomaterials requires not only standardized toxicity studies but also validated methods for nanomaterial surface characterization with known uncertainties. In this context, a first bilateral interlaboratory comparison on surface group quantification of nanomaterials is presented that assesses different reporter-free and labeling methods for the quantification of the total and accessible number of amine functionalities on commercially available silica nanoparticles that are widely used in the life sciences. The overall goal of this comparison is the identification of optimum methods as well as achievable measurement uncertainties and the comparability of the results across laboratories. We also examined the robustness and ease of implementation of the applied analytical methods and discussed method-inherent limitations. In summary, this comparison presents a first step toward the eventually required standardization of methods for surface group quantification.

Inter-laboratory Pressure Comparison Measurement In Gas Medium at ± 150 hPa Range

Results of interlaboratory comparisons and proficiency tests are a significant parameter for the calibration and testing laboratories for assuring the quality of test and calibration results performed by those laboratories. Accredited and non-accredited laboratories that have a quality system for their working areas are expected to join into inter-comparisons and proficiency tests in certain periods to show a degree of equivalence among the participant laboratories and assure their service quality. The necessity of participating in comparison measurements (ILC) and proficiency tests (PT) are stated in the EN ISO/IEC 17025:2017 International Standard that accredited laboratories or laboratories applying for accreditation must participate in ILC and PT from parameters related to measurement quantities within the scope of accreditation and have achieved successful results, and it is also a requirement sought by accreditation bodies. This study gives the organisation steps and the obtained results of a bilateral pressure comparison measurement of digital pressure gauge in the hydraulic medium between UME and an accredited laboratory in industry between ± 150 hPa.

Precise measurement of the thickness of silicon wafers by double-sided interferometer and bilateral comparison

The Length Standards Group at the National Metrology Institute of Japan has developed a double-sided interferometer (DSI) for non-contact thickness measurement, that is traceable to SI units. The measurement uncertainty of DSI was evaluated. The results of gauge block measurements were compared with those of a conventional gauge block interferometer and their equivalency within the claimed uncertainty was confirmed. The advantage of applying a DSI in measuring the thickness of silicon wafers is that it has absolute measurement traceable to SI units with high precision and independence from the refractive index of the sample material. The expanded uncertainty of silicon wafer thickness measurement was evaluated as 20 nm (the coverage factor k = 2). A bilateral comparison on silicon wafers’ thicknesses was conducted with Korea Research Institute of Standards and Science, using a different measurement technique from the spectral-domain interferometer. Results of 100 μm, 300 μm, 600 μm, and 950 μm-thick silicon wafers agreed well with absolute values of E n -numbers of 0.15 or less.

A bilateral comparison of NIST and PTB laser power standards for scale realization confidence by gravitational wave observatories

The gravitational wave (GW) observatories calibrate interferometer displacement using photon momentum, with laser power serving as the measurand. These observatories are traceable to the International System of Units through a primary standard maintained by the US’s National Metrology Institute (NMI), the National Institute of Standards and Technology (NIST). The bilateral degree of equivalence of laser power measurements for various NMIs indicated in the 2010 EUROMET.PR-S2 supplementary comparison reveals scale realization uncertainty unacceptably large for GW event parameterization. We offer here an analysis to identify the source of the discrepancy between the Physikalisch-Technische Bundesanstalt (PTB) and NIST results. Using an improved transfer standard in a bilateral comparison, with representatives of the Laser Interferometer Gravitational-Wave Observatory (LIGO) receiving results prior to their comparison, NIST and PTB demonstrated a degree of equivalence of −0.15% with an uncertainty of 0.95% (k = 2) for combined 100 mW and 300 mW comparison results.

Upper Quarter Y-Balance Test in Collegiate Softball Players: Bilateral Arm Comparison and Influence of Reach Order

The upper quarter Y-balance test is an upper extremity, closed kinetic chain assessment that requires individuals to reach in three directions while in a three-point plank position. The upper quarter Y-balance test was performed in 22 collegiate softball players (19.95 ± 1.52 years) to determine the (a) differences between throwing and nonthrowing (NT) sides and (b) influence of reach sequence. While stabilizing on the NT side, participants reached significantly further in the inferolateral direction than the throwing side (NT: 83.7 ± 12.2% arm length; throwing: 80.1 ± 10.5% arm length; p = .03; effect size = −0.57). Altering reach sequence significantly influenced medial reach (p &lt; .01, effect size = 0.66) and composite score (p = .017, effect size = 1.03) when stabilizing on the NT side. Asymmetries in upper quarter Y-balance test in collegiate softball players should be interpreted cautiously, and an ordered test sequence should be consistently followed.

Metrology of Zener-based secondary voltage standards

The BIPM (Bureau International des Poids et Mesures) has been carefully maintaining Zener diode secondary voltage standards (ZVS) for about 30 years, which are used in an ongoing international bilateral comparison program with national metrology institutes. The output voltages of the standards are corrected for their sensitivity to parameters such as their internal temperature (relative to the thermistor resistance of the Zener’s oven) and atmospheric pressure. In 2016 and 2017, these sensitivity coefficients were redetermined. The corresponding corrections vary between −7 parts in 107 kΩ−1 to +6 parts in 107 kΩ−1, and from +8 parts in 1010 hPa−1 to +2 parts in 109 hPa−1, respectively. In the worst case, the combination of the effect of temperature and pressure are comparable to the 1 f −1 noise floor of these standards (considered to be 1 part in 108 at the BIPM). Most of the sensitivity coefficients have not changed since their previous determination in 1998–2002 which seems to indicate that they are intrinsic characteristics of the ZVS, which are dependent upon the properties of the physical support of the Zener element itself (pressure sensitivity) and the intrinsic behaviour of the internal thermistor (temperature sensitivity). As a follow-up to the determination of the new sensitivity coefficients, the reproducibility of the ZVS calibration was also investigated, using three different and independent measurement setups, each built around a different and independent Josephson voltage standard. The metrological performance of the three primary setups were demonstrated to have an agreement of between 2 × 10−10 and 1 × 10−11 when compared directly. The comparison results of the calibration of the BIPM ZVS showed that most artefacts reach an agreement of a few parts in 109 while a very few can exhibit a considerable systematic error comparable to the 1 f −1 noise, which we suspect is due to a nonzero current from the measuring system flowing through the input impedance of the standard.

The Test Re-Test Reliability of A Novel Single Leg Hop Test (T-Drill Hop Test).

BackgroundFunctional training and testing are an important part of a comprehensive rehabilitation program stressing the neuromuscular system in ways that simulate athletic performance to help determine criteria for return to sport. There are numerous single leg hop tests that have been used for these purposes, however, the validity and clinical relevance has been questioned. Many of the functional performance tests assess only the sagittal plane or forward direction and may only partially assess a person’s athletic abilities. There is a need for reliable and valid functional tests to assess in a multi-directional manner.Purpose/HypothesisThe purpose of this study is to determine the test re-test reliability of a novel multi-directional timed single leg hop test (T-Drill Hop Test) for use in rehabilitation and performance assessments.Study DesignCross-sectional reliability study.MethodsFifty healthy recreationally active college age subjects, (23 males and 27 females) between the ages of 18 and 35, (mean age 23.48 with SD 3.82) consented to perform the test. The subjects hopped along a 10ft. x 10ft. “T” shaped course. Subjects performed two timed maximum effort trials of the T-Drill Hop Test on each leg with an interval of 3-7 days between the two testing days. Intraclass Correlation Coefficients (ICC) were calculated to determine intersession reliability.ResultsThe inter-rater reliability (ICC’s) for the entire group of 50 subjects ranged between .98 and 1.00 suggesting excellent reliability. The bilateral comparison, utilizing paired t-tests, of the T-Drill Hop Test demonstrated no significant differences between the time scores for the dominant and non-dominant legs for either males or females (p>.05).ConclusionThis study demonstrates the T-Drill Hop Test has excellent test re-test reliability. These results are important prior to validation and utilization as a clinical functional performance test.Levels of EvidenceLevel 2

Sosyal Hizmet Öğrencilerinin Sığınmacılara İlişkin Algı ve Tutumları: Bir Vakıf Üniversitesi Örneği

Göç olgusu, sebep ve sonuçları bakımından ülkelerin kamu politikaları üretmelerini teşvik eden itici bir güç olmaktadır. Aynı zamanda dünyada politika rejimlerindeki radikalleşme ve farklı dengeler ışığında önemli bir koz ya da handikap olabilmektedir. Ne var ki, söz konusu stratejilerin ülkeler lehine avantajları var gibi görünse de doğdukları ya da vatandaşı oldukları ülkeden bir yere hareket etmek zorunda kalanlar için çok boyutlu bir sosyal dışlanma sürecine kapı aralamaktadır. Bu durumda göçmenler, statüleri gereği çeşitli politik, ekonomik ve sosyal argümanlarla yüzleşmek zorunda kalmaktadırlar. Sosyal hizmet disiplini ise ekonomik, politik ve sosyal boyutlarıyla dışlanma yaşayan göçmen grupların, bulundukları ülkede birtakım hizmetlere erişiminde aracı rol oynamakta, sosyal çalışmacılar ise psiko-sosyal açıdan önemli görevler icra etmektedirler. Bu çalışmanın amacı, geleceğin sosyal çalışmacıları olarak sosyal hizmet eğitimi almakta olan öğrencilerin mesleki anlayışları çerçevesinde sığınmacılara yönelik tutumlarının anlamlı bir fark oluşturup oluşturmadığını ortaya koymaktır. Çalışmada elde edilen bulgulara göre, sosyal hizmet öğrencilerinin sığınmacılara karşı oldukça olumlu bir tutum sergiledikleri, haklarını savunmada onların yanlarında oldukları söylenebilir. Kısaca, mesleklerinin gereği olarak öğrenciler, sığınmacıların haklarının sağlanması için yoğunlukla destekleyici olmaktadır. İkili karşılaştırmalar neticesinde, lisans öğrencilerinin ön lisans öğrencilerine göre radikal olmayan çözüm stratejileri üretme hususunda daha kabullenici oldukları görülmektedir. Ayrıca öğrencilerin cinsiyetinin sığınmacılara yönelik tutumlarında etkili olmadığı görülmektedir.

Effectiveness of Hypericum perforatum Extract in the Treatment of Corrosive Esophageal Burns

Purpose The purpose of our study is to determine the effectiveness of “Hypericum perforatum” extract in corrosive esophageal burns and to shed light on the search for new treatments. Materials and methods A total of 32 Sprague Dawley rats were separated into 4 groups. A standard esophageal burn model was created. Group 1 was identified as the sham group. Group 2 was burned and no treatment was performed afterward. Group 3 was burned and then 2 cc/day H. perforatum extract was given for 21 days. Group 4 was not applied any process and 2 cc/day H. perforatum extract was given for 21 days. The rats were sacrificed and biopsy specimens were taken for histopathological examination for the presence of inflammation, fibrosis, and necrosis. Results There was a significant difference between groups in terms of inflammation, fibrosis, and necrosis. Furthermore, in the bilateral comparisons between the groups, there was a meaningful difference in terms of inflammation and fibrosis between Group 2 and Group 3. However, there was no meaningful difference between the same groups in terms of necrosis. Conclusion H. perforatum extract may be effective on inflammation, fibrosis, and necrosis in corrosive esophageal burns.

Spatial odor discrimination in the hawkmoth, Manduca sexta (L.)

ABSTRACTFlying insects track turbulent odor plumes to find mates, food and egg-laying sites. To maintain contact with the plume, insects are thought to adapt their flight control according to the distribution of odor in the plume using the timing of odor onsets and intervals between odor encounters. Although timing cues are important, few studies have addressed whether insects are capable of deriving spatial information about odor distribution from bilateral comparisons between their antennae in flight. The proboscis extension reflex (PER) associative learning protocol, originally developed to study odor learning in honeybees, was used as a tool to ask if hawkmoths, Manduca sexta, can discriminate between odor stimuli arriving on either antenna. We show moths discriminated the odor arrival side with an accuracy of >70%. Information about spatial distribution of odor stimuli may be available to moths searching for odor sources, opening the possibility that they use both spatial and temporal odor information.This article has an associated First Person interview with the first author of the paper.

Polypropylene as a Reference Material for Small Scale Horizontal Rate of Burning Instrument

Controlling the risks associated with the flammability of polymeric materials depends on their flammability tests, as well as the existence of reference materials which are important tools for ensuring the quality of measurement results. In this study, polypropylene (PP) was prepared and tested to be a certified reference material for horizontal burning rate test instrument (UL94) in accordance with ISO guides and standards. Differential scanning calorimetry (DSC) and Thermo gravimetric analysis (TGA) were used to characterize some of the thermal properties like melting point and decomposition temperature of PP. The certified value of the PP burning rate was assigned by analyzing the data obtained through bi-lateral laboratory comparison involving two competent laboratories. The results of the burning rate measurements for the participating laboratories were clearly consistent and harmonic. The certified value and expanded uncertainty were calculated using results of characterization, homogeneity study and stability assessment and were found 19.63 ± 1.2 mm/ min at approximate confidence level of 95 %.

A new calibration setup for lock-in amplifiers in the low frequency range and its validation in a bilateral comparison

This paper addresses the calibration of lock-in amplifiers in the low frequency range. A simple but effective calibration setup implemented at INRIM is described. This includes a stable low-voltage source, composed of a digital sine wave generator and a cascade of two voltage dividers, one inductive and one resistive. The magnitude error is the lock-in magnitude error, which can be determined with an uncertainty of the order of 10−4 or better, that is, two orders of magnitude lower than the typical lock-in accuracy specification. The system can operate with an input voltage from 0.1 µV to 10 µV and a frequency from a few hertz to about 1 kHz. The performances of the calibration setup were evaluated at 1 µV and 10 μV at 20 Hz and 103 Hz and compared with those of another existing setup, implemented at METAS, through a direct comparison in the framework of an EURAMET research project.

Hydrogen fuel quality for transport – First sampling and analysis comparison in Europe on hydrogen refuelling station (70 MPa) according to ISO 14687 and EN 17124.

Fuel cell electric vehicles are getting deployed exponentially in Europe. Hydrogen fuel quality regulations are getting into place in order to protect customers and ensure end-users satisfactory experiences. It became critical to have the capability to sample and analyse accurately hydrogen fuel delivered by hydrogen refuelling stations in Europe. This study presents two separate comparisons: the first bilateral comparison between two sampling systems (H2 Qualitizer) and (“H2 Sampling System” of Air Liquide) and the interlaboratory comparison between NPL and Air Liquide on hydrogen fuel quality testing according to EN 17124. The two sampling systems showed equivalent results for all contaminants for sampling at 70 MPa hydrogen refuelling stations. The two laboratories showed good agreement at 95% confidence level. Even if the study is limited due to the low number of samples, it demonstrates the equivalence of two sampling strategies and the ability of two laboratories to perform accurate measurement of hydrogen fuel quality.

Evaluation of Contractors Performance in Iraqi Construction Projects Using Multiple Criteria Complex Proportional Assessment Method (COPRAS)

The construction industry is a significant part of every economy and that performance assessment holds the key to its success in national socio-economic goals. Successful Construction projects are closely related to contractor’s performance, where increases a suitable contractor the chances of satisfactory completion of a project in time, cost and quality specified. Contractors’ performance can provide robust benchmarks for contractors and help to identify ways towards performance improvement. Contractor performance can be defined by the level and quality of projects delivered to clients. he objective of this research work is to study evaluate contractor performance for construction projects, and how it can be employed technical grounds (The Method Of Multiple Criteria Complex Proportional Assessment) in the assessment of contractors Performance for construction projects, through the identification of criteria used to select the best contractor in terms performance as well as determining the list contractors of to choose the optimal contractor of these terms. For achieving the goal of the research its data collecting from the literature that addressed the factors Affecting Contractor Performance and method of multiple criteria complex proportional assessment (COPRAS), and finally personal interviews of engineers, contractors and owners qualified. The results of data analysis for the sample and then Rank Order Centroid method (ROC) and distinctive in their application showed that criteria of the quality of work, project management, technical knowledge, and timeliness of performance are the most important criteria for bilateral comparisons between contractors. Finally, and by calculating the relative importance, priorities of alternatives, and the benefit degree we find that the C1 has received the largest share of the benefit and importance.In the end, was a set of conclusions and recommendations of various aspects of the topic from accelerating the application of techniques of decision- making multi-criteria in the evaluation of contractors performance in addition to expediting the application of the systems proposed by the researcher for the evaluation of contractors performance.

Female sacrococcygeal pilonidal sinus features and EQ-5D life quality survey and body image survey results: a clinical study

Aim: Pilonidal sinus disease (PSD) is not common in female patients. It is seen in adult women 2.2 to 4 times less than men. The most common age range is between 10 and 40. To date, there has been no randomized or retrospective study in the literature representing the general characteristics of women-specific pilonidal sinus cases and the quality of life questionnaire (EQ-5D) and body image questionnaire (BIQ) results. The purpose of this study is to show the general features, treatment principles and body image and quality of life (EQ-5D) survey results of the female pilonidal sinus cases. Material and Method: A retrospective clinical study was conducted with 29 women who were admitted to our clinic between June 2013 and May 2016 and treated with surgery by the pre-diagnosis of sacrococcygeal PSD. Patients received face-to-face body image questionnaire (BIQ) and quality of life questionnaire (EQ-5D) at the 2nd postoperative week. Results: The mean age was 27.07±5.63 years. BIQ cosmetic and self-confidence scores differ significantly between at least two groups (p=0.042 and p=0.021, respectively) in the favor of primer midline closure (PMC) group. As a result of bilateral comparisons made for the BIQ cosmetic score, there was a significant difference between the Limberg-Z plasty and the Karydakis group (p=0.039). Conclusion: Female patients who underwent PMC had better satisfaction with the appearance of their scar. The treatment of female PSD with minimally invasive techniques and primary closure techniques seems to be the best option for the selected patients.

Combination of apremilast and narrowband ultraviolet B light in the treatment of generalized vitiligo in skin phototypes IV to VI: A randomized split-body pilot study

To the Editor: Apremilast is an oral phosphodiesterase-4 inhibitor that is approved for the treatment of psoriasis.1 It was shown to be effective in controlling progression of vitiligo,2 but another study found that apremilast does not bring any additional benefit to narrowband ultraviolet B light (NB-UVB) phototherapy.3 That study, however, included a low proportion of skin phototypes (SPTs) IV to VI and lacked the advantage of a bilateral comparison study design. Our study evaluated the efficacy of apremilast plus NB-UVB phototherapy compared with NB-UVB phototherapy alone in patients with SPTs IV to VI with generalized vitiligo (≥20% body surface area).