Insights from 20 years of temperature parallel measurements in Mauritius around the turn of the 20^th Century

There is considerable import in creating more complete, better understood, holdings of early meteorological data. Such data permit an improved understanding of climate variability and long-term changes. Early records are particularly incomplete in the tropics, with implications for estimates of global and regional temperature. There is also a relatively low level of scientific understanding of how these measurements were made and, as a result, of their homogeneity and comparability to more modern techniques and measurements. Herein we describe and analyse a newly rescued set of long-term, up to six-way parallel measurements, undertaken over 1884–1903 in Mauritius, an island situated in the southern Indian Ocean. Data include: i) measurements from a well-ventilated room, ii) a shaded Thermograph; iii) instruments housed in a manner broadly equivalent to a modern Stevenson Screen; iv) a set of measurements by a Hygrometer mounted in a Stevenson Screen; and for a very much shorter period v) two additional Stevenson Screen configurations. All measurements were undertaken within roughly 80 metre radius. To our knowledge this is the first such multidecadal multi-instrument assessment of meteorological instrument transition impacts ever undertaken, providing potentially unique insights. The intercomparison also considers the impact of different ways of deriving daily and monthly averages. The long-term comparison is sufficient to robustly characterise systematic offsets between all the instruments and seasonally varying impacts. Differences between all techniques range from tenths of a degree Celsius to in excess of a degree Celsius and are considerably larger for maximum and minimum temperatures than for means or averages. Systematic differences of several tenths of a degree also exist for the different ways of deriving average / mean temperatures. All differences bar two average temperature series pairs are significant at the 0.01 level using a paired t-test. Given that all thermometers were regularly calibrated against a primary Kew standard thermometer this analysis highlights significant impacts of instrument exposure, housing, siting and measurement practices in early meteorological records. These results reaffirm the importance of thoroughly assessing the homogeneity of early meteorological records.

Development of the method of laser Doppler spectroscopy of nanoparticles in liquids and implementation of the method in the LAD-079 spectrometer

In this work, a method for physicochemical and biological optical studies of the nanoparticles size distribution is developed. Its implementation in the LAD-079 spectrometer is described. The distinctive features of the LAD-079 spectrometer include the following. Multi-angle parallel measurements of static and dynamic light scattering, scattering angle from 0–180 degrees. Probing at three wavelengths with the ability to analyze the polarization activity of the sample (488 nm, 532 nm, 650 nm). Programmable precision thermostat with an error less than 0.1 °C in the range 0 ÷ +80°C with the possibility of building and software implementation of the experiment plan. Robust monobloc design of the spectrometer that does not require adjustments and a special optical table. The ability to measure the size of dispersed nanoparticles in low-transparent liquids.

Possibilities to Estimate Daily Solar Radiation on 2-Axis Tracking Plane Using a Model Based on Temperature Amplitude

Significant errors may occur when estimating daily solar radiation in central Europe using empirical models based on air temperature (especially in the winter months). The first goal of this article is to investigate to what extent it is possible to increase the accuracy of the Hargreaves and Samani model, by using the calibration dedicated for each month. We also corrected the temperature amplitudes by narrowing the daily intervals from which the minimum and maximum values were taken. The second goal of this article is to compare the precision of the daily solar radiation estimation on the horizontal plane and on the 2-axis tracking plane. The database comprises the series of parallel measurements on both planes over a period of 10 years. We considered two procedures, direct and indirect, for the 2-axis tracking plane. The second procedure, dubbed “the first estimate horizontal than calculate tracking” is based on the strong relationship between daily solar radiations on both planes. The direct procedure allows for a slightly more accurate estimation. The estimation of daily radiation on the 2-axis tracking plane reflects the measured values worse than estimation on the horizontal plane. We discovered that the increase of estimation errors on the 2-axis tracking plane, compared to the horizontal one, is proportional to the increase in the coefficient of variability of the daily solar radiations.

Molecular-scale origins of wettability at petroleum–brine–carbonate interfaces

Wettability control of carbonates is a central concept for enhanced petroleum recovery, but a mechanistic understanding of the associated molecular-scale chemical processes remains unclear. We directly probe the interface of calcium carbonate (calcite) with natural petroleum oil, synthetic petroleum analogues, and aqueous brines to understand the molecular scale behavior at this interface. The calcite–petroleum interface structure is similar whether or not calcite was previously exposed to an aqueous brine, and is characterized by an adsorbed interfacial layer, significant structural changes within the calcite surface, and increased surface roughness. No evidence for an often-assumed thin-brine wetting layer at the calcite–petroleum interface is observed. These features differ from those observed at the calcite–brine interface, and for parallel measurements using model synthetic petroleum mixtures (consisting of representative components, including dodecane, toluene, and asphaltene). Changes to the interface after petroleum displacement by aqueous brines are also discussed.

Impacts of Built-Up Area Geometry on PM10 Levels: A Case Study in Brno, Czech Republic

This paper presents a statistical comparison of parallel hourly measurements of particulate matter smaller than 10 μm (PM10) from two monitoring stations that are located 560 m from each other in the northern part of Brno City. One monitoring station is located in a park, the other in a built-up area. The authors’ aim is to describe the influence of a built-up area geometry and nearby traffic intensity on modeling of PM10 pollution levels in the respective part of Brno. Furthermore, the purpose of this study is also to examine the influence of meteorological factors on the pollution levels; above all, to assess the influence of wind speed and direction, temperature change, and humidity change. In order to evaluate the obtained data, the following methods of mathematical statistics were applied: descriptive statistics, regression analysis, analysis of variance, and robust statistical tests. According to the results of the Passing–Bablok test, it can be stated that the parallel measurements of PM10 are significantly different. A regression model for PM10 pollution prediction was created and tested in terms of applicability; subsequently, it was used in order to compare measurements from both stations. It shows that in addition to the monitored meteorological factors, pollution levels are influenced mainly by traffic intensity and the geometry of the monitored built-up area.

Thermoanalytic interlaboratory experiment for identification of materials, substances and fire protection equipment

Проведен межлабораторный термогравиметрический эксперимент по идентификации огнезащитных составов интумесцентного типа. Использование дисперсионного анализа позволило установить значимость/незначимость различий в поведении исследуемых материалов при нагревании, выявить лаборатории, обладающие необходимыми компетенциями для проведения идентификации. Найдено, что применение различных водно-полимерных дисперсий даже близкого строения в составе огнезащитных материалов приводит к неидентичности их свойств. Представленный подход позволил однозначно установить неидентичность исследованных огнезащитных составов. The article deals with the problem of identification of materials, substances and means of fire protection according to GOST R 53293-09 using one of the methods of thermal analysis, namely, thermogravimetric analysis. The long-term practice demonstrated that the methodology presented in the standard did not always give a clear result when identifying objects. Therefore, the evaluation experiment was conducted simultaneously in several testing laboratories with the appropriate equipment. The tests were conducted in the laboratories of the FGBU VNIIPO EMERCOM of Russia, ANO «CISIS FMT», and two CCPS of the Lomonosov Moscow State University. The most complex and controversial objects for identification were studied, namely, thermally expanding (intumescent) flame retardants based on water-polymer dispersions, which are used to protect building structures in closed premises. The purpose of the work consists in more correctly identifying the differences in the samples of the identifier and the analyzed object by using methods of dispersion analysis (GOST R ISO 5725-1, 2-202) when processing the joint interlaboratory experiment. Thermogravimetric analysis of objects was performed in platinum crucibles on samples in the form of disks with a thickness of 0,2-0,3 mm, weight 5-7 mg, at a heating rate of 20 °C/min in the air flow (50-70 ml/min). As a result of the experiment, the significance/insignificance of differences between samples should be displayed. The opinion about the competence of the laboratories participating in the experiment was made. In each laboratory there were conducted two series of thermogravimetric tests in 30-700 °C temperature range including five parallel measurements in each series. Each independent single measurement for further processing was represented by the data array formed within the temperature range of 140-650 °C with a 5° step, in total 103 points in each measurement. The results were processed using Excel spreadsheets. In the context of dispersion analysis there were evaluated both mean values of conversion rates for all laboratories, and the convergence (repeatability) variance for each laboratory using the Student's test, and the inter-laboratory variance (reproducibility variance) using the Cochran’s С test. This procedure revealed the nature of the quasi-samples and established the identity/non-identity of the samples. The results of calculations are represented by the graphical dependence of the generalized average degrees of transformation of destruction processes of objects under the temperature as well as the difference between these characteristics for laboratories I-IV. The presented identification procedure allows both to uniquely solve the problem of significance/insignificance of differences between the test object and the identifier, and to distinguish samples that have a similar composition. The statistical characteristics of a single measurement are calculated. The convergence of parallel measurements for determination of statistical outliers is identified. Determination of the overall average difference for a series of degrees of transformation allows to calculate the Student's test and accept or reject the null hypothesis. The performance of the joint evaluative (interlaboratory) experiment allows not only to establish the significance/insignificance of differences in the behavior of the materials during heating, but also to identify laboratories that have the necessary competencies for identification. The case considered in this paper revealed that the use of various water-polymer dispersions of even close structure in the composition of fire-resistant materials leads to non-identity of their properties.

Aldosterone-Mediated Sodium Retention Is Reflected by the Serum Sodium to Urinary Sodium to (Serum Potassium)2 to Urinary Potassium (SUSPPUP) Index

The serum sodium to urinary sodium ratio divided by the (serum potassium)2 to urinary potassium ratio (SUSPPUP formula) reflects aldosterone action. We here prospectively investigated into the usefulness of the SUSPPUP ratio as a diagnostic tool in primary hyperaldosteronism. Parallel measurements of serum and urinary sodium and potassium concentrations (given in mmol/L) in the fasting state were done in 225 patients. Of them, 69 were diagnosed with primary aldosteronism (PA), 102 with essential hypertension (EH), 26 with adrenal insufficiency (AI) and 28 did not suffer from the above-mentioned disorders and were assigned to the reference group (REF). The result of the SUSPPUP formula was highest in the PA group (7.4, 4.2–12.3 L/mmol), followed by EH (3.2, 2.3–4.3 L/mmol), PA after surgery (3.9, 3.0–6.0 L/mmol), REF (3.4 ± 1.4 L/mmol) and AI (2.9 +/− 1.2 L/mmol). The best sensitivity in distinguishing PA from EH was reached by multiplication of the aldosterone to renin-ratio (ARR) with the SUSPPUP formula (92.7% at a cut off > 110 L/mmol), highest specificity was reached by the SUSPPUP determinations (87.2%). The integration of the SUSPPUP ratio into the ARR helps to improve the diagnosis of hyperaldosteronism substantially.

Problem of using electrodes made of shipbuilding steel to protect ship hull from corrosion

The article discusses the problem of corrosion that causes significant damage to the ship structures and mechanisms, reducing their service life. The experience of using different electrodes to control the electrochemical protection systems of steel hulls of auxiliary vessels is presented. The results of corrosion tests of PM-15 ship hull are presented, which included measurements of the hull potential at a given control point, using an electrical measuring device and two control electrodes. As the first electrode used an electric carbon product for electric machines. A ship hull steel plate was used as the second electrode. The investigated vessel stayed at the pier for a long time. Corrosion tests were carried out in the period within 10.10.2019-16.10.2019. The ship hull potential at the control point was controlled using 50 parallel measurements. Parallel measurements were performed with a specified time interval of 5 sec. between them. A qualified operator has been trained to perform corrosion studies. The accuracy of the measurements was determined on the basis of current regulatory documents. The test results show that the reliability of the control of electrochemical protection systems of the hull primarily depends on the type of electrode used. It has been demonstrated that the metrological characteristics of the results of control measurements depend on the period of using a steel plate. The results of scientific research help to select the right elements of the system of monitoring the effectiveness of electrochemical protection of the ships and ship crews.

Point-of-Care Measurement of Activated Clotting Time for Cardiac Surgery as measured by the Hemochron Signature Eliteand the Abbott i-STAT: Agreement, Concordance, and Clinical Reliability

Background: Since inadequate heparin anticoagulation and insufficient reversal can result in complications during cardiopulmonary bypass (CPB) surgery, heparin anticoagulation monitoring by point-of-care (POC) activated clotting time (ACT) measurements is essential for CPB initiation, maintainance, and anticoagulant reversal. However, concerns exist regarding reproducibility of ACT assays and comparability of devices. Methods: We evaluated the agreement of ACT assays using four parallel measurements performed on two commonly used devices each (i.e., two Hemochron Signature Elite (Hemochron) and two Abbott i-STAT (i-STAT) devices, respectively). Blood samples from 30 patients undergoing cardiac surgery on CPB were assayed at specified steps (baseline, after heparin administration, after protamine administration) with four parallel measurements (two of each device type) using commercial Kaolin activated assays provided by the respective manufactures. Measurements were compared between identical and different device types using linear regression, Bland-Altman analyses, and calculation of Cohen’s kappa coefficient. Results: Parallel i-STAT ACTs demonstrated a good linear correlation (r=0.985). Bias, as determined by Bland-Altman analysis, was low (-3.8s; 95% limits of agreement (LOA): -77.8 -70.2s), and Cohen’s Kappa demonstrated good agreement (kappa=0.809). Hemochron derived ACTs demonstrated worse linear correlation (r=0.782), larger bias with considerably broader LOA (-13.14s; 95%LOA:-316.3-290s), and lesser concordance between parallel assays (kappa=0.554). Although demonstrating a fair linear correlation (r=0.815), parallel measurements on different ACT-devices showed large bias (-20s; 95% LOA: -290-250s) and little concordance (kappa=0.368). Overall, disconcordant results according to clinically predefined target values were more frequent with the Hemochron than i-STAT. Furthermore, while discrepancies in ACT between two parallel iSTAT assays showed little or no clinical relevance, deviations from parallel Hemochron assays and iSTAT versus Hemochron measurements revealed marked and sometimes clinically critical deviations. Conclusion: Currently used ACT point-of-care devices cannot be used interchangeably. Furthermore, our data question the reliability of the Hemochron in assessing adequacy of heparin anticoagulation monitoring for CPB.

Point-of-Care Measurement of Activated Clotting Time for Cardiac Surgery as measured by the Hemochron Signature Eliteand the Abbott i-STAT: Agreement, Concordance, and Clinical Reliability

Background: Since inadequate heparin anticoagulation and insufficient reversal can result in complications during cardiopulmonary bypass (CPB) surgery, heparin anticoagulation monitoring by point-of-care (POC) activated clotting time (ACT) measurements is essential for CPB initiation, maintainance, and anticoagulant reversal. However, concerns exist regarding reproducibility of ACT assays and comparability of devices. Methods: We evaluated the agreement of ACT assays using four parallel measurements performed on two commonly used devices each (i.e., two Hemochron Signature Elite (Hemochron) and two Abbott i-STAT (i-STAT) devices, respectively). Blood samples from 30 patients undergoing cardiac surgery on CPB were assayed at specified steps (baseline, after heparin administration, after protamine administration) with four parallel measurements (two of each device type) using commercial Kaolin activated assays provided by the respective manufactures. Measurements were compared between identical and different device types using linear regression, Bland-Altman analyses, and calculation of Cohen’s kappa coefficient. Results: Parallel i-STAT ACTs demonstrated a good linear correlation (r=0.985). Bias, as determined by Bland-Altman analysis, was low (-3.8s; 95% limits of agreement (LOA): -77.8 -70.2s), and Cohen’s Kappa demonstrated good agreement (kappa=0.809). Hemochron derived ACTs demonstrated worse linear correlation (r=0.782), larger bias with considerably broader LOA (-13.14s; 95%LOA:-316.3-290s), and lesser concordance between parallel assays (kappa=0.554). Although demonstrating a fair linear correlation (r=0.815), parallel measurements on different ACT-devices showed large bias (-20s; 95% LOA: -290-250s) and little concordance (kappa=0.368). Overall, disconcordant results according to clinically predefined target values were more frequent with the Hemochron than i-STAT. Furthermore, while discrepancies in ACT between two parallel iSTAT assays showed little or no clinical relevance, deviations from parallel Hemochron assays and iSTAT versus Hemochron measurements revealed marked and sometimes clinically critical deviations. Conclusion: Currently used ACT point-of-care devices cannot be used interchangeably. Furthermore, our data question the reliability of the Hemochron in assessing adequacy of heparin anticoagulation monitoring for CPB.