Influence of the measurement configuration on the results of Raman microspectroscopy of human hair

Increasing interest in spectroscopic studies of human hair raises the question about the accuracy of measurement of their spectra and requires optimisation of experimental facilities. An original method of obtaining transverse hair sections without using a microtome and chemical influence is proposed. The results obtained by confocal Raman microspectroscopy of human hair differently oriented with respect to the optical axis of the measuring setup are compared. It is shown that, in addition to expected changes in the spectra measured at different distances from the hair periphery in the direction to its centre, the spectra measured in the case of hair excitation perpendicular and parallel to its axis are also considerably different.

P-BN20 An evaluation of the accuracy of sonography for the measurements of gallbladder polyps across 3 UK hospital trusts: should the surveillance guidelines be revised?

Background Transabdominal ultrasound scan (USS) is recommended for surveillance of gallbladder polyps (GBP), this is to stratify risk for premalignant potential. European Society of Gastrointestinal and Abdominal Radiology make recommendations based on increases of as small 2mm during sequential USS surveillance. Our aim is to determine the accuracy of USS in diagnosis and measurement of GBP. Methods Measurement data for all GBPs were gathered for three hospital trusts across a 12 year period and retrospectively reviewed. USS findings (diagnosis of GBP and GBP size) were compared with histological diagnosis and measurements, when both reports were available, in those patients who had underwent cholecystectomy at the time of data collection. Results For the first two hospital trusts, 778 USS were reviewed which identified patients with GBP. 78 patients had undergone cholecystectomy at time of data collection. Only 17/78 of patients had histological evidence of GBP. Of those without GBP, 37/61 had gallstones. For the third hospital trust, 41 GBP histological reports were identified, 20 could be directly compared with USS. Collectively 29 USS reports were directly compared with GBP histology reports. Only, 31% had results which were in agreement to within 1mm. The mean measurement discrepancy between both modalities was 5.41mm. Conclusions USS does not provide an accurate diagnosis of GBP, it is likely that USS misdiagnoses gallstones as GBP. Moreover, when comparing USS measurements with histological data, there is 31% accuracy of measurement to within 1mm in this cohort. Current guidelines recommend cholecystectomy if there is an interval change of 2mm or more; this data shows a measurement error of more than this.

Determination of probe non-linearity and error due to measurement position for direct measurement type of gauge block comparator and its measurement uncertainty

The non-linearity of probes is one of the important components in gauge block calibration by the mechanical comparative method of two gauges blocks at the same nominal length. However, an advanced method for gauge block calibration is a mechanical direct measurement method of two gauge blocks showing the greatest difference in nominal length of 25 mm. This method uses a special probe based on the interferential scanning principle to produce the signals to measure the displacement. In this paper, non-linearity and error due to measurement position were investigated as they related to the accuracy of measurement results. The differences in central length of pairs of standard gauge blocks made of steel were measured by optical interferometry with the measurement uncertainty (k=2) 23 nm. Length in the range of 5 μm to 25 mm was used in the experiment. Non-linearity of the probe was evaluated by the simple linear regression model. Various factors such as origin setting point, temperature, and vibration have been analysed. In the preliminary experiment, the non-linearity, position error, repeatability and retrace error over the measuring range 25 mm are 13 nm, -18 nm, 15 nm, and 10 nm respectively. The standard uncertainty of direct measurement type caused by non-linearity is 4 nm.

2.45 GHz Band Quadrature Microwave Frequency Discriminators with Integrated Correlators Based on Power Dividers and Rat-Race Hybrids

Instantaneous frequency measurement devices are useful for conducting extremely fast measurements of the current frequency value of microwave signals, even if their duration is extremely short. This paper presents the principle of determination of temporary values of the microwave signal phase and frequency using interferometer techniques, based on passive microwave components. Additionally, the structures and results of measurements of two novel versions of integrated microwave correlators for microwave frequency discriminators, made on a single printed circuit board, are shown. Three Wilkinson-type, single-stage power dividers, and two rat-race hybrids create the developed correlators. The developed devices were designed to work over a wide frequency range, i.e., of 1.6–3.1 GHz, and can be used to monitor Wi-Fi devices as well as pulse and CW radar systems operating in the S band. They can also be applied in passive radars and active Doppler radars. The view of the printed circuits boards and results of measurements are presented. Recommendations for improving the accuracy of measurement are proposed.

Freeze-Float System for High-throughput Measurement of Ice Nucleation

In this publication, we developed the high throughput screening implementation of freeze-float selection platform system we established in the previous publication. The goal of this publication is to expand the system to higher throughput and accuracy. In the following sections, we describe the steps for automated droplets generations, adaptation of freeze-float selection using controlled and uniform temperature cooling system, and semi-automated droplets detection program. We aimed to improve previously published system to add functional advantages, such as; a) increased efficiency of the screening with fewer manipulation steps; b) increased accuracy of measurement due to the increased sample size; c) increased uniformity of temperature distribution by incorporating the controlled-rate freezer. In the following sections, we describe the steps for automated droplets generations, freeze-float system adaptations using controlled and uniform temperature cooling system, and semi-automated droplets detection program.

The impact of stiffness increasing in construction of tire measuring device to measured results

The article analyzes the influence of the construction stiffness of the measuring device and its effort to the resulting measured results. The article deals with the possibility of increasing the accuracy of measurement and at the same time reducing the measurement deviation on the measuring device by increasing the rigidity of the structure of the device. In the introduction, the article describes the stiffness, errors and analyzes the possibilities of increasing the accuracy of measurement on the measuring device and examines the causes of measurement deviations. In the next part, the article offers the possibilities of increasing the rigidity and strength of the measuring device. In the practical part, the structural modification of the device increasing the overall rigidity and strength of the structure is presented. In the practical part we made a simulation of old device frame and modified frame. In the last part, the article compares the results of measurements before the structural modification and after the structural modification of the increase in stiffness.

Calibration of Tanks and Ships’ Tanks for Storage and Transportation of Liquids by Laser Scanning

The goal of the research is to improve the accuracy of measurement the volume and mass of oil and oil products by the stationary measuring tanks and ships’ tanks. It is possible to achieving this goal only by using the laser scanning at tanks calibration. Metrological and other technical requirements for laser scanners have been developed. It is proved by the results of mathematical modeling that only the compliance of scanners with the developed requirements makes it possible to achieve the set goal. It has been developed methods of measurements by laser scanners that allow to achieve an increase in the accuracy of determination the interval capacities of all types of the tanks. Methods, formulae and algorithms for interval capacities of tanks calculation are very complicated. Therefore, the interlaboratory comparisons for the interval capacities, calculated by laboratories own software developed for processing the results of the specified calibration are proposed. It is concluded that the developed requirements, methods and algorithms will allow, in several times, to increase the accuracy of determining the interval capacities of the tanks with a significant reduction in time for measurements and processing of their results.

FREE STATION TASK WITH DRONE

Using drones with different purposes than only taking photos is nowadays the main direction of drone development. Drones are made for package delivery, people transport, etc. Drone equipped by GNSS RTK and prism can be used as orientation point for the free station. The idea is using drone to get coordinates of total stations inappropriate for GNSS. such as high buildings and forest. The drone can fly above the obstacle causing inappropriate, so the GNSS will compute the position coordinates correctly. Total station will measure distance and angles on prism to get free station coordinates. This article deals with the accuracy of using two points in the free station task. Accuracy of measurement and data is based on real values. Drone can be used as the target if it is not windy, the position accuracy of the target on drone is 5 cm. Wind has no effect on the vertical position accuracy of the the drone. The results show that the same principles and limitations must be observed when measuring the free station task. Horizontal angle between orientation points must be bigger than 100 gon and the zenith angle must be at least 50 gon. The distance between orientation and free station must longer than consequent measured points.