Standard Measurement Conditions Research Articles

P‐115: The Optimized Method for Sparkle Contrast Measurement of Anti‐Glare Covered Vehicle Display

We have presented an optimized method for evaluating the visual sparkle contrast of anti‐glare covered vehicle display and compared the results to standard measurement conditions. By assessing the sparkle contrast changes under different ambient light conditions and different viewing angle conditions, and analyzing the results, we provide measurement recommendations for the sparkle rating evaluation of vehicle display.

Realizing Stable Perovskite Solar Cells with Efficiency Exceeding 25.6% Through Crystallization Kinetics and Spatial Orientation Regulation.

Organic-inorganic hybrid perovskites have emerged as highly promising candidates for photovoltaic applications, owing to the exceptional optoelectronic properties and low cost. Nonetheless, the performance and stability of solar cells suffer from the defect states of perovskite films aroused by non-optically active phases and non-centralized crystal orientation. Herein, a versatile organic molecule, Hydantoin, to modulate the crystallization of perovskite, is developed. Benefiting from the diverse functional groups, more spatially oriented perovskite films with high crystallinity are formed. This enhancement is accompanied by a conspicuous reduction in defect density, yielding efficiency of 25.66% (certified 25.15%), with superb environmental stability. Notably, under the standard measurement conditions (ISOS-L-1I), the maximum power point (MPP) output maintains 96.8% of the initial efficiency for 1600 h and exhibits excellent ion migration suppression. The synergistic regulation of crystallization and spatial orientation offers novel avenues for propelling perovskite solar cell (PSC) development.

Validation of rolling-stock interior noise simulation in viaduct and tunnel environments

Acoustic comfort for modern rolling stock is a standard design requirement. The use of standard measurement conditions (ballast and free-field conditions) is the best way to identify quiet vehicles but operators (specially metro operators and some suburban) prefer to set noise targets in their own infrastructure. Metro infrastructures are mainly today done with ballastless tracks either in elevated track (viaduct) or tunnels. Therefore it is critical for rolling stock suppliers to develop methodologies to simulate interior noise performances on those scenarios to be able to propose design solutions and to control the risks. In this paper, the methodology used by Alstom to simulate interior noise in tunnels and viaduct is described. Methodology uses databases of acoustic transfer functions between sound power level of noise sources and acoustic wall pressures around vehicles. These transfer functions are modified in function of the environment (viaduct or tunnel) taking into account the type of acoustic field. Then, analytical or numerical models of the train structure plus interiors are calculated. Simulation cases and validation of the models are discussed to evaluate the pertinence of using virtual validation instead of interior noise type tests.

Changes in Segmental Impedances and Selected Body Composition Parameters Assessed by Multi-Frequency Bioimpedance Analysis after Fluid Consumption in Healthy Young Population.

Objectives: Body composition (BC) analysis is a routine part of comprehensive public health care. Assessment of BC is more important source of information than BMI. Adherence to the standard measurement conditions is essential for the correct results. Our study aimed to examine the effect of acute fluid consumption on measures of body mass (BM), percentage of body fat (%BF), visceral fat (VF), percentage of body water (%BW), and impedance at 100 kHz (I100) and 20 kHz (I20) using segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) in a general healthy population. Methods: 95 consecutive healthy normal-weight adults (42 men; 53 women) were involved in the study (mean ± s.d.; age 23.9±1.6 years; body mass 68.3±14.1 kg). All subjects underwent two separate series of body composition (BC) measurements at 0 (BASELINE), 30, 60, 90 min (POST): the first series after drinking 600 ml of isotonic carbohydrate/electrolyte drink (IST) and the second after no fluid administration (CON). Individual measurements were performed in the morning on two consecutive days. Results: In the IST group, BM, VF (both P<0.001), and %BF (P<0.05) increased significantly at 30 min POST compared to BASELINE. BM and VF remained elevated at 90 min POST (both P<0.001). %BW decreased significantly at 30 min POST (P<0.01) then increased at 60 min (P<0.001) and 90 min (P<0.01) POST. There were no significant changes in I100. I20 increased significantly at 30 min POST (P<0.001) then decreased at 60 min (P<0.001) and 90 min POST (P<0.01) compared to BASELINE. In the CON group, BM and VF decreased below BASELINE at 90 min POST (P<0.001), %BF, %BW and I100 did not change significantly. The difference between IST and CON was statistically significant for all POST measurement times only in BM and VF (both P<0.001). The VF results are also underlined by the detected impedance changes in the trunk area at 20 kHz (B20) and 100 kHz (B100) at 60 min and 90 min (both P<0.001). Conclusions: Our study suggests that segmental impedances and BC measurement in healthy young normal-weight adults requires strict adherence to fluid restriction at least 90 min before the measurement to avoid false impedance values and overestimation of BM and VF.

Hypertension and depression among medical students: is there an association?

IntroductionSeveral studies suggested a higher prevalence of hypertension and depression among medical students. Patients with depression have a higher prevalence of hypertension and vice versa. In this study, we assessed the frequency of hypertension and depression in a sample of medical students and the impact of depression on hypertension. MethodsWe recruited medical students from the largest medical school in Jordan. For each participant, we measured blood pressure and heart rate under standardized measurement conditions. Participants were also surveyed using the 9-item Patient Health Questionnaire (PHQ-9). We performed univariate analysis followed by linear regression analysis of factors affecting mean arterial pressure. Results354 medical students were included. The mean age was 21 years. 196 (55.4%) were females and 158 (44.6%) were males. 139 (70.9%) of females had normal blood pressure (BP), 7 (3.6%) had elevated BP, 44 (22.4%) had stage 1 hypertension (HTN), and 6 (3.1%) had stage 2 HTN. Within males: 60 (38.0%) had normal BP, 27 (17.1%) had elevated BP, 55 (34.8%) had stage 1 HTN, and 16 (10.1%) had stage 2 HTN. 114 participants (32.2%) had no or minimal depression, 197 (55.6%) had mild-moderate depression and 43 (12.1%) had moderately severe-severe depression. There was an association between higher depression scores and higher diastolic blood pressure. ConclusionThe frequency of hypertension and depression was notably high in our sample. There was an association between higher depression scores and higher diastolic blood pressure. We strongly believe that this association should encourage us again to screen our hypertensive patients in general for depression and vice versa. We also recommend adopting screening programs for depression and hypertension in general.

Характеристика стійкого стану функцій спортсменів у видах спорту з варіативними умовами змагальної діяльності

The purpose of the study was to develop generalized and specific characteristics of the steady state of the highly qualified athletes, who specialize in the standard program of sports dance and boxing. Materials and methods. Twenty sportsmen-dancers and twenty boxers of high qualification took part in the research. Gas analysis. Measurements of О2 consumption reaction, СО2 emissions, minute volume of breathing were carried out using the MetaMax 3B analyzer. Ergometry. Modeling of standard conditions of measurement was carried out on the basis of bicycle ergometer Monark. Standard conditions are associated with the use of a given ergometric load power of 50 W. The composition of Cardiorespiratory Intermittent endurance test included eight accelerated 10-second intervals, eight 20-second rest intervals. The duration of the task is four minutes. Mathematic statistics. Descriptive statistics suggested determining the arithmetic mean – x ̅, standard deviation – S, as well as median – Me, maximum (max) and minimum (min) indices, 25% and 75% indices. Steady state is a period of competitive activity, in the process of which sportsmen demonstrate high level of technical and tactical skills and physical performance. Steady state diagnostics is an essential reserve for managing the functional support of special performance of athletes in sports with variable conditions of competitive activity. Results and discussion. An increase in the response of pulmonary ventilation indicates its role as a response to respiratory compensation of metabolic acidosis. Differences in the breathing response in standard measurement conditions are related to the specificity of the breathing response of athletes-dancers. To some extent, “artificial” management of the breathing response causes a decrease in the intensity of breathing cycles. Empirical knowledge indicates that this refers to the “aesthetic” component of the judges' assessment of the performance of the sports dance program. To some extent, this is related to the specifics of the formation of programs of special physical training, correction of certain structural components of functional maintenance of working capacity, in this case, the respiratory system. Another obvious fact is related to the structure of the load, when the intensity of the work of boxers causes more significant acidemic shifts and, as a result, predicts an increase in the reaction of pulmonary ventilation as a mechanism for removing excess CO2 during work. The increase (maintenance) of the O2 consumption response of athletes-dancers is associated with the formation of excess CO2 within the RER – 1.03–1.05 and excessive pulmonary ventilation in the range of 37.2–39.1. Boxers, respectively, with the formation of excess CO2 within the limits of RER – 1.07–1.09 and excessive pulmonary ventilation in the range of 40.0–44.1. The increase in excess ventilation in the third-fifth of dancers was 4.9%, 9.9% – in boxers, provided that the O2 consumption reaction remained stable. Conclusion. The steady state of the functional support of the special performance of athletes in sports with variable conditions of competitive activity ensures the stable development of cardio-respiratory system and aerobic energy supply in the middle of intense motor activity

Impact of aging on the energy efficiency of household refrigerating appliances

The parameters required to calculate the energy efficiency of household refrigerating appliances (i.e. refrigerators, freezers and their combinations) are determined by standard measurements. According to regulations, these measurements are carried out when the appliances are new. It is known from previous studies that various technical aging mechanisms can increase electrical energy consumption by up to 36% over a product lifespan of 18 years. In order to determine the time dependence of the energy consumption of household refrigerating appliances, repeated measurements are carried out in this work. Eleven new appliances are examined under standard measurement conditions. After just two years of operation, an additional energy consumption of up to 11% is determined. Furthermore, 21 older appliances that had previously been measured in new condition are tested again after up to 21 years of operation. For these older appliances, an average increase of energy consumption of 28% is found. For individual appliances, the maximum increase is 36%. An aging model is developed on the basis of these measurement results, which may help to predict the aging-related increase of energy consumption of household refrigerating appliances. This model shows an average increase in energy consumption of 27% for an appliance age of 16 years. Supplemental performance tests of eight compressors do not show any significant aging effects related to these devices after two years of operation. Furthermore, measurements of the thermal conductivity of aged polyurethane foam test samples are carried out and an increase of its thermal conductivity of 26% over a period of about three years is determined.

Spray deposition of sulfonated cellulose nanofibers as electrolyte membranes in fuel cells

Nanocellulose is a promising new membrane material for fuel cells, with much lower cost and environmental impact compared with Nafion or Aquivion. It is mechanically strong, is an excellent hydrogen barrier and has reasonable proton conductivity.Here, sulfonation of cellulose nanofibers is performed to enhance the conductivity (up to 2 × 10− 3 S cm− 1) without compromising the membrane integrity, and fuel cells are fabricated with 30 µm-thick “paper” membranes. The hydrogen crossover current is two orders of magnitude lower than for Nafion fuel cells with equivalent thickness, but the power density is rather low.Spray-coating is used to deposit 8 µm-thick membranes directly onto the electrocatalyst layer, in a process analogous to 3D printing or additive manufacturing. The resulting paper fuel cell has high current density (> 0.8 A cm− 2) and power density (156 mW cm− 2) under standard measurement conditions (H2/air; 80°C; 95% RH; 0.1 MPa), attributed to decreased membrane resistance. The cost of the spray-painted cellulose membranes is calculated to be ~ 50 $ m− 2, which is much lower than that of Nafion, even without taking into consideration economies of scale. This new concept in electrochemical energy conversion paves the way for the mass production of affordable, recyclable fuel cells.Graphic abstract

The Effect of Eccentricity of Concrete Specimen on Measured Value of Modulus of Elasticity

The measurement of the modulus of elasticity is a technologically demanding test and its correct implementation has a fundamental effect on the resulting measured value. The main influences that may affect the proper performance of the test include, for example, the shape and size of the test specimen, the method of obtaining the test specimen, the method of adjustment of contact area between specimen and hydraulic equipment, but also the eccentricity of the specimen in the test apparatus. The paper presents the results of an experiment focused on the influence of the eccentricity of the test specimen and the observance of standard measurement conditions. The standard determines the maximum strain difference on individual measuring sensors when the maximum test force is reached.

Efficient Non-polymeric Heterojunctions in Ternary Organic Solar Cells

We describe the use of a near IR non-fullerene low molecular weight organic semiconductor molecule, as electron acceptor, in combination with a wide band gap organic semiconductor electron donor, in efficient bulk heterojunction organic solar cells. The electron acceptor is a 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione-based molecule while the electron donor is a carbazole derivative. These two small molecules have complementary absorption spectra, and, thus, the heterojunction absorbs from 450 to 950 nm. The optimized photoactive layer shows power conversion efficiency of 7.44% under standard measurement conditions with an estimated energy loss as low as 0.55 eV. Identical solar cells, but using fullerene derivative, PC71BM, result in lower efficiency values (PCE = 5.07%) and greater energy losses (0.86 eV). The better performance of the non-fullerene-based small molecule organic solar cells is due to the higher LUMO energy level for the electron acceptor. Moreover, to improve further the efficiency of th...

Determination of lead at physiological level in human biological materials using the total reflection X‐ray fluorescence analysis

Total reflection X‐ray fluorescence (TXRF) analysis was applied in determination of low concentration of lead in samples of human biological materials. The determination of lead in human serum and hair samples is presented as an example. In serum samples, lead concentration was in the range from 0.013 to 0.051 μg/g (median 0.024 μg/g). The reference ranges of lead content in hair are from 1.41 to 4.08 μg/g for men and from 1.18 to 3.29 μg/g for women groups, respectively. Because of Pb concentration range close to the detection limit of the TXRF method, the measurement needed evaluation of the best analytical conditions. This paper presents the results of this evaluation, namely internal standard selection, measurement conditions, and quantitative calibration of the spectrometer. Finally, as a result of evaluation, the detection limit was found on the level 0.001 μg/g (water solution) and about 0.005 μg/g for human hair samples and 0.007 μg/g for serum samples. The obtained values reach nearly the physiological lead level. The presented results are of practical importance for lead concentration studies in human biological materials using the TXRF method. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Charge recombination losses in thiophene-substituted porphyrin dye-sensitized solar cells

Two new porphyrins that incorporate thiophene substituents as spacers between the conjugated porphyrin core and the anchoring cyanoacrylate group have been synthesised. The two dyes differ in the number of thiophene bridges; porphyrin 1a has only one thiophene group and porphyrin 1b has two thiophene rings connected by a double bond. The measured light-to-energy conversion efficiencies in 1a and 1b were assessed using two different electrolytes, LP1 and LP2, which differ in the presence of tert-butyl pyridine in LP1. An efficiency of 6% under standard measurement conditions has been achieved for 1a + LP1. However, for porphyrin 1b the use of electrolyte LP1 led to lower efficiencies and a value of approximately 4% was obtained. The differences between the two types of solar cells and the electrolytes have been studied in-depth using photo-induced time-resolved techniques such as CE (Charge Extraction) and TPV (Transient PhotoVoltage).

Indoline as electron donor unit in “Push–Pull” organic small molecules for solution processed organic solar cells: Effect of the molecular π-bridge on device efficiency

In this work we have synthesized and characterized four indoline-based small organic molecules for their use as electron donor moiety in bulk-heterojunction solution processed organic solar cells combined with PC70BM as electron acceptor. Our results show a wide range of light to energy efficiencies from 0.8% to 3.5% under standard measurement conditions. An initial analysis suggests that the main limitation is the device photocurrent due to the device film thickness. Yet, charge transfer dynamics were studied to correlate charge loss mechanisms to π-bridge structural variations and, moreover, mobility measurements were also carried out to fully explain these device limitations.

Record efficient upconverter solar cell devices with optimized bifacial silicon solar cells and monocrystalline BaY2F8:30% Er3+ upconverter

In this paper, we investigate Er3+-doped monocrystalline BaY2F8 as an upconverter material for crystalline silicon solar cells with the aim of making use of previously not-utilized sub-bandgap photons. Monocrystalline samples with 10%, 20% and 30% Er3+ doping were grown in a Czochralski furnace and subsequently attached to an adapted planar bifacial silicon solar cell with a 33.4mA/cm2 short-circuit current density under one-sun AM1.5G standard measurement conditions. Optical characterization revealed that for the investigated illumination conditions the 30% Er3+-doped samples showed the most promising properties, with a very high peak absorption coefficient of 45.1cm−1 at 1493nm and a high external (internal) upconversion quantum yield of 9.5±0.7% (10.1±1.6%) under 4740±250Wm−2 monochromatic irradiation at 1520nm. Solar simulator measurements of the upconverter solar cell device using the BaY2F8:30% Er3+ sample showed an additional short-circuit current density due to upconversion ΔjSC,UC of 17.2±3.0mA/cm2 at an illumination with a solar concentration of 94±17suns, equivalent to a record relative enhancement of the short-circuit current of 0.55±0.14%. This value constitutes to our knowledge more than a doubling compared to the previously highest published values and more than a 35-fold increase compared to values published three years ago.

Diarylamino-substituted tetraarylethene (TAE) as an efficient and robust hole transport material for 11% methyl ammonium lead iodide perovskite solar cells.

We report the synthesis and characterisation of tetra{4-[N,N-(4,4'-dimethoxydiphenylamino)]phenyl}ethene () as an efficient and robust hole transport material for its application in methyl ammonium lead iodide (MAPI) perovskite solar cells. The solar cells show light-to-energy conversion efficiencies as high as 11.0% under standard measurement conditions without the need of additional dopants.

A novel TiO2 nanorod/nanoparticle composite architecture to improve the performance of dye-sensitized solar cells

Abstract In this article, we first prove that the length increase of TiO 2 nanorods by extending reaction time is infeasible for improving dye-sensitized solar cells (DSSCs) efficiency because the longer growth time will lead to combination of nanorods from the roots part and formation of dense film. Then a TiO 2 nanorod-nanoparticle mesoporous film composite anode structure is designed and fabricated that serves as a model architecture for efficient cell devices as it simultaneously offers a large surface area, good light-scattering characteristics and a highly conductive pathway for charge carrier collection. Under standard solar cell measurement conditions, a photovoltaic conversion efficiency of 2.51% is obtained from the nanorod-nanoparticle film composite structure, which is higher than that of pure TiO 2 nanorods DSSC (1.11%). By another surface treatment process with TiCl 4 , the DSSC efficiency based on such composite TiO 2 anode is further improved to 3.25%.

Design Details of Multi-Functional Color Analyzer for Reflective, Transmittive and Emittive Surfaces

A multi-functional color analyzer instrument (MFCA) capable to measure reflective, transmittive and emittive surfaces is designed at TUBITAK UME Optics Group Laboratories. MFCA is composed of a novel designed optical light source based on mixture of spectral power distributions (SPDs) of two light emitting diodes (LEDs), a custom-made integrating sphere capable of meeting standard measurement conditions of 0°:d, 8°:d, and 0°:45°, two color detectors with different field-of-views which are designed to measure reflective or transmittive and emittive surfaces separately, self-designed three-channel transimpedance amplifiers having gain selection switches from 1 × 106 to 5 × 109 and a color evaluation software written on LabView 8.0. The linearity and color measurement performance at each measurement geometry of the designed instrument are characterized by using neutral density filters and a standard telespectroradiometer. Design details of MFCA and characterization results are presented herein.

Non‐invasive bioengineering methods in an intervention study in 1020 male metal workers: results and implications for occupational dermatology

Measurements of transepidermal water loss (TEWL) as an indicator of skin barrier function and colorimetry for quantifying erythema have been recommended for monitoring persons at risk of occupational hand dermatitis. This study examines the practicability and usefulness of biophysical measurements at the workplace. PATIENTS/MATERIAL/METHODS: A sample of 1020 male metal workers was enrolled; 800 participants were followed up for 1 year. TEWL results and colorimetry (a* value), respectively, were used as effectiveness outcomes, comparing the findings in the four study arms (skin care, skin protection, both combined, and control group). At 1 year follow-up, the TEWL was slightly but significantly lower in the group of participants randomized for application of barrier cream alone, indicating a protective effect. However, addressing both the individual absolute change of a* value and the differences of TEWL (delta-TEWL) of the dominant hand over the study period, no significant difference was found between the four groups. Dermatological examinations at the workplace cannot be replaced by bioengineering techniques. The supplementary benefit is apparently low, possibly because of difficulties in achieving standardized measurement conditions and other technical reasons.

The pH of aqueous bentonite suspensions

AbstractThe pH of aqueous bentonite suspensions is known to be influenced by carbonates present even in minor amounts. On the other hand, at high solid:liquid ratios (at standard pH measurement conditions: 2% w/w suspension), the type of exchangeable cation in the smectite is also known to determine pH (particularly Na+ or Ca2+). By cation-exchange tests we proved that exchanging the Ca2+ for Na+ results in an increase in the pH. However, this increase in pH was only found if excess salts were removed from the system (by washing or dialysis, respectively). The effect of the type of exchangeable cation can, at least partially, be explained by hydrolysis of Ca2+. On the other hand, a pronounced alkalinity of Na bentonites is observed which can, at least partially, be attributed to the hydrolysis of montmorillonite (Na+ is exchanged for H+ of water). The increase in the volume of the Stern layer, caused by increasing the degree of delamination, is also suggested to play a role. H+ and Na+ are concentrated in the Stern layer. Hence, increasing the Stern layer volume decreases the amount of H+ and Na+ in solution and thus increases pH. Unfortunately, both processes, montmorillonite hydrolysis and delamination, depend on the ionic strength. Distinguishing the processes quantitatively, therefore, is an analytical challenge, and impossible based on the data presented here.To model the pore-water chemistry of clays and clay stones, all of the above-mentioned processes have to be considered. It is possible that other reactions, not identified in the present work, contribute toward the pH values of aqueous bentonite suspensions.

TrackFly: Virtual reality for a behavioral system analysis in free-flying fruit flies

Modern neuroscience and the interest in biomimetic control design demand increasingly sophisticated experimental techniques that can be applied in freely moving animals under realistic behavioral conditions. To explore sensorimotor flight control mechanisms in free-flying fruit flies ( Drosophila melanogaster), we equipped a wind tunnel with a Virtual Reality (VR) display system based on standard digital hardware and a 3D path tracking system. We demonstrate the experimental power of this approach by example of a ‘one-parameter open loop’ testing paradigm. It provided (1) a straightforward measure of transient responses in presence of open loop visual stimulation; (2) high data throughput and standardized measurement conditions from process automation; and (3) simplified data analysis due to well-defined testing conditions. Being based on standard hardware and software techniques, our methods provide an affordable, easy to replicate and general solution for a broad range of behavioral applications in freely moving animals. Particular relevance for advanced behavioral research tools originates from the need to perform detailed behavioral analyses in genetically modified organisms and animal models for disease research.