scholarly journals Zircon Raman thermochronology: Data valuation and measurement protocol

2021 ◽  
Author(s):  
Birk Härtel ◽  
Raymond Jonckheere ◽  
Lothar Ratschbacher
Author(s):  
Erika Schutte ◽  
Jack Martin

Abstract An ellipsometry based measurement protocol was developed to evaluate changes to MEMS sensor surfaces which may occur during packaging using unpatterned test samples. This package-level technique has been used to measure the 0-20 Angstrom thin films that can form or deposit on die during the packaging process for a variety of packaging processing conditions. Correlations with device performance shows this to be a useful tool for packaged MEMS device and process characterization.


Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Syed Afaq Ali Shah ◽  
Muhammad Hassan Sayyad ◽  
Jinghua Sun ◽  
Zhongyi Guo

Due to the tremendous increase in power conversion efficiency (PCE) of organic–inorganic perovskite solar cells (PSCs), this technology has attracted much attention. Despite being the fastest-growing photovoltaic technology to date, bottlenecks such as current density–voltage (J–V) hysteresis have significantly limited further development. Current density measurements performed with different sweep scan speeds exhibit hysteresis and the photovoltaic parameters extracted from the current density–voltage measurements for both scan directions become questionable. A current density–voltage measurement protocol needs to be established which can be used to achieve reproducible results and to compare devices made in different laboratories. In this work, we report a hysteresis analysis of a hole-transport-material-free (HTM-free) carbon-counter-electrode-based PSC conducted by current density–voltage and impedance spectra measurements. The effect of sweep scan direction and time delay was examined on the J–V characteristics of the device. The hysteresis was observed to be strongly sweep scan direction and time delay dependent and decreased as the delay increased. The J–V analysis conducted in the reverse sweep scan direction at a lower sweep time delay of 0.2 s revealed very large increases in the short circuit current density and the power conversion efficiency of 57.7% and 56.1%, respectively, compared with the values obtained during the forward scan under the same conditions. Impedance spectroscopy (IS) investigations were carried out and the effects of sweep scan speed, time delay, and frequency were analyzed. The hysteresis was observed to be strongly sweep scan direction, sweep time delay, and frequency dependent. The correlation between J–V and IS data is provided. The wealth of photovoltaic and impendence spectroscopic data reported in this work on the hysteresis study of the HTM-free PSC may help in establishing a current density–voltage measurement protocol, identifying components and interfaces causing the hysteresis, and modeling of PSCs, eventually benefiting device performance and long-term stability.


2016 ◽  
Vol 74 (5) ◽  
pp. 380-384 ◽  
Author(s):  
Murat Aydin ◽  
Murat Eren Özen ◽  
Burcu Evlice ◽  
Matthew Ferguson ◽  
İlter Uzel
Keyword(s):  

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 790-790
Author(s):  
Dori Rosenberg ◽  
Rod Walker ◽  
Mikael Anne Greenwood-Hickman ◽  
KatieRose Richmire ◽  
John Bellettiere ◽  
...  

Abstract Few epidemiologic studies have examined device-measured sitting patterns by demographics and health status. The Adult Changes in Thought (ACT) study is an on-going epidemiologic study of adults age ≥65 years. We conducted a sub-study that added a thigh-worn activPAL device and sleep logs for 7 days to the measurement protocol. A total of 997 had valid wear time (≥4 days with 10-20 hours of data per day) and covariate data. activPAL sedentary pattern measures included number of sitting bouts lasting 30 minutes or more and mean sitting bout duration. On average, participants (56% female, 57% > age 75, 89% non-Hispanic white) sat in bouts lasting 17 minutes (SD = 12) and had 5.9 (SD = 1.7) bouts of sitting lasting 30 minutes or more. Participants who were older, were male, had obesity, had worse self-rated health, had depression, and had difficulty walking had longer sitting bouts and more prolonged bouts.


2015 ◽  
Vol 8 (10) ◽  
pp. 4453-4473 ◽  
Author(s):  
M. K. Kajos ◽  
P. Rantala ◽  
M. Hill ◽  
H. Hellén ◽  
J. Aalto ◽  
...  

Abstract. Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) are commonly used methods for automated in situ measurements of various volatile organic compounds (VOCs) in the atmosphere. In order to investigate the reliability of such measurements, we operated four automated analyzers using their normal field measurement protocol side by side at a boreal forest site. We measured methanol, acetaldehyde, acetone, benzene and toluene by two PTR-MS and two GC-MS instruments. The measurements were conducted in southern Finland between 13 April and 14 May 2012. This paper presents correlations and biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methanol, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference manifests as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50–100 % in the methanol emissions measured by commonly used methods.


Author(s):  
Shuyue Wei ◽  
Yongxin Tong ◽  
Zimu Zhou ◽  
Tianshu Song
Keyword(s):  

2018 ◽  
Author(s):  
Els Knaeps ◽  
David Doxaran ◽  
Ana Dogliotti ◽  
Bouchra Nechad ◽  
Kevin Ruddick ◽  
...  

Abstract. The SeaSWIR dataset consists of 137 ASD (Analytical Spectral Devices, Inc.) marine reflectances, 137 Total Suspended Matter (TSM) measurements and 97 turbidity measurements gathered at three turbid estuarine sites (Gironde, La Plata, Scheldt). The dataset is valuable because of the high quality measurements of the marine reflectance in the Short Wave InfraRed I region (SWIR-I: 1000–1200 nm) and SWIR-II (1200–1300 nm) and because of the wide range of TSM concentrations from 48 mg L−1 up to 1400 mg L−1. The ASD measurements were gathered using a detailed measurement protocol and were subjected to a strict quality control. The SeaSWIR marine reflectance is characterized by low reflectance at short wavelengths (


2019 ◽  
Author(s):  
Patrick Bergman ◽  
Maria Hagströmer

Abstract BACKGROUND Measuring physical activity and sedentary behavior accurately remains a challenge. When describing the uncertainty of mean values or when making group comparisons, minimising Standard Error of the Mean (SEM) is important. The sample size and the number of repeated observations within each subject influence the size of the SEM. In this study we have investigated how different combinations of sample sizes and repeated observations influence the magnitude of the SEM. METHODS A convenience sample were asked to wear an accelerometer for 28 consecutive days. Based on the within and between subject variances the SEM for the different combinations of sample sizes and number of monitored days was calculated. RESULTS Fifty subjects (67% women, mean±SD age 41±19 years) were included. The analyses showed, independent of which intensity level of physical activity or how measurement protocol was designed, that the largest reductions in SEM was seen as the sample size were increased. The same magnitude in reductions to SEM was not seen for increasing the number of repeated measurement days within each subject. CONCLUSION The most effective way of reducing the SEM is to have a large sample size rather than a long observation period within each individual. Even though the importance of reducing the SEM to increase the power of detecting differences between groups is well-known it is seldom considered when developing appropriate protocols for accelerometer based research. Therefore the results presented herein serves to highlight this fact and have the potential to stimulate debate and challenge current best practice recommendations of accelerometer based physical activity research.


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