AN UPDATE ON THE PERFORMANCE OF THE IN SITU 14C EXTRACTION LINE AT THE UNIVERSITY OF BERN

Radiocarbon ◽  
2020 ◽  
Vol 62 (5) ◽  
pp. 1371-1388
Author(s):  
M U Sliz ◽  
C Espic ◽  
B A Hofmann ◽  
I Leya ◽  
S Szidat
Keyword(s):  
Quartz Glass ◽  
Closed System ◽  
Published Data ◽  
Good Reproducibility ◽  
Combustion System ◽  
Advantages And Disadvantages ◽  
Field Samples ◽  
University Of Bern ◽  
The University

ABSTRACTWe present the current performance of the in situ radiocarbon (14C) extraction line at the University of Bern with an improved extraction and combustion system. After three major steps of improvement, the extraction of sample CO2 gas now takes place inside a platinum crucible, supported by an outer quartz-glass crucible. This setup allows us to operate the line as a closed system for several samples without breaking the vacuum. Measurements of procedural blanks and samples from our reference strewn field, Jiddat al Harasis 073, performed in our system all show a good reproducibility and, for the strewn field samples, consistency with published data. We describe each improvement step in detail, discussing the advantages and disadvantages of all tested setups. By sharing our knowledge, we aim to inform and prevent others from making the same or similar detours in establishing 14C extraction systems for extraterrestrial samples.

Current Performance and Preliminary Results of a New 14C Extraction Line for Meteorites at the University of Bern

Radiocarbon ◽  
2017 ◽  
Vol 60 (2) ◽  
pp. 601-615 ◽  
Author(s):  
Marianna Mészáros ◽  
Ingo Leya ◽  
Beda A Hofmann ◽  
Sönke Szidat
Keyword(s):  
High Precision ◽  
Gas Purification ◽  
Preliminary Results ◽  
Purification System ◽  
Interface System ◽  
University Of Bern ◽  
The University ◽  
Good Agreement ◽  
Terrestrial Age

AbstractHere, we introduce a new radiocarbon (14C) extraction line operating at the University of Bern, which was designed and built for the extraction of in situ 14C from meteorites. With this system, we achieved two important developments compared to other systems. First, using the MICADAS gas-interface system, 14C can directly be measured from the collected CO2 gas, i.e., without graphitization of the sample. Second, meteorite sample masses as low as ~0.05 g can be used for high precision and reproducibility. Prior to extraction in an oxygen atmosphere held at a pressure of ~20–30 mbar in an iridium crucible at 1600°C for 40 min, samples were preheated for 1 h in a constant oxygen flow at 500°C and continuous pumping. Gas purification followed the method described previously (e.g., Hippe et al. 2009). While the blank levels for preheated samples are low (<2×104 14C atoms), the blanks for non-preheated samples are high, therefore those results cannot be used. We also report preliminary results for the L-chondrite JaH 073. The terrestrial age of 17.7±0.4 ka is in good agreement with previous results for the same sample of this meteorite, confirming that the extraction line, the gas purification system, and the AMS measurements are all reliable.

scholarly journals Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1409
Author(s):  
Hamdhani Hamdhani ◽  
Drew E. Eppehimer ◽  
David Walker ◽  
Michael T. Bogan
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Water Quality Monitoring ◽  
Ambient Light ◽  
Calibration Equation ◽  
Field Samples ◽  
Potential Use

Chlorophyll-a measurements are an important factor in the water quality monitoring of surface waters, especially for determining the trophic status and ecosystem management. However, a collection of field samples for extractive analysis in a laboratory may not fully represent the field conditions. Handheld fluorometers that can measure chlorophyll-a in situ are available, but their performance in waters with a variety of potential light-interfering substances has not yet been tested. We tested a handheld fluorometer for sensitivity to ambient light and turbidity and compared these findings with EPA Method 445.0 using water samples obtained from two urban lakes in Tucson, Arizona, USA. Our results suggested that the probe was not sensitive to ambient light and performed well at low chlorophyll-a concentrations (<25 µg/L) across a range of turbidity levels (50–70 NTU). However, the performance was lower when the chlorophyll-a concentrations were >25 µg/L and turbidity levels were <50 NTU. To account for this discrepancy, we developed a calibration equation to use for this handheld fluorometer when field monitoring for potential harmful algal blooms in water bodies.

Study of transient heating using an in situ combustion system

2017 ◽  
Vol 114 ◽  
pp. 685-692
Author(s):  
Fabián E. Cano Ardila ◽  
Andrés A. Amell Arrieta
Keyword(s):  
Combustion System ◽  
Transient Heating ◽  
In Situ Combustion

scholarly journals Rapid and simple prenatal diagnosis of common chromosome disorders: advantages and disadvantages of the molecular methods FISH and QF-PCR

Reproduction ◽  
2003 ◽  
pp. 279-297 ◽  
Author(s):  
MA Hulten ◽  
S Dhanjal ◽  
B Pertl
Keyword(s):  
Prenatal Diagnosis ◽  
Sex Chromosome ◽  
Chromosome Analysis ◽  
Maternal Serum ◽  
Molecular Techniques ◽  
Maternal Serum Screening ◽  
Advantages And Disadvantages ◽  
Microscopy Analysis ◽  
Chromosome Disorder

Molecular techniques have been developed for prenatal diagnosis of the most common chromosome disorders (trisomies 21, 13, 18 and sex chromosome aneuploidies) where results are available within a day or two. This involves fluorescence in situ hybridization (FISH) and microscopy analysis of fetal cells or quantitative fluorescence polymerase chain reaction (QF-PCR) on fetal DNA. Guidance is provided on the technological pitfalls in setting up and running these methods. Both methods are reliable, and the risk for misdiagnosis is low, although slightly higher for FISH. FISH is also more labour intensive than QF-PCR, the latter lending itself more easily to automation. These tests have been used as a preamble to full chromosome analysis by microscopy. However, there is a trend to apply the tests as 'stand-alone' tests for women who are at relatively low risk of having a baby with a chromosome disorder, in particular that associated with advanced age or results of maternal serum screening programmes. These women comprise the majority of those currently offered prenatal diagnosis with respect to fetal chromosome disorders and if introduced on a larger scale, the use of FISH and QF-PCR would lead to substantial economical savings. The implication, on the other hand, is that around one in 500 to one in 1000 cases with a mentally and/or physically disabling chromosome disorder would remain undiagnosed.

In-situ simulation

Trauma ◽  
2017 ◽  
Vol 20 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Louise Schofield ◽  
Emma Welfare ◽  
Simon Mercer
Keyword(s):  
Medical Emergency ◽  
In Situ Simulation ◽  
Advantages And Disadvantages ◽  
Medical Emergency Teams ◽  
Clinical Workplace ◽  
Trauma Teams ◽  
New Guidelines

‘In-situ’ simulation or simulation ‘in the original place’ is gaining popularity as an educational modality. This article discusses the advantages and disadvantages of performing simulation in the clinical workplace drawing on the authors’ experience, particularly for trauma teams and medical emergency teams. ‘In-situ’ simulation is a valuable tool for testing new guidelines and assessing for latent errors in the workplace.

Versatile thin layer spectroelectrochemical cell employing specular reflectance

1987 ◽  
Vol 65 (5) ◽  
pp. 919-923 ◽  
Author(s):  
A. Scott Hinman ◽  
Brad J. Pavelich
Keyword(s):  
Thin Layer ◽  
Specular Reflection ◽  
Incident Light ◽  
Tetrabutylammonium Perchlorate ◽  
Specular Reflectance ◽  
Advantages And Disadvantages ◽  
Ftir Characterization ◽  
Sandwich Type

A versatile thin layer spectroelectrochemical cell employing specular reflection of the incident light beam from the electrode surface is described. Its application to in-situ uv–vis and FTIR characterization of the products of electrochemical reactions and to thin layer voltammetry and coulometry as well as conventional cyclic voltammetry is demonstrated for the oxidation of tetraphenylporphinatozinc in dichloroethane/tetrabutylammonium perchlorate solution. The advantages and disadvantages of this type of cell as compared to more conventional sandwich type optically transparent thin layer electrodes are discussed.

Analysis of the Test Method of Quartz Glass Optical Homogeneity

2017 ◽  
Vol 726 ◽  
pp. 414-418
Author(s):  
Bo Fu ◽  
Hui Wang ◽  
Zhu Feng Shao
Keyword(s):  
Quartz Glass ◽  
Measurement Accuracy ◽  
Test Methods ◽  
Test Method ◽  
Wavefront Aberration ◽  
Optical Homogeneity ◽  
Advantages And Disadvantages ◽  
Interference Measurement ◽  
Optical Quartz Glass

The optical quartz glass is widely applied in optical system , photo communications，inertial navigation，etc.It must have high optical homogeneity. Optical homogeneity of the optical quartz glass directly affects the wavefront quality of the optical transmission system, and changes the wavefront aberration of the system. How to accurately determine the optical homogeneity of the quartz glass is especially important. Currently，the method of test for optical homogeneity mainly used by interference principle. This paper analyzes various existing interference measurement method and test equipment. Summarized the advantages and disadvantages of various test methods，using range and measurement accuracy.

Color and Coloristic Tasks in the Organization of the Methodology of Educational Projects in the Training of Architects and Designers at the University

2021 ◽  
pp. 57-61
Author(s):  
N. Ul'yanova
Keyword(s):  
Educational Activity ◽  
Project Work ◽  
Educational Work ◽  
Educational Design ◽  
Color Palette ◽  
Advantages And Disadvantages ◽  
Space Organization ◽  
Design Solutions ◽  
Architecture And Design ◽  
The University

The article is devoted to the meaning and use of the possibilities of color and pictorial combinations in architecture and design, when performing educational project tasks. The study examines the emerging problems in the organization of educational work. The purpose of the study is to create a comprehensive design methodology with the inclusion of a module of coloristic and color aspects. Possible methods of organizing project educational work are proposed. The advantages and disadvantages of performing these tasks are analyzed. The methods of project work are aimed at creating convenient and at the same time aesthetic architectural objects. The methods under consideration are based on practical work, which is the basis of any educational activity in the training of higher school specialists. When forming the educational methodology, the nature and technological possibilities of using color in the design of architectural and design solutions were taken into account. The presented project proposals are based on a practical experiment and demonstrate the possibilities of planning coloristic tasks. The study determines the problem based on the analysis of modern buildings and its architectural solutions. The analysis of this topic highlights the insufficient training of future specialists in the field of using the possibilities of color in architecture and design of residential and public buildings. The research suggests and analyzes artistic and aesthetic technologies of space organization. The results of the study put forward new tasks in the planning of educational design solutions, using color, harmony of the color palette, subordinate to the color and coloristic unity of the environment.

Comparing Coding Viewing and Recording Methods to Quantify Embedded Instruction Learning Trials

2022 ◽  
pp. 105381512110695
Author(s):  
Mackenzie K. Martin ◽  
Patricia A. Snyder ◽  
Brian Reichow ◽  
Crystal D. Bishop
Keyword(s):  
Correlation Coefficients ◽  
Computer Assisted ◽  
Systematic Observation ◽  
Embedded Instruction ◽  
Advantages And Disadvantages ◽  
Observation Systems ◽  
Pencil And Paper ◽  
Dependent Samples ◽  
Learning Trials

The purpose of this study was to examine the comparability of counts of embedded instruction learning trials when different methods of viewing and recording direct behavioral observations were used. In 13 classrooms, while videotaping embedded instruction implementation for a larger randomized controlled efficacy trial was occurring, teachers’ implementation of trials was coded in situ using pencil-and-paper methods. Videos were later coded using computer-assisted methods. Dependent-samples t tests, Pearson product-moment correlation coefficients, and additional score agreement calculations were conducted. Statistically significant differences were found in the estimates of trial frequency. Correlational analyses showed positive and strong relationships between the coding methods. Coding agreement was higher across the entire observation versus during 10-min continuous event blocks. In situ coding took significantly less time than video coding. Results provide empirical evidence for the advantages and disadvantages of common viewing and recording methods for quantifying behavior as part of systematic observation systems.

Paleopathological study of the Egyptian mummies collected in Italy: the Anubis project

1970 ◽  
Vol 80 (1) ◽  
Author(s):  
Rosalba Ciranni ◽  
Donata Pangoli ◽  
Valentina Giuffra ◽  
DAvide Caramella ◽  
Edda Bresciani ◽  
...  
Keyword(s):  
X Rays ◽  
Axial Tomography ◽  
Technical Problems ◽  
Histological Studies ◽  
Computed Axial Tomography ◽  
The University ◽  
First Time

Eighty-five Egyptian mummies belonging to different dynastic periods and collected in a number of Italian museums, have been censed and submitted for paleopathological research. In most cases the presence of bandages required the application of X- rays and computed axial tomography (CAT). Fifty-two mummies have been studied in situ with Xrays; twelve with CAT scanning. Technical problems kept us from investigating eleven of the censed mummies. In a few cases it was possible to perform autopsies, endoscopy, or histological studies. The mummies submitted for X- rays were divided into two groups: The first group thirty-six mummies studied by the team of Paleopathology-Egyptology of the University of Pisa were studied for the first time. The second group was composed of twenty-six mummies studied elsewhere in Italy. Those results also have been included in the Anubi Project database.

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