scholarly journals Recommendations for handling bitumen prior to FTIR spectroscopy

2022 ◽  
Vol 55 (2) ◽  
Author(s):  
Johannes Mirwald ◽  
Drilon Nura ◽  
Bernhard Hofko

AbstractThe application of chemical analysis on bituminous materials has increased drastically over the past decades. One of the most common spectroscopic methods used in the field of research is Attenuated Total Reflection (ATR) Fourier Transform Infrared (FTIR) spectroscopy. Since ATR-FTIR is a surface sensitive method, sample or specimen handling of a complex material like bitumen prior to its analysis needs to be considered, especially for people new to the field or analysis technique. This study looks at the impact of heating time and temperature as well as storage time and conditions on the oxidation of the bituminous specimen. Four binders from the same crude oil source but different specification classes (unmodified and styrene–butadiene–styrene polymer modified) and two binders from different crude oil sources were investigated. The results show that heating small quantities of bitumen at 180 °C for up to 30 min has little impact on the formation of oxidized species, when proper thermal monitoring is conducted. Special cases where oxidation does occur are reported in detail. Furthermore, strong oxidation is induced by day light, when bitumen is stored behind glass with no UV radiation present, which can reach short-term ageing level within 1 h. Thus, heating bitumen at 180 °C for 5–10 min followed by storage in the dark, climatized room and measured within one hour after preparation is recommended. These results should act as recommendation for future specimen handling prior to FTIR spectroscopic analysis to ensure unbiased and comparable measurements.

Radiocarbon ◽  
2016 ◽  
Vol 58 (1) ◽  
pp. 131-145 ◽  
Author(s):  
M Lebon ◽  
I Reiche ◽  
X Gallet ◽  
L Bellot-Gurlet ◽  
A Zazzo

AbstractExpensive and time-consuming preparation procedures for radiocarbon and stable isotope analyses can be conducted on archaeological bone samples even if no collagen is preserved. Such unsuccessful preparation can lead to the partial destruction of valuable archaeological material. Establishing a rapid prescreening method for evaluating the amount of bone collagen while minimizing the impact of sampling constitutes a challenge for the preservation of archaeological collections. This study proposes and discusses a new methodology to detect and quantify collagen content in archaeological bone samples by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. A total of 42 Pleistocene to modern bone samples were selected according to their nitrogen content measured using an elemental analyzer. Comparison of collagen content estimation using ATR-FTIR and mass spectrometry reveals that some of the studied samples are contaminated by a nitrogen source coming from the burial environment. Two different FTIR calibration approaches were tested on the uncontaminated samples: peak-to-peak ratio and multivariate regression (PLS). The two approaches yield similar results with a good correlation of ATR-FTIR analyses and N wt% from 0.7 to 4wt% (R²=0.97–0.99; standard error of estimation ±0.22 to 0.25wt%). While collagen content remains difficult to detect in poorly preserved bones (less than ~3wt%), ATR-FTIR analysis can be a fast alternative for sample screening to optimize the sampling strategy and avoid partial destruction of valuable samples that do not contain enough collagen for further analysis.


2015 ◽  
Vol 22 (04) ◽  
pp. 26-50
Author(s):  
Ngoc Tran Thi Bich ◽  
Huong Pham Hoang Cam

This paper aims to examine the main determinants of inflation in Vietnam during the period from 2002Q1 to 2013Q2. The cointegration theory and the Vector Error Correction Model (VECM) approach are used to examine the impact of domestic credit, interest rate, budget deficit, and crude oil prices on inflation in both long and short terms. The results show that while there are long-term relations among inflation and the others, such factors as oil prices, domestic credit, and interest rate, in the short run, have no impact on fluctuations of inflation. Particularly, the budget deficit itself actually has a short-run impact, but its level is fundamentally weak. The cause of the current inflation is mainly due to public's expectations of the inflation in the last period. Although the error correction, from the long-run relationship, has affected inflation in the short run, the coefficient is small and insignificant. In other words, it means that the speed of the adjustment is very low or near zero. This also implies that once the relationship among inflation, domestic credit, interest rate, budget deficit, and crude oil prices deviate from the long-term trend, it will take the economy a lot of time to return to the equilibrium state.


2019 ◽  
Vol 5 ◽  
pp. 104
Author(s):  
Suhendra Purnawan ◽  
Subari Yanto ◽  
Ernawati S.Kaseng

This study aims to describe the profile of vegetation diversity in the mangrove ecosystem in Tamuku Village, Bone-Bone-Bone District, North Luwu Regency. This research is a qualitative research using survey methods. The data collection technique uses the Quadrant Line Transect Survey technique. The data analysis technique uses the thinking flow which is divided into three stages, namely describing phenomena, classifying them, and seeing how the concepts that emerge are related to each other. The results of this study are the profile of mangrove vegetation in Tamuku Village, which is still found 16 varieties of true mangrove vegetation and 7 varieties of mangrove vegetation joined in the coastal area of Tamuku Village, Bone-Bone District, North Luwu Regency, South Sulawesi. The condition of mangrove vegetation in Tamuku Village is currently very worrying due to human activities that cause damage such as the project of normalization of flow, opening of new farms, disposal of garbage, water pollution due to chemicals, and exploitation of mangrove forests for living needs. The impact is ecosystem damage and reduced vegetation area as a place to grow and develop mangroves.


2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Arief Hidayatullah Khamainy ◽  
Dessy Novitasari Laras Asih

The research was carried out to find the influence of training material and methods of training toward workability. The study was conducted respectively from an employee of PD BPR Bantul Yogyakarta. The purpose of this research is expected to be useful for stakeholders in seeing CSR disclosure in the company in testing and analyzing its effect on the company's financial performance and with the presence of anti-corruption exposure, whether it will strengthen the impact of CSR disclosure on the company's financial performance. The study population in this study were all mining companies registered on the Indonesia Stock Exchange in 2016-2018 with a total of 63 companies. The research sample was taken using a random sampling technique that was calculated by the Slovin formula so that 54 samples were obtained for analysis. Linear Regression Analysis and Moderation Regression Analysis were chosen as the analysis technique used in this study. The results show that CSR disclosure does not affect the company's financial performance, and anti-corruption disclosure does not affect the relationship between the two.


2009 ◽  
Vol 46 (3) ◽  
pp. 137-152 ◽  
Author(s):  
Mile Djurdjevic ◽  
Glenn Byczynski ◽  
Carola Schechowiak ◽  
Hagen Stieler ◽  
Jelena Pavlovic

Author(s):  
Manimegalai Kavarthalai ◽  
Vimala Ponnuswamy

A theoretical study of a squeezing ferro-nanofluid flow including thermal effects is carried out with application to bearings and articular cartilages. A representational geometry of the thin layer of a ferro-nanofluid squeezed between a flat rigid disk and a thin porous bed is considered. The flow behaviours and heat transfer in the fluid and porous regions are investigated. The mathematical problem is formulated based on the Neuringer–Rosensweig model for ferro-nanofluids in the fluid region including an external magnetic field, Darcy law for the porous region and Beavers–Joseph slip condition at the fluid–porous interface. The expressions for velocity, fluid film thickness, contact time, fluid flux, streamlines, pathlines, mean temperature and heat transfer rate in the fluid and porous regions are obtained by using a perturbation method. An asymptotic solution for the fluid layer thickness is also presented. The problem is also solved by a numerical method and the results by asymptotic analysis, perturbation and numerical methods are obtained assuming a constant force squeezing state and are compared. It is shown that the results obtained by all the methods agree well with each other. The effects of various parameters such as Darcy number, Beavers–Joseph constant and magnetization parameter on the flow behaviours, contact time, mean temperature and heat transfer rate are investigated. The novel results showing the impact of using ferro-nanofluids in the two applications under consideration are presented. The results under special cases are further compared with the existing results in the literature and are found to agree well.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Szabolcs Blazsek ◽  
Alvaro Escribano ◽  
Adrian Licht

Abstract A new class of multivariate nonlinear quasi-vector autoregressive (QVAR) models is introduced. It is a Markov switching score-driven model with stochastic seasonality for the multivariate t-distribution (MS-Seasonal-t-QVAR). As an extension, we allow for the possibility of having common-trends and nonlinear co-integration. Score-driven nonlinear updates of local level and seasonality are used, which are robust to outliers within each regime. We show that VAR integrated moving average (VARIMA) type filters are special cases of QVAR filters. Using exclusion, sign, and elasticity identification restrictions in MS-Seasonal-t-QVAR with common-trends, we provide short-run and long-run impulse response functions for the global crude oil market.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 519
Author(s):  
Vitalii Bezgin ◽  
Agata Dudek ◽  
Adam Gnatowski

This paper proposes and presents the chemical modification of linear hydroxyethers (LHE) with different molecular weights (380, 640, and 1830 g/mol) with the addition of three types of rubbers (polysulfide rubber (PSR), polychloroprene rubber (PCR), and styrene-butadiene rubber (SBR)). The main purpose of choosing this type of modification and the materials used was the possibility to use it in industrial settings. The modification process was conducted for a very wide range of modifier additions (rubber) per 100 g LHE. The materials obtained in the study were subjected to strength tests in order to determine the effect of the modification on functional properties. Mechanical properties of the modified materials were improved after the application of the modifier (rubber) to polyhydroxyether (up to certain modifier content). The most favorable changes in the tested materials were registered in the modification of LHE-1830 with PSR. In the case of LHE-380 and LHE-640 modified in cyclohexanol (CH) and chloroform (CF) solutions, an increase in the values of the tested properties was also obtained, but to a lesser extent than for LHE-1830. The largest changes were registered for LHE-1830 with PSR in CH solution: from 12.1 to 15.3 MPa for compressive strength tests, from 0.8 to 1.5 MPa for tensile testing, from 0.8 to 14.7 MPa for shear strength, and from 1% to 6.5% for the maximum elongation. The analysis of the available literature showed that the modification proposed by the authors has not yet been presented in any previous scientific paper.


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