scholarly journals Soluble Salts Quantitative Characterization and Thermodynamic Modeling on Roman Bricks to Assess the Origin of Their Formation

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2866
Author(s):  
Claudia Scatigno ◽  
Nagore Prieto-Taboada ◽  
Giulia Festa ◽  
Juan Manuel Madariaga
Keyword(s):  
Archaeological Site ◽  
Risk Level ◽  
Salt Weathering ◽  
Soluble Salts ◽  
High Concentration ◽  
Quantitative Characterization ◽  
Chromatography Analysis ◽  
Acidic Gases ◽  
Hygroscopic Moisture ◽  
Ostia Antica

The environmental weathering and the formation of efflorescences on the brick walls are studied at the “Casa di Diana” Mithraeum at Ostia Antica archaeological site. Previous studies on subsoil, bedrock, hydrological systems and environmental conditions, and new ion chromatography analysis combined with ECOS-RUNSALT and Medusa-Hydra thermodynamic modelling software, had allowed us to identify the subsoil contamination related to soluble salts. The atmospheric acidic gases, CO2 and SO2, are determined as the main salt weathering species. A dry deposition after a subsequent hydration action from the shallow freshwater aquifer that reaches up to 1 m on the walls is identified as the mechanism of salt formation. An evaluation of potential sources such as the nearby Fiumicino airport, CO2-rich gases inputs from fumaroles and CO2 inputs was also debated. The risk level of contamination the surfaces of the materials should be considered mildly/very polluted with a medium/high risk of hygroscopic moisture due to the high concentration of sulphates.

Bone Cave: A Severely Disturbed Cave Site in Central Oregon

2005 ◽  
Vol 26 (2) ◽  
pp. 221-244 ◽  
Author(s):  
Jeffrey R. Ferguson ◽  
Craig E. Skinner
Keyword(s):  
Field Research ◽  
Archaeological Site ◽  
Time Span ◽  
Early Holocene ◽  
Political Environment ◽  
Limited Time ◽  
Faunal Remains ◽  
High Concentration ◽  
Processing Site ◽  
Disturbed Site

The presence of obsidian artifacts available for hydration and sourcing analysis, a high concentration of well-preserved faunal remains, a limited time span of occupation, and a wealth of obsidian research in the region, make Bone Cave an ideal example of an often ignored class of archaeological site. Although highly disturbed, analysis of the excavation results allowed us to determine that Bone Cave served as a probable pre-Mazama (prior to 6850 B.P.) rabbit processing site during the Early Holocene. The disturbed site of Bone Cave shows that field research is possible even in a region or political environment in which the excavation of intact sites is not.

scholarly journals How to remove the influence of trace water from the absorption spectra of SWNTs dispersed in ionic liquids

2011 ◽  
Vol 2 ◽  
pp. 653-658 ◽  
Author(s):  
Juan Yang ◽  
Daqi Zhang ◽  
Yan Li
Keyword(s):  
Ionic Liquids ◽  
Absorption Spectra ◽  
Pure Water ◽  
High Concentration ◽  
Quantitative Characterization ◽  
Intrinsic Structure ◽  
Nir Absorption ◽  
Walled Carbon Nanotubes ◽  
Trace Water

Single-walled carbon nanotubes (SWNTs) can be efficiently dispersed in the imidazolium-based ionic liquids (ILs), at relatively high concentration, with their intrinsic structure and properties retained. Due to the hygroscopicity of the ILs, water bands may be introduced in the absorption spectra of IL-dispersed SWNTs and cause problems in spectral deconvolution and further analysis. In order to remove this influence, a quantitative characterization of the trace water in [BMIM]+[PF6]− and [BMIM]+[BF4]− was carried out by means of UV–vis-NIR absorption spectroscopy. A simple yet effective method involving spectral subtraction of the water bands was utilized, and almost no difference was found between the spectra of the dry IL-dispersed SWNT samples treated under vacuum for 10 hours and the spectra of the untreated samples with subtraction of the pure water spectrum. This result makes it more convenient to characterize SWNTs with absorption spectra in the IL-dispersion system, even in the presence of trace amount of water.

Calculating and communicating ensemble-based volcanic ash concentration risk for aviation

2021 ◽  
Author(s):  
Natalie Harvey ◽  
Helen Dacre ◽  
Antonio Capponi
Keyword(s):  
Volcanic Ash ◽  
Numerical Models ◽  
Volcanic Eruptions ◽  
Risk Level ◽  
Aircraft Icing ◽  
Risk Matrix ◽  
High Concentration ◽  
Forecast Lead Time ◽  
Aviation Hazards ◽  
Robust Decisions

<p>During volcanic eruptions Volcanic Ash Advisory Centers (VAAC) produce forecasts of ash location and concentration. However, these forecasts are deterministic and do not take into account the inherent uncertainty in the forecasts due to incomplete knowledge of the volcano’s eruption characteristics and imperfect representation of atmospheric processes in numerical models. This means flight operators have incomplete information regarding the risk of flying following an eruption, which could result in overly conservative decisions being made. There is a need for a new generation of volcanic ash hazard charts allowing end users to make fast and robust decisions using risk estimates based on  state-of-the-art probabilistic forecast methods .</p><p> </p><p>In this presentation, a method for visualizing ash concentration matrix using a risk-matrix approach will be applied to two volcanic eruptions, Grimsvotn (2011) and Raikoke (2019). These risk-matrix graphics reduce the ensemble information into an easy-to-use decision-making tool. In this work the risk level is determined by combining the concentration of volcanic ash and the likelihood of that concentration occurring.</p><p> </p><p>When applying this technique to the Grimsvotn eruption, the airspace containing volcanic ash concentrations deemed to be associated with the highest risk (high likelihood of exceeding a high concentration threshold) to aviation are reduced by over 85% compared to using an ensemble that gives an ash distribution similar to the VAAC issued deterministic forecast. The reduction during the Raikoke eruption can be as much as 40% at a forecast lead time of 48 hours. This has the potential to reduce the disruption to airline operations.  This tool could be extended to include other aviation hazards, such as desert dust, aircraft icing and clear air turbulence.</p><p> </p>

AIRPORT ALoSP AND INTEGRATED RISK APPROACH FOR SSPs

2021 ◽  
Vol 11 (2) ◽  
pp. 21-43
Author(s):  
Daniel Cunha ◽  
Michelle Andrade ◽  
Javã Silva
Keyword(s):  
Risk Index ◽  
Safety Performance ◽  
Risk Level ◽  
Total Risk ◽  
High Concentration ◽  
Integrated Risk ◽  
Risk Approach ◽  
Risk Recurrence ◽  
Better Than ◽  
Do So

This work proposed the development of a methodology for risk management in airports for ICAO’s State Safety Programmes (SSP). To do so we investigated the nature of the airport safety events occurred in busiest Brazilian airports and proposed a risk index capable to provide the Acceptable Level of Safety Performance (ALoSP) ICAO demands to their signatory States. The approach allowed us to rank airports per their risk in relation to the ALoSP calculated and proposed State optimized regulatory actions to where the risk is. Research found the high concentration on risk recurrence among 31 airports. Only 4 concentrated 30% of all the recurrence of risk, 8 were responsible for 50% and 17 represented approximately 80% of the total risk load in Brazilian airport operations. Five groups of airports are proposed as per their safety performance (Safety+2, Safety+1, Neutral, Safety-1 and Safety-2). Their measured performance showed statistically significant differences. Safety+1 group presented a safety performance 1.49 times better than ALoSP and 3.52 times better than worst group of airports (Safety-2). The Safety+2 group is 3.76 times safer than ALoSP and 8.88 times safer than Safety-2 group. Safety-1 group presented a risk level 1.51 times higher than ALoSP and Safety-2 performed 2.35 times riskier than the ALoSP. This matrix way of problem solving brings more effectiveness and rationality to the SSP’s, amplifying their effectiveness.

scholarly journals Nanofiltration Process for Enhanced Treatment of RO Brine Discharge

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 212
Author(s):  
Mohamed E.A. Ali
Keyword(s):  
Major Ions ◽  
Water Discharge ◽  
Life Time ◽  
Total Hardness ◽  
Water Type ◽  
Saturation Indices ◽  
Soluble Salts ◽  
High Concentration ◽  
Desalination Plants ◽  
Divalent Salts

Brine discharge of reverse osmosis (RO) desalination plants represents a challenge for both inland and coastal desalination plants. Zero-liquid discharge (ZLD) can be accomplished by using additional stages of RO, which can recycle that brine water, but the key challenge is the high concentration of divalent salts. These divalent salts (especially calcium and magnesium salts) forms a scaling layer on the RO membrane surfaces and hence shorten the life-time of the membranes. In this study, the nanofiltration (NF) procedure was used to remove divalent ions from the brine discharge to minimize the load on additional stages of RO membranes. One of the most critical considerations influencing the selection of an effective NF is the water type, which is expected here by calculation of some hydrochemical parameters (major ions, hypothetical soluble salts (electrolyte), and saturation indices). NF experiments were undertaken on a lab-scale using a low-pressure hand-made system of 4–7 bar. Synthetic single salts solutions and two real brine water discharge (brackish (BWRO) and seawater (SWRO) desalination plants) were used as a feed solution for NF system. The chemical characteristics of the RO-feed, RO-brine, NF-permeate, and NF-reject in were investigated. Electrolyte concentrations and saturation indices were determined based on the concentration of the major ions and the NETPATH software package, respectively. Calculations reveal that the brine concentrate samples contained mostly MgSO4 and MgCl2 soluble salts. The results show that 79–89% of the total dissolved salts (TDS) and 96–98% of the total hardness (TH) were retained using the NF process. The salt rejection of the NF membrane follows the order of CaSO4, Na2SO4, MgSO4, MgCl2, and NaCl with a percent of 97.4, 97.3, 95.2, 93.4, and 79%, respectively.

scholarly journals Improvement of Flavonoids in Lemon Seeds on Oxidative Damage of Human Embryonic Kidney 293T Cells Induced by H2O2

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Dingyi Yang ◽  
Yong Jiang ◽  
Yuqing Wang ◽  
Qianqian Lei ◽  
Xin Zhao ◽  
...  
Keyword(s):  
Survival Rate ◽  
Oxidative Damage ◽  
High Performance ◽  
Quantitative Polymerase Chain Reaction ◽  
Survival Rates ◽  
Human Embryonic Kidney ◽  
High Concentration ◽  
Stress Injury ◽  
Chromatography Analysis

In this study, flavonoids in lemon seeds (FLS) were used to assess its improvement on the oxidative damage of human embryonic kidney 293T cells (HEK 293T cells) induced by H2O2. In vitro experiments showed that the survival rates of HEK 293T cells treated with different flavonoid concentrations (50 μg/mL, 100 μg/mL, and 150 μg/mL) exceeded 95%, indicating no significant toxic effect. Compared with the normal group, H2O2 (0.3 mmol/L) resulted significantly in oxidative stress injury of HEK 293T cells. The survival rate of the damaged cells increased after treatment with flavonoids, and the survival rate of cells treated with a high concentration (150 μg/mL) of flavonoids was 76.2%. Flavonoids also effectively inhibited H2O2-induced apoptosis. At the same time, flavonoid treatment significantly reduced the malondialdehyde content in cells and increased the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px). Quantitative polymerase chain reaction (qPCR) and Western blot analysis also suggested that FLS upregulated mRNA and protein expressions of CAT, SOD (SOD1, SOD2), GSH (GSH1), and GSH-Px in H2O2-induced oxidative damage of HEK 293T cells. The high-performance liquid chromatography analysis demonstrated that FLS contained six compounds, including gallocatechin, caffeic acid, epicatechin, vitexin, quercetin, and hesperidin. FLS were proven to have a good antioxidant capacity in vitro and improve significantly the oxidative damage of HEK 293T cells induced by H2O2. The biological activity value warrants investigation in additional studies.

scholarly journals Are Ministry of Environment holding times for nitrate and nitrite tests in drinking water justified?

2014 ◽  
Author(s):  
Vu Nguyen ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock ◽  
Kevin Soulsbury
Keyword(s):  
Drinking Water ◽  
Ion Chromatography ◽  
Well Water ◽  
High Concentration ◽  
Potential Health ◽  
Test Strips ◽  
Chromatography Analysis ◽  
Background Exposure ◽  
The Difference ◽  
Nitrate And Nitrite

  Background: Exposure to nitrate and nitrite in high concentration is associated with various health issues in humans such as methemoglobinemia, gastric and bladder cancers. Surface and ground water is vulnerable to nitrate and nitrite contamination which can have a significant impact to communities that use the water for consumption. Methods: Ion chromatography analysis of nitrate and nitrite degradation over time in well water from Abbotsford-Sumas Aquifer was performed in an analytical chemistry study. Nitrate and nitrite test strips marketed for testing drinking water were also used and results were compared to ion chromatography results. Results: Test strips used were unable to detect the level of nitrate/nitrite in the well water sample drawn from the Abbotsford-Sumas aquifer. Ion chromatography, IC, methods were able to detect measurable amounts of nitrates which resulted from concentrations of 1.17 mg/L NO3 as N to 1.13 mg/L NO3 as N from day 0 to 31 of the sampling date. The concentration decreased 0.04 mg/L NO3 as N over 31 days. Nitrites tested by IC were below the detection limit. Conclusion: In regards to nitrates, the MOE holding times are justified in that the concentrations were statistically different (p = 0.0001) from day 0 to day 31 from the sampling date indicating a change of concentration of the chemical due to time. However, the difference was not of a magnitude that may impact public health practices/policies. Test strips comparisons with EPA IC methods were non-conclusive since test strips were unable to detect measurable amounts of nitrate/nitrites. Future studies of nitrate concentrations with respect to chemical and biological components in water may lead to a greater understanding of its change in the environment and thus its association with other potential health hazards.  

Geophysical and geochemical techniques to assess the origin of rising damp of a Roman building (Ostia Antica archaeological site)

2016 ◽  
Vol 129 ◽  
pp. 49-57 ◽  
Author(s):  
E. Cardarelli ◽  
G. De Donno ◽  
C. Scatigno ◽  
I. Oliveti ◽  
M. Preite Martinez ◽  
...  
Keyword(s):  
Archaeological Site ◽  
Ostia Antica ◽  
Rising Damp

scholarly journals Identification of three species commonly known as “daqingye” by internal leaf anatomy and high-performance liquid chromatography analyses

2018 ◽  
Vol 87 (1) ◽  
Author(s):  
Yingjiao Zhang ◽  
Yongqing Zhu ◽  
Jian Chen ◽  
Chen Xia ◽  
Junling Deng ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Leaf Anatomy ◽  
High Performance ◽  
Chemical Constituents ◽  
Single Cells ◽  
Morphological Observation ◽  
High Concentration ◽  
Chromatography Analysis ◽  
Polygonum Tinctorium

The macroscopic and microscopic morphologies and indigo and indirubin concentration of the traditional Chinese medicine herbs <em>Isatis indigotica</em> Fort., <em>Polygonum tinctorium</em> Ait., and <em>Baphicacanthus cusia</em> (Nees) Bremek, all commonly known as “daqingye”, were determined and compared. The morphological analyses indicated that <em>I. indigotica</em> has leaves with winged petioles and no glandular hairs or crystals, <em>P. tinctorium</em> has leaves with membranous ocrea and clusters of calcium oxalate, and <em>B. cusia</em> has palisade cells in the mesophyll running over the main vein and single cells containing calcium carbonate crystals. Indigo and indirubin are chemical constituents that have been previously isolated from daqingye and were selected in this study as identification markers for high-performance liquid chromatography analysis due to their pharmacological activities. The chromatographic results showed that indigo and indirubin concentration varied significantly among the three species: high concentration of both indigo and indirubin were observed in <em>I. indigotica</em>, the highest concentration among the three daqingye plants was found in <em>P. tinctorium</em> but with low levels of indirubin, and the concentration of indigo and indirubin was quite low in <em>B. cusia</em>. In summary, three different species commonly known as daqingye were accurately distinguished by morphological observation, internal leaf anatomy analysis, and chromatographic analysis.

Sign in / Sign up

Export Citation Format

Share Document