Opening the black box: soil microcosm experiments reveal soot-black carbon short-term oxidation and influence on organic carbon mineralisation

2021 ◽  
Author(s):  
Marta Crispo ◽  
Duncan D. Cameron ◽  
Will Meredith ◽  
Aaron Eveleigh ◽  
Nicos Ladommatos ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Fossil Fuels ◽  
Isotope Ratio Mass Spectrometry ◽  
Soil Microcosm ◽  
Short Term ◽  
Carbon Mineralisation ◽  
Significant Difference ◽  
Global Carbon ◽  
Over Time

<p>Black carbon (BC), the product of the incomplete combustion of fossil fuels and biomass, is ubiquitous in soils globally. Although BC is a major soil carbon pool, its effects on the global carbon cycle have not yet been resolved. It is deemed to represent a large stable pool in soils turning over on geological timescales, but research suggests it can alter soil biogeochemical cycling including that of ecosystem-derived organic carbon. Here, we established two soil microcosm chamber experiments: experiment one added <sup>13</sup>C organic carbon to soil with and without added BC (soot and biochar) to investigate whether it suppressed organic carbon mineralisation; experiment two added <sup>13</sup>C BC (soot) to soil to establish whether it is mineralised in soil over a short timescale. Gases were sampled over six-months and analysed using isotope ratio mass spectrometry. In experiment one we found that the efflux of <sup>13</sup>C organic carbon from the soil decreased over time, but the addition of soot to soil significantly reduced the mineralisation of organic carbon from 32% of the total supplied without soot to 14% of the total supplied with soot. In contrast, there was not a significant difference after the addition of biochar in the flux of δ <sup>13</sup>CO<sub>2 </sub>from the organic carbon added to the soil. In experiment two, we found that the efflux <sup>13</sup>C from soil with added <sup>13</sup>C labelled soot significantly differed from the control, but this efflux declined over time. There was a cumulative loss of 0.17% <sup>13</sup>C from soot over the experiment.These experimental results represent a step-change in understanding the influence of BC continuum on carbon dynamics, which has major consequences for the way we measure, monitor and manage soils for carbon storage and sequestration in the future.</p>

Fracking, Warming, and Systemic Leadership

2018 ◽  
Author(s):  
William R. Thompson ◽  
Leila Zakhirova
Keyword(s):  
Global Warming ◽  
Fossil Fuels ◽  
New Technology ◽  
Strong Relationship ◽  
The United States ◽  
Extraction Methods ◽  
Short Term ◽  
The Past ◽  
Significant Difference ◽  
International Standing

In the past, states with access to cheap and abundant sources of energy were able to develop radical new technology that paired core innovations with new fuels. Given the strong relationship between global warming and fossil fuels, in this chapter we ask whether the emergence of unconventional fuels and extraction methods are likely to make a significant difference for the relative international standing of the United States now and China perhaps later. Should the expansion of less expensive but older sources of energy, thanks to fracking technologies, help states maintain or regain systemic leadership? Our answer is that fracking will be advantageous in the short term but much less so when it comes to longer-term considerations such as global warming and systemic leadership. More likely, this innovation will only protract the transition away from fossil fuels.

scholarly journals Sampling, Filtering, and Analysis Protocols to Detect Black Carbon, Organic Carbon, and Total Carbon in Seasonal Surface Snow in an Urban Background and Arctic Finland (>60° N)

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 923
Author(s):  
Outi Meinander ◽  
Enna Heikkinen ◽  
Minna Aurela ◽  
Antti Hyvärinen
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Laboratory Experiments ◽  
Elemental Carbon ◽  
Total Carbon ◽  
The Arctic ◽  
Urban Background ◽  
Wrong Side ◽  
Global Carbon ◽  
Snow Samples

Black carbon (BC), organic carbon (OC), and total carbon (TC) in snow are important for their climatic and cryospheric effects. They are also part of the global carbon cycle. Atmospheric black and organic carbon (including brown carbon) may deposit and darken snow surfaces. Currently, there are no standardized methods for sampling, filtering, and analysis protocols to detect carbon in snow. Here, we describe our current methods and protocols to detect carbon in seasonal snow using the OCEC thermal optical method, a European standard for atmospheric elemental carbon (EC). We analyzed snow collected within and around the urban background SMEARIII (Station for Measuring Ecosystem-Atmosphere Relations) at Kumpula (60° N) and the Arctic GAW (Global Atmospheric Watch) station at Sodankylä (67° N). The median BC, OC, and TC in snow samples (ntot = 30) in Kumpula were 1118, 5279, and 6396 ppb, and in Sodankylä, they were 19, 1751, and 629 ppb. Laboratory experiments showed that error due to carbon attached to a sampling bag (n = 11) was <0.01%. Sonication slightly increased the measured EC, while wetting the filter or filtering the wrong side up indicated a possible sample loss. Finally, we discuss the benefits and drawbacks of OCEC to detect carbon in snow.

scholarly journals Particulate and Dissolved Black Carbon in Bohai and Laizhou Bays, China: Distributions, Sources, and Contrasts Under Two Distinct Fluvial Hydrological Regimes

2021 ◽  
Vol 9 ◽  
Author(s):  
Yin Fang ◽  
Guopei Huang ◽  
Yingjun Chen ◽  
Limin Hu ◽  
Jun Lin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Sampling Period ◽  
Climatic Conditions ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Sampling Campaign ◽  
Bottom Waters ◽  
Global Carbon ◽  
Hydrological Regimes

Coastal seas, including coastal bays, are the geographically critical transitional zone that links terrestrial and open oceanic ecosystems. Organic carbon cycling in this area is a dynamic and disproportionally key component in the global carbon cycle and budget. As the thermally-transformed organic carbon produced exclusively from the incomplete combustion of biomass and fossil fuels, the recalcitrance and resultant longer environmental residence times result in important implications of black carbon (BC) in the global carbon budget. However, the environmental dynamics of BC in coastal seas have not well been constrained. In this study, we conducted one seawater sampling campaign in the high-intensity BC emission influenced Bohai Bay (BHB) and Laizhou Bay (LZB) in 2013, and quantified both particulate and dissolved BC (PBC and DBC). We elaborated the distributions, sources, and associated influencing factors of PBC and DBC in BHB and LZB in 2013, and simultaneously contrasted the PBC and DBC quantity and quality under two distinct fluvial hydrological regimes of 2013 and 2014 [discussed in Fang et al. (Environ. Sci. Technol., 2021, 55, 788–796)]. Except for the overwhelmingly high PBC in northern BHB caused by anthropogenic point-source emission, horizontally, both PBC and DBC showed a seaward decreasing trend, suggesting that riverine discharge was the major source for PBC and DBC. Vertically, in contrast to the uniform concentrations of DBC between surface and bottom waters, the PBC levels in bottom waters was significantly higher than that in surface waters, which was primarily resulted from the intense sediment re-suspension process during this sampling period. The nearly simultaneous investigations in 2013 and 2014 revealed consistent spatial patterns of PBC and DBC quantity and quality. But significantly lower PBC and DBC quantity and quality were found in 2014 than in 2013, which were largely due to the significantly different climatic conditions (including the watershed hydrology and sunlit radiation) between these 2 years.

Extrakorporális és intrakorporális anasztomózis rövid távú eredményeinek összehasonlítása malignus daganat miatt végzett laparoszkópos jobb oldali hemikolektómia esetén

2020 ◽  
Vol 73 (4) ◽  
pp. 148-152
Author(s):  
Kornél Vajda ◽  
László Sikorszki
Keyword(s):  
Length Of Stay ◽  
Gold Standard ◽  
Average Length ◽  
Colon Surgery ◽  
Right Hemicolectomy ◽  
Malignant Tumours ◽  
Short Term ◽  
Significant Difference ◽  
Laparoscopic Assisted ◽  
Laparoscopic Hemicolectomy

Összefoglaló. Bevezetés: A laparoszkópia térhódítása a jobb oldali colon műtéteknél is nyilvánvaló. Ma legtöbb helyen a laparoszkóposan asszisztált jobb oldali hemikolektómia extrakorporális anasztomózissal a gold standard. A morbiditás randomizált vizsgálatok alapján még 30% körüli. A technikai fejlődés lehetővé tette az intrakorporális anasztomózist. Célkitűzés: Retrospektív módon elemezni rosszindulatú jobb oldali vastagbéldaganat miatt végzett laparoszkópos hemikolektómiák rövid távú eredményeit a két módszer összehasonlításával. Eredmények: 2018. 01. 01. – 2019. 12. 31. között 184 jobb oldali hemikolektómiát végeztünk, ezek közül 122 történt malignus betegség miatt. 51 esetben nyitott és 71 esetben laparoszkópos műtét történt. 37 férfi (átlagéletkor: 70,59 év) és 34 nő (átlagéletkor: 72,14 év) volt. 50 esetben extrakorporális (EA) és 21 esetben pedig intrakorporális anasztomózist (IA) végeztünk. Az EA csoportban 18, míg az IA csoportban 3 szövődmény alakult ki 30 napon belül (p = 0,067). Az EA csoportból 3, az IA csoportból 1 beteget veszítettünk el 30 napon belül (p = 0,66). Az átlagos ápolási idő az EA csoportban 9,48 (5–32) nap, míg az IA csoportban 6,52 (4–19) nap volt (p = 0,001) a szövődményes esetekkel együtt. A szövődményes esetek nélkül az EA csoportban 6,35 (5–10) nap, az IA csoportban pedig 5,55 (4–8) napnak bizonyult (p = 0,09). A műtéti idő pedig az EA csoportban 147 (90–240) perc, az IA csoportban pedig 146,47 (90–265) perc volt (p = 0,11). Konklúzió: Az irodalommal összhangban azt találtuk, hogy IA esetén kevesebb a szövődmény, ezzel is összefüggésben rövidebb az átlagos ápolási idő, és a műtéti időt tekintve nincs szignifikáns különbség. Ezeket figyelembe véve az intrakorporális anasztomózis javasolható jobb oldali laparoszkópos hemikolektómia esetén. Summary. Introduction: Laparoscopy became evident for right-sided colon surgery too. Today the laparoscopic-assisted right-hemicolectomy is the gold standard with extracorporeal anastomosis. Morbidity according to randomized trials is still approximately 30%. The development of the surgical technique resulted in the creation of intracorporeal anastomosis. Our aim was to compare the short-term results of the two methods. Aim: To analyse the short-term results of right-sided hemicolectomy that were performed due to malignant tumours with the comparison of the two methods. Results: A cohort of 184 right-sided hemicolectomy were performed from 01.01.2018 to 31.12.2019 from which 122 were operated on because of a malignant disease. 51 open and 71 laparoscopic operations were performed. The average age of 37 men and 34 women were 70.59 and 72.14 years, respectively. 50 patients underwent extracorporeal (EA) anastomosis and 21 intracorporeal (IA) anastomosis. Within 30 days the number of complications were 18 in the EA group and 3 in the IA group (p = 0.067). 3 from the EA group and 1 from IA group died within 30 days (p = 0.66). The average length of stay were 9.48 days in the EA group and 6.52 days in the IA group together with the complicated cases (p = 0.001) while 6.35 days and 5.55 days without the complicated cases (p = 0.09). The average duration of operation was 147 minutes in the EA and 146.47 minutes in the IA group (p = 0.11). Conclusion: We found concordance with the literature that there are fewer complications in case of IA which might be related to shorter length of stay. There is no significant difference between the surgical times. Bearing these facts in mind, IA might be suggested for right- sided laparoscopic hemicolectomy.

Effect of short-term use of oral contraceptive pills on intraocular pressure

2020 ◽  
Vol 35 (3) ◽  
Author(s):  
Tayyaba Gul Malik ◽  
Hina Nadeem ◽  
Eiman Ayesha ◽  
Rabail Alam
Keyword(s):  
Oral Contraceptive ◽  
Childbearing Age ◽  
Short Term ◽  
Oral Contraceptive Pills ◽  
Contraceptive Pills ◽  
Time Period ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Short Time

Objective: To study the effect of short-term use of oral contraceptive pills on intra-ocular pressures of women of childbearing age.   Methods: It was a comparative observational study, conducted at Arif memorial teaching hospital and Allied hospital Faisalabad for a period of six months. Hundred female subjects were divided into two groups of 50 each. Group A, included females, who had been taking oral contraceptive pills (OCP) for more than 6 months and less than 36 months. Group B, included 50 age-matched controls, who had never used OCP. Ophthalmic and systemic history was taken. Careful Slit lamp examination was performed and intraocular pressures (IOP) were measured using Goldman Applanation tonometer. Fundus examination was done to rule out any posterior segment disease. After collection of data, we analyzed and compared the intra ocular pressures between the two groups by using ANOVA in SPSS version 21.   Results: Average duration of using OCP was 14.9 months. There was no significant difference of Cup to Disc ratios between the two groups (p= 0.109). However, significant difference was noted between the IOP of OCP group and controls. (p=0.000). Conclusion: OCP significantly increase IOP even when used for short time period.

Evaluating ozone dose for AOC removal in two-step GAC filters

1998 ◽  
Vol 37 (9) ◽  
pp. 113-120 ◽  
Author(s):  
R. Vahala ◽  
T. Ala-Peijari ◽  
J. Rintala ◽  
R. Laukkanen
Keyword(s):  
Activated Carbon ◽  
Organic Carbon ◽  
Second Step ◽  
Humic Lake ◽  
Short Term ◽  
Feasible Method ◽  
Assimilable Organic Carbon ◽  
Water Treatment Plants ◽  
Ozone Dose ◽  
Ozonated Water

Upgrading an existing post-ozonation plant with two-step granular activated carbon (GAC) filtration for assimilable organic carbon (AOC) removal was studied. The effects of ozone dose on AOC formation and its removal in the subsequent two-step GAC filtration was studied using chemically pretreated 2 to 14° C humic lake water. Two parallel pilot-plant trains with different ozone doses (0 to 1.2 mgO3/mgTOC) and a short-term ozonation study were performed. The optimum ozone dose for maximum AOC formation was 0.4–0.5 mgO3/mgTOC. The AOC-P17 of ozonated water was three-fold higher and AOC-NOX over ten-fold higher than in non-ozonated water, while the following biofiltration (first step) removed 51% and 72% of AOC-P17 and AOC-NOX, respectively. The adsorber (second step) contributed to less than 10% of the overall AOC reduction. It appeared that biofiltration is a feasible method in upgrading water treatment plants for AOC removal even when treating cold humic waters, while the subsequent adsorber seems to have less significance for AOC removal.

T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study

2020 ◽  
Vol 16 (2) ◽  
pp. 164-173
Author(s):  
Zeineb Tbini ◽  
Mokhtar Mars ◽  
Mouna Bouaziz
Keyword(s):  
Relaxation Time ◽  
Achilles Tendon ◽  
Clinical Score ◽  
3 Tesla ◽  
Acquisition Time ◽  
Short Term ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Spin Echo Sequence ◽  
Significant Difference

Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.

The Short-Term and Long-Term Impacts of Sarbanes-Oxley Act on Composition and Characteristics of Corporate Board of Directors

2015 ◽  
Vol 5 (4) ◽  
Author(s):  
Halil Kaya ◽  
Gaurango Banerjee
Keyword(s):  
Board Composition ◽  
Corporate Boards ◽  
Corporate Accountability ◽  
Corporate Board ◽  
Short Term ◽  
Dual Roles ◽  
Board Characteristics ◽  
Sarbanes Oxley ◽  
Over Time

The paper examines the Sarbanes-Oxley (2002) Acts immediate impact on board composition and characteristics as well as possible reversals in its impact over time. Effects on directors age and tenure are analyzed over the 2001-06 sample period. Female participation in corporate boards is also studied in the pre-SOX and post-SOX periods. The dual roles of directors in being a member of the board as well as serving as either CEO, CFO, Chairman, Co-Chair, Founder, or Lead Director of their respective companies is also examined. We observe a short-term impact of SOX on board compositions due to changes seen in board characteristics between 2001 (pre-SOX), and 2003-05 short-term period (post-SOX). Also, we observe a reversal of board characteristics in 2006 to pre-SOX levels implying that the effects of SOX on board composition were short-lived, and needs to be monitored over time to ensure adherence to corporate accountability guidelines over the long-term.

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