Micromeasurement of total and regional CO2 productions in the one-day-old chick embryo.

A conductometric micromethod combined with image analysis system has been developed allowing to determine the CO2 production within 'two-dimensional' tissues, i.e., flat and thin cell layers or epithelial sheets. The preparation was mounted into an airtight chamber separated in two compartments by a thin silicone membrane permeable to gases. The lower compartment contained the nutritive medium and the preparation. The upper compartment and a conductivity measuring capillary connected in series were perfused with a solution of Ba(OH)2. The CO2 produced by the tissue precipitated as BaCO3 and the resulting decrease of electrical conductivity was linearly related to the total CO2 production. In addition, the pattern of CO2 production was directly observable as the BaCO3 crystals formed upon the silicone membrane over the regions which produced CO2. The spatial distribution of the crystals was quantified by video image processing and the regional CO2 production evaluated with a spatial resolution of 100 microns. This new microtechnique was originally developed to study the CO2 production in the early chick blastoderm which is a disc 1-5 cells thick. At the stage of young neurula the CO2 production was found to be 235 +/- 37 nmol.h-1 (mean +/- SD; n = 10) per blastoderm and large variations of local CO2 production were detected from one region to another (from 0.6 to 6.5 nmol.h-1.mm-2). These results indicate a high metabolic and functional differentiation of cells within the blastoderm. The possible applications and improvements of such a microtechnique are discussed.

Controls on 13C and 14C variability in soil CO2

14C dating of groundwater depends on the isotopic composition of both the solid carbonate and the soil CO2 and requires the use of 14C age correction models. To better assess the variability of the 14C activity of soil CO2 (A14Csoil-CO2) and the δ13C of soil CO2 (δ13Csoil-CO2), which are two parameters used in 14C age correction models, we studied the different processes involving carbon isotopes in the soil. The approach used experimental data from two sites in France (Fontainebleau sands and Astian sands) and a steady-state transport model. In most cases, the 14C activity (A14C) of atmospheric CO2 is directly used in the 14C age correction models as the A14Csoil-CO2. However, we demonstrate that since 1950, the evolution of the A14Csoil-CO2 reflects the competition between the fluxes of root-derived CO2 and organic matter-derived CO2. Therefore, the A14Csoil-CO2 must be used to date groundwater that is younger than 60 years old. Moreover, the δ13C of soil CO2 (δ13Csoil-CO2) showed large seasonal variations that must be taken into account in selecting the δ13Csoil-CO2 for 14C age correction models.

CO2 Laser Cutting of Particleboard, HDF and MDF

The purpose of this thesis is to reveal how the laser cutting parameters influence lasercutting of particleboard, HDF and MDF. The literature review introduces the basic principle of CO2 laser, CO2 laser equipment and its usage in cutting of wood-based materials. The experimental part focuses on the discussion and analysis ofthe test data and attempts to draw conclusions on the influence of various parameters, including laser power, focal length of the lens and cutting gas, on the cutting speed and kerf quality. The tested materials include various thicknesses of particleboard, HDF and MDF samples. A TRUMPF TLF2700 HQ laser equipment was used for the experiments. To obtain valid data, the test samples must be completely cut through without any bonding of wood fibre. The maximum cutting speed is linear dependent on the laser power in thecondition that the other parameters are constant. For each thickness of a specific material type, there is a minimum laser power for cutting. Normally, the topand bottom kerf widths increase with the enhancement of laser power. There may be a critical laser power which can generate the minimum cross-sectional kerf width. Lens of larger focal length may achieve higher cutting speed. As the focal length becomes larger, the top kerf width tends to increase while the bottom andcross-sectional kerf widths to the opposite. Of all cutting gases, oxygen can help achieve higher cutting speed. The gas pressure of nitrogen does not seem to have strong influence on the cutting result. Generally, 2 bar air is more preferable for higher cutting speed. For particleboard and MDF samples of larger thickness than 12 mm, 2 bar argon can be used to reach remarkably higher cutting speed than the 5 bar. Generally, the 190.5 mm lens can produce smallest total kerf width. The kerf sides of thicker samples are darker than the thinner ones. The sample darkness tends to be lower as laser power increased. 63.5 mm lens seemed tocause more darkness than other lens. 5 bar cutting gases can produce less dark side kerfs than 2 bar ones. Oxygen normally causes darker kerfs than other gases. No distinct differences were found between nitrogen and argon.

CO2:n käyttö puhdistuksessa ja inerttinä kaasuna öljynjalostusympäristössä

Tutkimuksen tavoitteena on löytää CO2:lle puhdistus- ja inertointikohteita öljynjalostusympäristöstä. CO2:na käytettäisiin Porvoon vetylaitokselta sivutuotteena tulevaa CO2:a. Vetylaitokselta saatava CO2-virta ei ole riittävän puhdasta käytettäväksi suoraan pesuissa ja inertoinnissa. CO2:n eri olomuotoja voidaan käyttää puhdistuksessa. Tutkimuksen lähtökohtana olleen ylikriittisen CO2:n tehokkuus perustuu sen liuottavuuteen. Huonosti liukenevien aineiden liukoisuus ylikriittiseen CO2:in paranee lisäaineiden ja pinta-aktiivisten aineiden käytöllä. Kiinteä CO2 jäädyttää ja poistaa epäpuhtauden sublimoitumisesta aiheutuvan paineaallon voimasta. Kuivajääpuhdistus soveltuu parhaiten tasaisten pintojen puhdistamiseen. Ylikriittisellä CO2:lla onnistuu nykyisellä teknologialla vain pienien kappaleiden puhdistaminen. Kuivajääpuhdistuksen toimivuutta kokeiltiin käytännössä Neste Oilin Porvoon jalostamolla hyvin tuloksin. Tasaisilta pinnoilta saatiin poistetuksi bitumia ja rasvakerros. Käyttökustannusvertailussa osoittautui ylikriittistä CO2:a käyttävä laitteisto halvemmaksi ja kuivajääpuhallus kalliimmaksi kuin konventionaaliset menetelmät. Säiliöiden paineistamiseen ja inertointiin käytetään yleisesti N2:ä. N2:llä inertoitavia kohteita voitaisiin korvata CO2:lla. CO2:n käyttöä rajoittavia seikkoja on hinta ja sen reaktiivisuus alkalimetallien kanssa. Vertailtaessa näiden kahden liukoisuuksia hiilivetyihin osoittautui CO2 monin kerroin liukoisemmaksi. Tämän ominaisuuden ansiosta CO2 voisi olla hyvä väliaine laitteiden hiilivetyvapaaksi saattamisessa.

Fertilidade do solo e estado nutricional do cafeeiro cultivado em atmosfera enriquecida com CO2

Resumo: O objetivo deste trabalho foi avaliar os efeitos de concentrações de CO2 atmosférico nos atributos químicos do solo, na linha (cafeeiro) e na entrelinha (braquiária), e nos teores de macronutrientes em folhas do cafeeiro. Utilizou-se o delineamento de blocos ao acaso, com parcelas subdivididas e seis repetições. Os tratamentos consistiram de dois níveis de CO2 atmosférico, 390 e 550 μmol mol-1. A amostragem de solo foi realizada na linha e na entrelinha do cafeeiro, em 2013 e 2014, nas camadas de 0-5,0, 5,0-10, 10-20 e 20-40 cm, e de 0-10, 10-20 e 20-40 cm, respectivamente. Avaliaram-se pH, teores de Ca2+, Mg2+, K, P e S disponíveis, saturação por bases e matéria orgânica do solo. Em 2013 e 2014, houve redução nos teores de P na linha do cafeeiro, com o aumento da concentração de CO2. Em 2014, houve redução nos teores de K disponível no solo e aumento dos teores de K na folha do cafeeiro sob 550 μmol mol-1 de CO2. Em cafeeiro cultivado em atmosfera enriquecida com CO2, o teor de P disponível no solo é o que mais reduz, o que indica a necessidade de reposição adequada deste nutriente.

CO2-laserin soveltaminen WFU-paperin reunan leikkaamiseen

Tämän diplomityön tarkoitus oli selvittää CO2-laserin soveltuvuutta paperin reunan leikkaamiseen ennen liimapuristinta nopealle modernilleWFU-paperikoneelle. Merkittävimmät leikkauskokeet tehtiin leikkaamalla paperirataa todenmukaisissa olosuhteissa koekoneella. Koeleikkauksissa tutkittiin myös päällystettyjen paperilajien CO2-laserleikkausta. Paperin reunan koeleikkauksia suoritettiin leikkauspöytää vasten sekä telaa vasten. Leikkauspöytänä käytettiin korkeapainevesileikkaimelle suunniteltua leikkauspöytää, jota paranneltiin tämän työn yhteydessä paremmin laserleikkaukselle sopivaksi. Telaa vasten suoritetuilla leikkauksilla lasertehon tarve oli suurempi verrattuna pöytää vasten leikkaukseen samalla leikkausnopeudella ja samalla paperilajilla. Laserlaitteiston mitoittaminen oikein pelkkien arkkileikkauskokeiden perusteella ei ollut mahdollista. Myös rullilla tapahtuvia leikkauskokeita tarvittiin. Pöytää vasten tapahtuvaan leikkaamiseen tarvitaan 1000 W laserlaite paperin molemmille reunoille. Tämän tehoiset laserlaitteet riittävät kaikille Changshun PK 1:n paperilajeille niiden lajikohtaiseen maksimiajonopeuteen. Testatuista kolmesta polttovälistä antoi 5" polttoväli parhaat leikkaustulokset. Polttopisteen paikka voi vaihdella ± 0.75 mm paperin pinnasta vaikuttamatta silti merkittävästi lasertehon tarpeeseen. Laserleikatun paperin reuna oli hyvälaatuinen, eikä laserleikkaus aiheuttanut paperille epätoivottuja asioita kuten mustumista.

The Effect of Adding CO2 to Hypoxic Inspired Gas on Cerebral Blood Flow Velocity and Breathing during Incremental Exercise

Hypoxia increases the ventilatory response to exercise, which leads to hyperventilation-induced hypocapnia and subsequent reduction in cerebral blood flow (CBF). We studied the effects of adding CO2 to a hypoxic inspired gas on CBF during heavy exercise in an altitude naïve population. We hypothesized that augmented inspired CO2 and hypoxia would exert synergistic effects on increasing CBF during exercise, which would improve exercise capacity compared to hypocapnic hypoxia. We also examined the responsiveness of CO2 and O2 chemoreception on the regulation ventilation (E) during incremental exercise. We measured middle cerebral artery velocity (MCAv; index of CBF), E, end-tidal PCO2, respiratory compensation threshold (RC) and ventilatory response to exercise (E slope) in ten healthy men during incremental cycling to exhaustion in normoxia and hypoxia (FIO2 = 0.10) with and without augmenting the fraction of inspired CO2 (FICO2). During exercise in normoxia, augmenting FICO2 elevated MCAv throughout exercise and lowered both RC onset andE slope below RC (P<0.05). In hypoxia, MCAv and E slope below RC during exercise were elevated, while the onset of RC occurred at lower exercise intensity (P<0.05). Augmenting FICO2 in hypoxia increased E at RC (P<0.05) but no difference was observed in RC onset, MCAv, or E slope below RC (P>0.05). The E slope above RC was unchanged with either hypoxia or augmented FICO2 (P>0.05). We found augmenting FICO2 increased CBF during sub-maximal exercise in normoxia, but not in hypoxia, indicating that the 'normal' cerebrovascular response to hypercapnia is blunted during exercise in hypoxia, possibly due to an exhaustion of cerebral vasodilatory reserve. This finding may explain the lack of improvement of exercise capacity in hypoxia with augmented CO2. Our data further indicate that, during exercise below RC, chemoreception is responsive, while above RC the ventilatory response to CO2 is blunted.

Emissão de etileno e de CO2 em mamão 'Sunrise Solo' e 'Golden'

Frutos de mamoeiro 'Sunrise Solo' e 'Golden' foram armazenados a 10º C e a 25º C e monitorados diariamente quanto às emissões de CO2 e de C2H4, observando-se a evolução do índice de cor de casca. A não-alteração do índice de cor de casca, ao longo dos 20 dias de conservação a 10º C, refletiu a influência da refrigeração na retenção do metabolismo dos mamões. Houve dois incrementos da respiração e da emissão de etileno, no quarto dia e entre o oitavo e o nono dia, nos frutos armazenados a 25º C. A temperatura de 10º C deteve a respiração climatérica do mamão e a emissão de etileno, comprovando que o seu metabolismo se reduz, permitindo que os frutos apresentem aspecto imaturo após 20 dias de armazenamento.

Short communication. Potential to mitigate anthropogenic CO2 emissions by tillage reduction in dryland soils of Spain

Spain is one of the countries with the highest greenhouse gas (GHG) emissions within the EU-27. Consequently, mitigation strategies need to be reported and quantified to accomplish the goals and requirements of the Kyoto Protocol. In this study, a first estimation of the carbon (C) mitigation potential of tillage reduction in Mediterranean rainfed Spain is presented. Results from eight studies carried out in Spain under rainfed agriculture to investigate the effects of no-tillage (NT) and reduced tillage (RT) compared with conventional tillage (CT) on soil organic carbon (SOC) were used. For current land surface under conservation tillage, NT and RT are sequestering 0.14 and 0.08 Tg C yr-1, respectively. Those rates represent 1.1% and 0.6% of the total CO2 emissions generated from agricultural activities in Spain during 2006. Alternatively, in a hypothetical scenario where all the arable dryland was under either NT or RT management, SOC sequestration would be 2.18 and 0.72 Tg C yr-1 representing 17.4% and 5.8% of the total 2006 CO2 equivalent emissions generated from the agricultural sector in Spain. This is a significant estimate that would help to achieve GHG emissions targets for the current commitment period of the Kyoto Protocol.

Does ear C sink strength contributes to the overcoming of photosynthetic acclimation of wheat plants exposed to elevated CO2?

Wheat plants (Triticum durum Desf., cv. Regallo) were grown in the field to study the effects of contrasting [CO2] conditions (700 versus 370 μmol mol−1) on growth, photosynthetic performance, and C management during the post-anthesis period. The aim was to test whether a restricted capacity of sink organs to utilize photosynthates drives a loss of photosynthetic capacity in elevated CO2. The ambient 13C/12C isotopic composition (δ13C) of air CO2 was changed from-10.2 in ambient [CO2] to-23.6 under elevated [CO2] between the 7th and the 14th days after anthesis in order to study C assimilation and partitioning between leaves and ears. Elevated [CO2] had no significant effect on biomass production and grain filling, and caused an accumulation of C compounds in leaves. This was accompanied by up-regulation of phosphoglycerate mutase and ATP synthase protein content, together with down-regulation of adenosine diphosphate glucose pyrophosphatase protein. Growth in elevated [CO2] negatively affected Rubisco and Rubisco activase protein content and induced photosynthetic down-regulation. CO2 enrichment caused a specific decrease in Rubisco content, together with decreases in the amino acid and total N content of leaves. The C labelling revealed that in flag leaves, part of the C fixed during grain filling was stored as starch and structural C compounds whereas the rest of the labelled C (mainly in the form of soluble sugars) was completely respired 48 h after the end of labelling. Although labelled C was not detected in the δ13C of ear total organic matter and respired CO2, soluble sugar δ13C revealed that a small amount of labelled C reached the ear. The 12CO2 labelling suggests that during the beginning of post-anthesis the ear did not contribute towards overcoming flag leaf carbohydrate accumulation, and this had a consequent effect on protein expression and photosynthetic acclimation.

Qualidade de caqui 'Rama forte' após armazenamento refrigerado, influenciada pelos tratamentos 1-MCP e/ou CO2

Avaliaram-se os efeitos dos tratamentos com CO2 e 1-MCP (1-metilciclopropeno) sobre a adstringência (índice de tanino), firmeza da polpa e distúrbios da epiderme em caqui 'Rama Forte'. Frutos foram tratados com 1-MCP por 24 h, logo após a colheita e/ou com alto CO2 (70%) por 24 ou 48 h, um dia após a colheita ou após o armazenamento refrigerado (AR). Os caquis foram armazenados sob atmosfera modificada a 0 ºC, por 45 dias, e a seguir mantidos a 23 ºC, por 9 dias. Frutos-controle (não tratados com 1-MCP nem com CO2) amoleceram em três dias e perderam aproximadamente 50% da adstringência em 6 dias após o AR. A exposição ao CO2 acelerou a redução da adstringência. Esse efeito do CO2 foi menor em frutos tratados com 1-MCP, especialmente quando o CO2 foi aplicado após o AR, por apenas 24 h. O tratamento com 1-MCP inibiu o amolecimento e a redução da adstringência, especialmente nos frutos não tratados com CO2. O amolecimento de frutos tratados com 1-MCP foi maior quando a exposição ao CO2 ocorreu antes do AR. A combinação dos tratamentos com 1-MCP e alto CO2 reduziu a incidência de podridões e manchas translúcidas, mas não alterou o desenvolvimento de pintas pretas ('estrias'). Os resultados indicam que é possível induzir perda da adstringência sem excessiva perda da firmeza da polpa de caquis 'Rama Forte' após o AR pela associação dos tratamentos com 1-MCP logo após a colheita e alto CO2 após o AR.

CO2-päästötaseenhallinta terästeollisuudessa

Tämän diplomityön tavoitteena oli kehittää hiilidioksiditaseen hallintamenetelmää Rautaruukin toiminnoille päästökaupan olosuhteissa. Taseenhallintamenetelmä sisältää päästöjen laskennan sekä päästöoikeuksien hallintaan liittyviä asioita. EU:n laajuisen päästökaupan reunaehdot määrittelee päästökauppadirektiivi ja sen antama päästöjen seurantaa ja raportointia koskeva monitorointiohje. Työssä on tarkasteltu hiilidioksidipäästöhistoriaa ja laskentamenetelmiä niiden Rautaruukin toimipaikkojen kohdalta, joiden oletetaan kuuluvan EU:n päästökaupan piiriin. Toimipaikoista on tarkasteltu erityisesti Raahen ja Koverharin terästehtaita, sillä ne muodostavat merkittävimmän osuuden konsernin Suomen toimipaikkojen hiilidioksidipäästöistä. Muita tarkasteltavia toimipaikkoja ovat Hämeenlinnan ja Dalsbrukin valssaamot Suomessa, Smedjebackenin terästehdas ja Boxholmin valssaamo Ruotsissa, Mo i Ranan terästehdas ja Profilerin valssaamo Norjassa sekä Nedstaalin valssaamo Hollannissa. Kustannustehokkaan ja hallitun päästökaupankäynnin perustaksi yritystasolla tarvitaan päästötaseenhallintamenetelmä, jonka avulla voidaan määrittää syntyneet päästöt komission monitorointiohjeen vaatimalla tavalla, arvioida tulevia päästömääriä sekä hallita päästökaupankäyntiä. Päästökaupanhallintaan sisältyviä asioita ovat saadut ilmaiset päästöoikeudet, ostettavien tai myytävien oikeuksien määrä, kaupankäynnin ajankohta, päästöoikeuksien erilaiset hankintamahdollisuudet, päästöoikeuksien hinnanmuodostus ja riskienhallinta.

Probabilistic electrical resistivity tomography of a CO2 sequestration analog

Electrical resistivity tomography (ERT) is a well-established method for geophysical characterization and has shown potential for monitoring geologic CO2 sequestration, due to its sensitivity to electrical resistivity contrasts generated by liquid/gas saturation variability. In contrast to deterministic inversion approaches, probabilistic inversion provides the full posterior probability density function of the saturation field and accounts for the uncertainties inherent in the petrophysical parameters relating the resistivity to saturation. In this study, the data are from benchtop ERT experiments conducted during gas injection into a quasi-2D brine-saturated sand chamber with a packing that mimics a simple anticlinal geological reservoir. The saturation fields are estimated by Markov chain Monte Carlo inversion of the measured data and compared to independent saturation measurements from light transmission through the chamber. Different model parameterizations are evaluated in terms of the recovered saturation and petrophysical parameter values. The saturation field is parameterized (1) in Cartesian coordinates, (2) by means of its discrete cosine transform coefficients, and (3) by fixed saturation values in structural elements whose shape and location is assumed known or represented by an arbitrary Gaussian Bell structure. Results show that the estimated saturation fields are in overall agreement with saturations measured by light transmission, but differ strongly in terms of parameter estimates, parameter uncertainties and computational intensity. Discretization in the frequency domain (as in the discrete cosine transform parameterization) provides more accurate models at a lower computational cost compared to spatially discretized (Cartesian) models. A priori knowledge about the expected geologic structures allows for non-discretized model descriptions with markedly reduced degrees of freedom. Constraining the solutions to the known injected gas volume improved estimates of saturation and parameter values of the petrophysical relationship. (C) 2014 Elsevier B.V. All rights reserved.