Mitigation of methane and nitrous oxide emissions from flood-irrigated rice by no incorporation of winter crop residues into the soil

Winter cover crops are sources of C and N in flooded rice production systems, but very little is known about the effect of crop residue management and quality on soil methane (CH4) and nitrous oxide (N2O) emissions. This study was conducted in pots in a greenhouse to evaluate the influence of crop residue management (incorporated into the soil or left on the soil surface) and the type of cover-crop residues (ryegrass and serradella) on CH4 and N2O emissions from a flooded Albaqualf soil cultivated with rice (Oryza sativa L.). The closed chamber technique was used for air sampling and the CH4 and N2O concentrations were analyzed by gas chromatography. Soil solution was sampled at two soil depths (2 and 20 cm), simultaneously to air sampling, and the contents of dissolved organic C (DOC), NO3-, NH4+, Mn2+, and Fe2+ were analyzed. Methane and N2O emissions from the soil where crop residues had been left on the surface were lower than from soil with incorporated residues. The type of crop residue had no effect on the CH4 emissions, while higher N2O emissions were observed from serradella (leguminous) than from ryegrass, but only when the residues were left on the soil surface. The more intense soil reduction verified in the deeper soil layer (20 cm), as evidenced by higher contents of reduced metal species (Mn2+ and Fe2+), and the close relationship between CH4 emission and the DOC contents in the deeper layer indicated that the sub-surface layer was the main CH4 source of the flooded soil with incorporated crop residues. The adoption of management strategies in which crop residues are left on the soil surface is crucial to minimize soil CH4 and N2O emissions from irrigated rice fields. In these production systems, CH4 accounts for more than 90 % of the partial global warming potential (CH4+N2O) and, thus, should be the main focus of research.

Nonrelativistic bound states at finite temperature. II. Muonic hydrogen

We illustrate how to apply modern effective field-theory techniques and dimensional regularization to factorize the various scales, which appear in QED bound states at finite temperature. We focus here on the muonic hydrogen atom. Vacuum polarization effects make the physics of this atom at finite temperature very close to that of heavy quarkonium states. We comment on the implications of our results for these states in the quark gluon plasma. In particular, we estimate the effects of a finite-charm quark mass in the dissociation temperature of bottomonium.

Calorimetry of hydrogen desorption from a-Si nanoparticles

The process of hydrogen desorption from amorphous silicon (a-Si) nanoparticles grown by plasma-enhanced chemical vapor deposition (PECVD) has been analyzed by differential scanning calorimetry (DSC), mass spectrometry, and infrared spectroscopy, with the aim of quantifying the energy exchanged. Two exothermic peaks centered at 330 and 410 C have been detected with energies per H atom of about 50 meV. This value has been compared with the results of theoretical calculations and is found to agree with the dissociation energy of Si-H groups of about 3.25 eV per H atom, provided that the formation energy per dangling bond in a-Si is about 1.15 eV. It is shown that this result is valid for a-Si:H films, too.

Debris Mitigation Methods for Bridge Piers, Final Repory, June 2012

Debris accumulation on bridge piers is an on-going national problem that can obstruct the waterway openings at bridges and result in significant erosion of stream banks and scour at abutments and piers. In some cases, the accumulation of debris can adversely affect the operation of the waterway opening or cause failure of the structure. In addition, removal of debris accumulation is difficult, time consuming, and expensive for maintenance programs. This research involves a literature search of publications, products, and pier design recommendations that provide a cost effective method to mitigate debris accumulation at bridges. In addition, a nationwide survey was conducted to determine the state-of-the-practice and the results are presented within.

Hydrogen isotope fractionations between amphiboles, micas, and fluids in alkaline igneous intrusions

RÉSUMÉ DE LA THÈSE Les teneurs des amphiboles en éléments majeurs et en isotopes stables ont été analysées dans plusieurs complexes ignés alcalins et hyperalcalins, dans le but de déterminer l'importance des variations de composition des minéraux pour le fractionnement isotopique de l'hydrogène dans un système naturel minéral-magma-fluide. Cette étude se concentre principalement sur les syénites néphéliniques de complexes intrusifs alcalins bien connus mais à chimie variable, dont les amphiboles, ainsi que d'autres silicates hydratés tels que micas et eudialytes, lorsque cela était possible, ont été séparés. L'intérêt principal s'est porté sur le complexe alcalin d'Ilímaussaq de la Province du Gardar, au Sud du Groenland. Dans une optique de comparaison, nous avons collecté et analysé d'autres échantillons provenant du complexe de Tugtutôq (Sud Groenland), des complexes de Khibina et Lovozero (Péninsule de Kola, Russie), du Mont St-Hilaire et du Mont Royal (Canada) et de 6 autres du nord-ouest de la Namibie (Cape Cross, Okenyenya, Messum, Etaneno, Kalkfeld,et Okorusu). Les compositions isotopiques de l'hydrogène des amphiboles des ces différentes zones présentent de grandes variations (-227 à -700/00), ce qui est atypique pour des magmas d'origine mantellique. Les valeurs comprises entre -80 et -400/00 indiquent une provenance du manteau. Ces larges variations de compositions ainsi que l'extrême appauvrissement en isotope lourd de l'hydrogène (D), en comparaison avec d'autres roches ignées, semblent être propres.aux roches alcalines et hyperalcalines de ce type, ce qui indiquerait un processus commun. Les différents complexes alcalins choisis présentent un large intervalle de composition chimique des amphiboles. La caractérisation des amphiboles par microscopie électronique et par spectroscopie Mössbauer contribuent à observer le contrôle du Fe sur le fractionnement des isotopes de l'hydrogène. En effet, cela a mis en évidence un contrôle du Fe sur le fractionnement et même, dans le cas du complexe hyperalcalin d'Ilímaussaq, une relation entre le rapport Fei3+/FeT et les variations du rapport D/H. Les complexes étudiés diffèrent de par leur index agpaïtique (Na+K/Al) et également de par leur contenu en fer. Les plus hautes valeurs en Fe (27-35 wt%) et en éléments alcalins dans les amphiboles, ainsi que les teneurs de D/H les plus basses et leur grande variation, sont celles du complexe d'Ilímaussaq. Les amphiboles de la Péninsule de Kola et du Canada sont similaires, mais toutefois moins appauvries en D. En ce qui concerne les amphiboles des complexes du NO de la Namibie, elles présentent des compositions isotopiques de l'hydrogène magmatiques normales (-73 à -100 0/00), contiennent moins de Fe (15-17 wt%) et sont fortement enrichies en Ca et moins en Na. Dans ce cas, l'alcalinité est moins importante en comparaison des autres complexes étudiés. En dehors des teneurs en éléments alcalins des amphiboles, l'alcalinité des fluides s'avère également un facteur important, ce qui est cohérent avec certaines suggestions à partir de systèmes expérimentaux. Afin de mieux contraindre ce facteur, des expériences d'échanges hydrothermaux entre les amphiboles et les fluides de salinité différente ont été effectuées en simulant des conditions naturelles. L'approximation d'amphiboles naturelles de complexes ignés alcalins, couplée aux expériences d'échange, aide à préciser les facteurs contrôlant le fractionnement des isotopes de l'hydrogène dans les roches alcalines. Les valeurs extrêmement basses de 3D des amphiboles de ces complexes alcalins peuvent être dues à une combinaison de différents facteurs, telles qu'une haute alcalinité, une haute teneur en Fe et une faible profondeur d'intrusion. Les grandes variations ainsi que les faibles valeurs de SD des amphiboles étudiées peuvent résulter d'un processus magmatique interne et il est peu probable que de l'eau météorique soit impliquée et/ou que le dégazage magmatique ait joué un rôle. THESIS ABSTRACT Major element and stable isotope compositions of amphiboles were analyzed from a number of alkaline and peralkaline igneous complexes in order to determine the importance of compositional variations in minerals to hydrogen isotope fractionations in natural mineral-melt-fluid systems. The thesis mainly focuses on nepheline syenites of well-studied, but chemically variable alkaline intrusive rocks, from which amphiboles and, if possible, other hydrous silicates such as micas and eudialytes were separated. The system of primary interest was the alkaline Ilímaussaq Complex of the Gardar Province of South Greenland. For the purpose of comparison additional samples were collected and examined from the Tugtutôq Complex (South Greenland), the Khibina and Lovozero Complexes (Kola Peninsular, Russia), Mount St-Hilaire and Mount Royal (Canada) and six further complexes from NW Namibia (Cape Cross, Okenyenya, Messum, Etaneno, Kalkfeld, and Okorusu). The hydrogen isotope compositions of amphiboles from the localities studied differ greatly, which is atypical for amphiboles from mantle, range between - 227 and - 700/00 (latter compatible with a simple mantle origin). As this wide range in compositions and the extreme depletion in the heavy hydrogen isotope (D) content relative to other igneous rocks appear to be unique to alkaline to peralkaline rocks of this type, a common process is indicated. The different alkaline complexes chosen cover a wide range of amphibole chemical compositions. Detailed chemical characterization of amphiboles by electron microprobe and Mössbauer spectroscopy analyses helped to constrain the control of Fe on the H-isotope fractionations. Complete characterization of the chemical compositions of the amphiboles support Fe-control on fractionations and at least for the peralkaline Ilímaussaq complex a relationship between Fe3+/FeT ratios and variations in D/H. The studied complexes differ in their agpaitic index (Na+K/Al) and also in their Fe-content. The most iron (27-35 wt. %) and alkaline element rich amphiboles, with the lowermost D/H ratio, as well with very wide range, are the ones from Ilímaussaq complex. Similar, but less D depleted amphiboles are from the Kola Peninsula and the Canadian localities. The complexes described from NW Namibia have amphiboles with normal magmatic hydrogen isotope composition (-730/00 to -1000/00), and have less Fe-content (15-17 wt. %), and are more Ca-and less Na-rich. In this case alkalinity is not that important in comparison to the other studied complexes. Beside the alkaline element contents in the amphiboles, the alkalinity of the fluids has been found to be an important factor, in conjunction with earlier suggestions from experimental systems. To further constrain this factor, hydrothermal exchange experiments between amphiboles and fluids of different salinity simulating natural conditions were performed. The approach of examining natural amphiboles from alkaline igneous complexes in parallel to performing exchange experiments - helped to further constrain the factors controlling the H-isotope fractionations in alkaline rocks. The observed changes between the hydrogen and oxygen isotope compositions of amphiboles and fluids before and after the experiments suggest that another phase was produced during the experiments, which influenced the final hydrogen isotope composition of the system. This presumably hydrous phase has also influenced the Fe3 +/Fe2+ ratio of the amphiboles, which became more oxidized. The extremely low SD values of amphiboles in these alkaline complexes may be due to a combination of different factors such as high alkalinity, high Fe-content, and shallow intrusion depths. This wide range and the low SD values of the amphiboles studied might be a result of internal, magmatic processes and it is unlikely that meteoric water was involved and/or magmatic degassing played an important role. RÉSUMÉ DE LA THÈSE (pour le grand public) Fractionnement isotopique de l'hydrogène entre amphiboles, micas et fluides dans des intrusions alcalines Zsófia Wáczek Directeur de thèse, Prof. Torsten W. Vennemann Institut de Minéralogie et Géochimie, Université de Lausanne Les roches alcalines et celles qui leurs sont associées sont des sources importantes de nombreux minéraux et minerais, tels l'apatite, le niobium, le diamant et autres pierres précieuses. Cette étude se concentre sur des complexes alcalins localisés dans le sud du Groenland, au Canada, dans la péninsule de Kola en Russie et au nord-ouest de la Namibie. Ces complexes sont composés de roches ayant cristallisé à partir de magmas et de fluides très enrichis en alcalins. Cet enrichissement permet la précipitation de minéraux inhabituels riches en potassium et/ou sodium, telles les amphiboles sodiques, également enrichies en fer. Les amphiboles étudiées ont des compositions calciques, sodi-calciques et sodiques, qui reflètent leurs différents environnements de formation. Des études précédentes ont révélé une large gamme de rapports isotopiques de l'hydrogène dans les amphiboles de roches hyperalcalines, dont certains extrêmement bas. Cette variation importante est très intrigante, sachant que des valeurs entre -40 et -800/00 correspondent à des silicates ignés hydratés et non altérés, alors que des valeurs descendant jusqu'a -1500/00 nécessiteraient une altération par de l'eau météorique et/ou une contamination par les roches environnantes ou des sédiments riches en matière organique. Dans lé cas précis du complexe d'Ilímaussaq (sud du Groenland), aucune de ces explications n'a pu être démontrée et des valeurs encore plus faibles ont été trouvées. Le complexe d'Ilímaussaq présente des valeurs de rapport isotopique de l'hydrogène entre -227 et -500/00 dans les amphiboles. Une origine mantellique permet d'expliquer les valeurs élevées, mais d'autres processus doivent entrer en jeu pour engendrer les valeurs les plus négatives. C'est à l'identification de ces processus que nous nous sommes attachés dans ce travail. Les grandes variations observées dans les teneurs en fer et dans le rapport Fe3+/FeT des roches et des minéraux de ces complexes sont corrélées avec d'autres paramètres chimiques, tels que la composition isotopique de l'hydrogène dans les amphiboles. Nous avons dès lors abordé les questions suivantes: quelle est la relation entre la teneur en fer des amphiboles et leur composition isotopique? Que nous apprennent les changements de la teneur en fer et les changements dans le rapport Fe3+/FeT sur les processus pétrologiques dans ces roches? Pour répondre à ces questions, nous avons analysé les compositions isotopiques de l'oxygène et de l'hydrogène dans les amphiboles et d'autres silicates hydratés. La composition chimique et le rapport Fe3+/FeT des amphiboles ont également été déterminés. Des expériences hydrothermales simulant des conditions naturelles ont été entreprises afin de mieux comprendre les processus de fractionnement isotopiques dans ces systèmes très alcalins. Nos conclusions sont les suivantes: (1) Les valeurs extrêmement faibles ainsi que les larges variations des rapports isotopiques de l'hydrogène des amphiboles de ces complexes alcalins sont dues à une combinaison de facteurs tels que la forte alcalinité, la haute teneur en fer et la profondeur très faible de l'intrusion. (2) Ces valeurs sont probablement le résultat de processus magmatiques internes. (3) Il est peu probable que les eaux météoriques et/ou le dégazage magmatique aient joué un rôle lors de la formation de ces amphiboles. (4) Certaines corrélations, en accord avec les études précédentes, ont pu être trouvées au niveau des concentrations en fer. (5) Dans le cas du complexe d'Ilímaussaq exclusivement, une relation a été trouvée entre le rapport Fe3+/FeT et la composition isotopique de l'hydrogène des amphiboles.

Risk Mitigation Strategies for Operations and Maintenance Activities, Final Report, April 2012

The objective of this research was to investigate the application of integrated risk modeling to operations and maintenance activities, specifically moving operations, such as pavement testing, pavement marking, painting, snow removal, shoulder work, mowing, and so forth. The ultimate goal is to reduce the frequency and intensity of loss events (property damage, personal injury, and fatality) during operations and maintenance activities. This report includes a literature review that identifies the current and common practices adopted by different state departments of transportation (DOTs) and other transportation agencies for safe and efficient highway operations and maintenance (O/M) activities. The final appendix to the report includes information for eight innovative O/M risk mitigation technologies/equipment and covers the following for these technologies/equipment: Appropriate conditions for deployment Performance/effectiveness, depending on hazard/activity Cost to purchase Cost to operate and maintain Availability (resources and references)

Magnesium hydrogen breath test using end-expiratory sampling to assess achlorhydria in pernicious anaemia patients

A modified magnesium hydrogen breath test, using end expiratory breath sampling, is described to investigate achlorhydria. The efficacy of this test in the diagnostic investigation of pernicious anaemia was compared with that of serum pepsinogen I. Twenty one patients with pernicious anaemia--that is, patients with achlorhydria--and 22 with healed duodenal ulcer and normal chlorhydria were studied. Magnesium hydrogen breath test, serum pepsinogen I, serum gastrin, and standard gastric acid secretory tests were performed in all subjects. The mean (SEM) hydrogen peak value was lower in patients with pernicious anaemia than in the duodenal ulcer group (21.7 (1.9) v 71.3 (5.2) ppm; p = 0.00005). The hydrogen peak value had a 95.2% sensitivity and a 100% specificity to detect pentagastrin resistant achlorhydria. Mean serum pepsinogen I concentrations were also significantly lower in patients with pernicious anaemia than in the duodenal ulcer group (10.7 (2.7) v 123.6 (11.8) micrograms/l p = 0.00005). Sensitivity and specificity to detect pernicious anaemia were both 100% for pepsinogen I. It is concluded that this modified magnesium hydrogen breath test is a simple, noninvasive, cost effective, and accurate method to assess achlorhydria and may be useful in the diagnostic investigation of patients with suspected pernicious anaemia.

Nonempirical cluster-model study of the chemisorption of atomic hydrogen on the (111) surface of diamondlike crystals

The interaction of atomic hydrogen with C4H9, Si4H9, and Ge4H9 model clusters has been studied using all-electron and pseudopotential ab initio Hartree-Fock computations with basis sets of increasing flexibility. The results show that the effect of polarization functions is important in order to reproduce the experimental findings, but their inclusion only for the atoms directly involved in the chemisorption bond is usually sufficient. For the systems H-C4H9 and H-Si4H9 all-electron and pseudopotential results are in excellent agreement when basis sets of comparable quality are used. Besides, semiempirical modified-neglect-of-differential-overlap computations provide quite reliable results both for diamond and silicon and have been used to investigate larger model clusters. The results confirm the local nature of chemisorption and further justify the use of minimal X4H9 model clusters.

Combination of carbon isotope ratio with hydrogen isotope ratio determinations in sports drug testing.

Carbon isotope ratio (CIR) analysis has been routinely and successfully applied to doping control analysis for many years to uncover the misuse of endogenous steroids such as testosterone. Over the years, several challenges and limitations of this approach became apparent, e.g., the influence of inadequate chromatographic separation on CIR values or the emergence of steroid preparations comprising identical CIRs as endogenous steroids. While the latter has been addressed recently by the implementation of hydrogen isotope ratios (HIR), an improved sample preparation for CIR avoiding co-eluting compounds is presented herein together with newly established reference values of those endogenous steroids being relevant for doping controls. From the fraction of glucuronidated steroids 5β-pregnane-3α,20α-diol, 5α-androst-16-en-3α-ol, 3α-Hydroxy-5β-androstane-11,17-dione, 3α-hydroxy-5α-androstan-17-one (ANDRO), 3α-hydroxy-5β-androstan-17-one (ETIO), 3β-hydroxy-androst-5-en-17-one (DHEA), 5α- and 5β-androstane-3α,17β-diol (5aDIOL and 5bDIOL), 17β-hydroxy-androst-4-en-3-one and 17α-hydroxy-androst-4-en-3-one were included. In addition, sulfate conjugates of ANDRO, ETIO, DHEA, 3β-hydroxy-5α-androstan-17-one plus 17α- and androst-5-ene-3β,17β-diol were considered and analyzed after acidic solvolysis. The results obtained for the reference population encompassing n = 67 males and females confirmed earlier findings regarding factors influencing endogenous CIR. Variations in sample preparation influenced CIR measurements especially for 5aDIOL and 5bDIOL, the most valuable steroidal analytes for the detection of testosterone misuse. Earlier investigations on the HIR of the same reference population enabled the evaluation of combined measurements of CIR and HIR and its usefulness regarding both steroid metabolism studies and doping control analysis. The combination of both stable isotopes would allow for lower reference limits providing the same statistical power and certainty to distinguish between the endo- or exogenous origin of a urinary steroid.

Evaluation of Mitigation for Safety Concerns on Low-Volume, Unpaved Rural Roads, 2013.

The Institute for Transportation (InTrans) at Iowa State University completed work on an in-depth study of crash history on lowvolume, rural roads in Iowa in December 2010. Results indicated that unpaved roads with traffic volumes greater than 100 vehicles per day (vpd) exhibit significantly higher crash frequencies, rates, and densities than any other class of low-volume road examined, paved or unpaved. The total mileage for this class of roadway in Iowa is only about 4,400 miles, spread over 99 counties in the state, which is certainly a manageable number of miles for individual rural agencies. The purpose of this study was to identify and examine several unpaved, local road segments with higher than average crash frequencies, select and undertake potentially-beneficial mitigation, and evaluate the results as time allowed. A variety of low-cost options were considered, including engineering improvements, enhanced efforts by law enforcement, and educational initiatives. Using input, active support, and participation from local agencies and state and Federal safety advocates, the study afforded a unique opportunity to examine useful tools for local rural agencies to utilize in addressing safety on this particular type of roadway.

Evaluation of Mitigation for Safety Concerns on Low-Volume, Unpaved Rural Roads: Tech Transfer Summary, 2013.

The Institute for Transportation (InTrans) at Iowa State University completed work on an in-depth study of crash history on lowvolume, rural roads in Iowa in December 2010. Results indicated that unpaved roads with traffic volumes greater than 100 vehicles per day (vpd) exhibit significantly higher crash frequencies, rates, and densities than any other class of low-volume road examined, paved or unpaved. The total mileage for this class of roadway in Iowa is only about 4,400 miles, spread over 99 counties in the state, which is certainly a manageable number of miles for individual rural agencies. The purpose of this study was to identify and examine several unpaved, local road segments with higher than average crash frequencies, select and undertake potentially-beneficial mitigation, and evaluate the results as time allowed. A variety of low-cost options were considered, including engineering improvements, enhanced efforts by law enforcement, and educational initiatives. Using input, active support, and participation from local agencies and state and Federal safety advocates, the study afforded a unique opportunity to examine useful tools for local rural agencies to utilize in addressing safety on this particular type of roadway.

Western Iowa Missouri River Flooding -- Geo-Infrastructure Damage Assessment, Repair and Mitigation Strategies, TR-638, 2013

The 2011 Missouri River flooding caused significant damage to many geo-infrastructure systems including levees, bridge abutments/foundations, paved and unpaved roadways, culverts, and embankment slopes in western Iowa. The flooding resulted in closures of several interchanges along Interstate 29 and of more than 100 miles of secondary roads in western Iowa, causing severe inconvenience to residents and losses to local businesses. The main goals of this research project were to assist county and city engineers by deploying and using advanced technologies to rapidly assess the damage to geo-infrastructure and develop effective repair and mitigation strategies and solutions for use during future flood events in Iowa. The research team visited selected sites in western Iowa to conduct field reconnaissance, in situ testing on bridge abutment backfills that were affected by floods, flooded and non-flooded secondary roadways, and culverts. In situ testing was conducted shortly after the flood waters receded, and several months after flooding to evaluate recovery and performance. Tests included falling weight deflectometer, dynamic cone penetrometer, three-dimensional (3D) laser scanning, ground penetrating radar, and hand auger soil sampling. Field results indicated significant differences in roadway support characteristics between flooded and non-flooded areas. Support characteristics in some flooded areas recovered over time, while others did not. Voids were detected in culvert and bridge abutment backfill materials shortly after flooding and several months after flooding. A catalog of field assessment techniques and 20 potential repair/mitigation solutions are provided in this report. A flow chart relating the damages observed, assessment techniques, and potential repair/mitigation solutions is provided. These options are discussed for paved/unpaved roads, culverts, and bridge abutments, and are applicable for both primary and secondary roadways.

Feasibility of Cooperative Development of Wetland Mitigation Projects, TR-526, 2006

The Iowa Department of Transportation (Iowa DOT) currently performs wetland mitigation on a project-by-project basis. At the same time, other agencies like the Iowa Department of Natural Resources and Natural Resource Conservation Service are performing wetland restoration projects, and counties and cities may be mitigating wetland losses as well. This project examined the feasibility of developing cooperative wetland mitigation projects in order to utilize state and local resources more efficiently to benefit both Iowa and local communities. The project accomplished the following objectives: (1) Identified and characterized cooperative wetland mitigation programs nationwide; (2) Developed a needs assessment through a survey of state, county, and large city agencies in Iowa to describe wetland mitigation programs and determine challenges with mitigation and program improvements, including long-term risks associated with maintenance and monitoring programs; (3) Surveyed state, county, and city agencies and organizations to identify resources available for developing cooperative mitigation projects and procedures; (4) Developed a conceptual framework for cooperative wetland mitigation.

U.S. landowner behavior, land use and land cover changes, and climate change mitigation

Abstract