Effects of peripartum biotin supplementation of dairy cows on milk production and milk composition with emphasis on fatty acids profile

Forty Holstein dairy cows receiving a 38% concentrate diet based on maize silage were assigned to either a control group, either a biotin group, receiving 20 mg of biotin per day from 15 days before expected calving date and for 120 days after calving. Milk production was measured daily, milk fat content, protein content, urea and somatic cell counts were determined weekly from week 2 to week 17 of lactation. The profile of milk fatty acids was determined at weeks 3 and 10. Plasma glucose and blood betahydroxybutyrate were determined before calving and at weeks 1, 2, 3, 5, 7 and 10 of lactation. Biotin supplementation resulted in an increased milk production in multiparous cows during weeks 2 to 6, but the effect was no more significant between 7 and 17 weeks of lactation. Milk protein percent was decreased by 0.1% in multiparous cows. Milk fat content was not affected by biotin, and milk fat daily production tended to increase during early lactation. In milk fat, biotin supplementation tended to decrease the proportion of fatty acids with less than 16 carbons at week 3, but the daily amount was not affected. Biotin tended to decrease biohydrogenation intermediates, increased C16:1 at week 3, and tended to increase cis-9 C18:1 at weeks 3 and 10. After 7 weeks of lactation, biotin tended to increase blood beta-hydroxybutyrate in multiparous cows with values remaining in a normal range, and decreased plasma glucose in primiparous cows. These modifications of plasma parameters, milk protein content and profile of milk fatty acids could be due to a higher lipid mobilisation from adipose tissue driven by the increased milk production

Conclusions and perspectives: Perspectives for future research-and-development projects on biological

The review of published scientific literature on the biological control of selected pests and diseases has lead to the identification of clear knowledge gaps highlighted in previous chapters. Further bottlenecks were revealed by seeking the possible reasons for the striking discrepancy between the rich inventory of potential biocontrol agents described by scientists and a very small number of commercial products on the market. To complement these analyses, the participants of Research Activity 4.3 of the European Network ENDURE organized consultations of experts (scientists, extension specialists and representatives of the Biocontrol industry) at the occasion of scientific meetings of three Working Groups of IOBC-wpr

Expert-based development of a standard in CO2 sequestration monitoring technology

Bureau of Economic Geolog

Impact of Mixed Gas Stream on CO2 Plume Characteristics during and after Carbon Storage Operations in Saline Aquifers

The goal of this short study was to explain the effects of CO2 stream impurities (CH4 and N2) on (1) plume spread, (2) rate and extent of major trapping mechanisms, (3) CO2 storage capacity, and (4) well injectivity. The injection-stream base case consists of a 95% CO2 stream with 2.5% CH4 and N2. We varied the CO2 fraction from 75% to 100% (on a mole basis), defining three bounding cases: CO2BC, CH4BC, and N2BC containing 100% CO2, 75% CO2 and 25% CH4, and 75% CO2 and 25% N2, respectively. In a parametric study of the stream composition, we defined a simple generic reservoir with a uniform permeability of 300 md, a dip of 2°, and porosity of 25%. The model contains 120 300-ft-long cells in the dip direction and also includes four baffles with no permeability parallel to its top and bottom. The gas was injected for 30 years at a depth of about 6,000 ft and at a rate of 26 MMSCFD (equivalent to 0.5 Mt/yr of pure CO2) in a single well located in the downdip section of the model and perforated in the lower third of the 1,000-ft thickness of the injection formation. Temperature is constant at 135°F. Results are numerically monitored for 1,000 yr after start of injection. The modeling was done using CMG-GEM software, and we used a user-defined set of PVT properties. A sensitivity analysis on important model parameters was also done to assess their importance relative to the parametric-study results. The study considers only the two trapping mechanisms (residual saturation and brine dissolution) largely impacted by injection-stream composition. Plume spread, or maximum extent, is a strong function of composition. The maximum extent ranges from 10,350 ft for CO2BC to more than twice the distance for CH4BC (22,250 ft) and N2BC (24,250 ft) and varies approximately linearly for intermediate values. Similarly, time for the plume to reach the top of the formation varies from 14 yr (N2BC) to 18 yr (CH4BC) to 60 yr (CO2BC). The main difference between gas components is solubility in brine—CO2 is approximately 10 times more soluble than CH4 and N2 on a mole basis. The buoyant driving force, expressed as the ratio of gas-brine density difference to gas viscosity, is also approximately four times higher in the CH4BC and N2BC cases, and the ratio keeps increasing because the fraction of CH4 and N2 increases as CO2 dissolves.Bureau of Economic Geolog

Impact of CO2 Impurities on Storage Performance and Assurance - Report on Tasks 3 and 4 (Geochemistry) Prepared for: CO2 Capture Project (Phase III)

This document presents the results of Tasks 3 and 4 out of 5 tasks, focusing on the geochemical impacts of impurities in the CO2 stream. Tasks 1 and 2 were dedicated to examining the effects on flow behavior. The impurities primarily consist of N2, O2, and Ar, with several minor reactive species potentially added, including CO, H2, SOx, and other trace gases. The research methodology involved laboratory autoclave experiments combined with geochemical numerical modeling. The autoclave utilized in the experiments is a 250-ml reactor capable of withstanding temperatures up to 150°C and pressures up to 400 bars, simulating conditions observed in reservoirs at depths of up to 12,000 ft. Pressure and temperature were automatically controlled by a computer, and the system allowed for water sampling during the experiments. Typically, 10 to 15 samples of the solution were collected during each experiment, which lasted 5 to 10 days. Rock samples were exposed to either a supercritical mixture of CO2 and O2 (generally 3.5% molar) or pure supercritical CO2, filling approximately half of the reactor cell. The other half of the cell contained a single core fragment or several large fragments (~8g total) submerged in approximately 140 ml of synthetic brine (~1.88 mol NaCl, corresponding to a TDS of 100,000-110,000 mg/L). The study analyzed three types of clastic rock samples: 1. A "dirty sandstone" of Miocene age obtained from a deep well in the shallow offshore region off the Texas coast. 2. A relatively clean sandstone from the Cretaceous-age Cardium Formation in Alberta. 3. A chlorite-rich sandstone from the Tuscaloosa Formation in Mississippi, sourced from the Cranfield site, which has been extensively studied by BEG for several years.Bureau of Economic Geolog

Ground Water Surface Water Interactions in Texas

Groundwater-surface water interactions need to be evaluated to optimize water management in Texas. This study provides an overview of the impacts of groundwater-surface water (gw-sw) interactions on water quality and water quantity using available data. A literature review was conducted to assess the status of knowledge of gw-sw interactions. A total of 300 references were compiled. References were subdivided into those related to water quantity issues, water quality including point and nonpoint sources of contamination, and methods such as seepage and temperature approaches and modeling analyses. Additional topics covered by the reference list include impacts of climate variability and land use/land cover changes on gw-sw interactions and ecological issues. A compilation of data and information sources for assessing gw-sw interactions in Texas is also provided. This section includes web links to online report catalogs and databases and a listing of offline reports and catalogs provided by state and federal agencies.Bureau of Economic Geolog

Measuring and Modeling Fault Density for Plume-Fault Encounter Probability Estimation

Emission of carbon dioxide from fossil-fueled power generation stations contributes to global climate change. Storage of this carbon dioxide within the pores of geologic strata (geologic carbon storage) is one approach to mitigating the climate change that would otherwise occur. The large storage volume needed for this mitigation requires injection into brine-filled pore space in reservoir strata overlain by cap rocks. One of the main concerns of storage in such rocks is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available. This necessitates a method for using available fault data to develop an estimate of the likelihood of injected carbon dioxide encountering and migrating up a fault, primarily due to buoyancy. Fault population statistics provide one of the main inputs to calculate the encounter probability. Previous fault population statistics work is shown to be applicable to areal fault density statistics. This result is applied to a case study in the southern portion of the San Joaquin Basin with the result that the probability of a carbon dioxide plume from a previously planned injection had a 3% chance of encountering a fully seal offsetting fault

Impact of CO2 Impurities on Storage Performance and Assurance -Report on Task 5 (Integration of Flow and Geochemistry) and Final Report Prepared for: CO2 Capture Project (Phase III)

A key impediment to carbon capture and storage is the cost of CO2 capture, particularly for conventional power plants whose flue gas is dominated by gases other than CO2. Waste gas streams from power plants that use novel technologies (such as oxyfuel, the focus of this work) can circumvent the capture step thanks to their CO2-rich composition (CO2 > 90%), but at the expense of CO2 stream purity. In addition to CO2, two non-reactive gases make up the bulk of impurities: N2 and Ar. O2 is the most commonly cited reactive gas, with molar concentrations ranging from 5%. Other minor species may also be present. Relatively high purity levels must be achieved to avoid compression and complications in pipeline transportation (two-phase flow) and, potentially, subsurface impacts. This work investigates the latter, which, in turn, informs techno-economic assessments of capture and transportation economics. Subsurface impacts of an impure CO2 stream could be twofold: (1) complicate flow behavior and reduce static capacity due to density and viscosity differences and (2) undermine reservoir and top seal integrity due to reactions with reactive species (O2, CO, SOx). To address the first issue, we conducted a desktop study using a numerical modeling tool and performed laboratory experiments to determine the actual viscosity and density of the mixtures. Information on the solubility of these various mixture components in the aqueous phase under various pressure, temperature, and salinity conditions was also collected. An important observation controlling all study results was that the viscosity and density of the mixtures considered are lower than those of pure CO2 at the same temperatures and pressures. It follows that a plume of CO2 with impurities, moving updip with no barrier, will migrate farther from the point of injection but will be trapped through residual saturation sooner than a plume of pure CO2, possibly enhancing dissolution primarily because it is exposed to more rock/brine volume. However, a larger plume means that a larger area must be defined and monitored for leakage pathways, such as faults and wells, but the faster trapping translates into a shorter monitoring period. Equally important is that contrasts of viscosity and density between pure CO2 and a CO2 mixture decrease with depth, suggesting that differences in flow behavior and storage capacity are proportionally reduced with depth.Bureau of Economic Geolog

Case studies of the application of the Certification Framework to two geologic carbon sequestration sites

We have developed a certification framework (CF) for certifying that the risks of geologic carbon sequestration (GCS) sites are below agreed-upon thresholds. The CF is based on effective trapping of CO2, the proposed concept that takes into account both the probability and impact of CO2 leakage. The CF uses probability estimates of the intersection of conductive faults and wells with the CO2 plume along with modeled fluxes or concentrations of CO2 as proxies for impacts to compartments (such as potable groundwater) to calculate CO2 leakage risk. In order to test and refine the approach, we applied the CF to (1) a hypothetical large-scale GCS project in the Texas Gulf Coast, and (2) WESTCARB's Phase III GCS pilot in the southern San Joaquin Valley, California

Monitoring Stray Natural Gas in Groundwater With Dissolved Nitrogen. An Example From Parker County, Texas

Concern that hydraulic fracturing and natural gas production contaminates groundwater requires techniques to attribute and estimate methane flux. Although dissolved alkane and noble gas chemistry may distinguish thermogenic and microbial methane, low solubility and concentration of methane in atmosphereâ equilibrated groundwater precludes the use of methane to differentiate locations affected by high and low flux of stray methane. We present a method to estimate stray gas infiltration into groundwater using dissolved nitrogen. Due to the high concentration of nitrogen in atmosphericâ recharged groundwater and low concentration in natural gas, dissolved nitrogen in groundwater is much less sensitive to change than dissolved methane and may differentiate groundwater affected high and low flux of stray natural gas. We report alkane and nitrogen chemistry from shallow groundwater wells and eight natural gas production wells in the Barnett Shale footprint to attribute methane and estimate mixing ratios of thermogenic natural gas to groundwater. Most groundwater wells have trace to nondetect concentrations of methane. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas from the Barnett Shale and/or shallower Strawn Group suggesting that localized migration of natural gas occurred. Twoâ component mixing models constructed with dissolved nitrogen concentrations and isotope values identify three wells that were likely affected by a large influx of natural gas with gas:water mixing ratios approaching 1:5. Most groundwater wells, even those with greater than 10â mg/L methane, have dissolved nitrogen chemistry typical of atmosphereâ equilibrated groundwater suggesting natural gas:water mixing ratios smaller than 1:20.Plain Language SummaryHydraulic fracturing, horizontal drilling, and associated natural gas production have dramatically changed the energy landscape across America over the past 10 years. Along with this renaissance in the energy sector has come public concern that hydraulic fracturing may contaminate groundwater. In this study we measure the chemistry of dissolved gas from shallow groundwater wells located above the Barnett Shale natural gas play, a tight gas reservoir located west of the Dallasâ Fort Worth Metroplex. We compare groundwater chemistry results to natural gas chemistry results from nearby production wells. Most groundwater wells have trace to nondetectible concentrations of methane, consistent with no measurable infiltration of natural gas into shallow groundwater. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas. Using dissolved nitrogen and alkane concentrations and their stable isotope ratios in combination with chemical mixing models, we conclude that natural gas transported from the shallower Strawn Group affected these groundwater wells rather than natural gas from the deeper Barnett Shale, which is the target of hydraulic fracturing in this area. These results suggest that hydraulic fracturing has not affected shallow groundwater drinking sources in this area.Key PointsDissolved nitrogen in groundwater provides a means to differentiate highâ and lowâ flux infiltration of stray gasNitrogen concentrations and isotope values may attribute natural gas sourcesPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/1/wrcr23523.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/2/wrcr23523_am.pd