Academic literature on the topic 'Gas production rate'

The traditional optimum modes of gas-lift production are usually established by taking the injected gas rate as a decision variable and maximum oil production as the objective function. After solving the model, the injected gas rates of single wells are obtained, and then the oil productions of single wells, the total oil productions of well groups and economic profit can be obtained. However, the models do not take both different types of gas-lift performance curves (GLPCs) and the cost factors of gas-lift production technique into account. On the basis of GLPCs, this paper introduces the factors of a gas-lift production technique, which includes the water cut of crude oil, cost of gas injection and water treatment, and oil and gas prices. The concept of a gas-lift economic performance curve (GLEPC) is proposed, and an optimum gas allocation model is established, considering different types of GLPCs and taking economic benefits as the objective, and the model is solved by the method of mixed penalty function. Taking gas-lift well group JD as an example, four gas-lift gas allocation schemes are obtained, and the proposed economical optimum model is applied to optimize gas allocation and analyze profit. What is more, the oil production rate and the result of optimum gas allocation taking maximum oil production rate as the objective in the model are calculated and compared. Then the gas allocation scheme with maximum economical profit is selected, and the significance of considering different types of GLPCs and taking economic benefits as the objective to gas allocation is confirmed.

Two in vitro trials were carried out to study the effects of supplementing vitamin E (V_E) on rumen fermentation. In Trial I, four levels of V_E product (purity 50%), i.e. 0, 15, 30, and 60 mg/kg dry matter (DM) of feed (equivalent to 0, 7.5, 15, 30 IU V_E/kg DM) were supplemented to a typical feed mixture, respectively, as experimental treatments. The gas test technique of Menke et al. (1979) was used to measure gas and volatile fatty acid (VFA) production. In Trial II, the in vitro incubation technique of Zhao and Lebzien (2000) was used to determine DM disappearance rate and utilizable crude protein (uCP). Four levels of V_E, i.e. 0, 7.5, 15, 30 IU/kg DM were supplemented to the same feed mixture as in Trial I, respectively, as experimental treatments. The results showed that supplementing V_E increased total gas production (P < 0.01) and tended to increase methane (CH₄) production (P = 0.087). Supplementing V_E also increased total VFA (P < 0.05) and propionate (P < 0.05), tended to increase acetate production (P = 0.084), and significantly increased DM disappearance rate (P < 0.05) and uCP (P < 0.01). It was concluded that supplementing V_E at 30 IU/kg DM under the conditions of present trials with 11.1 IU/kg DM in the feed mixture improved in vitro rumen fermentation of feed mixture. Further research is necessary to confirm the effects of supplementing V_E using in vivo trials.

Underground gas storage reservoirs (UGSRs) are used to keep the natural gas supply smooth. Native natural gas is commonly used as cushion gas to maintain the reservoir pressure and cannot be extracted in the depleted gas reservoir transformed UGSR, which leads to wasting huge amounts of this natural energy resource. CO2 is an alternative gas to avoid this particular issue. However, the mixing of CO2 and CH4 in the UGSR challenges the application of CO2 as cushion gas. In this work, the Donghae gas reservoir is used to investigate the suitability of using CO2 as cushion gas in depleted gas reservoir transformed UGSR. The impact of the geological and engineering parameters, including the CO2 fraction for cushion gas, reservoir temperature, reservoir permeability, residual water and production rate, on the reservoir pressure, gas mixing behavior, and CO2 production are analyzed detailly based on the 15 years cyclic gas injection and production. The results showed that the maximum accepted CO2 concentration for cushion gas is 9% under the condition of production and injection for 120 d and 180 d in a production cycle at a rate of 4.05 kg/s and 2.7 kg/s, respectively. The typical curve of the mixing zone thickness can be divided into four stages, which include the increasing stage, the smooth stage, the suddenly increasing stage, and the periodic change stage. In the periodic change stage, the mixed zone increases with the increasing of CO2 fraction, temperature, production rate, and the decreasing of permeability and water saturation. The CO2 fraction in cushion gas, reservoir permeability, and production rate have a significant effect on the breakthrough of CO2 in the production well, while the effect of water saturation and temperature is limited.

Decay and accumulation of blanket peat in the Northern Pennine region of England are considered, both in quantitative and qualitative terms. Productivity on the surface of these peat bogs is not unusually high, suggesting that a low decay rate may be responsible for the accumulation of the peat. Considerable study has formerly been made of the aerobic decay processes, at the expense of the parallel anaerobic processes, which have largely hitherto been considered negligible. Yet a current mathematical model of peat accumulation suggests that it is likely to be the anaerobic decay rate which determines the total depth of peat which may accumulate. Further, such models intimate that a very small absolute change in the anaerobic decay rate will have an unexpectedly large effect on the potential steady state depth of peat. The present study concentrates on obtaining measurements of anaerobic decay rates, and on identifying the possible limiting environmental factors of the decay. The design of a sampler to collect gas samples in situ from blanket peat is described. The components of particular interest in the samples are CH4 and C02. Gas concentrations down eight peat profiles at two sites are monitored over two seasons. Simultaneous surface flux measurements above pool, lawn and hummock microhabitats are also made. Water level, temperature, pH, redox potential, depth of the sulphide zone and total sulphide concentration are recorded on each field visit. The results from the gas sample analyses are discussed in relation to the environmental factors and in relation to our present understanding of peat decay rates and their consequences on peat accumulation. The anaerobic decay rate is calculated, and is confirmed to be several orders of magnitude less than that in the overlying aerobic peat. It is shown that the methane is not fossil, but is continually being produced at all depths. Rates of gas production are calculated. Annual methane and carbon dioxide losses from entire peat bogs are calculated to contribute a significant amount to carbon cycling, on a site-specific and global scale.

The International Energy Agency (IEA) expects total natural gas output in the EU to decrease from 216 billion cubic meters per year (bcm/year) in 2006 to 90 bcm/year in 2030. For the same period, EU demand for natural gas is forecast to increase rapidly. In 2006 demand for natural gas in the EU amounted to 532 bcm/year. By 2030, it is expected to reach 680 bcm/year. As a consequence, the widening gap between EU production and consumption requires a 90% increase of import volumes between 2006 and 2030. The main sources of imported gas for the EU are Russia and Norway. Between them they accounted for 62% of the EU’s gas imports in 2006. The objective of this thesis is to assess the potential future levels of gas supplies to the EU from its two main suppliers, Norway and Russia. Scenarios for future natural gas production potential for Norway and Russia have been modeled utilizing a bottom-up approach, building field-by-field, and individual modeling has been made for giant and semi- giant gas fields. In order to forecast the production profile for an individual giant natural gas field a Giant Gas Field Model (GGF-model) has been developed. The GGF-model has also been applied to production from an aggregate of fields, such as production from small fields and undiscovered resources. Energy security in the EU is heavily dependent on gas supplies from a relatively small number of giant gas fields. In Norway almost all production originates from 18 fields of which 9 can be considered as giant fields. In Russia 36 giant fields account for essentially all gas production. There is limited potential for increased gas exports from Norway to the EU, and all of the scenarios investigated show Norwegian gas production in decline by 2030. Norwegian pipeline gas exports to the EU may even be, by 2030, 20 bcm/year lower than today’s level. The maximum increase in exports of Russian gas supplies to the EU amount to only 45% by 2030. In real numbers this means a mere increase of about 70 bcm In addition, there are a number of potential downside factors for future Russian gas supplies to the European markets. Consequently, a 90% increase of import volumes to the EU by 2030 will be impossible to achieve. From a European energy security perspective the dependence of pipeline gas imports is not the only energy security problem to be in the limelight, the question of physical availability of overall gas supplies deserves serious attention as well. There is a lively discussion regarding the geopolitical implications of European dependence on imported gas from Russia. However, the results of this thesis suggest that when assessing the future gas demand of the EU it would be of equal importance to be concerned about diminishing availability of global gas supplies.

For enhancing anaerobic sludge digestion and biogas recovery, an increase in organic load rate (OLR) from 1.0 to 3.0kgVS/(m3·day) was imposed upon a new anaerobic digestion process combined with a sludge recirculation. The new setup requires a traditional mesophilic anaerobic digester coupled with a centrifuge for maintaining relatively high solid content within the digester. The hypothesis of this study was that increasing continuously OLR from 1.0 to 3.0kgVS/(m3·day) in a pilot-scale anaerobic digester with recycled sludge would not badly influence the digester stability, based on which biogas production would be enhanced. To test this hypothesis, a continuous 73-day study with laboratory experiment was conducted. Due to scarcity of original feeding sludge and its deteriorating quality, OLR had to be increased relied on introduction of extra sludge followed by measurement of total solid (TS) and volatile solid (VS) contents in both feeding sludge and digester sludge, for calculating OLR and examining its variations. To assess the relationship between biogas production and OLR, a measurement of gas yield and methane content was a necessity, performed by applying a biogas flow meter and MSA AUER EX-METER II (P). Moreover, temperature, pH value, volatile fatty acid (VFA) and alkalinity must be tested frequently, for the purpose of preventing system failure. The results demonstrate that the digester succeeded in withstanding an OLR up to 3.15kgVS/(m3·day). Furthermore, an enhancement in biogas yield and methane content were observed after increasing the OLR by introducing extra sludge. Biogas production measurement performed during this study indicated that biogas yield was enhanced by 73%, with a maximum production of 14.5m3/day, when OLR was increased from 2.05 to 3.15kgVS/(m3·day). However, methane content was merely promoted by 10.5%, to the highest value of 63%, with the same increase in OLR. Specific gas production (SGP), as another means of evaluating the relationship between biogas production and OLR, was observed to be 0.65Nm3/kg VSin averagely.

An investigation was undertaken to determine the feasibility of increasing the hydrogen production rate by coupling the water gas shift (WGS) process to the hybrid sulphur process (HyS). This investigation also involved the technical and economical analysis of the water gas shift and the H2 separation by means of Pressure swing adsorption (PSA) process. A technical analysis of the water gas shift reaction was determined under the operating conditions selected on the basis of some information available in the literature. The high temperature system (HTS) and low temperature system (LTS) reactors were assumed to be operated at temperatures of 350°C and 200°C, respectively. The operating pressure for both reactors was assumed to be 30 atmospheres. The H2 production rate of the partial oxidation (POX) and the WGS processes was 242T/D, which is approximately two times the amount produced by the HyS process alone. The PSA was used for the purification process leading to a hydrogen product with a purity of 99.99%. From the total H2 produced by the POX and the WGS processes only 90 percent of H2 is recovered in the PSA. The unrecovered H2 leaves the PSA as a purge gas together with C02 and traces of CH4, CO, and saturated H20. The estimated capital cost of the WGS plant with PSA is about US$50 million. The production cost is highly dependent on the cost of all of the required raw materials and utilities involved. The production cost obtained was US $1.41/kg H2 based on the input cost of synthesis gas as produced by the POX process. In this case the production cost of synthesis gas based on US $6/GJ for natural gas and US $0/Ton for oxygen was estimated to be US $0.154/kg. By increasing the oxygen and natural gas cost, the corresponding increase in synthesis gas has resulted in an increase in H2 production cost of US $1.84/kg.
Thesis (M.Sc. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

The interruption cost for one hour of a petrochemical plant is 33 times higher than that of the average interruption cost for industrial plants across all industries. In addition to the high cost of loss of production, interruptions to the operations of petrochemical and gas-toliquid plants pose safety and environmental hazards. Thus it is necessary to better understand the reliability requirements of petrochemical and gas-to-liquid plants. This study investigated the reliability of electrical distribution networks used in petrochemical and gas-to-liquid plants compared to those used in other industrial plants. A model was developed that can be used to establish the adequacy of the reliability of a distribution network in terms of the components and network topologies used. This model was validated against data that had been collected by the IEEE and applied to an actual petrochemical plant. Over 19 years’ worth of data regarding the trips that have occurred on the distribution network of an existing petrochemical plant was collected and manipulated in order to calculate the reliability indices associated with the equipment used to make up thisRecommended Practice for the Design of Reliable Industrial and Commercial Power Systems. The cost of loss of production and the capital costs associated with increased reliability were calculated for a section of the existing petrochemical plant. The reliability associated with different network topologies that could possibly be used to supply power to this section of the plant were modelled using an appropriate software package. The resulting total cost of ownership over the life of the plant associated with each topology was then calculated in order to establish which network topology is the most appropriate for petrochemical and gas-to-liquid plants. It was concluded the components that affect the reliability of an industrial distribution network are different to those that affect a utility distribution network. These components were listed and compared. It was found that the reliability indices that were calculated for the components that affect the reliability of a petrochemical plant were similar to those provided by the IEEE. 17 out of 20 of the indices that were calculated were within the required factor of deviation. Generally the failure rates of components used in petrochemical plants were very similar to those given in the IEEE Gold Book, while the MTTR’s for the components used in petrochemical plants were found to be slightly better than those given in the IEEE Gold Book. The effect of network topology was found to be significant, with small changes in the topology of a network resulting in large variations in the reliability of the network. It was also found that the most appropriate type of network topology to use in the design of the electrical distribution network of a petrochemical plant is the dual radial network. This is the most conservative of the commonly used network topologies and is the one that is currently used in the existing plant that was studied. Due to the high cost of loss of production in petrochemical plants it was established that any incremental improvement in the reliability of the dual radial network would be beneficial to the total cost of ownership of such a plant. Such incremental improvement of the reliability of the distribution network could be cost effectively achieved by adopting a conservative maintenance strategy and the establishment of a conservative spares inventory. Before this study was undertaken, there was no literature around the reliability of electrical distribution networks that focused specifically on petrochemical and gas-to-liquid plants. This study produced a set of reliability indices and a model that electrical engineers can use in the reliability analysis of petrochemical and gas-to-liquid plants. Furthermore it shows that, because the cost of loss of production in petrochemical plants is so high, the most conservative distribution network design and maintenance philosophies should always be used. distribution network. These reliability indices were compared to those given by the IEEE
Dissertation (MEng)--University of Pretoria, 2013.
gm2014
Electrical, Electronic and Computer Engineering
unrestricted

This thesis is a study of naturally occurring radioactive materials (NORM) activity concentration, gamma dose rate and radon (222Rn) exhalation from the waste streams of large-scale onshore petroleum operations. Types of activities covered included; sludge recovery from separation tanks, sludge farming, NORM storage, scaling in oil tubulars, scaling in gas production and sedimentation in produced water evaporation ponds. Field work was conducted in the arid desert terrain of an operational oil exploration and production region in the Sultanate of Oman. The main radionuclides found were 226Ra and 210Pb (238U - series), 228Ra and 228Th (232Th - series), and 227Ac (235U - series), along with 40K. All activity concentrations were higher than the ambient soil level and varied over several orders of magnitude. The range of gamma dose rates at a 1 m height above ground for the farm treated sludge had a range of 0.06 0.43 µSv h 1, and an average close to the ambient soil mean of 0.086 ± 0.014 µSv h 1, whereas the untreated sludge gamma dose rates had a range of 0.07 1.78 µSv h 1, and a mean of 0.456 ± 0.303 µSv h 1. The geometric mean of ambient soil 222Rn exhalation rate for area surrounding the sludge was mBq m 2 s 1. Radon exhalation rates reported in oil waste products were all higher than the ambient soil value and varied over three orders of magnitude. This study resulted in some unique findings including: (i) detection of radiotoxic 227Ac in the oil scales and sludge, (ii) need of a new empirical relation between petroleum sludge activity concentrations and gamma dose rates, and (iii) assessment of exhalation of 222Rn from oil sludge. Additionally the study investigated a method to determine oil scale and sludge age by the use of inherent behaviour of radionuclides as 228Ra:226Ra and 228Th:228Ra activity ratios.

This thesis is a study of naturally occurring radioactive materials (NORM) activity concentration, gamma dose rate and radon (222Rn) exhalation from the waste streams of large-scale onshore petroleum operations. Types of activities covered included; sludge recovery from separation tanks, sludge farming, NORM storage, scaling in oil tubulars, scaling in gas production and sedimentation in produced water evaporation ponds. Field work was conducted in the arid desert terrain of an operational oil exploration and production region in the Sultanate of Oman. The main radionuclides found were 226Ra and 210Pb (238U - series), 228Ra and 228Th (232Th - series), and 227Ac (235U - series), along with 40K. All activity concentrations were higher than the ambient soil level and varied over several orders of magnitude. The range of gamma dose rates at a 1 m height above ground for the farm treated sludge had a range of 0.06 0.43 µSv h 1, and an average close to the ambient soil mean of 0.086 ± 0.014 µSv h 1, whereas the untreated sludge gamma dose rates had a range of 0.07 1.78 µSv h 1, and a mean of 0.456 ± 0.303 µSv h 1. The geometric mean of ambient soil 222Rn exhalation rate for area surrounding the sludge was mBq m 2 s 1. Radon exhalation rates reported in oil waste products were all higher than the ambient soil value and varied over three orders of magnitude. This study resulted in some unique findings including: (i) detection of radiotoxic 227Ac in the oil scales and sludge, (ii) need of a new empirical relation between petroleum sludge activity concentrations and gamma dose rates, and (iii) assessment of exhalation of 222Rn from oil sludge. Additionally the study investigated a method to determine oil scale and sludge age by the use of inherent behaviour of radionuclides as 228Ra:226Ra and 228Th:228Ra activity ratios.

AD is regarded as a sustainable technology that could assist the UK Government meet internationally agreed GHG emission targets by 2050. However, the mature status of the technology is based on expensive systems that rely on high energy feedstock to be profitable. Meanwhile, the natural biodegradation of cow slurry is a recognised contributor to climate change despite having a relatively low CH4 potential because of the large volumes produced. Economic mixing is essential to the cost-effectiveness of farm AD but techniques applied are not always appropriate as slurry is a shear thinning thixotropic Herschel-Bulkley fluid and therefore challenging to mix. The apparent viscosity of slurry and the shear stress induced was most influenced by solids content (exponential change) followed by temperature (linear). Most shear thinning occurred before a rising shear rate of 20s-1 was achieved with the fluid acting near-Newtonian above. Thixotropic recovery occurred within 1 hour of resting. Rheological values were also much higher than previously reported. Highest CH4 production occurred in the first 10 days of the batch process using a range of mixing regimes with different shear rates and rest periods. During fed-batch operations, changing shear rate had a minimal effect on CH4 production using a 30-day HRT whereas shorter rest periods increased production. Specific CH4 production rate was highest when feeding and mixing coincided. However, when HRT was reduced (OLR increased) the CH4 produced by all mixed regimes significantly increased with highest values being achieved using high intensity mixing rested for short periods. Lower HRTs also requires smaller digesters. Parasitic mixing energy invariably had the most influence on net energy production. Signs of instability were evident after 20 days using the low HRT. Significant microbial adaptation was also observed as the experiments progressed. The research outcomes demonstrate that mixing regime and HRT can be managed to maximise net energy production whilst reducing capital expenditure.

This work examines the isotopic composition and abundance of helium in a number of different crustal environments with a view to understanding its production and transport in the crust. The work was largely carried out using existing instrumentation, but a dedicated interface was also built to allow computer control of a quadrupole mass spectrometer for rare gas abundance pattern determination. Conventional calculations of the radiogenic ³He/⁴He production ratio based on the assumption of a chemically homogeneous composition cannot adequately account for the ³He/⁴He ratio in waters from the Carnmenellis Granite of SW England. Alpha tracking and back-scattered electron microscopy show that the majority of the U and Th are concentrated in volumetrically insignificant accessory minerals. A new model has been devised, taking this heterogeneity into account, to explain the Carnmenellis data. Helium isotopic analysis of the granite itself revealed isotopic disequilibrium with the circulating waters. This may be related to differential release of ³He and ⁴He associated with different formation sites. A survey was made of the helium abundance and isotopic composition of groundwaters from the Pannonian Basin of Hungary in order to study the behaviour of mantle-derived fluids in an area of major recent crustal extension and volcanism. More than 80 samples were analysed covering most of the basin, and almost all contained a component of mantle-derived helium. Although ³He/⁴He ratio is not clearly correlated with the surface expression of volcanism, it may act as an indicator of intrusion at depth. The ³He flux through the Hungarian crust is ≈4 atoms.cm^-2.s^-2. If the mechanism of extraction is partial melting, then by analogy with melt production at mid-ocean ridges, addition of a 20-40 metre layer of basalt (for 5-10% partial melting) must be added to the Hungarian crust in a million years to support the present day ³He flux.

Дисертація присвячена удосконаленню методів глинокислотного діяння на присвердловинну зону пласта з використанням борофтористоводневої кислоти. З цією метою проаналізовано сучасний стан використання глинокислотних розчинів на основі фтористоводневої, кремнійфтористоводневої та борофтористоводневої кислот. Для розроблення ефективних технологій глинокислотного діяння проведено дослідження основних властивостей розчинів борофтористоводневої кислоти -розчинності бентонітової глини залежно від різних чинників (концентрація різних кислот, неіоногенних та катіонактивних ПАР, водорозчинних полімерів тощо), диспергування глинистих нашарувань в глинокислотних розчинах різного складу, розчинності карбонатної породи, корозійної активності розчинів борофтористоводневої кислоти як самостійно, так і в суміші з інгібіторами кислотної корозії, впливу нагнітання глинокислотних розчинів на проникність порід-колекторів. На основі лабораторних досліджень запропоновано дев'ять базових рецептур глинокислотних розчинів на основі борофтористоводневої кислоти, які можна використовувати за трьома основними технологіями. Дослідно-промислові випробування та подальше впровадження розроблених технологій глинокислотного діяння у видобувних свердловинах ПАТ "Укрнафта" підтвердили правильність отриманих результатів та їх ефективність в промислових умовах. Технологічна ефективність розроблених технологій глинокислотного діяння підтверджена результатами гідродинамічних досліджень свердловин до і після проведеного оброблення.
Диссертация посвящена совершенствованию методов глинокислотного воздействия на прискважинную зону пласта с использованием борофтористоводородной кислоты. С этой целью проанализировано современное состояние использования глинокислотных растворов на основе фтористоводородной, кремнийфтористоводородной и борофтористоводородной кислот. Для разработки эффективных технологий глинокислотного воздействия проведены исследования основных свойств растворов борофтористоводородной кислоты - растворимости бентонитовой глины в зависимости от различных факторов (концентрация различных кислот, неионогенных и катионактивных ПАВ, водорастворимых полимеров и другое), диспергирования глинистых компонентов в глинокислотных растворах различного состава, растворимости карбонатной породы, коррозионной активности растворов борофтористоводородной кислоты как самостоятельно, так и в смеси с ингибиторами кислотной коррозии, влияния нагнетания глинокислотных растворов на проницаемость пород-коллекторов. В ходе исследований установлено, что дополнительный ввод в раствор борофтористоводородной кислоты фтористоводородной или соляной кислоты обеспечивает увеличение скорости растворения бентонита в 1,1 - 1,3 раза, а уксусной или фосфорной кислоты, поверхностно-активных веществ и водорастворимых полимеров - снижение растворимости бентонита в 1,2 - 17,5 раз. Способность борофтористоводородной кислоты (скорость разрушения бентонитовых образцов 630 - 1380 г/м2мин) в отличие от фтористоводородной (скорость разрушения 60 г/м2мин) к увеличению скорости разрушения глинистых образований может быть использована в технологиях разглинизации призабойной зоны пласта. Наиболее эффективными ингибиторами кислотной коррозии для использования в растворах борофтористо водородной кислоты являются ИКУ-118, Додикор-2725 та А1-600, которые при этом также обеспечивают незначительное снижение скорости растворения бентонита. Снижение скорости растворения глинистых минералов при использовании борофтористоводородной кислоты при концентрациях 1 - 10 % в условиях ее фильтрации через терригенный поровый коллектор обеспечивает снижение степени образования пелитовых частиц, которые в свою очередь не оказывают негативного влияния на проницаемость образцов горнах пород. Следует учитывать, что при самостоятельном использовании борофтористоводородной кислоты увеличение коэффициента проницаемости наблюдается только в образцах с карбонатностю до 2,5- 3 %. При большей карбонатности образцов горных пород необходимо применять дополнительные мероприятия для снижения карбонатности породы (ввод соляной или иной кислоты в раствор борофтористоводородной кислоты, предварительное нагнетание кислотного раствора. На основе лабораторных исследований рекомендованы девять основных рецептур глинокислотных растворов на основе борофтористоводородной кислоты, которые можно использовать за тремя основными технологиями. Опытнопромысловые испытания и последующее использование разработанных технологий глинокислотного воздействия в добывающих скважинах ОАО "Укрнафта" (на протяжении 2002 - 2010 гг. с использованием новых кислотных систем проведено 119 скважино-операций, что обеспечило дополнительную добычу 89,5 тыс. т нефти с конденсатом и 63,5 млн. м3 газа при успешности работ - 86,5 %) подтвердили правильность полученных результатов и их эффектавность в промысловых условиях. Технологическая эффективность разработанных технологий глинокислотного воздействия подтверждена результатами гидродинамических исследований скважин до и после проведенных обработок. Установлено, что в зависимости от технологии воздействия и состава глинокислотного раствора обеспечивается исключительное воздействие или на призабойную, или на отдаленную зону пласта, или одновременное воздействие на призабойную и отдаленную зону пласта.
The thesis is devoted to the problems of method advancement of mud-acid treatment of downhole and step-out well zones using boricfluorhydric acid. The modem use of mud-acid solutions based on hydrofluoric, silicafluorhydric and boricfluorhydric acids is analysed. The basic properties of boricfluorhydric acid solutions - solubility of bentonite clay depending on various factors (concentration of different acids, non-ionogen and cation-active surfactants, water-soluble polymers, etc.), dispersion of clay layers in mud-acid solutions of different composition, solubility of carbonate rocks, corrosion activity of boricfluorhydric acid solutions both independently and in mixture with inhibitors of acid corrosion, effect of mud-acid solutions injection on the permeability of reservoir rocks are studied to develop effective technologies of mud-acid treatment. Nine basic formulae of mud-acid solutions based on boricfluorhydric acid that can be used in three main technological schemes are offered on the basis of laboratory studies. Field testing and subsequent implementation of the developed technologies of mud-acid treatment of producing wells of public company "Ukrnafta" proved the results and their effectiveness in field conditions . Technological efficiency of the developed technologies of acid treatment confirmed the results of hydrodynamic investigations of wells before and after the treatment.

AbstractWorldwide wind power capacity is increasing, while the environmental footprint and economic cost of energy produced decrease. However, wind power generation is weather-dependent. At a high penetration rate, storage systems such as power-to-gas may become necessary to adjust electricity production to consumption. This research work presents the environmental life cycle performance of wind power accounting for the energy storage induced by the temporal variability of weather-dependent production and consumption. A case study in which wind power installations are combined with a power-to-gas system in Denmark to provide electricity according to the national load consumption profile was considered. Results highlight an increase, roughly by a factor 2, of the carbon footprint coming from both energy storage infrastructure and induced losses, but remain significantly, at least ten times, lower than fossil counterparts.

AbstractThermal decomposition kinetics of Polypropylene (PP) waste is extremely important with respect to valorisation of waste plastics and production of utilizable components viz. chemicals, fuel oil & gas. The present research study focuses on pyrolysis kinetics of PP waste, which is present as a fraction of municipal plastic waste through distributed activation energy model (DAEM). The decomposition kinetics for PP follows a Gaussian distribution, where the normal distribution curves were centred corresponding to activation energy of 224 kJ/mol. The standard deviation of the distribution for the PP sample was found to be 22 kJ/mol indicating its wider distribution of decomposition range. The data validation has been carried out by comparing the rate parameter and extent of conversion values calculated through DAEM model with the Thermogravimetric analysis (TGA) experiments carried out for PP at various heating rates of 5, 10, 20 and 40 °C/min.

AbstractThe status quo in the global oil, gas, and coal industries in terms of their economic value, geographic distribution, and company structures is given. The current fossil fuel production volumes and decline rates required under 1.5 °C-compatible pathways for coal, oil, and natural gas are discussed. The assumptions made when calculating scope 1 and 2 emissions and current and future energy intensities are defined. The role of power and gas utilities under the OECM 1.5 °C scenario is discussed, together with the projected trajectories for renewable power- and heat-generating plants and those for hydrogen and synthetic fuel. Future structures of the global primary and secondary energy industries are suggested.

AbstractXylitol has been recognized by the US Department of Energy (DOE) as one of the top 12 value-added chemicals obtained from biomass, with a world market of 200,000 tonnes per year. The global xylitol market is expected to reach a value of US$ 1 Billion by 2026 growing at a compound annual growth rate (CAGR) of 5.8% during 2021–2026. Historically, the commercial xylitol production process has been dependent on the chemical hydrogenation of xylose. Several xylitol production plants, mainly in China that use the chemical process have had to reduce their production capacity to address regulations governing sustainability and environmental standards. In this chapter, key challenges and possible solutions for fermentative xylitol production at commercial scale are discussed in terms of: (1) Feedstock supply for commercial production plants; (2) Industrial biomass pretreatment; and (3) Lessons learned from industrial operations. These are drawn together to identify technology gaps and scaling-up challenges in light of the capital expenditure required to build a state-of-the art xylitol industrial biotechnology (IB) production facility and the potential to reduce climate change impact and contribute towards achieving net-zero targets.

AbstractChow and Rincon review the energy sector of North America, which plays a critical role in the economy of the U.S., Canada, and Mexico. The American shale oil and gas revolution, which drove production to historical peaks, will have diminished but still significant impact, including globally. High energy consumption rates in the U.S. and Canada challenge reaching climate policy goals, under heightened public pressure, and the search for alternatives to fossil fuels. Mexico will be more focused on economic development and energy access. The U.S. will continue to emphasize energy innovation, driven by public investment in research and development and private capital in commercial applications.

AbstractMethods and techniques are described for automated measurements of greenhouse gases (GHGs) in both the laboratory and the field. Robotic systems are currently available to measure the entire range of gases evolved from soils including dinitrogen (N2). These systems usually work on an exchange of the atmospheric N2with helium (He) so that N2 fluxes can be determined. Laboratory systems are often used in microbiology to determine kinetic response reactions via the dynamics of all gaseous N species such as nitric oxide (NO), nitrous oxide (N2O), and N2. Latest He incubation techniques also take plants into account, in order to study the effect of plant–soil interactions on GHGsand N2 production. The advantage of automated in-field techniques is that GHG emission rates can be determined at a high temporal resolution. This allows, for instance, to determine diurnal response reactions (e.g. with temperature) and GHG dynamics over longer time periods.

A theory is presented for predicting the production rate of turbulent spots. The theory, based on that by Mayle-Schulz for bypass transition, leads to a new correlation for the spot production rate in boundary layer flows with a zero pressure gradient. The correlation, which agrees reasonably well with data, clearly shows the effects of both free-stream turbulence level and length scale. In addition, the theory provides an estimate for the lowest level of free-stream turbulence causing bypass transition.

Feed inputs represent the largest variable cost of producing meat and milk from ruminant animals. Thus, strategies that improve the efficiency of feed utilization are needed to improve the global competitiveness of Israeli and U.S. cattle industries, and mitigate their environmental impact through reductions in nutrient excretions and greenhouse gas emissions. Implementation of innovative technologies that will enhance genetic merit for feed efficiency is arguably one of the most cost-effective strategies to meet future demands for animal-protein foods in an environmentally sustainable manner. While considerable genetic variation in feed efficiency exist within cattle populations, the expense of measuring individual-animal feed intake has precluded implementation of selection programs that target this trait. Residual feed intake (RFI) is a trait that quantifies between-animal variation in feed intake beyond that expected to meet energy requirements for maintenance and production, with efficient animals being those that eat less than expected for a given size and level of production. There remains a critical need to understand the biological drivers for genetic variation in RFI to facilitate development of effective selection programs in the future. Therefore, the aim of this project was to determine the biological basis for phenotypic variation in RFI of growing and lactating cattle, and discover metabolic biomarkers of RFI for early and more cost-effective selection of cattle for feed efficiency. Objectives were to: (1) Characterize the phenotypic relationships between RFI and production traits (growth or lactation), (2) Quantify inter-animal variation in residual HP, (3) Determine if divergent RFIphenotypes differ in HP, residual HP, recovered energy and digestibility, and (4) Determine if divergent RFI phenotypes differ in physical activity, feeding behavior traits, serum hormones and metabolites and hepatic mitochondrial traits. The major research findings from this project to date include: In lactating dairy cattle, substantial phenotypic variation in RFI was demonstrated as cows classified as having low RMEI consumed 17% less MEI than high-RMEI cows despite having similar body size and lactation productivity. Further, between-animal variation in RMEI was found to moderately associated with differences in RHP demonstrating that maintenance energy requirements contribute to observed differences in RFI. Quantifying energetic efficiency of dairy cows using RHP revealed that substantial changes occur as week of lactation advances—thus it will be critical to measure RMEI at a standardized stage of lactation. Finally, to determine RMEI in lactating dairy cows, individual DMI and production data should be collected for a minimum of 6 wk. We demonstrated that a favorably association exists between RFI in growing heifers and efficiency of forage utilization in pregnant cows. Therefore, results indicate that female progeny from parents selected for low RFI during postweaning development will also be efficient as mature females, which has positive implications for both dairy and beef cattle industries. Results from the beef cattle studies further extend our knowledge regarding the biological drivers of phenotypic variation in RFI of growing animals, and demonstrate that significant differences in feeding behavioral patterns, digestibility and heart rate exist between animals with divergent RFI. Feeding behavior traits may be an effective biomarker trait for RFI in beef and dairy cattle. There are differences in mitochondrial acceptor control and respiratory control ratios between calves with divergent RFI suggesting that variation in mitochondrial metabolism may be visible at the genome level. Multiple genes associated with mitochondrial energy processes are altered by RFI phenotype and some of these genes are associated with mitochondrial energy expenditure and major cellular pathways involved in regulation of immune responses and energy metabolism.

The Summary for Urban Policymakers (SUP) initiative provides a distillation of the IPCC reports into accessible and targeted summaries that can help inform action at city and regional scales. Volume I in the series, What the Latest Physical Science of Climate Change Means for Cities, identified the ways in which human-induced climate change is affecting every region of the world, and the cities and urban areas therein. Volume II, Climate Change in Cities and Urban Areas: Impacts, Adaptation and Vulnerability, assessed the feasibility and effectiveness of different adaptation options. To achieve climate resilient development, synergies between policies and actions for climate change adaptation, mitigation and other development goals are needed. This third volume in the series, What the Latest Science on Climate Change Mitigation Means For Cities and Urban Areas offers a concise and accessible distillation of the IPCC Working Group III Report for urban policymakers. The 21st century is characterized by a rapidly growing urban population, urban land expansion and associated rise in demand for resources, infrastructure and services. These trends are expected to drive the growth in emissions from urban consumption and production through 2100, although the rate of urban emissions growth will depend on the type of urbanisation and the speed and scale of mitigation action implemented. Aggressive and ambitious policies for transition towards net zero greenhouse gas emissions can be implemented in cities and urban areas, while contributing to sustainable development. Ultimately, mitigation action and adaptation are interdependent processes, and pursuing these actions together can promote sustainable development.

Barbados, through its Barbados National Energy Policy (BNEP) 2019-2030, announced its commitment to achieving 100 percent renewable energy and carbon neutrality by 2030. This commitment creates an opportunity for the GoB to manage the impact of the transition toward renewable clean energy by introducing measures to transform the way revenue from energy is collected thereby avoiding unnecessary fiscal costs. The purpose of this study is to calculate the revenue gap derived from Barbados 2030 energy transition goal of having a revenue-neutral transition and propose and evaluate various policy measures that could help seize opportunities to close that gap. The simulation model suggests that the energy transition would result in an estimated BBD$105 million in revenue losses a year by following the BNEP. Such a reduction would create a significant fiscal gap that would need to be addressed through the introduction of new forms of taxes or changes to current taxes in order to adapt tax collection to revenue creation from the new clean energy economy. A wide range of tax policy options and issues surrounding their effective implementation were discussed such as: increased taxes on fossil fuels, a change in the VAT rate, mileage taxes on electric and hybrid vehicles, and taxes on renewable energy production. Each of these new tax approaches can help address the fiscal gap estimated above.

1.1 Macroeconomic summary Economic recovery has consistently outperformed the technical staff’s expectations following a steep decline in activity in the second quarter of 2020. At the same time, total and core inflation rates have fallen and remain at low levels, suggesting that a significant element of the reactivation of Colombia’s economy has been related to recovery in potential GDP. This would support the technical staff’s diagnosis of weak aggregate demand and ample excess capacity. The most recently available data on 2020 growth suggests a contraction in economic activity of 6.8%, lower than estimates from January’s Monetary Policy Report (-7.2%). High-frequency indicators suggest that economic performance was significantly more dynamic than expected in January, despite mobility restrictions and quarantine measures. This has also come amid declines in total and core inflation, the latter of which was below January projections if controlling for certain relative price changes. This suggests that the unexpected strength of recent growth contains elements of demand, and that excess capacity, while significant, could be lower than previously estimated. Nevertheless, uncertainty over the measurement of excess capacity continues to be unusually high and marked both by variations in the way different economic sectors and spending components have been affected by the pandemic, and by uneven price behavior. The size of excess capacity, and in particular the evolution of the pandemic in forthcoming quarters, constitute substantial risks to the macroeconomic forecast presented in this report. Despite the unexpected strength of the recovery, the technical staff continues to project ample excess capacity that is expected to remain on the forecast horizon, alongside core inflation that will likely remain below the target. Domestic demand remains below 2019 levels amid unusually significant uncertainty over the size of excess capacity in the economy. High national unemployment (14.6% for February 2021) reflects a loose labor market, while observed total and core inflation continue to be below 2%. Inflationary pressures from the exchange rate are expected to continue to be low, with relatively little pass-through on inflation. This would be compatible with a negative output gap. Excess productive capacity and the expectation of core inflation below the 3% target on the forecast horizon provide a basis for an expansive monetary policy posture. The technical staff’s assessment of certain shocks and their expected effects on the economy, as well as the presence of several sources of uncertainty and related assumptions about their potential macroeconomic impacts, remain a feature of this report. The coronavirus pandemic, in particular, continues to affect the public health environment, and the reopening of Colombia’s economy remains incomplete. The technical staff’s assessment is that the COVID-19 shock has affected both aggregate demand and supply, but that the impact on demand has been deeper and more persistent. Given this persistence, the central forecast accounts for a gradual tightening of the output gap in the absence of new waves of contagion, and as vaccination campaigns progress. The central forecast continues to include an expected increase of total and core inflation rates in the second quarter of 2021, alongside the lapse of the temporary price relief measures put in place in 2020. Additional COVID-19 outbreaks (of uncertain duration and intensity) represent a significant risk factor that could affect these projections. Additionally, the forecast continues to include an upward trend in sovereign risk premiums, reflected by higher levels of public debt that in the wake of the pandemic are likely to persist on the forecast horizon, even in the context of a fiscal adjustment. At the same time, the projection accounts for the shortterm effects on private domestic demand from a fiscal adjustment along the lines of the one currently being proposed by the national government. This would be compatible with a gradual recovery of private domestic demand in 2022. The size and characteristics of the fiscal adjustment that is ultimately implemented, as well as the corresponding market response, represent another source of forecast uncertainty. Newly available information offers evidence of the potential for significant changes to the macroeconomic scenario, though without altering the general diagnosis described above. The most recent data on inflation, growth, fiscal policy, and international financial conditions suggests a more dynamic economy than previously expected. However, a third wave of the pandemic has delayed the re-opening of Colombia’s economy and brought with it a deceleration in economic activity. Detailed descriptions of these considerations and subsequent changes to the macroeconomic forecast are presented below. The expected annual decline in GDP (-0.3%) in the first quarter of 2021 appears to have been less pronounced than projected in January (-4.8%). Partial closures in January to address a second wave of COVID-19 appear to have had a less significant negative impact on the economy than previously estimated. This is reflected in figures related to mobility, energy demand, industry and retail sales, foreign trade, commercial transactions from selected banks, and the national statistics agency’s (DANE) economic tracking indicator (ISE). Output is now expected to have declined annually in the first quarter by 0.3%. Private consumption likely continued to recover, registering levels somewhat above those from the previous year, while public consumption likely increased significantly. While a recovery in investment in both housing and in other buildings and structures is expected, overall investment levels in this case likely continued to be low, and gross fixed capital formation is expected to continue to show significant annual declines. Imports likely recovered to again outpace exports, though both are expected to register significant annual declines. Economic activity that outpaced projections, an increase in oil prices and other export products, and an expected increase in public spending this year account for the upward revision to the 2021 growth forecast (from 4.6% with a range between 2% and 6% in January, to 6.0% with a range between 3% and 7% in April). As a result, the output gap is expected to be smaller and to tighten more rapidly than projected in the previous report, though it is still expected to remain in negative territory on the forecast horizon. Wide forecast intervals reflect the fact that the future evolution of the COVID-19 pandemic remains a significant source of uncertainty on these projections. The delay in the recovery of economic activity as a result of the resurgence of COVID-19 in the first quarter appears to have been less significant than projected in the January report. The central forecast scenario expects this improved performance to continue in 2021 alongside increased consumer and business confidence. Low real interest rates and an active credit supply would also support this dynamic, and the overall conditions would be expected to spur a recovery in consumption and investment. Increased growth in public spending and public works based on the national government’s spending plan (Plan Financiero del Gobierno) are other factors to consider. Additionally, an expected recovery in global demand and higher projected prices for oil and coffee would further contribute to improved external revenues and would favor investment, in particular in the oil sector. Given the above, the technical staff’s 2021 growth forecast has been revised upward from 4.6% in January (range from 2% to 6%) to 6.0% in April (range from 3% to 7%). These projections account for the potential for the third wave of COVID-19 to have a larger and more persistent effect on the economy than the previous wave, while also supposing that there will not be any additional significant waves of the pandemic and that mobility restrictions will be relaxed as a result. Economic growth in 2022 is expected to be 3%, with a range between 1% and 5%. This figure would be lower than projected in the January report (3.6% with a range between 2% and 6%), due to a higher base of comparison given the upward revision to expected GDP in 2021. This forecast also takes into account the likely effects on private demand of a fiscal adjustment of the size currently being proposed by the national government, and which would come into effect in 2022. Excess in productive capacity is now expected to be lower than estimated in January but continues to be significant and affected by high levels of uncertainty, as reflected in the wide forecast intervals. The possibility of new waves of the virus (of uncertain intensity and duration) represents a significant downward risk to projected GDP growth, and is signaled by the lower limits of the ranges provided in this report. Inflation (1.51%) and inflation excluding food and regulated items (0.94%) declined in March compared to December, continuing below the 3% target. The decline in inflation in this period was below projections, explained in large part by unanticipated increases in the costs of certain foods (3.92%) and regulated items (1.52%). An increase in international food and shipping prices, increased foreign demand for beef, and specific upward pressures on perishable food supplies appear to explain a lower-than-expected deceleration in the consumer price index (CPI) for foods. An unexpected increase in regulated items prices came amid unanticipated increases in international fuel prices, on some utilities rates, and for regulated education prices. The decline in annual inflation excluding food and regulated items between December and March was in line with projections from January, though this included downward pressure from a significant reduction in telecommunications rates due to the imminent entry of a new operator. When controlling for the effects of this relative price change, inflation excluding food and regulated items exceeds levels forecast in the previous report. Within this indicator of core inflation, the CPI for goods (1.05%) accelerated due to a reversion of the effects of the VAT-free day in November, which was largely accounted for in February, and possibly by the transmission of a recent depreciation of the peso on domestic prices for certain items (electric and household appliances). For their part, services prices decelerated and showed the lowest rate of annual growth (0.89%) among the large consumer baskets in the CPI. Within the services basket, the annual change in rental prices continued to decline, while those services that continue to experience the most significant restrictions on returning to normal operations (tourism, cinemas, nightlife, etc.) continued to register significant price declines. As previously mentioned, telephone rates also fell significantly due to increased competition in the market. Total inflation is expected to continue to be affected by ample excesses in productive capacity for the remainder of 2021 and 2022, though less so than projected in January. As a result, convergence to the inflation target is now expected to be somewhat faster than estimated in the previous report, assuming the absence of significant additional outbreaks of COVID-19. The technical staff’s year-end inflation projections for 2021 and 2022 have increased, suggesting figures around 3% due largely to variation in food and regulated items prices. The projection for inflation excluding food and regulated items also increased, but remains below 3%. Price relief measures on indirect taxes implemented in 2020 are expected to lapse in the second quarter of 2021, generating a one-off effect on prices and temporarily affecting inflation excluding food and regulated items. However, indexation to low levels of past inflation, weak demand, and ample excess productive capacity are expected to keep core inflation below the target, near 2.3% at the end of 2021 (previously 2.1%). The reversion in 2021 of the effects of some price relief measures on utility rates from 2020 should lead to an increase in the CPI for regulated items in the second half of this year. Annual price changes are now expected to be higher than estimated in the January report due to an increased expected path for fuel prices and unanticipated increases in regulated education prices. The projection for the CPI for foods has increased compared to the previous report, taking into account certain factors that were not anticipated in January (a less favorable agricultural cycle, increased pressure from international prices, and transport costs). Given the above, year-end annual inflation for 2021 and 2022 is now expected to be 3% and 2.8%, respectively, which would be above projections from January (2.3% and 2,7%). For its part, expected inflation based on analyst surveys suggests year-end inflation in 2021 and 2022 of 2.8% and 3.1%, respectively. There remains significant uncertainty surrounding the inflation forecasts included in this report due to several factors: 1) the evolution of the pandemic; 2) the difficulty in evaluating the size and persistence of excess productive capacity; 3) the timing and manner in which price relief measures will lapse; and 4) the future behavior of food prices. Projected 2021 growth in foreign demand (4.4% to 5.2%) and the supposed average oil price (USD 53 to USD 61 per Brent benchmark barrel) were both revised upward. An increase in long-term international interest rates has been reflected in a depreciation of the peso and could result in relatively tighter external financial conditions for emerging market economies, including Colombia. Average growth among Colombia’s trade partners was greater than expected in the fourth quarter of 2020. This, together with a sizable fiscal stimulus approved in the United States and the onset of a massive global vaccination campaign, largely explains the projected increase in foreign demand growth in 2021. The resilience of the goods market in the face of global crisis and an expected normalization in international trade are additional factors. These considerations and the expected continuation of a gradual reduction of mobility restrictions abroad suggest that Colombia’s trade partners could grow on average by 5.2% in 2021 and around 3.4% in 2022. The improved prospects for global economic growth have led to an increase in current and expected oil prices. Production interruptions due to a heavy winter, reduced inventories, and increased supply restrictions instituted by producing countries have also contributed to the increase. Meanwhile, market forecasts and recent Federal Reserve pronouncements suggest that the benchmark interest rate in the U.S. will remain stable for the next two years. Nevertheless, a significant increase in public spending in the country has fostered expectations for greater growth and inflation, as well as increased uncertainty over the moment in which a normalization of monetary policy might begin. This has been reflected in an increase in long-term interest rates. In this context, emerging market economies in the region, including Colombia, have registered increases in sovereign risk premiums and long-term domestic interest rates, and a depreciation of local currencies against the dollar. Recent outbreaks of COVID-19 in several of these economies; limits on vaccine supply and the slow pace of immunization campaigns in some countries; a significant increase in public debt; and tensions between the United States and China, among other factors, all add to a high level of uncertainty surrounding interest rate spreads, external financing conditions, and the future performance of risk premiums. The impact that this environment could have on the exchange rate and on domestic financing conditions represent risks to the macroeconomic and monetary policy forecasts. Domestic financial conditions continue to favor recovery in economic activity. The transmission of reductions to the policy interest rate on credit rates has been significant. The banking portfolio continues to recover amid circumstances that have affected both the supply and demand for loans, and in which some credit risks have materialized. Preferential and ordinary commercial interest rates have fallen to a similar degree as the benchmark interest rate. As is generally the case, this transmission has come at a slower pace for consumer credit rates, and has been further delayed in the case of mortgage rates. Commercial credit levels stabilized above pre-pandemic levels in March, following an increase resulting from significant liquidity requirements for businesses in the second quarter of 2020. The consumer credit portfolio continued to recover and has now surpassed February 2020 levels, though overall growth in the portfolio remains low. At the same time, portfolio projections and default indicators have increased, and credit establishment earnings have come down. Despite this, credit disbursements continue to recover and solvency indicators remain well above regulatory minimums. 1.2 Monetary policy decision In its meetings in March and April the BDBR left the benchmark interest rate unchanged at 1.75%.

Ruminants provide human society with high quality food from non-human-edible resources, but their emissions negatively impact the environment via greenhouse gas production. The rumen and its resident microorganisms dictate both processes. The overall goal of this project was to determine whether a causal relationship exists between the rumen microbiome and the host animal's physiology, and if so, to isolate and examine the specific determinants that enable this causality. To this end, we divided the project into three specific parts: (1) determining the feed efficiency of 200 milking cows, (2) determining whether the feed- efficiency phenotype can be transferred by transplantation and (3) isolating and examining microbial consortia that can affect the feed-efficiency phenotype by their transplantation into germ-free ruminants. We finally included 1000 dairy cow metadata in our study that revealed a global core microbiome present in the rumen whose composition and abundance predicted many of the cows’ production phenotypes, including methane emission. Certain members of the core microbiome are heritable and have strong associations to cardinal rumen metabolites and fermentation products that govern the efficiency of milk production. These heritable core microbes therefore present primary targets for rumen manipulation towards sustainable and environmentally friendly agriculture. We then went beyond examining the metagenomic content, and asked whether microbes behave differently with relation to the host efficiency state. We sampled twelve animals with two extreme efficiency phenotypes, high efficiency and low efficiency where the first represents animals that maximize energy utilization from their feed whilst the later represents animals with very low utilization of the energy from their feed. Our analysis revealed differences in two host efficiency states in terms of the microbial expression profiles both with regards to protein identities and quantities. Another aim of the proposal was the cultivation of undescribed rumen microorganisms is one of the most important tasks in rumen microbiology. Our findings from phylogenetic analysis of cultured OTUs on the lower branches of the phylogenetic tree suggest that multifactorial traits govern cultivability. Interestingly, most of the cultured OTUs belonged to the rare rumen biosphere. These cultured OTUs could not be detected in the rumen microbiome, even when we surveyed it across 38 rumen microbiome samples. These findings add another unique dimension to the complexity of the rumen microbiome and suggest that a large number of different organisms can be cultured in a single cultivation effort. In the context of the grant, the establishment of ruminant germ-free facility was possible and preliminary experiments were successful, which open up the way for direct applications of the new concepts discovered here, prior to the larger scale implementation at the agricultural level.

The whitefly (Bemisia tabaci) is a serious agricultural pest that afflicts a wide variety of ornamental and vegetable crop species. To enable survival on a great diversity of host plants, whiteflies must have the ability to avoid or detoxify numerous different plant defensive chemicals. Such toxins include a group of insect-deterrent molecules called glucosinolates (GSs), which also provide the pungent taste of Brassica vegetables such as radish and cabbage. In our BARD grant, we used the whitefly B. tabaci and Arabidopsis (a Brassica plant model) defense mutants and transgenic lines, to gain comprehensive understanding both on plant defense pathways against whiteflies and whitefly defense strategies against plants. Our major focus was on GSs. We produced transgenic Arabidopsis plants accumulating high levels of GSs. At the first step, we examined how exposure to high levels of GSs affects decision making and performance of whiteflies when provided plants with normal levels or high levels of GSs. Our major conclusions can be divided into three: (I) exposure to plants accumulating high levels of GSs, negatively affected the performance of both whitefly adult females and immature; (II) whitefly adult females are likely to be capable of sensing different levels of GSs in their host plants and are able to choose, for oviposition, the host plant on which their offspring survive and develop better (preference-performance relationship); (III) the dual presence of plants with normal levels and high levels of GSs, confused whitefly adult females, and led to difficulties in making a choice between the different host plants. These findings have an applicative perspective. Whiteflies are known as a serious pest of Brassica cropping systems. If the differences found here on adjacent small plants translate to field situations, intercropping with closely-related Brassica cultivars could negatively influence whitefly population build-up. At the second step, we characterized the defensive mechanisms whiteflies use to detoxify GSs and other plant toxins. We identified five detoxification genes, which can be considered as putative "key" general induced detoxifiers because their expression-levels responded to several unrelated plant toxic compounds. This knowledge is currently used (using new funding) to develop a new technology that will allow the production of pestresistant crops capable of protecting themselves from whiteflies by silencing insect detoxification genes without which successful host utilization can not occur. Finally, we made an effort to identify defense genes that deter whitefly performance, by infesting with whiteflies, wild-type and defense mutated Arabidopsis plants. The infested plants were used to construct deep-sequencing expression libraries. The 30- 50 million sequence reads per library, provide an unbiased and quantitative assessment of gene expression and contain sequences from both Arabidopsis and whiteflies. Therefore, the libraries give us sequence data that can be mined for both the plant and insect gene expression responses. An intensive analysis of these datasets is underway. We also conducted electrical penetration graph (EPG) recordings of whiteflies feeding on Arabidopsis wild-type and defense mutant plants in order to determine the time-point and feeding behavior in which plant-defense genes are expressed. We are in the process of analyzing the recordings and calculating 125 feeding behavior parameters for each whitefly. From the analyses conducted so far we conclude that the Arabidopsis defense mutants do not affect adult feeding behavior in the same manner that they affect immatures development. Analysis of the immatures feeding behavior is not yet completed, but if it shows the same disconnect between feeding behavior data and developmental rate data, we would conclude that the differences in the defense mutants are due to a qualitative effect based on the chemical constituency of the phloem sap.