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In this study, CeO2 rods (CeO2/r), cubes (CeO2/c) and octahedra (CeO2/o) supported catalysts with identical Ru particle size were prepared. Trend in the activity of these catalysts for CO2 methanation was compared with the trend in their oxygen vacancy concentration measured after calcination. Ru/CeO2/r outperforms the other two catalysts with a reaction rate of 11.0 × 10−8 mol s -1 m Ru -2 and selectivity to methane of 99% at 250 °C. Temperature-programmed reduction (TPR), Raman and X-ray photoemission spectroscopy (XPS) results confirms that Ru addition enhances reduction of CeO2. Also, Ru/CeO2/r is more reducible and contains more oxygen vacancies as compared to Ru/CeO2/o and Ru/CeO2/c, both after calcination as well as under reducing conditions. H2 consumption during TPR shows removal of oxygen equivalent to about 3 monolayers, implying diffusion of vacancies into the subsurface or bulk of CeO2. The catalyst with the highest concentration of oxygen vacancies is also the most active catalyst, suggesting that reactive adsorption CO2 at an oxygen vacancy is the rate determining step.

1st International Conference on Sustainable Water Processing -- SEP 11-14, 2016 -- Sitges, SPAIN, WOS: 000471238900003, Wastewater treatment and low energy consumption are two important environmental issues. In this work, a challenging treatment problem of leather industry wastewater is chosen as a case study to combine the issue of energy and treatment efficiency using a common denominator of oxygen demand. Tannery wastewater is known for its highly contaminated structure. Due to the acidic nature of the effluent, conventional methods do not perform well for tannery wastes, so an electrochemical process is a reasonable approach for the problem. Since electrochemical reactors use electricity, the energy efficiency of such plants should be simultaneously considered for overall sustainability. The electricity production partially results in carbon footprints and consumption of oxygen. In this work, the electrochemical treatment results were assessed through total chromium removal and chemical oxygen demand (COD) reduction. As expected, the electrochemical process parameters (reactor types, electrode variations, electrical current density, etc.) as well as the process duration affect the treatment performance. Meanwhile, these parameters also affect energy consumption. Although the energy consumption has been previously researched, (i) "the oxygen equivalent of the required energy" and (ii) "oxygen demand reduction of the wastewater" were not considered simultaneously before. In this work, the used energy is represented in terms of consumed oxygen at the current electric generation profile (in Turkey and in USA). It is argued that, as the consumed energy increases, the consumed oxygen also increases, causing a separate pollution (in terms of COD and other indirect effects). The combined production/consumption profiles as well as energy efficient parameter settings are investigated by experiments. It is observed that the combined oxygen demand (i.e. reduced on the treatment side and increased at the power generation side) starts exhibiting an overall increase at early treatment stages. For example, at an electrical current setting of 20 mA/cm(2) and pH of 7, using electro-coagulation with aluminum electrodes, treatment reaches to 82% COD removal (from 1024 mg/L to 180.71 mg/L) at 8.33 kWh/m(3), corresponding to consuming 3.23 g/L oxygen at average energy production settings in Turkey. The oxygen consumption using electro-Fenton exhibits similar results. The necessity of renewable energy utilization or an earlier treatment termination is concluded, Scientific and Technological Research Council of Turkey (TUBITAK) [115Y841]; Anadolu University Research Fund [BAP - 1601F026], This work has been supported in parts by the Scientific and Technological Research Council of Turkey (TUBITAK - contract no. 115Y841) and Anadolu University Research Fund (BAP - 1601F026).

Oxygen carrier materials were synthesized using five different types of manganese ores with addition of iron oxide (Fe2O3), and they were investigated for their reactivity and properties in chemical looping with oxygen uncoupling (CLOU). Two different Mn/Fe molar ratios (1:2 and 2:1) were examined. The samples were manufactured by using a lab-scale extrusion method followed by sintering at 950 degrees C for 4 h. To measure their reactivity, the materials were exposed to gaseous CH4 and syngas (50:50 CO/H-2) as well as solid fuel (petroleum coke), in a batch fluidized-bed reactor. With CH4, the materials based on ores from Brazil and Gabon with a Mn/Fe molar ratio 2:1 showed the best reactivity. For reduction using syngas, samples based on Eastern European and South African ores provided higher amounts of oxygen equivalent, up to 3-5% of their mass. To investigate the ability of the samples to release gas-phase oxygen, solid fuel experiments using 0.1 g of petroleum coke in a bed of 10 g oxygen carrier were performed at 950 degrees C with Brazilian, Gabon, and Eastern European ores. In these solid fuel tests samples with a Mn/Fe molar ratio of 1:2 showed higher uncoupling rates. Based on X-ray diffraction analysis, the primary phase detected in all fresh particles was the oxidized form of MnyFe1-yOx, that is, bixbyite [(Mn,Fe)(2)O-3]. All of the particles showed sufficiently high crushing strength (> 2N) and a reasonable attrition resistance (attrition index < 6 wt% h(-1)). This suggests that the materials could be suitable for practical applications. It is concluded that the oxygen carriers made by manganese ores have the potential to be used as oxygen carriers for chemical-looping combustion and chemical looping with oxygen uncoupling.

The proper design of aeration systems for bioreactors is critical since it can represent up to 50% of the operational and capital cost at water reclamation facilities. Transferring the actual amount of oxygen needed to meet the oxygen demand of the wastewater requires α- and β-factors, which are used for calculating the actual oxygen transfer rate (AOTR) under process conditions based on the standard oxygen transfer rate (SOTR). The SOTR is measured in tap water at 20°C, 1 atmospheric pressure, and 0 mg L−1 of dissolved oxygen (DO). In this investigation, two 11.4-L bench-scale completely mixed activated process (CMAS) reactors were operated at various solid retention times (SRTs) to ascertain the relationship between the α-factor and SRT, and between the β-factor and SRT. The second goal was to determine if actual oxygen uptake rates (AOURs) are equal to calculated oxygen uptake rates (COURs) based on mass balances. Each reactor was supplied with 0.84 L m−1 of air resulting in SOTRs of 14.3 and 1...

Oxygen supply is the primary factor in ensuring human survival in confined spaces. Compared with high pressure oxygen bottles, potassium superoxide oxygen board has advantages such as small size, large oxygen storage per unit volume, absorbing carbon dioxide while providing oxygen. However, the release rate of chemical oxygen in a confined space relates to the concentration of carbon dioxide, temperature, humidity and other environmental parameters. To meet human survival needs within the refuge chamber, this paper made experiments on potassium superoxide oxygen production performance factors, including humidity test, carbon dioxide concentrations test, surface spray wet test and so on. Through tests the amount and the rate of oxygen production, and the removal efficiency of carbon dioxide of potassium superoxide in different situations are obtained. And through a human survival experiment, the potassium superoxide oxygen board can satisfy the human body needs is validated. These all provide basis for the establishment of auxiliary oxygen supply facility in the refuge chamber.

depletion (e.g., � 0.7 to þ0.3 mg L � 1 d � 1 ) were examined in a field study conducted in the western part of the central basin of Lake Erie in 2008 and 2009. Data were obtained from a spatial array of moorings as well as sampling cruises that examined the physical and biological conditions needed to investigate the dynamics of the oxygen depletion and create a vertical oxygen budget. The flux of oxygen through the thermocline to the hypolimnion was a significant source of oxygen equivalent to � 18% of the total oxygen depletion in the hypolimnion over the stratified period. The total oxygen depletion in the hypolimnion was due to equivalent amounts of hypolimnetic oxygen demand due to respiration in the water column and flux of oxygen to the bottom due to sediment oxygen demand. This latter finding was strongly dependent on hypolimnion thickness in Lake Erie, which also appeared to be an important parameter driving the rate of oxygen depletion by controlling the vertical volumetric fluxes and hence the competition between vertical flux and community respiration in the hypolimnion of shallow lakes.

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Agradecemos a compreensão. on 2016-08-19T19:37:08Z (GMT) Submitted by WILLIAN EIJI MIYAGI null (wemiyagi@hotmail.com) on 2016-08-22T22:01:16Z No. of bitstreams: 1 Dissertação final com ficha catalográfica.pdf: 2345213 bytes, checksum: 181f4a573486a33a82db142470ca14bd (MD5) Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-23T16:34:25Z (GMT) No. of bitstreams: 1 miyagi_we_me_rcla.pdf: 2345213 bytes, checksum: 181f4a573486a33a82db142470ca14bd (MD5) Made available in DSpace on 2016-08-23T16:34:25Z (GMT). No. of bitstreams: 1 miyagi_we_me_rcla.pdf: 2345213 bytes, checksum: 181f4a573486a33a82db142470ca14bd (MD5) Previous issue date: 2016-08-12 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O presente estudo se propôs a investigar questões relacionadas a validade, reprodutibilidade e sensibilidade de um protocolo alternativo para estimativa do máximo déficit acumulado de oxigênio em apenas uma sessão de esforço supramáximo (MAODALT) em cicloergômetro. Para responder essas questões foram realizados quatro experimentos, que tiveram como objetivos: verificar a validade do MAODALT e a influência da utilização de diferentes intensidades de exercício supramáximo (Experimento 1); verificar possíveis associações entre o MAODALT e as variáveis de desempenho provenientes do teste de Wingate (WAnT) (Experimento 2); verificar a sensibilidade do MAODALT em discriminar indivíduos com diferentes níveis de treinamento (Experimento 3); verificar o efeito da ingestão aguda de cafeína sobre o MAODALT (Experimento 4). No experimento 1, catorze indivíduos moderadamente ativos (26±6 anos) foram submetidos a um teste incremental máximo para determinação do consumo máximo de oxigênio ("V" ̇O2MAX) e da intensidade associada ao "V" ̇O2MAX (i"V" ̇O2MAX), dez exercícios em intensidades submáximas (30-90% da i"V" ̇O2MAX) e oito exercícios em intensidades supramáximas (100-150% da i"V" ̇O2MAX). Ainda, onze ciclistas (28±4 anos) foram submetidos a um teste incremental e a dois esforços supramáximos (teste e reteste) na intensidade que apresentou o melhor nível de concordância com o máximo déficit acumulado de oxigênio determinado de modo convencional (MAODC). No experimento 2, quinze ciclistas de mountain biking do sexo masculino (31±5 anos) foram submetidos a um teste incremental, um esforço supramáximo à intensidade de 115% da i"V" ̇O2MAX e um WAnT. No Experimento 3, cinquenta e cinco sujeitos foram divididos em três grupos: não treinados, recreacionalmente treinados e treinados. Em seguida, foram submetidos ao teste incremental e a um esforço supramáximo. E no Experimento 4, catorze ciclistas do sexo masculino (30±6 anos) foram submetidos a um teste incremental e a dois esforços supramáximos suplementando previamente cafeína (6 mg•kg-1) ou placebo (dextrose) em um desenho duplo cego e cruzado. Como resultados gerais, foi verificado que: 1) MAODALT é um procedimento válido para estimar a capacidade anaeróbia, mas sofre influência da intensidade supramáxima; 2) a intensidade de exercício supramáximo que apresentou o melhor nível de associação com o MAODC correspondeu a 115% da i"V" ̇O2MAX; 3) MAODALT apresentou associações com as variáveis do WAnT; 4) MAODALT parece ser sensível em discriminar indivíduos com diferentes níveis de treinamento; 5) a ingestão aguda de cafeína melhorou o tempo até a exaustão, mas o MAODALT permaneceu inalterado. Conclui-se que o MAODALT é válido para estimativa da capacidade anaeróbia, reprodutível à intensidade de 115% da i"V" ̇O2MAX, apresenta associações com o desempenho em teste anaeróbio, é sensível em discriminar indivíduos com diferentes níveis de aptidão física e permanece inalterado após suplementação aguda de cafeína. The present study was proposed to verify issues related to the validity, reliability and sensibility of an alternative protocol to estimate the maximal accumulated oxygen deficit using only supramaximal effort (MAODALT) in cycling. In order to answer these questions, four experiments were carried out with the following objectives: to verify the validity of MAODALT and the effect of the use of different supramaximal intensities (Experiment 1); to verify possible associations between the MAODALT and performance in the Wingate test (WAnT) (Experiment 2); to verify the sensibility of MAODALT in to discriminate individuals with different training status (Experiment 3); to verify the effect of caffeine acute ingestion on MAODALT (Experiment 4). In the Experiment 1, fourteen active men (26±6 years) performed a maximal incremental test to determine the maximal oxygen uptake ("V" ̇O2MAX) and the intensity associated to "V" ̇O2MAX (i"V" ̇O2MAX), ten submaximal efforts (30-90% da i"V" ̇O2MAX) and eight supramaximal efforts (100-150% da i"V" ̇O2MAX). In addition, eleven cyclists (28±4 years) were submitted to a maximal incremental test and two supramaximal efforts at intensity that presented the best level of agreement with the maximal accumulated oxygen deficit determined by conventional method (MAODC). In Experiment 2, fifteen mountain biking men cyclists (31±5 years) performed a maximal incremental test, a supramaximal effort at 115% of the i"V" ̇O2MAX and a WAnT. In Experiment 3, fifty-five men were divided in three groups: untrained, recreationally trained and trained. The subjects performed a maximal incremental test and a supramaximal effort. In Experiment 4, fourteen cyclists male (30±6 years) were submitted to a maximal incremental test and two supramaximal efforts previously supplementing caffeine (6 mg•kg-1) or placebo (dextrose) in a double blind and crossover design. Such as results, it was verified that: 1) the MAODALT is a valid procedure to estimate the anaerobic capacity, however suffer influence of the supramaximal effort intensity; 2) The supramaximal intensity that presented the best level of agreement with the MAODC corresponds to 115% of the i"V" ̇O2MAX; 3) the MAODALT expressed in absolute values showed associations with the anaerobic performance evaluated in the WAnT; 4) the MAODALT seems to be sensible in to discriminate individuals with different training status. 5) The caffeine acute ingestion improved the time to exhaustion in the supramaximal effort, however, the MAODALT remained unaltered. Therefore, we concluded that the MAODALT is a valid procedure to estimate the anaerobic capacity, reproducible at 115% of i"V" ̇O2MAX, presents associations with the performance in anaerobic test, remains unaltered after caffeine supplementation and is sensible in to discriminate individuals with different physical fitness. FAPESP: 2014/02892-5

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-05T18:42:10Z No. of bitstreams: 1 Plinio dos Santos Ramos Tese CEHB.pdf: 2246054 bytes, checksum: 28c335cf66fcb86474e4a4cbef694a9a (MD5) Made available in DSpace on 2021-01-05T18:42:10Z (GMT). No. of bitstreams: 1 Plinio dos Santos Ramos Tese CEHB.pdf: 2246054 bytes, checksum: 28c335cf66fcb86474e4a4cbef694a9a (MD5) Previous issue date: 2015-08-10 The ventilatory variables obtained through the analysis of expired gases during cardiopulmonary maximal exercise test (CPET) have been the target of several and consistent studies, both from a physiologic and clinical-epidemiological perspective; however, there is still information to be further explored. In this sense, this dissertation explores methodological, physiological and clinical aspects of the minimal value of the ventilatory equivalent for oxygen obtained in a given minute of an incremental exercise carried in a lower limb cyclergometer, and thereafter named cardiorespiratory optimal point (COP). In this context, the dissertation comprised four original studies with the following objectives: 1) to determine the COP behavior as a function of gender and age in healthy adults and its association with other CPET variables; 2) to investigate COP stability in a maximal CPET performed in a lower limb cyclergometer; 3) to analyze the COP behavior in patients with panic disorder and 4) to investigate the prognostic value of COP for all-cause mortality in individuals aged between 40 and 85 years old. In the first study, 624 healthy subjects underwent maximal CPET were selected to describe the behavior of COP. It was found that the COP increases with age, it is smaller in men 23.2 ± 4.48 vs 25.0 ± 5.14 (p 30 was associated with a higher all-cause mortality (RR = 6.86; 95% CI = 3.69 to 12.75, p 30 de POC foram associados com maior mortalidade (p

Testing were carried out on two steels. The first was microalloyed with Nb and second with Ti, Nb and V. The impact toughness of weld metals of these steels was evaluated using an instrumented Charpy pendulum. Five different gas mixtures (Ar, CO2, O2) were used to determine the optimal gas shielded metal arc process for both steels. The oxygen equivalent was used as a representative parameter of a mixture to follow, in particularly, its effect on the microstructure, toughness and crack propagation energy of the weld metal. For these investigated steels, the optimum gas mixture was established (5%CO2, 0.91%O2, balance Ar), which provided the maximum crack propagation energy, due to the microstructure which consisted dominantly of acicular ferrite.

A water quality modeling study was performed in a macrophyte dominated river. A computer model, MACRIV (macrophyte growing river) was formulated to incorporate diurnal dissolved oxygen variations and nutrient uptake/recycle caused by all aquatic plants, including macrophytes. In this model, the aquatic plant is represented as an equivalent amount of dissolved oxygen by reach, which varies diurnally as well as seasonally depending upon solar radiation, temperature, and nutrients. The solar radiation is computed in the model based on the latitude, Julian day, and real-time of day. The model simulates seven coupled state variables (BOD (CBOD or 5-day BOD), DO (daily average value or diurnal variation), organic nitrogen, ammonia nitrogen, nitrite/nitrate nitrogen, total organic phosphorus, dissolved inorganic phosphorus (DIP)) and two non-coupled variables (a first-order decay substance, and a conservative substance). Through a stoichiometric relationship between plant protoplasm and physiological processes including photosynthesis, respiration, and death, the water quality variables interacting with aquatic plants are computed in the model. The model was calibrated and verified against data collected from an impounded river in which macrophytes play an important role in defining water quality dynamics. There were reasonable agreements between model predictions and the field measurements both for steady-state water quality and diurnal dissolved oxygen. The overall study demonstrated that the developed MACRIV model can simulate the most important parameters involved in waste load allocation studies in macrophyte growing rivers, such as diurnal DO variation, BOD (autochtonous and allochtonous), ammonia toxicity, and nutrient dynamics.

An artificial gill was developed using a concentrated hemoglobin solution containing inositol hexaphosphate (IHP), as the oxygen carrier solution, with the oxygen affinity controlled by temperature. Oxygen dissolved in sea water is first taken up from water to the oxygen carrier solution at 293 K. The oxygen carrier solution is then heated and the oxygen is released from the oxygen carrier solution to expired air at 310 K. The enhancement factors of the oxygen carrier solution that indicate its performance were obtained from the oxygen uptake rate and oxygen release rate. The values were approximately 3 at oxygen uptake and 16 at oxygen release. The scale-up for a human being at rest was estimated using these values, and the optimal operating condition was determined. The required membrane surface area for a human being is 63.8 m 2 . The oxygen partial pressure of inspiration is 20.7 kPa, adequate for the respiration. These indicate the feasibility of a compact and portable artificial gill device.

The oxygen ‘cascade' is really a ‘whirlpool'. Mitochondrial oxygen consumption ‘sucks' the body's oxygen tensions down below the inspired oxygen tension, generating both the oxygen extraction or flux from atmosphere to cell and the tension gradients between atmosphere and cell. Oxygen flux is demand generated. Oxygen consumption determines the oxygen extraction which determines the residual haemoglobin saturation at any point along a capillary. Since this saturation determines the capillary oxygen tension, rather than vice versa, rotation of the haemoglobin saturation curve gives the oxygen extraction curve. The shape and location of the oxygen extraction curve maintains capillary and therefore intracellular oxygen tension over a wide range of oxygen extraction, minimizing the threshold oxygen supply needed to avoid supply dependency. Above this threshold, oxygen flux is supply independent, so is unaffected by increasing inspired oxygen tension, cardiac output or haemoglobin concentration.

Liquid Argon Time Projection Chambers (LArTPCs) show promise as scalable devices for the large detectors needed for long-baseline neutrino oscillation physics. Over the last several years at Fermilab a staged approach to developing the technology for large detectors has been developed. The TPC detectors require ultra-pure liquid argon with respect to electronegative contaminants such as oxygen and water. The tolerable electronegative contamination level may be as pure as 60 parts per trillion of oxygen. Three liquid argon cryostats operated at Fermilab have achieved the extreme purity required by TPCs. These three cryostats used evacuation to remove atmospheric contaminants as the first purification step prior to filling with liquid argon. Future physics experiments may require very large detectors with tens of kilotonnes of liquid argon mass. The capability to evacuate such large cryostats adds significant cost to the cryostat itself in addition to the cost of a large scale vacuum pumping system. This paper describes a 30 ton liquid argon cryostat at Fermilab which uses purging to remove atmospheric contaminants instead of evacuation as the first purification step. This cryostat has achieved electronegative contamination levels better than 60 parts per trillion of oxygen equivalent. The results of this liquid argon purity demonstration will strongly influence the design of future TPC cryostats.

Development of an artificial gill, for the uptake of oxygen from water to air, requires an increase in oxygen transfer rate. In the present study, oxygen transfer rate was enhanced using a washed red blood cell suspension as a thermo-responsive oxygen carrier solution, which changes oxygen affinity with temperature. Oxygen dissolved in water first combined with the oxygen carrier solution at a low temperature using a membrane module. The oxygen carrier solution was then heated to release oxygen into the air using a second membrane module. The water flow rate required to sustain a human being at rest was greatly reduced by heating the oxygen carrier solution due to increase in the limit of the oxygen partial pressure of water of which can be transferred, compared with when oxygen was transferred directly from water. The required membrane surface area is 225 m 2 , sufficient for the development of a compact artificial gill.

Oxygen transport through a dense oxygen conducting ceramic membrane is driven by an oxygen activity gradient imposed by the gas streams on either side of the membrane. The oxygen activity on each side of the membrane is altered as oxygen is transported across the membrane. Thus, the oxygen activity gradient will not be the same in each region of a membrane and will generate a different oxygen flux. This interaction between the oxygen gradient and the oxygen flux can produce a lower average oxygen flux across the membrane, can mask differences between materials, and can explain the dependence of oxygen flux on oxygen activity. An oxygen flux model has been developed that takes into account the rate of oxygen transport across the membrane, the reducing gas flow rate and the reducing gas composition when determining the oxygen activity gradient imposed on the membrane. The model was validated by collecting oxygen flux data for a dense perovskite ceramic membrane at 1000°C under a wide range of concentrations and flow rates of CO and CO 2 on one side and air on the other side of the membrane. The results show that an order of magnitude variation in the oxygen flux can be produced merely by changing the reducing gas flow rate. These results can help explain differences in oxygen flux data reported over a range of conditions and shed light on the rate limiting step in oxygen transport through dense oxygen conducting ceramic membranes.

Главным ограничителем доставки кислорода к скелетным мышцам является способность миокарда доставлять к ним кровь. Околопредельные возможности дыхательной системы существенно выше, чем истинное усиление во время максимальной мышечной нагрузки. Дополнительная вентиляция необходима в условиях стартов, особенно в среднегорье и при высокой температуре окружающей среды. Газовый гомеостаз обеспечивается с участием целенаправленной регуляции параметров дыхательного цикла в динамических ситуациях тренировочно-соревновательных воздействий. Регуляция легочной вентиляции, поддержание сбалансированного газового состава крови, удовлетворения кислородного запроса организма в условиях больших тренировочных нагрузок (БТН), восстановление метаболических резервов тканей и гомеостаза крови интегративно определяют деятельность функциональных систем, физическую работоспособность и спортивную результативность. Представлены результаты эргоспирометрических исследований в лабораторных условиях на заключительном этапе подготовки к универсиаде РФ. Выявлены половые особенности у ориентировщиков в покое, при достижении анаэробного порога, максимального уровня нагрузки, отношений максимальных и на уровне АнП показателей соответственно к должным и справочным. Показаны особенности восстановления изучаемых значений. Полученные данные позволяют отслеживать состояние и адекватную физическую работоспособность, занимающихся спортивным ориентированием на разных этапах и периодах макроцикла подготовки (тренировочных воздействий и восстановления). Сегодня принято говорить о нейрогуморальной регуляции дыхания при БТН, вызывающих стресс-напряжение. The ability of myocardium to deliver blood to skeletal muscles mainly restrains the oxygen delivery to the muscles. The capability of respiratory system is much higher thana true enhancement during the maximum muscular load. The additional ventilation is necessary in the context of starts, in particular in middle mountains and at high temperatures of the environment. The gas homeostasis is provided with the help of a purposeful regulation of respiratory cycle parameters in dynamic situations of training and contest influence. The regulation of pulmonary ventilation, maintenance of balanced gas composition of blood, satisfaction of oxygen demand of a human body in terms of intensified training load (ITL), recovery of metabolic reserves of issues and blood homeostasis define the activity of functional systems, physical efficiency and sports results. The results of ergospirometrical studies among orienteeringsportsmen under the conditions of laboratory research at the final stage of training for the Student Games (Universiade) held in Russia are presented. The age peculiarities of orienteering sportsmen at rest, when achieving an anaerobic threshold, maximum level of load, relations of maximum and at the level of anaerobic threshold indicators in relation to normal and reference indicators correspondingly are specified. The characteristics of recovery of examined issues are mentioned. The obtained results enable to control a state andan adequate physical efficiency of people who take up orienteering at different stages and in periods of training macro cycles (training influence and recovery). Today it’s necessary to mention a neurohumoral regulation of breathing during intensified training load causing stress and tension. Исаев А.П., заслуженный деятель науки РФ, доктор биологических наук, профессор, заведующий кафедрой теории и методики физической культуры и спорта, Южно-Уральский государственный университет (Челябинск), tmfcs@mail.ru. Епишев В.В., кандидат биологических наук, доцент кафедры теории и методики физической культуры и спорта, Южно-Уральский государственный университет (Челябинск), tmfcs@mail.ru. Маматов Э.Э., соискатель кафедры теории и методики физической культуры и спорта, Южно-Уральский государственный университет (Челябинск). A.P. Isaev, South Ural State University, Chelyabinsk, Russian Federation, tmfcs@mail.ru, V.V. Epishev, South Ural State University, Chelyabinsk, Russian Federation, tmfcs@mail.ru, E.E. Mamatov, South Ural State University, Chelyabinsk, Russian Federation

The susceptibility of commercially pure (CP) to stress corrosion cracking (SCC) in seawater has been widely investigated under suitable laboratory testing conditions. Susceptibility is produced when the material contains certain levels of Al and/or O which increase the hardness and yield stress of the metal. Interstitial elements such as nitrogen and carbon affect the susceptibility in a similar way by their effect upon the mechanical properties. These have been related 2 to an equivalent oxygen content O*, where : O* = O + 2N + 2/3C (wt%). In this communication an attempt is made to investigate the effect of Fe additions on the susceptibility of titanium alloys of varying oxygen equivalent contents.

The combined effects of oxygen, nitrogen and carbon, expressed as an oxygen equivalent {O}, and, also, the influence of residual iron content, on the stress-corrosion behaviour of commercially-pure titanium when strained slowly to failure while in contact with sea water have been investigated. The fracture morphologies exhibited comprised a mixture of cleaved facets and areas of low-energy ductile rupture of the alpha phase, referred to as flutes or flutings. An increase in the {O} content resulted in an increase in the number of cleaved facets and in the associated continuity of the observed cleavage fracture. The cleaved facets were not exactly smooth surfaces, but were comprised of facets separated by small steps. The latter have been associated with slight differences in orientation between the cleavage planes and the crack-propagation plane. Flutings which were well developed in low residual iron-containing titanium allowed the joining of two cleavage planes in two different grains sharing a common boundary. However, when two cleavage planes were unable to join by a single-fluted system, a two-fluted system which met at a grain boundary became operative. Increased residual iron levels were found to eliminate stress-corrosion susceptibility; hence, the non-occurrence of cleavage fracture in low {O} titanium. In high {O}-containing material, cleavage fracture was observed, but with a much reduced continuity of the cleavage fracture.

Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood plasma drops and the nitrogen concentration gradient becomes directed from blood to tissue. On the assumption of weak interaction between the inert nitrogen and the human tissue, normal osmosis for the nitrogen transport takes place. Thus, the directions of anomalous osmotic flow caused by the oxygen concentration gradient coincide with the directions of normal osmotic flow, caused by the nitrogen concentration gradient. This leads to the conclusion that the presence of nitrogen in the human body promotes the oxygen delivery under HBO conditions, rendering the overall success of the hyperbaric oxygen treatment procedure.

The fluxes of oxygen into sediments and the release rate of COD, methane and nitrogen after deposition of fresh sewage sludge were measured in an experimental laboratory apparatus. Effects of the initial surface loading revealed a progressive contribution of COD release to the flux of oxygen equivalent to increased loading. Lower oxygen concentrations had the same effect. The actual conversion rate of the organics in the sediments was lower than the potential maximal aerobic degradation rate and higher than the anaerobic rate of hydrolysis. Preferential oxidation of soluble organics at the sediment interface over particulate material limits the release of COD except for high-loaded systems or at low DO concentrations.

Measurement of dissolved oxygen (DO) is essential in biochemical engineering processes. A steady-state condition in the production of single-cell protein (SCP) can be reached by keeping the DO level constant, while the viable protein is continuously harvested. The concentration of protein is proportional to oxygen uptake rate. Control of DO would achieve steady SCP production. Variation of DO may affect retention time and other process variables such as substrate and product concentrations, retention time, dilution rate, and aeration rate. Microbial activities are monitored by the oxygen uptake rate from the supplied air or oxygen. The rate of oxygen transfer from the gas phase to liquid phase is important. At high-cell densities, the cell growth is limited by the availability of oxygen in the medium. The growth of aerobic bacteria in the fermenter is then controlled by the availability of oxygen, substrate, energy sources, and enzymes. Air has to be supplied for aerobic process to enhance the cell growth; oxygen limitation may cause a reduction in the growth rate. The supplied oxygen from the gas phase has to penetrate into the microorganism.

Aim: Demand oxygen delivery systems (DODSs) were developed to secure the mobility of patients requiring oxygen therapy. The aim of the present study was to compare the efficacy of two currently available DODS with continuous oxygen administration (CONT). Patients: Thirteen patients with COPD (mean [ SD] FEV1 ,2 8 5.2% predicted; mean PO2, 56.4 8.1 mm Hg [breathing room air]). Intervention: Treatment for 30 min with CONT at a flow rate of 2 L/min, with the DODSs Oxytron 3 (Weinmann; Hamburg, Germany) or DeVilbiss EX 3000 (Somerset, PA) in random sequence. Arterialized blood samples were obtained from a hyperaemized ear lobe after 15 and 30 min. Results: After 15 min, no significant differences in PO2 or arterial oxygen saturation (SaO2) were observed. In comparison with CONT (mean PO2, 70.5 10.4 mm Hg; mean SaO2, 94.8 2.13%), oxygenation with the Oxytron 3 (mean PO2, 66.3 10.3 mm Hg; mean SaO2, 93.5 2.6%) was significantly less after 30 min when measured independently by blood gas analysis and pulse oximetry. The DeVilbiss EX 3000 (mean PO2, 69.1 12.0 mm Hg; mean SaO2, 94.5 3.2%) and CONT showed no differences. Conclusions: PO2 did not reach equilibrium after 15 min of treatment with the DODSs. The titration of a patient to a DODS is recommended, since simply accepting the manufacturer’s information on oxygen equivalent does not guarantee an adequate supply of oxygen. (CHEST 2005; 128:2082–2087)

In this paper we present a successful experimental test of filling a volume of 6 m$^3$ with argon gas, starting from normal ambient air and reducing the impurities content down to few parts per million (ppm) oxygen equivalent. This level of contamination was directly monitored measuring the slow component of the scintillation light of the Ar gas, which is sensitive to {\it all} sources of impurities affecting directly the argon scintillation., Comment: 9 pages, 6 figures, to appear in Proc. 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba, March 2010

Magnesium ferrite (MgFe2O4) is a moderately selective catalyst for butadiene formation from n-butenes via oxidative dehydrogenation (OXD). However, both the activity and selectivity decrease irreversibly as the catalyst ages, and these changes have been correlated with bulk phase solid-state changes that occur in reducing atmospheres at temperatures above 300 °C. The fresh catalyst contained a 5% α-Fe2O3 impurity phase whose disappearance paralleled the activity/selectivity decline. These conclusions were confirmed by X-ray, Mossbauer, and magnetic susceptibility measurements. In addition, TGA (thermogravimetric analysis) experiments suggested that oxygen equivalent to about 6.4 layers could be slowly removed by evacuation at elevated temperatures in the range of 530 °C. This labile oxygen is probably related to the OXD activity. A proposed deactivation mechanism attributes the loss of selectivity to an increased population of Fe2+ sites at the expense of Fe3+ sites. A process that would stabilize the Fe3+ population in the MgFe2O4 matrix would presumably decrease the deactivation and result in a more stable catalyst.

A purification system based on reduced copper and molecular sieve has been built for a 7 m3 liquid argon time projection chamber and it has been succesfully tested. After the initial purification an attenuation length of 0.7 m at 0.5 kV cm−1 was measured by drifting electrons over distances up to 28 cm. Further purification yielded attenuation lengths ≥ 3.7 m at 0.5 kV cm− which corresponds to an impurity level of ≤ 0.2 ppb oxygen equivalent.

Tensile tests on high purity (6 × 10−4 oxygen equivalent) and commercial purity (6 × 10−3 oxygen equivalent) zirconium were performed between 77 and 1000 K in order to evaluate dynamic strain aging. A comparison with earlier data from two equivalent titanium compositions yielded the following; reducing the interstitial concentration to the zone refined iodide level removes most evidence of strain aging in both zirconium and titanium. At this impurity concentration, zirconium also shows a greatly reduced thermally activated flow stress component. This was not observed in titanium. At the commercial purity level, both metals exhibit strain aging phenomena. These are much weaker, however, in Zr than in Ti. Even at this impurity level Zr does not exhibit a strain aging yield point, the Portevin-Le Chatelier effect or a well defined work hardening rate peak. All of these latter are found in commercial purity Ti. Several other aspects of DSA, while observed in Zr, are less pronounced than in Ti. The principal interstitial impurity in these materials is oxygen. Oxygen in solid solution strongly increases the(c/a) ratio of Ti, but has little effect on this ratio in Zr. This distortion of the Ti hcp lattice may account, in part, for the greater strength of DSA in this metal.

On the basis of the sulfur isotope age curve of marine sulfate evaporites and currently available numerical data for the sulfur cycle the stationary terrestrial sulfate reservoir has been calculated as a function of time for the last 600×106 yr, this also giving information on the partial inventory of photosynthetic oxygen locked up in sedimentary and marine SO42−. The results obtained confirm previous concepts (arrived at by geochemical flux models) of a sizable interchange of material between both sedimentary sulfur reservoirs and, accordingly, varying amounts of oxygen stored as sedimentary sulfate (this amount fluctuating between some 0.5 and 1.5×1022 g during the Phanerozoic). With the constancy of the sedimentary δ13Ccarb record indicating that the crustal Corg reservoir and its stoichiometric oxygen equivalent (i.e., total photosynthetic oxygen) did not change very much during the last quarter of the earth's history, fluctuations in sulfate oxygen must have been buffered by the two other O2 inventories, namely, oxygen fixed as Fe(III) oxide and free oxygen of the atmosphere. Although the main responsibility for balancing variations in sedimentary sulfate would go to the fixed oxygen because of its overwhelming size, repercussions on the free oxygen can by no means be excluded. If we accept a variation of free oxygen proportionate to that of the sum of the two reservoirs as a minimum requirement, then atmospheric PO2 can be expected to have fluctuated during the Phanerozoic within some ±20% of its present level.

Theoretic equations are developed to determine what concentrations of oxygen must be breathed at any altitude to maintain the "oxygen equivalent" of air a t given altitudes—i.e., the same alveolar oxygen pressure. The partial pressures of water vapor and carbon dioxide are taken into account, as well as the variation of the pressure of carbon dioxide with the alveolar oxygen pressure. Six curves are given on a chart showing the oxygen concentrations required a t any altitude to maintain the oxygen equivalent of air a t sea level and a t altitudes of 5,000, 10,000, 15,000, 20,000, and 25,000 ft. Altitudes of 33,800, 40,000, and 46,000 ft. with pure oxygen are equivalent to air at sea level, 10,000 and 20,000 ft., respectively. I t is shown tha t these equivalents are nearly independent of the assumptions as to the state of physiologic adaptation and should be applicable to all individuals.

Dissolved oxygen levels in fermentation systems are affected by (a) gas flow rate, (b) degree of agitation, and (c) oxygen partial pressure in the gas. Since the first two variables cannot easily be separated, a method for dissolved oxygen control has been devised based on the variation of oxygen partial pressure in the gas. Oxygen and nitrogen are fed to a special mixing valve capable of varying the proportions of the two gases while keeping the total flow rate constant. A dissolved oxygen electrode and control system adjust the valve setting to automatically maintain a preset oxygen level. Oxygen analyzers, monitoring the inlet and outlet gas streams, provide additional information from which oxygen absorption and uptake rates may be determined. The system provides a means for the quantitative and independent study of aeration and agitation effects. In addition, it offers a basis for routine control of oxygen levels in plant fermentation equipment.

A mass of circumstantial evidence is presented to indicate that the main source of alloy losses in open-hearth tapping is oxidation by air, with the steel apparently reacting with an amount of oxygen equivalent to about 30 times its own volume of air. The effect is erratic from heat to heat, depending largely on turbulence and distance of free fall of the stream of liquid metal.

We have studied the influence of the nature of the electrolyte on the film-formation oxygen yield during the anodic oxidation of niobium. This yield R is defined as the ratio of the amount of oxygen contained in the films (measured by nuclear microanalysis) to the amount of bivalent oxygen equivalent to the oxidation charge. It has been shown that niobium behaves qualitatively like tantalum: R is greater than 1 for films formed in concentrated acids, implying a large incorporation of anions, characteristic of the acids, of the type A x O y n − . The quantitative estimations of the anion incorporation rate deduced from determination of oxygen are in good agreement with those obtained from the direct analysis of nitrogen for films formed in concentrated nitric acid. The influence on the oxygen yield of the formation field and the temperature is also studied and discussed.

Kinetic equations describing biological growth, substrate removal, and oxygen utilization with the activated sludge process were modified and used to describe the corresponding phenomena in a completely mixed and continuous flow denitrification process. The process kinetics differ primarily with respect to the dependency of variables and process yields. The oxygen equivalent of the nitrates is the independent variable and substrate or carbon source is a dependent variable in the denitrification process. The rate of nitrate reduction was shown, from experimental data, to be a linear function of the sludge loading, and the ratio of substrate applied to nitrate reduced, BOD/N, was constant over this particular range of sludge loadings. The BOD/N ratio was shown to be a function of both the substrate characteristics and the denitrification process employed.

The boundary zone between different water masses in the open sea has been recognized by fishermen as a good fishing ground of various migratory fishes inhabiting in cold or warm waters. Many works have been done by many investigators on the physical aspects of the boundary zone and the ecology of individual fishes involved in it. The most of these works have been rather conformed with qualitative concepts which have been recognized for many years. For the standpoint of fisheries, however, more quantitative approaches will be required. At the first step, we consider the plankton population in the boundary zone as an indispensable source of energy to support the metabolic activity of fishes. Under this assumption, the boundary zone should be the place where the active metabolic exchange of energy is taking place between fishes and their environments, and it must be more fertile in the food materials than other areas. The present work attempts to evaluate the fertility of the boundary zone in precise terms of metabolic energy source by chemical methods. For this purpose, it is desirable to determine the, organic content of the plankton population by direct analyses of the samples collected with plankton nets. However, there are difficulties of dtvising a plankton net suitable enough to meet the demands of this work and at the same time simple enough to be usable for practical application. In addition, we have neither the information nor the available data for the development of such work. Hence, the studies are developed for methods of estimating the approximate organic content of the plankton populations by the increase of the oxygen from a certain oxygen level in a given region. The outline of the estimation and the assumptions involved will be only briefly summarized here. If all the waters from which the production of phytoplankton had been. originated were saturated with oxygen, and the oxygen exchange with the atmosphere during the period of the production had no significant effects upon the distribution of the oxygen, it might be expected that the oxygen supersaturation would be approximately equivalent to the amount of the oxygen liberated by photosyn. thesis of the plant. Under such conditions, the amount of organic material synthesized by the phytoplankton in a unit volume of water can be expressed as carbon corresponding to the oxygen increase, since for every molecule of carbon dioxide utilized by phytoplankton, one molecule of oxygen is liberated. In many cases, however, the organic carbon synthesized by phytoplankton is converted by grazing processes into that of the other forms of organisms such as zooplankton, fishes and other larger animals, and partly returned to carbon dioxide through metabolic processes or by disintegration of the organisms. On the other hand, the oxygen of waters should be reduced remaining the oxygen equivalent to the organic carbon of the plankton population. Hence, assuming that the respiratory quotient is 1, it is possible to estimate the carbon c?ntent of plankton population contained in a unit volume of waters by using the observed supersaturation of the waters. However, it is considered that the oxygen supersaturated by the phytcplankton in the surface water may be partly driven off towards the atmosphere. On the other hand, it has been already known by many workers that in the euphotic layer, for each milligram of phosphorus utilized in photosynthesis, the phytoplankton will take up 76ml. of CO2 and release the same volume of oxygen, and at lower levels, where regeneration is taking place, the consumption of 76ml.

While a high sensitivity of the work function to gaseous contaminants is generally characteristic of metals which adsorb the common gases strongly, barium combines outstanding work function stability with an exceptional affinity for these gases. The paradox is investigated by administering measured quantities of oxygen to vapor-deposited barium surfaces at known rates, with concurrent monitoring of the work function. It is found (1) that when clean barium is exposed suddenly to a massive dose of oxygen, its work function is lowered by 0.32 ev; (2) that the work function of the heavily oxygenated surface remains constant for 5 days and then drifts very slowly toward the clean-metal value, and (3) that when oxygen is administered to a barium surface slowly (2\ifmmode\times\else\texttimes\fi{}${10}^{13}$ molecules per ${\mathrm{cm}}^{2}$ per hour) no change of work function occurs during or after the absorption of a quantity of oxygen equivalent to 100 complete monolayers of the oxide.The results are interpreted as stemming from two processes which compete for control of the surface; the expected surface oxidation and a restorative process involving engulfment of oxygen ions. The mechanism of engulfment is discussed.

The following new KNO 3 - I 2 hybrid cycle was devised. Since reactions (7) and (8) were well known in the industrial manufacture of nitric acid, thermochemical reaction (6) and electrolysis (9) were studied experimentally. In reaction (6), KNO 3 converts to KI quantitatively and rapidly, reacting with gaseous iodine at 1000 K. Effects of temperature, flow rate of a carrier gas and molar ratio of I 2 /KNO 3 were examined. Since KNO 3 decomposes to KNO 2 evolving oxygen above 870 K, the oxygen equivalent to that of the water decomposition is separable. Polarizations for various combinations of anolyte (KI - I 2 solution), catholyte (HNO 3 - KNO 3 solution) electrode material and temperature were investigated. The polarizations were small up to about 1000 mA cm −2 . An ion-exchange membrane was selected from the point of durability for the electrolyte solutions and electric resistance. Based on these measurements, cell voltage at current density of 100 mA cm −2 at 348 K was assumed to be about 0.7 V.

Publisher Summary This chapter discusses tissue oxygen supply and critical oxygen pressure. It is well known that for the whole animal as well as for the isolated organ, in a certain range, the O2 consumption, vO2, is independent of the O2 offered by the respired gas mixture or by the arterial blood. It is found that when oxygen is reduced below this range, a reaction threshold is reached and compensatory mechanisms are put into action to maintain the O2 consumption and, thus, the energy consumption at the same level. There is a point at which the compensatory mechanisms are exhausted. This state can be called critical threshold, critical state of oxygen supply, or simply critical oxygen supply. It means, in this state the oxygen supply limits the oxygen consumption.

SUMMARY: In four strains of Escherichia coli B/r (ORNL), B (ORNL), B (Hill), Bs (Hill) protection by β-mercaptoethylamine (MEA) exceeded that observed for oxygen removal by nitrogen bubbling. Although only a slight decrease of protection was found with strain Bs (Hill) when oxygen was removed by nitrogen bubbling, the protection afforded by MEA in excess of that achieved by nitrogen bubbling was similar with all four strains. The data suggest that at least two mechanisms for protection by MEA may operate simultaneously in some bacteria and that one of these is a removal of oxygen equivalent to that achieved by nitrogen gas bubbling.

In the study of metabolic reactions, it is frequently desirable to observe the oxygen concentration in a solution that bathes the tissues under study to obtain a measure of the rate of oxygen utilization. Typically, either the oxygen is depleted in a matter of minutes and the test terminated or the ratio of solution to tissue is so large that meaningful measurernents are difficult. For tests in which the oxygen is taken from the surrounding gas, Wager and Porter (1961) have described a solution to the problem in which a manometric measurement of p02 con trolled the electrolytic production of oxygen which then had to be released into the atmosphere surrounding the tissue. The instrument described here also employs a pO2 measurernent to control the electrolytic production of oxygen, but a much greater speed of response is obtained by 1) the use of a Clark-type electrode for PO2 measurement, and 2) producing the oxygen directly in the solution that surrounds the test material. The hydrogen that is also formed in the electrolysis is sufficiently isolated from the tissue under test that no noticeable effects are produced. Furthermore, agreement between the net electrical charge involved in the electrolysis and the resulting amount of oxygen produced was within 5%, using published values" of the partial pressure of oxygen in air-saturated water as a standard.

Subcutaneous tissue oxygen is: 1. (1)|The least hazardous, most economical measurement of peripheral oxygen delivery currently available. 2. (2)|a quantitative indicator of the level of oxygen debt in the critically ill. 3. (3)|a most sensitive real-time monitor for sudden changes in the O 2 transport system.

Although hypothermia decreases cardiac output, oxygen consumption by the tissues is thought to decrease proportionately, so that tissue hypoxia does not occur. Hemodilution has been shown to increase cardiac output and tissue oxygenation. We hypothesize that hemodilution may be harmful by increasing cardiac output and oxygen need in excess of oxygen delivery. Oxygen consumption (V02) and arterial and venous blood gases were measured directly in 5 anesthetized dogs before and after cooling to 30°C and again after hemodilution (H) with Dextran 75. Cardiac index (CI), oxygen delivery (D02), oxygen extraction rate (02 ext) and oxygen equivalent (02 eq) were then calculated. Results are shown in the table below. (H=hemodilution, V02 units are cc/kg/min, *p

The presence of low levels of oxygen may have profound effects on the cytotoxic activity of radiation, radiosensitizers, and bioreductive alkylating agents. As others have shown, low oxygen tensions may significantly alter rates of cellular and chemical oxygen consumption. When experiments are performed at very low oxygen concentrations, the opposing effects of oxygen leakage into and cellular/chemical oxygen consumption from the system can lead to unpredictable results. Use of a newly designed, highly sensitive Clark-type oxygen sensor has permitted accurate and reproducible measurement of low levels of oxygen. Cellular depletion of oxygen at various cell densities has been monitored for a series of oxygen tensions in solution and the corresponding respiration rates have been calculated. Although oxygen depletion was found to be quite significant at low oxygen tensions, not all oxygen present could be removed by cellular respiration. Respiration rate decreased as oxygen tension decreased and approached zero at low oxygen tensions. This result was independent of cell density. A model is presented to account for the observed effect of oxygen tension on cellular oxygen utilization.