Gradual Temperature Research Articles

Inaccurate or disparate temperature cues? Seasonal acclimation of terrestrial and aquatic locomotor capacity in newts

Summary 1. Many organisms respond to seasonal temperature fluctuations by the reversible modification of whole‐animal performance. Semiaquatic ectotherms, which possess this acclimatory capacity in swimming speed, lack the plastic response in terrestrial locomotor performance and vice versa. Theory predicts that the presence of reversible (seasonal) thermal acclimation or fixed phenotypes depends on the predictability of future thermal conditions (i.e. accuracy of temperature cues) in a given environment. Alternatively, comparative data suggest that thermal acclimation is induced by disparate temperature cues in water and on land. 2. We tested both predictions by examining the seasonal acclimation response in thermal sensitivity of maximal swimming and running speed in adult alpine newts, Ichthyosaura (formerly Triturus) alpestris. 3. Following the seasonal variation in environmental temperatures, we exposed newts to 5 °C from November to March and, after a gradual temperature increase, to either a constant (15 °C) or fluctuating (10–20 °C) thermal regime from May to June. At the end of each treatment, we measured newt swimming and running capacity at five temperatures (range 5–25 °C). In the field, hourly temperatures were recorded in various aquatic and terrestrial microhabitats to obtain information about the predictability of thermal conditions in both environments. 4. Seasonal acclimation shaped the thermal sensitivity of swimming speed under both constant and fluctuating temperature treatments. Thermal sensitivity of running speed was markedly modified by a fluctuating thermal regime so that newts ran at the highest test temperature faster than cold‐acclimated individuals. Natural thermal environment contained a similar proportion of predictable variation in water and on land. 5. Complex seasonal acclimation of locomotor capacity in newts was influenced by the disparate thermal cues, i.e. mean acclimation temperature or diel temperature fluctuations, rather than by the different accuracy of these cues in water and on land. Future confrontations of theory with empirical data will require more attention not only on the assumptions of adaptive thermal acclimation but also on the ecologically relevant thermal conditions during acclimation experiments.

Cell and tissue level responses to gradual temperature raising in digestive gland of mussels from sites with different levels of environmental stress

Cell and tissue level responses to gradual temperature raising in digestive gland of mussels from sites with different levels of environmental stress

Numerical simulation on bake-out of the ITER diagnostic upper port plug

The diagnostic upper port plug in ITER is fixed to the upper port of the vacuum vessel as a cantilevered beam with bolts and forms a primary vacuum boundary. It needs to be baked out for outgassing before normal operation. This study calculated the required bake-out time and the transient thermal stress during baking for the diagnostic upper port plug. The calculation was done through numerical simulation. The analysis took into consideration the gradual temperature increase of working fluid. In order to look into the effect of radiation heat transfer from the upper port plug to the vacuum vessel port, the upper vacuum vessel port was included in this analysis.

Polarized Raman scattering study of blue bronze Tl 0.3MoO 3

Temperature dependent polarized Raman spectra of quasi-one dimensional blue bronze Tl 0.3MoO 3 are reported on a frequency range 100–1100 cm −1. Frequency shift and splitting in some modes were observed, revealing the role of the alkali atom. Many new modes emerge at 170 K accompanied by charge density wave (CDW) formation, and show gradual temperature dependent intensity and line-width, implying the second order nature of CDW transition. A frequency “jump” is found for many Raman vibrational modes in Tl 0.3MoO 3 near 110 K, confirming that the transition from an incommensurate to commensurate state occurs around this temperature. In addition, only three stretching vibration modes of terminal MoO bonds are observed for (xx) polarizations from 800 to 1100 cm −1 at 300 K; new modes appear only when the temperature drops below 110 K and are ascribed to the splitting of the mode at 931 cm −1 due to commensurate state formation.

Recent and future warm extreme events and high-mountain slope stability

The number of large slope failures in some high-mountain regions such as the European Alps has increased during the past two to three decades. There is concern that recent climate change is driving this increase in slope failures, thus possibly further exacerbating the hazard in the future. Although the effects of a gradual temperature rise on glaciers and permafrost have been extensively studied, the impacts of short-term, unusually warm temperature increases on slope stability in high mountains remain largely unexplored. We describe several large slope failures in rock and ice in recent years in Alaska, New Zealand and the European Alps, and analyse weather patterns in the days and weeks before the failures. Although we did not find one general temperature pattern, all the failures were preceded by unusually warm periods; some happened immediately after temperatures suddenly dropped to freezing. We assessed the frequency of warm extremes in the future by analysing eight regional climate models from the recently completed European Union programme ENSEMBLES for the central Swiss Alps. The models show an increase in the higher frequency of high-temperature events for the period 2001-2050 compared with a 1951-2000 reference period. Warm events lasting 5, 10 and 30 days are projected to increase by about 1.5-4 times by 2050 and in some models by up to 10 times. Warm extremes can trigger large landslides in temperature-sensitive high mountains by enhancing the production of water by melt of snow and ice, and by rapid thaw. Although these processes reduce slope strength, they must be considered within the local geological, glaciological and topographic context of a slope.

Detection of low bottom water oxygen concentrations in the North Sea; implications for monitoring and assessment of ecosystem health

Abstract. This paper presents new results from high temporal resolution observations over two years (2007 and 2008) from instrumented moorings deployed in the central North Sea, at the Oyster Grounds and on the northern slope of Dogger Bank (North Dogger). The water column was stratified in the summer at both sites, leading to limited exchange of the water in the bottom mixed layer. Data from these moorings revealed the variable nature of summer oxygen depletion at the Oyster Grounds. The combination of in situ and ship-based measurements allowed the physical and biological conditions leading to decreasing dissolved oxygen concentrations in bottom water to be examined. In 2007 and 2008, the concentration of dissolved oxygen in the bottom water at both sites was observed to decrease throughout the summer period after the onset of stratification. Depleted dissolved oxygen concentration (6.5 mg l−1, 71% saturation) was measured at the North Dogger, a site which is not significantly influenced by anthropogenic nutrient inputs. Lower oxygen saturation (5.2 mg l−1, 60% saturation) was measured for short durations at the Oyster Grounds. The seasonal increase in bottom water temperature accounted for 55% of the decrease in dissolved oxygen concentration at the Oyster Grounds compared to 10% at North Dogger. Dissolved oxygen concentration in bottom water at the Oyster Grounds was shown to be strongly influenced by short term events including storms and pulses of particulate organic matter input. In contrast, dissolved oxygen concentration in bottom water at the North Dogger reflected longer seasonal processes such as a gradual temperature increase over the summer and a more steady supply of particulate organic matter to the bottom mixed layer. The differences between the study sites shows the need for an improved understanding of the mechanisms driving these processes if the use of oxygen in marine management and ensuring ecosystem health is to be meaningful and successful in the future. These high frequency observations provide greater understanding of the nature of the depletion in bottom oxygen concentration in the North Sea.

Noninvasive Focused Monitoring and Irradiation of Head Tissue Phantoms at Microwave Frequencies

In this study, new aspects of our research regarding a novel hybrid system able to provide focused microwave radiometric temperature and/or conductivity measurements and hyperthermia treatment via microwave irradiation are presented. On one hand, it is examined whether the system is capable of sensing real-time progressive local variations of temperature and/or conductivity in customized phantom setups; on the other hand, the focusing attributes of the system are explored for different positions and types of phantoms used for hyperthermia in conjunction with dielectric matching layers surrounding the areas of interest. The main module of the system is an ellipsoidal cavity, which provides the appropriate focusing of the electromagnetic energy on the area of interest. The system has been used for the past few years in experiments with different configuration setups including phantom, animal, and human volunteer measurements yielding promising outcome. The present results show that the system is able to detect local concentrated gradual temperature and conductivity variations expressed as an increase of the output radiometric voltage. Moreover, when contactless focused hyperthermia is performed, the results show significant temperature increase at specific phantom areas. In this case, the effect of the dielectric matching layers placed around the phantoms is critical, thus resulting in the enhancement of the energy penetration depth.

Fire-resistant nonwovens of EVOH and PET treated with amorphous sodium polyborate

Nonwovens made of poly(ethylene terephthalate) (PET) and ethylene–vinyl alcohol copolymer (EVOH) are found to become highly fire resistant by treating with amorphous sodium polyborate (SPB). The fire-resistant nonwovens with 10-mm thickness show a gradual temperature increase up to 127 °C and no hole, when their back sides are fired with a gas burner for 12 min. The analysis using the EPMA and the DTA/TG indicates that the SPB foam promotes the formation of char (carbon) layer, and that the char layer together with the SPB foam insulates inside from the oxygen and the heat.

Cave atmosphere controls on stalagmite growth rate and palaeoclimate records

Abstract Cave atmosphere P CO 2 partially controls calcite deposition on stalagmites by changing the thermodynamic drive of drip water to deposit calcite. The dissolved carbon dioxide contained in karstic percolation water is generally controlled by the soil P CO 2 , and this CO 2 will degas in any void spaces with a lower P CO 2 , including caves. If void space P CO 2 is higher than the P CO 2 of the water, dissolution may occur. Measured cave air P CO 2 ranges of several caves in different climate regimes suggest that soil temperature is a major control on cave air P CO 2 , but that the observed trend deviates from the modelled trend when soil carbon dioxide production is moisture-limited. Calcite deposition models illustrate how soil and cave air P CO 2 can influence stalagmite growth rates, and demonstrate how gradual temperature changes can skew the geochemical proxy signal in stalagmites in favour of certain seasons and eventually can result in total cessation of growth.

Palynological records of climate and oceanic conditions in the late Pleistocene and Holocene of the Nile Cone, Southeastern Mediterranean, Egypt

Variations in palynomorph concentrations and relative abundances, including pollen and spores, organic‐walled dinoflagellate cysts, and amorphous organic matter (AOM), were studied in sediment core NC Core 2 from the upper slope (1,030 m water depth) of the Nile Cone, southeastern Mediterranean, Egypt. Each sample represents palynomorph deposition for intervals of around 500–1,000 years, and this study provides the first detailed palynological record for the Nile Cone. The dinoflagellate cyst assemblages and AOM production reflect changes in surface water temperature and river discharge in response to climate forcing as marked by variations in pollen and spore indicators of semi‐desert vegetation and tropical Monsoon intensity. The basal sediments (approximately 14,600–9400 yr before present [BP]) contain high concentrations and relative abundances of Polysphaeridium zoharyi, Polysphaeridium spp., Spiniferites elongatus, and Spiniferites spp. during the transition from postglacial to interglacial conditions. Variations in these taxa and total Impagidinium spp. suggest a gradual temperature increase, interrupted by a pre‐Holocene cool interval around 11,000 yr BP. The high African monsoon index for this pre‐Holocene time corresponds with pollen evidence of relatively high Nile discharge. The organic‐rich S1 sapropel sediments, dated as around 9,500–6,270 yrBP, were deposited several thousand years later, during a time of lower Monsoonindex, wanner surface water, and increased dinoflagellate cyst production. This was accompanied by moderate Nile flooding and oxygen‐deficient or anoxic bottom water on the upper Nile Cone, mainly supporting the increased production and carbon import hypothesis for eastern Mediterranean S1 formation. Dinoflagellate cyst assemblages in the Nile Cone S1 differ from those of the deeper, more northern Levantine and Cretan basins in the near absence of heterotrophic protoperidinioid cysts, despite the uniformly high organic S1 carbon content. The prevailing climate during the formation of sapropelic sediments in the southeastern Mediterranean was tropical to subtropical, but was interrupted by an early cooler interval with reduced humidity, as marked by re‐appearance of Spiniferites elongatus and increased Ephedra pollen. The carbonate‐rich surface layers were probably deposited under warm dry climatic conditions with minimum Nile input, but evidence of oxidation prevents detailed interpretation.

A Thermal Decomposition Model of Aminoguanidium 5,5′‐Azobis‐1H‐Tetrazolate and the Effect of Pressure and Particle Size on the Rate of Decomposition

AbstractThe temperature histories of aminoguanidinium 5,5′‐azobis‐1H‐tetrazolate (C4H14N18, AGAT) were measured in order to construct a thermal decomposition model of the compound. The effects of chamber pressure and AGAT particle size were also examined. The results of the study suggest that the thermal decomposition of AGAT occurs in three phases: solid phase, condensed phase, and residue. It was found that the condensed phase consists of decomposition zone I where dramatic temperature rise occurs, decomposition zone II where gradual temperature rise occurs, and the cooling zone where decomposition and temperature stop rising. It was also suggested that the temperature of the decomposition surface which is the interface of the solid phase and the condensed phase was ∼500 K, and that N2 and NH3 were suggested to occur in the vicinity of the decomposition surface of decomposition zone I. In addition, it was suggested that the thickness of the decomposition zones I and II decreases and that the maximum‐temperature‐reached increases with an increase in atmospheric pressure. The rate of decomposition of AGAT was found to follow Vieille's equation and the rate of decomposition increases with an increase in pressure. The rate of decomposition increased slightly with an increase in particle size.

Phasic and tonic fluctuations in brain, muscle, and skin temperatures during motivated drinking behavior in rats: Physiological correlates of motivation and reward

Since brain metabolism is accompanied by heat production, measurement of brain temperature offers a method for assessing global alterations in metabolic neural activity. This approach, high-resolution (5-s bin) temperature recording from the nucleus accumbens (NAcc), temporal muscle, and facial skin, was used to study motivated drinking behavior in rats. Experienced animals were presented with a cup containing 5-ml of Coca-Cola® (Coke) beverage that resulted, within certain latencies, in initiation of a continuous chain of licking until all liquid was fully consumed. While cup presentation induced rapid, gradual NAcc temperature increase peaking at the start of drinking, temperatures slowly decreased during Coke consumption, but phasically increased again in the post-consumption period when rats were hyperactive, showing multiple interactions with an empty cup. Muscle temperatures followed a similar pattern, but the changes were weaker and delayed compared to those in the brain. Skin temperature rapidly dropped after cup presentation, steadily maintained at low levels during consumption, and slowly restored during the post-consumption period. Substitution of the expected Coke with either sugar-free Diet Coke® or water resulted in numerous drinking attempts but ultimately no consumption. During these tests, locomotor activation was much greater and more prolonged, brain and muscle temperatures increased monophasically, and their elevation was significantly greater than that with regular Coke tests. Food deprivation decreased drinking latencies, did not change the pattern of temperature fluctuations during Coke consumption, but temperature elevations were greater than in controls. Our data suggest sustained neural activation triggered by appetitive stimuli and associated with activational (seeking) aspects of appetitive motivated behavior. This seeking-related activation is rapidly ceased following consumption, suggesting this change as a neural correlate of reward. In contrast, inability to obtain an expected reward maintains neural activation and seeking behavior, resulting in larger deviations in physiological parameters.

Temperature Effect on Water Extractability of Cadmium, Copper, Lead and Zinc from Composted Organic Solid Wastes of South-West Nigeria

The effect of temperature changes (10 to 80 °C) on water-extractable metal (Zn, Cu, Cd and Pb) concentrations of composted wastes of Nigerian origin was investigated in batch extraction experiments. Metal concentrations were measured using a calibrated atomic absorption spectrophometer after acid digestions. Results showed that the water-extractable metal fractions (I) did not exceed 10% of total metal concentrations of the bulk composts, which corresponded to 0.30 to 6.63% for Zn, 0.09 to 7.51% for Pb, 1.83 to 9.29% for Cu and 0.67 to 9.23% for Cd. Water extractable metal fraction showed positive correlations (r = 0.137 to 0.917*; p* < 0.01) for Cu, Cd and Pb in most cases but negative for Zn (−0.067 to −0.445). Simulations revealed that a steady temperature rise from 0.1 to 1.5 °C might increase I by 0.13 to 168% for all the metals, although stability to gradual temperature rise was demonstrated in some instances. The study revealed that the degree of temperature effect on water extractability of heavy metals from the bulk composts was dependent on metal type, compost formulation and waste type.

Possible Multiple Gap Superconductivity with Line Nodes in Heavily Hole-Doped Superconductor KFe2As2 Studied by 75As Nuclear Quadrupole Resonance and Specific Heat

We report the 75 As nuclear quadrupole resonance (NQR) and specific heat measurements of the heavily hole-doped superconductor KFe 2 As 2 (superconducting transition temperature T c ≃3.5 K). The spin-lattice relaxation rate 1/ T 1 in the superconducting state exhibits a gradual temperature dependence with no coherence peak below T c . The quasiparticle specific heat C QP / T shows a small jump, which is about 30% of the electronic specific heat coefficient just below T c . The C QP / T suggests the existence of low-energy quasiparticle excitation at the lowest measurement temperature T =0.4 K≃ T c /10. The T dependences of 1/ T 1 and C QP / T can be explained by a multiple nodal superconducting gap scenario rather than by a multiple fully gapped s ± -wave scenario determined using simple gap analysis.

Survival at low temperature of larvae of the pine processionary moth Thaumetopoea pityocampa from an area of range expansion

Abstract1 Larvae of Thaumetopoea pityocampa (Lepidoptera: Notodontidae) develop throughout the winter, although their feeding activity and survival can be impaired by adverse climatic factors. The present study investigated the survival at low temperature of larvae originating from a population with range expansion in an alpine valley in Northern Italy.2 The supercooling point of individually analysed larvae averaged at −7 °C. This value insufficiently described the cold hardiness of the larvae; 39% of the tested larvae were alive when returned to room temperature immediately after freezing. When larval colonies inside their nest were exposed to −17 °C for 1 h after gradual temperature decrease, survival was 70.4%.3 Rearing of larvae in the laboratory at different day/night temperatures indicated an effect of cumulative chill injury on larvae. A logistic regression explained the relationship between negative thermal sum (h°C below 0 °C) received in the laboratory experiment and larval survival. A similar relationship was demonstrated between negative thermal sum and survival of larval colonies in the field.4 In the laboratory experiment, some tested larvae were able to survive for up to 8 weeks without feeding depending on rearing temperature. As expected, feeding occurred only when larvae were reared at temperatures of 9 °C day/0 °C night.5 We classify the larvae of T. pityocampa as being moderate freezing tolerant. The winter behaviour allows this species to track climate warming by a rapid expansion into those areas that become compatible with the insect’s development.

IDENTIFYING ACETICLASTIC AND HYDROGENOTROPHIC METHANOGENS IN PSYCHROPHILIC AND MESOPHILIC GRANULAR SLUDGES TREATING SYNTHETIC SEWAGE BY MEANS OF FISH AND CSLM

ABSTRACT Aceticlastic and hydrogenotrophic methanogens were comparatively investigated by 16S rRNA‐based fluorescence in situ hybridization (FISH) technique combined with Confocal Scanning Laser Microscopy (CSLM) to evaluate temperature influence on two functional groups of methanogens. Microorganisms were grown in the form of anaerobic granular sludge in two lab‐scale Upflow Anaerobic Sludge Bed (UASB) reactors fed with synthetic wastewater and operated at psychrophilic and mesophilic temperature conditions. Since hydrogenotrophic and aceticlastic methanogenesis are known to play a crucial role, digestion may be effectively blocked if these processes are ceased due to unfavorable environmental temperature conditions. Mesophilic (35 ± 2C) and psychrophilic (10 ± 1C) reactors were inoculated by the same mesophilic granules taken from a full‐scale UASB reactor. According to FISH results, Archaea representing methanogens were found dominating at bottom sampling ports of reactors and dominant member of Archaea was the genus aceticlastic Methanosaeta (MX825). Other aceticlastic methanogen such as Methanosarcina‐like (SARCI645) species were also identified which were higher in psychrophilic granules. Members of order Methanobacteriales (MB310) constituted the major hydrogenothrophic methanogens in both reactors, whereas other hydrogenothrophic methanogens members of order Methanococcales (MC1109) and Methanogenium (MG1200) relatives were absent. Abundance of originally mesophilic Methanosaeta‐related Archaea under low temperature conditions demonstrated the adaptive capacity of microorganisms to psychrophilic conditions. This might be attributed to enzymatic alterations in Methanosaeta cells originating from seed sludge, which were exposed to sub‐mesophilic temperatures at start‐up and then to psychrophilic conditions during gradual temperature decreases. Both sludge granules remained undisturbed and kept their rigidity even after exposure to very low temperatures. Quantification study was done using Image Pro‐plus Version 4.0. Archaeal cells detected with probe ARC915 were found around 60% of the 4,6‐diamidino‐2‐phenylindole stained cells at both reactors. Methanosaeta spp./Archaea ratios for mesophilic and psychrophilic UASB reactors were calculated as 71% and 84%, respectively. FISH and CSLM results together with quantification study showed that the microbial community of anaerobic granular sludges was dominated by Methanosaeta spp. which was identified as the major methanogenic Archaea.PRACTICAL APPLICATIONSSince effects on bioreactor performances were correlated to variations in microbial diversity, investigation of methanogenic diversity in anaerobic reactors is important during operation. Identification of microorganisms should be done for formation, stability, and physiological properties of the biomass in bioreactors, which is a key factor during process performance evaluation. Monitoring the changes in dominant archea of seed added at start‐up, gives information on system performance. A detailed investigation on diversity, structure and function of mixed microbial communities in anaerobic reactors is necessary to improve treatment efficiency and stability against inhibitory compounds. Among 16S rRNA based microbial identification techniques, FISH is a well‐known technique that helps determination of dominant species by giving a detailed analysis of microbial populations while CSLM is the most appropriate method for monitoring the formation of 3‐D structure of microbial biomass. In this study, temperature influence on aceticlastic and hydrogenotrophic methanogen groups was evaluated using FISH coupled with CSLM.

Thermo-hydraulic analysis of the gradual cool-down to 80 K of the ITER toroidal field coil

A time-dependent thermo-hydraulic simulation for an ITER toroidal field (TF) coil gradual cool-down to 80 K has been performed using a new FORTRAN code. The code is based on a 1D helium flow and 1D multi-region solid heat conduction model. The whole TF coil is simulated taking into account thermal conduction between winding pack and case, which are cooled down separately. To limit coil mechanical stresses and coolant pressure drop in the cooling channels, an improved cool-down mode has been developed based on the analysis. Typical and gradual cool-down temperature distributions of TF coil and case are presented. The results indicate that gradual cool-down to 80 K can be achieved in 3 weeks.

Dual emission of temperature-induced betacarboline self-associated hydrogen bond aggregates

A systematic study of the influence of the gradual temperature decrease on the UV-vis absorption and fluorescence emission spectra of betacarboline, 9H-pyrido[3,4-b]indole, BC, and other model systems, such as BC plus N(9)-methyl-9H-pyrido[3,4-b]indole, MBC, and BC plus pyridine, PY, has been carried out in 2-methylbutane, 2MB. These studies have allowed the conclusion that the temperature decrease favours the formation of hydrogen-bonded self-associated BC aggregates. The initial red shifts of the absorption and emission bands and the fluorescence quenching have been ascribed to the formation of hydrogen bond BC dimers with a proton transfer structure, PTC. In these adducts, the fluorescence is quenched by an electron-driven proton transfer process. However, because the quenching rate constant decreases upon decreasing the temperature, the emission intensity later increases without modification of the wavelength maxima. At the lowest temperatures, these dimeric PTC complexes further aggregate. We propose that they form ground state cyclic tetrameric adducts in which both nitrogen atoms of each BC unit are hydrogen bonded. The tautomeric forms of these tetrameric complexes, generated by a quadruple proton transfer, emit dual fluorescence, from its locally excited state, LE, and its intramolecular charge transfer state, ICT.

Oligocene biogeography of the North Pacific (Implications of Mollusks)

First biogeographic maps are proposed for the late Eocene-Oligocene of the North Pacific. The maps are compiled based on distribution of 120 molluscan species studied in 30 reference sections of the region. The analyzed Machigar (Sakhalin), Rategin, Amanina-Gakh (western Kamchatka), Asagai-Momidziyama (Japan) type assemblages and their age analogues are well known and described long ago. Over 50 schematic biogeographic maps illustrate distribution areas of different taxa in the late Eocene, early Oligocene, and late Oligocene epochs. Some of them characterize distribution areas of individual species, while the others depict habitat areas of typical (Machigar and Rategin) assemblages or certain genera different in terms of their thermotropism. Analysis of the maps resulted in recognition of the Japan-Kamchatka and Kamchatka-North American paleoprovinces, and indications of general gradual seawater temperature decrease during the Oligocene are defined. The attention is paid to the commenced diversification of North Pacific biota that leads to formation of boreal communities and also to different-rank the amphipacific dusjunctions.

J0801-4-3 温度分布制御型マイクロフローリアクタにおける自着火の簡略化モデル(次世代燃料と新しい燃焼技術,エンジン,動カシステム(4))

A simplified modeling approach is presented for autoignition in a fine micro flowreactor having a gradual temperature increase on the inner surface of the reactor tube wall in the axial direction. Autoignition in the flowreactor is described as a transient, spatially zero-dimensional problem by defining the control volume flowing in the reactor which has convective heat transfer with reactor wall. By this approach, the computational load could be drastically reduced and autoignition temperatures for a stoichiometric methane/air mixture estimated by the proposed model were in qualitative agreement with those obtained by previous experiments. Furthermore, a new normalized sensitivity coefficient for the autoignition temperature in the micro flowreactor was introduced. Sensitivity analysis by this sensitivity coefficient with GRI-mech 3.0 successfully identified essential elementary reactions for autoignition and the cause of the insufficient performance of C1-chemistry for the autoignition process.