Conditions Of Temperature Increase Research Articles

Increasing temperature and sulfate enhances the efficiency of methane abatement in an anaerobic oxidation of methane bioreactor (AOMB) system

Controlling methane emission sources is important for the sustainable application of energy from the deep sea to alleviate methane-induced global warming. The anaerobic oxidation of methane (AOM) process coupled with sulfate reduction (SR) plays a key role in seafloor methane biofiltration. However, the mechanisms for the enhancement of the methane abatement efficiency in an AOM reaction system and the responses of temperature and sulfate concentration remain known. To cover the knowledge gap, this study investigated the enhancement of methane abatement in a self-manufactured AOMB system for 230 days via increasing temperatures and sulfate concentrations. The primary conclusions are as follows: (a) AOM and SR rates were significantly elevated at the conditions of temperature increase (8 to 15 °C) and sulfate addition (+15 mM). (b) Sulfate and temperature were key factors influencing the diversity of archaea and bacterial communities. (c) ANME-2c, ANME-1b, SEEP-SRB1, and Halodesulfovibrio were dominant genera of methane‑sulfur cycling in the system. (d) Functional gene prediction revealed that the coupling of methane oxidation and dissimilatory sulfate reduction was responsible for the methane abatement. Our findings provide new insights into the enhancement of methane abatement efficiency in the deep sea and the application of AOM reaction systems.

Immunological and oxidative stress responses of the bivalve Scrobicularia plana to distinct patterns of heatwaves

As a consequence of global warming, extreme events, such as marine heatwaves (MHW), have been increasing in frequency and intensity with negative effects on aquatic organisms. This innovative study evaluated for the first time, the immunological and physiological response of the estuarine edible bivalve Scrobicularia plana to different heatwaves, with distinct duration and recovery periods. So, extensive immune (total haemocyte count - THC, haemocyte viability, phagocytosis rate, respiratory oxidative burst of haemocytes, total protein, protease activity, nitric oxide and bactericidal activity of plasma) and oxidative stress (lipid peroxidation - LPO, superoxide dismutase - SOD, catalase - CAT and glutathione-S-Transferase - GST) analyses were performed in an experimental study that tested the impact of heatwaves during 25 days. The survival and condition of S. plana were not affected by the exposure to the extreme events. However, our data suggested that longer heatwaves with shorter recovery periods can be more challenging for the species, since THC and phagocytic activity were most affected under the temperature increase conditions. Regarding the oxidative status, the species increased its SOD activity while MDA production slightly declined to the increase of temperature, protecting the organism from cellular damage. These results indicate that S. plana has a great capacity to adapt to environmental temperature changes, however, the expected higher frequency/duration of heatwaves with climate change trends can cause some debility of the species face to other stressors, which can compromise its success in the future.

The Analysis of Ultimate Strength of Stiffened Panels Exposed to Fire Under Temperature Increase Condition

The Analysis of Ultimate Strength of Stiffened Panels Exposed to Fire Under Temperature Increase Condition

Вплив температури на ріст і життєздатність міцелію штамів мікофільного гриба Cladobotryum dendroides

У статті представлені результати досліджень впливу різних значень температур (від 18±0,3°С до 45±0,3°С) на швидкість росту, морфологію колоній та життєздатність міцелію 5 штамів Cladobotryum dendroides, що виділені з уражених павутинною цвіллю плодових тіл їстівного гриба Agaricus bisporus. Установлено, що оптимальною температурою для всіх штамів на картопляно-глюкозному агаризованому середовищі була 25±0,3°С. Збільшення температури на 6°С (с 25±0,3°С до 31±0,3°С) спричинило значне зменшення швидкості росту – для різних штамів – у 65–120 разів. Зниження температури на 7°С (с 25±0,3°С до 18±0,3°С) не настільки негативно вплинуло на швидкість росту досліджених штамів – цей показник знизився в 3–5 разів, порівняно зі швидкістю росту при оптимальній температурі. Установлено, що температура 35±0,3°С була критичною для росту міцелію трьох із 5 досліджених штамів, а для двох інших штамів значення критичної температури було на 1°С нижче й становило 34±0,3°С. Продемонстровано, що міцелій жодного з досліджених штамів C. dendroides не ріс при температурах -18±0,3°С, 5±0,3°С і 15± 0,3°С. Однак при перенесенні культур в умови оптимальної температури ріст відновився. Швидкість росту при цьому незначно відрізнялася від відповідних ростових показників штамів, культивованих при оптимальній температурі. Отже, показники температур -18±0,3°С, 5±0,3°С та 15±0,3°С спричиняють фунгістатичну дію на ріст міцелію досліджених штамів C. dendroides. У результаті дослідження впливу температури на морфологічні особливості росту міцелію штамів C. dendroides установлено, що при підвищенні температури інкубації (30±0,3°С, 31±0,3°С, 34±0,3°С) колонії всіх штамів набувають характерних морфологічних ознак: край колонії стає нерівним, колір колонії змінюється з блідо-жовтого або жовтого на рожевий, темно-бурий чи темно-вишневий, реверзум змінює колір із жовтого на темно-бурий або темно-вишневий.

THE ROLE OF SOLAR RADIATION IN NATURE AND USING IT IN THE MANUFACTURE OF THE FOREST-INDUSTRIAL COMPLEX

According to the complex thermogravimetric and differential thermal analysis, a comparison was made between the heat-storage properties of mixtures of salts-crystalline hydrates, the thermal effects of processes that accompany the reciprocal reaction that occurs when solar energy is accumulated in gelio-thermal collectors. The latter have a high practical value for use in the forest-industrial complex. Physical properties of foreign analogues of heat carriers are shown. The physical properties of salts for use in gel dryers have been analyzed, the equation for determining the peak area of the endothermic effect is given, and a comparison has been made to select the most relevant component for the inclusion of solar drying cells in the system. The samples were analyzed in conditions of temperature increase, that is, the reverse processes taking place in heat-storage devices were realized. Dependences of the fluctuations of temperature of external atmospheric air from hour of day are shown. The advantages of using passive solar systems in the forest-industry complexes are presented, and the possibilities of introduction on production are analyzed. Due to own research, as well as other scientists, determines what determines the growth of phytomass. The options for determining the density of solar radiation (direct and scattered) are specified. The principal scheme of the solar-dryer developed in the NLTI of Ukraine is shown.

The formation of Al2O3 nanoparticles in the oxidation of aluminum by water under sub- and supercritical conditions

Massive aluminum samples were oxidized by sub- and supercritical water with the formation of (AlOOH) n and (Al2O3) n nanoparticles. The release of H2 began at 523 K when the reagents were heated uniformly to 700 K. The time lag of the beginning of oxidation was 140 s when supercritical water was injected into a reactor with aluminum samples at 665 K and 23.1 MPa. Oxidized aluminum powders were analyzed using a transmission electron microscope. Predominantly large (300–400 nm) α-Al2O3 particles were formed when supercritical water was injected into a reactor with aluminum. Smaller (20–50 nm) γ-Al2O3 particles were also observed in samples oxidized by water vapor under temperature increase conditions. Kinetic equations describing the rate of H2 formation in the reaction of H2O with aluminum were obtained. Possible nanostructuring mechanisms are discussed.

História de soterramento e diagênese em arenitos do Grupo Itararé: implicações na qualidade de reservatórios

The imposed diagenetic conditions to the sandstones of the Itarare Group during progressive burial, were analyzed through de integration of subsidence history of the basin with mesodiagenetic products evaluation. The burial history and compaction of the sedimentary column was based on regional stratigraphy correlation, using composite logs, thickness variation, lithology content and erosive rate. The geohistory curves with subsidence and uplift phases were based on previous works of stratigraphy. The Itarare Group deposition was related to high subsidence rate in the Parana Basin. This high subsidence rate had great influence in the sandstones porosity, mainly in chemical compacting action, decurrent of pressure and temperature increase conditions for the burial gradual. Is also distinguished the quartz overgrowths development, abundant anhydrite cementation and partial dissolution of the cements and detritics components.

História de soterramento e diagênese em arenitos do Grupo ltararé - implicações na qualidade de reservatórios

The imposed diagenetic conditions to the sandstones of the Itararé Group during progressive burial, were analyzed through de integration of subsidence history of the basin with mesodiagenetic products evaluation. The burial history and compaction of the sedimentary column was based on regional stratigraphy correlation, using composite logs, thickness variation, lithology content and erosive rate. The geohistory curves with subsidence and uplift phases were based on previous works of stratigraphy. The Itararé Group deposition was related to high subsidence rate in the Parana Basin. This high subsidence rate had great influence in the sandstones porosity, mainly in chemical compacting action, decurrent of pressure and temperature increase conditions for the burial gradual. Is also distinguished the quartz overgrowths development, abundant anhydrite cementation and partial dissolution of the cements and detritics components.

Kinetic study on the exothermic first‐stage decomposition reaction of 2,4,8,10‐tetranitro‐2,4,8,10‐tetraazaspiro[5,5]undecane‐3,9‐dione

AbstractUnder linear temperature increase condition the thermal behavior and kinetic parameters of the exothermic fmt‐stage decomposition reaction of the title compound were studied by means of DSC and TG‐DTG. The empirical kinetic model function in differential form, apparent activation energy and pre‐exponential constant of this reaction are α0.122(1−α)0.528, 216.4 kJ·mol−1 and 1020.51 s−1 respectively. The critical temperature of thermal explosion of the compound is 222.25 °C. The values of Δ≠S, Δ≠H, and Δ≠G and of this reaction are 108.3 J·mol−1K−1, 205.1 kJ·mol−1 and 151.4 kJ·mol−1, respectively.

Kinetics and mechanism of the exothermic first‐stage decomposition reaction of dinitroglycoluril

AbstractUnder linear temperature increase condition, the thermal behavior, mechanism and kinetic parameters of the exothermic decomposition reaction of the title compound have been studied by means of DSC and IR. The initial stage of the mechanism was proposed. The empirical kinetic model function in differential form, apparent activation energy and pre‐exponential constant of the exothermic decomposition reaction are a 0.526, 207.0 kJ·mol−1 and 1018.49s‐1, respectively. The critical temperature of thermal explosion of the compound is 252.87 °C. The values of ΔS≠, ΔH≠ and ΔG≠ of the reaction are 128.4 J·mol‐1.K−1, 218.9 kJ·mol−1 and 152.7 kJ·mol−1, respectively.

Kinetics and mechanism of the exothermic first-stage decomposition reaction for 1,5-dimethyl-2,6-bis(2,2,2-trinitroethyl)-4,8-dinitroglycoluril

Under linear temperature increase condition the thermal behavior, mechanism and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound have been studied by means of DSC, TG–DTG and IR. The reaction mechanism was proposed. The kinetic model function in differential form, apparent activation energy and pre-exponential constant of this reaction are (1− α) 0.5, 194.7 kJ mol −1 and 10 18.45 s −1, respectively. The critical temperature of thermal explosion of the compound is 200.8 °C. The values of Δ S ≠, Δ H ≠ and Δ G ≠ of this reaction are 133.3 J mol −1 K −1, 203.9 kJ mol −1 and 142.0 kJ mol −1, respectively.

Kinetics of Formation of ZnSe Nanocrystals under Linear Temperature Increase Condition

The kinetics of formation of ZnSe nanocrystals from the complex ZnSe(C2H8N2) has been investigated by means of non isothermal TG DTG at various heating rates of 5.0,10.0,15.0 and 20.0 ℃ · min- 1.The results show that the formation of ZnSe nanocrystals was controlled by three dimension diffusion.The most probable kinetic function in differential form,and in integral form,the apparent activation energy(E) and the pre exponential constant(A) of the process are f(α )=,G(α )=[(1+ α )1/3- 1]2,209.61 kJ· mol- 1 and 1015.7 s- 1,respectively.The kinetics equation is IMG SRC="IMAGE/07290039.JPG" HEIGHT=24 WIDTH=298The calculated results are in accordance with the experiments.ZnO nanocrystal with less than 40 nm size has also been obtained from ZnSe nanocrystals.

Kinetics and mechanism of the exothermic first-stage decomposition reaction for 1,4-dinitro-3,6-bis(trinitroethyl) glycoluril

Under linear temperature increase condition the thermal behaviour, mechanism and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound have been studied by means of DSC, TG-DTG and IR. The reaction mechanism could be expressed by the following . The apparent activation energy, pre-exponential constant and reaction order of this reaction are 203.1 kJ mol −1, 10 19.9 s −1 and 0, respectively. The critical temperature of thermal explosion of the compound is 191.4 °C. The values of Δ S ≠ Δ H ≠ and Δ G ≠of this reaction are 132.5 J mol −1, 199.09 and 138.74 kJ mol −1, respectively.

Effect of temperature on the aggregation of Skeletonema costatum (Bacillariophyceae) and the implication for carbon flux in coastal waters

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 174:223-231 (1998) - doi:10.3354/meps174223 Effect of temperature on the aggregation of Skeletonema costatum (Bacillariophyceae) and the implication for carbon flux in coastal waters Daniel C. O. Thornton*, Brenda Thake School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, United Kingdom *Present address: Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom. E-mail: dan@essex.ac.uk ABSTRACT: Skeletonema costatum (Greville) Cleve was isolated from a mucilaginous algal bloom in the Northern Adriatic Sea during April 1993. In nitrate-limited continuous culture the formation of aggregations of cells was positively correlated with temperature. Raising the temperature from 10 to 20°C caused cells to aggregate without a change in culture biomass. Reducing the temperature to 10°C caused washout of the aggregates, again with no change in biomass. In batch culture there was a positive relationship between aggregate concentration and temperature at 10, 15, 20 and 25°C. Aggregates and the cell surface of S. costatum adsorbed Alcian blue, a stain for acid and sulphated polysaccharides. Disruption of the aggregates on addition of 0.2 M Na2EDTA indicated that cross-linking between polysaccharides by divalent cations (probably Ca2+ in seawater) bound the aggregates together. Aggregates may form in situ under conditions of temperature increase and high phytoplankton biomass. Surface water temperature increased by 0.2°C d-1 in the second half of July 1992 in the Northern Adriatic, coinciding with a chlorophyll a increase of 10 to 50 µg l-1. A temperature difference of 1.2°C was observed at 2 stations 4 m apart in May 1992 on either side of a plume front associated with the River Po; transfer of phytoplankton in eddies from cold to warm waters may lead to the formation of aggregates. Aggregate disruption may occur with the sinking of aggregates from surface waters to the relatively cool waters below the thermocline. The temperature decrease through the thermocline varied between 2.7 and 4.1°C in May 1992. The relationship between aggregation and temperature may be an important factor in determining the flux rate of fixed carbon and nutrients from the photic zone to deeper waters and the sea bed. Aggregated cultures had significantly higher sinking rates than unaggregated cultures. KEY WORDS: Diatom · Aggregation · Temperature · Continuous culture · Marine snow · Skeletonema costatum Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 174. Publication date: November 26, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.

Studies of the adsorbed water layers on solid surfaces by means of the thermal analysis special technique

The paper presents the thermogravimetric studies of water film properties on the solid surfaces using the programmed desorption under the quasi-isothermal conditions. The samples wetted in a different way before the measurements were heated under the suitable quasi-isothermal conditions of temperature increase in the derivatograph using a platinum labyrinth crucible in order to evaporate water films from the surface. During the measurements, the mass loss Q-TG and the differential Q-DTG curves were registered as a function of temperature and/or time which are characterized by the inflections showing individual stages of water desorption from the samples. On the basis of experimental data, the surface wetting mechanism and kinetics of the thermodesorption of water films, discontinuous properties of adsorbed water layers on porous surfaces, adsorption capacity of samples and nature of active sites (e.g. hydroxyl groups) have been presented. It was stated that this method could be successfully applied in the studies of adsorbed water films and surface wetting phenomena.

Thermal behaviour of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-tricyclo (7,3,0,03,7) dodecane-5,11-dione

Abstract The thermal decomposition process of the title compound (HHTDD) under the conditions of vacuum and water vapour has been studied by using a highly sensitive Bourdon manometer. This process can be divided into induction period, acceleration period and deceleration period. All the decomposition curves exhibit the typical sigmoid shape. The relationship between the induction period (tin) and the temperature (T) of the thermal decomposition of HHTDD in the temperature range 60 ∼ 120°C can be expressed by the following equations: and Acid and water are the principal factors affecting the stability of HHTDD. Water, especially has a devastating influence on HHTDD. Under linear temperature increase condition, the apparent activation energy of the thermal decomposition reaction of HHTDD is about 160 kJ mol−1. The neutral hydrolytic reaction equation and ion dissociation process of HHTDD are proposed.

Thermal behaviour of 3-nitro-1,2,4-triazol-5-one and its salts

3-Nitro-1,2,4-triazol-5-one (NTO) is a new explosive with high energy and low sensitivity, whose salt derivatives are also very useful. Under linear temperature increase conditions, the mechanisms and kinetic parameters of thermal decomposition of NTO and M · (NTO) m· nH 2O (M  Cu, m  2, n  4; M  Pb, H 3NCH 2CH 2NH 3, m  2, n 0; M  K, NH 4, m  1, n 1) are obtained by TG, DSC, IR and X-ray diffraction. The thermal decomposition processes of Cu·(NTO) 2·4H 2O and K·NTO·H 2O can be divided into three stages: dehydration, ring breaking, and forming metal oxide. However the thermal decomposition process of Pb·(NTO) 2 has only two stages because there is no crystal water. The decomposition process of NH 4·NTO·H 2O has three stages as well, but they are dehydration, deamination, and decomposition reaction of NTO, which is formed in the second stage. However, if the sample is sealed in a closed stainless steel cell, or the ammonia produced in the second stage does not escape as fast as it is produced, the gaseous ammonia will catalyse the decomposition of NTO.

Kinetics and mechanism of the exothermic first-stage decomposition reaction for 1-nitro-3-(β,β,β-trinitroethyl)-2-imidazolidinone

Under linear temperature increase condition the thermal behavior, mechanism and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound have been studied by means of DSC, TG, DTA, IR and mass spectrometry. The mechanism of above-mentioned reaction could be expressed by the following scheme. The apparent activation energy, pre-exponential constant and reaction order of this reaction are 112 kJ/mol, 109.62sec−1 and 0 respectively.

A study of reaction between RDX and urea by a single non-isothermal DSC curve

A method and a relative formula for estimating the critical temperature of thermal explosion for explosives under linear temperature increase conditions are presented. The experimental and calculated results show that the reaction between RDX and the incompatible additive, urea, can be characterized and evaluated with the changes in value of eight criteria. (The apparent activation energy (E), the pre-exponential constant (A), the reaction order (n), the initial point (T O), at which the DSC curve deviates from the baseline, the maximum peak temperature of the DSC curve (T m), the heat-temperature quotient (H O/T mthe activating entrop (ΔS #) and the critical temperature of thermal explosion (T b) obtained by a single non-isothermal DSC curve.

Evaluation of kinetic constants for the solid state reactions under linear temperature increase conditions

The theory of solid state reaction kinetics considers the dependence of reaction rates on temperature ( T) and progress of the reaction (α). The term describing the dependence of reaction rates on temperature is usually assumed to be an Arrhenius-type equation: k( T) = Z exp(— E/RT), or the equation predicted by transition state theory: k( T) = ZT b exp(— E/RT). With these assumptions, the equation g(α) = tk( T) has been derived, and this form has been satisfactorily applied for the description of solid state reaction kinetics under isothermal conditions. In this work equations similar to those applied in the case of isothermal conditions are proposed for describing the reaction kinetics under linear temperature increase conditions ▪ if k( T) = Z exp(— E/RT) ▪ if k( T) = ZT b exp(— E/RT) An attempt has been made to apply the above equations, as well as the differential form from the first equation dα/d t = f(α) Z(1 + E/RT) exp(— E/RT) to a non-isothermal thermogravimetric experiment. The evaluated kinetic constants are in good agreement with those estimated previously by applying widely used methods of calculation. Therefore, these equations may be considered as simpler and more adequate forms for the description of reaction kinetics under linear temperature increase conditions. Two new statistical functions have been applied in this work which permit the evaluation of E and Z from any kinetic equation. These functions may be used instead of the linear interpolation method, because they allow one to distinguish more easily between possible forms of g(α) or f(α) functions. This approach is recommended especially if one intends to use differential kinetic equations.