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The production of high quality ductile cast iron requires different and complex inoculants. Besides iron and silicon, they also contain alloying elements such as zirconium, strontium, barium, calcium and rare earth metals. The addition of these elements reduces carbide solidification and increases the number of eutectic cells, which improves the quality of the cast iron produced. This study investigates the process of incipient melting of a complex barium inoculant and its effects on graphite nucleation. In the study, the sample was prepared by introducing the inoculant grain into the melt of the ductile iron. The region between the inoculant grain and the less inoculated matrix was examined metallographically using light and scanning electron microscopy. We used energy dispersion spectroscopy to determine the phases in the microstructure formed. It was found that graphite particles can already nucleate and grow in solid particles when the inoculant is still dissolving and also from the melt where the Ba and Ca concentrations are high and form BaO·CaO phases that serve as nuclei for graphite growth. [ABSTRACT FROM AUTHOR]

Hydrogen fuel has significant potential for various applications under MILD combustion conditions. This study investigates the impact of H 2 mass fraction (ranging from 10 % to 100 %) on the structure of the combustion zone and the emission rules of NO x in the JHC burner utilizing the detailed mechanism GRI-Mech 2.11. A contraction of the reaction zone and a decrease in the ignition delay is observed when the H 2 ratio increases. Increasing H 2 concentration results in the gradual loss of MILD combustion characteristics in the reaction area, and the downstream region gradually transforms to High Temperature Combustion. The MILD reaction volume at Y O2 = 6 % is only 69 % compared to that at Y O2 = 3 %. Higher Y O2 has a more significant impact on the relative increment of NO emissions. The NNH route consistently predominates, and increasing H 2 ratio amplifies the production of thermal NO x and weakens the NO-reburning mechanism. • Transition of reaction area from MILD to HTC is observed in pure hydrogen cases. • The boundary of pure hydrogen fuel under MILD combustion conditions is depicted. • Contributions of different NO formation routes under MILD conditions are conducted. • Trend of NO generation pathways with changing hydrogen ratio is revealed. [ABSTRACT FROM AUTHOR]

The paper discusses specifics of the process of carbothermic reduction of metallurgical silicon in ore-smelting furnaces. The reaction zone represents a heating area for the charge materials, formed around the electrodes in all electric furnaces, and facilitates the release of thermal energy by passing electric current through a resistance and/or by creating an electric arc, change in the aggregate state of the loaded materials (e.g., quartzite, bituminous coal, needle coke), and a complex of chemical reactions that occur within such materials. When properly controlled, the operating conditions of the ore-smelting furnace provide optimal specific performance relative to specific power consumption. However, in case of deviations, such as high or low placement of the electrodes, excess or lack of reducing agent in the charge material, furnace throat level being too high or too low relative to technical guidelines, electrode voltage imbalance, etc., the furnace performance can be significantly reduced due to a non-conformant granulometric composition. If the furnace is operated with such deviations for extended periods of time, an emergency shutdown may occur. If the power generated at the electrode is insufficient, the reaction zone becomes significantly narrower, this leads to a change in the rate of chemical reactions. The excessive power levels, on the other hand, may cause intensive entrainment of microsilica along with the formation of blowholes capable of disabling water-cooled panels or shutting down the furnace transformer due to an overload. The location of the reaction zone in the furnace space plays a key role in ensuring effective operation of the ore-smelting furnace. Shifting of the reaction zone upward or downward may result in the grade drop of metallurgical silicon and reduced performance of the furnace, which will subsequently increase the product cost. [ABSTRACT FROM AUTHOR]

For NOx removal from diesel exhaust, the selective catalytic reduction (SCR) is the most common abatement technology. However, low engine load scenarios such as city driving and cold start phases demand efficient NOx reduction clearly below 200 °C, which is difficult to achieve with SCR. Hence, this work investigates the potential of the low-temperature NOx reduction with H2 in diesel exhaust. A monolithic Pt/WOx/ZrO2 catalyst, recently reported as highly active, was evaluated in synthetic and real diesel exhaust. The monolith demonstrated high deNOx activity between 130 and 215 °C in the synthetic exhaust including peak conversion of 90% with N2 selectivity up to 85%. CO/HC components were shown to inhibit the H2-deNOx conversion thus requiring a pre-oxidation catalyst in practice. Furthermore, studies performed in an optical reactor indicated strong heat evolution along the monolith. As a result, the reaction kinetics was accelerated with an enhanced consumption of H2 limiting the H2-deNOx efficiency above 200 °C. Stationary tests in diesel engine exhaust substantiated the low-temperature H2-deNOx performance of the monolith including NOx conversions up to 80% at temperatures as low as 135 °C. [ABSTRACT FROM AUTHOR]

The paper considers the issues of interaction of the molten metal at the interface of explosively welded NiCr/titanium alloy laminated composites with the reaction zone formed during heat treatment, as well as the features of its destruction after welding. It was established that the molten metal is a heterogeneous mixture based on Ni(Cr,Ti) and Ti(Ni,Al) solid solutions and NiTi and Ni3Ti intermetallic compounds. The estimated existence time of molten metal areas in the liquid state was ~10−8–10−11 s. The obtained values are comparable with the time of the unloading wave arrival at the contact surface, which is the reason for the presence of fracture areas in the form of detachments on the fracture surface. Continuous nanometer-size interlayers with an amorphous structure, due to the ultra-high cooling rate of the liquid melt, induce viscous destruction of the interface. Heat treatment at temperatures of 700 and 850 °C led to the formation of a layered reaction zone at the NiCr/Ti boundary, consisting of interlayers of solid solutions based on Ti2Ni, TiNi, and TiNi3 intermetallic compounds, as well as inclusions of a Cr(Ti) solid solution. The diffusion flow gradient was predominantly directed into the titanium alloy. [ABSTRACT FROM AUTHOR]

To investigate the process and chemistry of mineral reaction zone formation, we conducted detailed petrographic observations and chemical analysis of rocks and minerals of spinel lherzolite xenoliths from basanites of Tumusun volcano (Baikal Rift Zone). The reaction zones gradually disappear from contact toward the center of the xenoliths. The influence of basanite melt on major and trace element composition of secondary minerals of reaction zones is notable only at a distance up to 100–200 μm from the contact. At a distance of 0.3–1.0 mm from the contact, the major and trace composition of secondary clinopyroxenes from the orthopyroxene reaction zone indicates their formation from a melt formed by dissolution of orthopyroxene and influenced by the element diffusion from basanite melt. Inside xenoliths, the secondary minerals have Mg# values equal to or higher than Mg# of primary minerals, and secondary clinopyroxenes inherit their depleted or enriched REE pattern from primary pyroxenes. The compositional variations in secondary clinopyroxenes testify melt heterogeneity. Clinopyroxene rims have slightly higher LILE and similar abundances of other trace elements compared to clinopyroxene cores. This is consistent with the model developed from experimental studies: due to the interaction with basanite, incongruent dissolution of orthopyroxene occurs to form a melt which circulates in lherzolite and leads to pyroxenes and spinel dissolution. Diffusion of elements from basanite results in lherzolite enrichment in K, Na, Rb, Ba, La, and Ce, which are incorporated in feldspars and clinopyroxene of reaction zones as well as in feldspar veinlets. Non-dissolved mineral cores are homogenous and similar in major and trace element composition to primary minerals without reaction rims. [ABSTRACT FROM AUTHOR]

The problem to obtain casting molds for titanium alloys is not resolved in full. It is primarily due to the high reactivity of titanium alloys resulting in their interaction with refractory materials. This reduces the quality of the castings due to the formation of various defects. The interaction of VT1-0 grade titanium in the liquid state with CaO, ZrO2 and CaZrO3 were studied. The processes occurring at the contact boundary between these substances and a change in the structure and microhardness of titanium castings near this boundary were described herein. The data obtained showed the disadvantages of molding materials based on CaO and CaZrO3. The features revealed for the interaction of a titanium melt with CaZrO3, where a highly porous CaTiO3 layer has been formed in the reaction zone,made it possible to recommend this compound as a promising material to cast molds in order to produce castings from titanium alloys. [ABSTRACT FROM AUTHOR]

Pure ammonia MILD combustion is studied numerically in a furnace. The effects of furnace wall temperature and dilution of inlet air with nitrogen on the characteristics of reaction zone (RZ), temperature distribution and exhaust emissions are investigated. The results show that lowering the furnace wall temperature and adding diluent to the inlet air, result in expansion of the RZ, reduction of fuel and oxidizer consumption rates, lower Damkohler, increased turbulent Reynolds and more similar RZ properties to the distributed combustion regime in the combustion regimes diagram. At a lower concentration of oxygen in the oxidizer, a higher threshold wall temperature is required for stable MILD combustion. Reducing the wall temperature and oxygen mole fraction in the oxidizer, increases the uniformity of temperature distribution. Analysis of exhaust emissions shows that reducing wall temperature and oxygen level in the oxidizer stream can significantly reduce NOx pollution, however, N 2 O emission rises. • Pure ammonia MILD combustion studied numerically in a furnace. • Reaction zone is defined based on NNH mole fraction distribution. • Higher minimum wall temperature is needed for stable combustion using diluted air. • Lower wall temperature and air dilution lead to more distributed reaction zone. • Air dilution and lower wall temperature result in lower NOx and higher N 2 O. [ABSTRACT FROM AUTHOR]

To investigate the process and chemistry of mineral reaction zone formation, we conducted detailed petrographic observations and chemical analysis of rocks and minerals of spinel lherzolite xenoliths from basanites of Tumusun volcano (Baikal Rift Zone). The reaction zones gradually disappear from contact toward the center of the xenoliths. The influence of basanite melt on major and trace element composition of secondary minerals of reaction zones is notable only at a distance up to 100–200 μm from the contact. At a distance of 0.3–1.0 mm from the contact, the major and trace composition of secondary clinopyroxenes from the orthopyroxene reaction zone indicates their formation from a melt formed by dissolution of orthopyroxene and influenced by the element diffusion from basanite melt. Inside xenoliths, the secondary minerals have Mg# values equal to or higher than Mg# of primary minerals, and secondary clinopyroxenes inherit their depleted or enriched REE pattern from primary pyroxenes. The compositional variations in secondary clinopyroxenes testify melt heterogeneity. Clinopyroxene rims have slightly higher LILE and similar abundances of other trace elements compared to clinopyroxene cores. This is consistent with the model developed from experimental studies: due to the interaction with basanite, incongruent dissolution of orthopyroxene occurs to form a melt which circulates in lherzolite and leads to pyroxenes and spinel dissolution. Diffusion of elements from basanite results in lherzolite enrichment in K, Na, Rb, Ba, La, and Ce, which are incorporated in feldspars and clinopyroxene of reaction zones as well as in feldspar veinlets. Non-dissolved mineral cores are homogenous and similar in major and trace element composition to primary minerals without reaction rims.

This study evaluates the applicability of nano-sized calcium peroxide (CaO2) as a source of H2O2 to remediate 2,4-dichlorophenol (2,4-DCP) contaminated groundwater via the advanced oxidation process (AOP). First, the effect and mechanism of 2,4-DCP degradation by CaO2 at different Fe concentrations were studied (Fenton reaction). We found that at high Fe concentrations, 2,4-DCP almost completely degrades via primarily the oxidation of ·OH within 5 h. At low Fe concentrations, the degradation rate of 2,4-DCP decreased rapidly. The main mechanism was the combined action of ·OH and O2·−. Without Fe, the 2,4-DCP degradation reached 13.6% in 213 h, primarily via the heterogeneous reaction on the surface of CaO2. Besides, 2,4-DCP degradation was significantly affected by solution pH. When the solution pH was>10, the degradation was almost completely inhibited. Thus, we adopted a two-dimensional water tank experiment to study the remediation efficiency CaO2 on the water sample. We noticed that the degradation took place mainly in regions of pH < 10 (i.e., CaO2 distribution area), both upstream and downstream of the tank. After 28 days of treatment, the average 2,4-DCP degradation level was ≈36.5%. Given the inadequacy of the results, we recommend that groundwater remediation using nano CaO2: (1) a buffer solution should be added to retard the rapid increase in pH, and (2) the nano CaO2 should be injected copiously in batches to reduce CaO2 deposition. [ABSTRACT FROM AUTHOR]

The liquids produced by the pyrolysis process with biomass as the raw material are popularly called bio-oil. The reaction zone temperature in the pyrolysis process affects the liquid yield in a non-sweeping gas fixed-bed reactor. This research aims to obtain the effect of temperature in the reaction zone on the liquid yield. Camphor wood was fed into the reactor as raw material. An electric heater was controlled using the proportional integral differential (PID) controller to keep the reactor temperature constant at 500°C as an optimum decomposition temperature. To control the vapor temperature in the reaction zone, an electric heater was mounted on the wall of the reaction zone, which was equipped with a PID controller to keep the temperature constant. To convert the pyrolysis vapor into liquid, a double pipe condenser was used in the system. This study showed that the liquid yield increases as the vapor temperature increases. The rise in vapor temperature from an ambient temperature to 200°C increases the liquid yield 17.0 wt% with a low heating rate, 5 wt% with a heating rate of 8°C/minute and 4.5 wt% with a heating rate of 17°C/minute. Early condensation occurred due to the low temperature of the vapor at the reaction zone.

The article focuses on the study of the nature of dust and smoke generation in the gas-oxygen blowing of a converter bath. The main causes of metal waste are determined. The influence of the main parameters of the process on the loss of metal at the dust discharge and evaporation of iron in the reaction zone are studied. The metal pulverization due to floating CO bubbles is evaluated. This pulverization is determined by the rate at which they rise to the bath surface. The characteristic features of the temperature regime of the reaction zone and the heat balance upon the addition of fuel to the oxygen flow are determined. The addition of fuel to oxygen makes it possible to increase the heat input into the bath, while reducing the rate of decarburization. This favors the reduction in the amount of discharged dust formed at the rupture and crushing of metal films by gas bubbles. The influence of using combustion product oxygen on the oxidation of metal impurities is considered. The blowing of carbon and alloyed steel for mill rollers is used as an example to show that the main qualities of gas-oxygen blowing are the decomposition degrees of CO2 and H2O in the bath. These indicators determine the oxidizing and heating properties of the air blast. The change in the total, consumed heat and its losses with exhaust gases are evaluated, depending on the degree, to which the oxygen flow is diluted with natural gas (methane). In these conditions, the use of submersible combustion torches with the change in their oxidizing ability makes it possible to solve various process tasks, including the provision of an efficient procedure of reducing dust emission in the converter process. [ABSTRACT FROM AUTHOR]

Fluid infiltration into metacarbonates is a key mechanism to induce orogenic decarbonation, which influences the global carbon cycle and long‐term climate evolution. Little is known regarding the fluid pathways during episodic infiltration events and how flow patterns control time‐integrated CO2 outflux. We investigate the "vein‐like" polycrystalline mineral reaction zones (PMRZs) in dolomite marbles (Mogok metamorphic belt, Myanmar), which are formed by metasomatism via the infiltration of Si–Al–K–Ti–Zr‐bearing fluids. The petrographic textures and mineral U–Pb chronology reveal three episodes of fluid influx in a single PMRZ: (1) the initial episode (Stage‐I) transformed most dolomite into Mg‐rich silicates/oxides and calcite at ∼35–36 Ma indicated by baddeleyite cores; (2) baddeleyite rims gave ages of ∼23–24 Ma, representing a subsequent infiltration episode (Stage‐II) that modified Stage‐I minerals via a dissolution–precipitation mechanism; (3) the final episode (Stage‐III) is recorded by zircon replacing baddeleyite, which yielded ages of ∼17 Ma. Stage‐III fluid has a higher SiO2 activity and XCO2 [CO2/(CO2 + H2O)] than Stage‐I/Stage‐II fluids. Thermodynamic and mass‐balance analyses indicate that Stage‐I infiltration causes >62–67% loss of CO2 by both dolomite‐consuming reactions and calcite dissolution, whereas the latter two infiltration episodes induce <12–18% loss of CO2 via calcite dissolution. Our results provide compelling evidence that repeated episodes of infiltration (each separated in time by 7–13 Ma) occurred along a single channel in marbles. The initial infiltration episode may create high‐permeability regions, offering favorable channels for later‐stage fluids that transfer obviously less CO2 than the initial metasomatism. This considerably complicates a quantitative assessment of CO2 liberation from metacarbonates during orogenesis. Key Points: Gem‐bearing reaction zones in Mogok marbles record three episodes of fluid infiltration each separated in time by 7–13 MaInitial fluid infiltration drives dolomite‐consuming reactions and produces high‐permeability zones that channelize later fluid transportEffect of multiple fluid infiltration episodes on metamorphic CO2 release from marbles in orogenic belts is assessed [ABSTRACT FROM AUTHOR]

The results presented in this study illustrate the multiple roles of seawater salinity toward the sonochemical degradation, at variable frequencies (300–1700 kHz), of several hazardous substances, i.e. propylparaben (PPR) endocrine disruptor and several synthetic dyes: naphthol blue black (NBB), malachite green (MG), basic red 29 (BR29), acid orange 7 (AO7), Rhodamine B (RhB) and basic fuchsin (BF). Sonochemical treatment degraded all pollutants in seawater at faster rates than in deionized water. The seawater-salts through increasing the ionic strength of the solution act as a potential pusher of hydrophilic pollutants toward the reactive interfacial area of cavitation bubbles. Additionally, the salts reduce the bubble coalescence, which yields higher number of active bubbles in the irradiating media. Analysing the degradation rate of PPR and NBB with two heterogeneous models based on Langmuir kinetics mechanism indicated that the bubble interfacial area was the preferred reaction zone for the ultrasonic degradation of PPR and NBB in seawater. [ABSTRACT FROM AUTHOR]

Numerical simulations are performed on a can-type combustor in order to indentify various flow features. Elementary flow features like jet-in-crossflow, opposed jets, swirl and recirculation zones are present in a combined form. Momentum flux ratio between axial air flow and radial primary air jets from the circumference of the combustor is an important parameter. While increasing mass flow rate of the radial jet, the jet-in-cross flow structure changes to opposed jet. Swirl of axial jet is favourable for opposed jet configuration. A step provided at the close vicinity of the primary jet allows the primary jet expansion and its flow structure is affected at the entrance of the combustor to favour for jet-in-cross flow configuration. The opposed jet configuration provides large recirculation at the upstream due to merging of vortices arising from swirl of axial jet and upstream movement of primary air jet. This helps in holding the flame and also for effective combustion. However, there is a lower temperature region at the downstream core of the combustor due to penetration of primary air jets. On the other hand, jet-in-crossflow configuration has shown hotter zone at the downstream core of the combustor. Hence, effective utilization of flow structure can be considered in future design. [ABSTRACT FROM AUTHOR]

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To investigate the detonation characteristics and the detonation wave profiles of the melt-cast aluminized explosive RBOL-2 (DNAN/HMX/aluminum/other additives), the particle velocity of the interface between the explosive and the Lithium-Fluoride (LiF) window and the free-surface velocity of the copper plate accelerated are measured by using the DISAR interferometer system. It is found that, for RBOL-2 explosive, the reaction zone length is 202 ± 2.5 ns/1.073 ± 0.013 mm, the particle velocity and the pressure at the Von Neumann spike are 2364 ± 3 m/s and 41.80 ± 0.07 GPa, respectively, and the particle velocity and the pressure at the Chapman-Jouguet point are 1564 ± 3 m/s and 25.42 ± 0.05 GPa, respectively. Moreover, the parameters of the Jones-Wilkins-Lee (JWL) equation of state of the RBOL-2 explosive are also determined by the genetic optimization algorithm and the measured free surface velocity of the copper plate. [ABSTRACT FROM AUTHOR]

In the paper, results of a research on braze welded joints of copper-lined 10CrMo9-10 (10H2M) steel tubes made by CMT arc braze welding are presented. As a filler metal, silicon bronze was applied. Results of metallographic examinations with the use of light microscopy, electron scanning microscopy and X-ray microanalysis are presented. Mechanical properties of the joints were assessed on the grounds of static tensile test, technological bending test, as well as hardness measurements. Quality of the obtained joints was good. No cracks were observed in the brazed joints and the obtained mechanical properties were satisfactory. [ABSTRACT FROM AUTHOR]

• NH 3 flame has much lower temperature rise and larger reaction zone than CH 4. • NO x emission of NH 3 flame is two orders higher than CH 4 at equivalence ratio < 1. • NO x emissions of both flames increase rapidly with coflow oxygen concentration. • NO x emission mainly comes from NO while N 2 O is important at low temperature. • MILD combustion can reduce the NO x emission of NH 3 flame by 1–2 orders. Moderate or intense low-oxygen dilution (MILD) combustion is suitable for solving the problems of unstable flames and high NO x emissions (E NO x) of ammonia fuels; however, studies on this are rare. This paper numerically investigates the MILD combustion characteristics of a premixed NH 3 /air jet flame in hot coflow (JHC) under different jet equivalence ratios (Φ J), coflow temperatures (T C), and oxygen levels (X O2,C). For comparison, similar CH 4 /air MILD-JHC flame characteristics are calculated. The results show that the NH 3 flame generally has a lower temperature increase and heat release, as well as a larger reaction zone, than CH 4. This suggests that the NH 3 flame can develop into a MILD regime more easily than CH 4. E NO x of the NH 3 flame is two orders of magnitude higher than that of CH 4 flame at all T C and X O2,C values for Φ J < 1. At Φ J > 1, E NO x of the NH 3 flame rapidly decreases to nearly zero, but unburned NH 3 emissions (E NH3) and H 2 emissions (E H2) are significantly high (∼1000 ppm) and the combustion efficiency is low. Moreover, E NO x increases rapidly (gradually) with X O2,C (T C), whereas E NH3 and E H2 are considerably low at T C ≥ 1300 K and X O2,C ≥ 1% for the NH 3 flame. E NO x primarily originates from NO; however, N 2 O is also important at low Φ J and T C values. Therefore, considering E NO x , E NH3 , E H2 and the burning efficiency, the optimal conditions for NH 3 MILD combustion are Φ J = 1, T C ≥ 1500 K, and X O2,C = 1%–3%. In addition, compared with conventional flames, NH 3 MILD combustion can reduce E NO x by one to two orders of magnitude. [ABSTRACT FROM AUTHOR]

Background. In modern conditions, the BOP-process is the main method of mass use steel product production. At the same time, due to the shortage of high-quality charge materials, resource and energy-saving technologies are particularly relevant. To optimize the BOP-process under modern conditions, it is promising to use improved oxygen lances for top blowing in comparison with known designs. Objective. An important stage in the development of advanced steel production technologies is obtaining information on the thermodynamic model of blowing a converter bath through a three-tier lance with the elaboration of the regularities of oxidation processes within the reaction zone of a 160-ton industrial converter. Methods. The analysis that was carried out has a theoretical nature and is based on the definition of the influence of temperature and pressure on the regularities of oxidation processes within the reaction zones formed when oxygen jets are introduced into the volume of a metal bath, foamed slag-metallic emulsion and waste gases in the working space of the converter. As a thermodynamic parameter, the Gibbs energy was used to estimate the probability of chemical reactions. The pressure effect on the oxidation processes in the converter bath was evaluated in accordance with the Van’t Hoff formula. Results. The thermodynamic features of oxidation processes in the 160-ton BOF bath using a three-tier lance are presented. Primary reaction zone is characterized by the occurrence of oxidation of manganese, silicon, carbon, and iron by gaseous oxygen. In the secondary reaction zone there are chemical reactions of the oxidation of silicon and carbon dissolved in the metal by oxygen, as well as the reduction of iron oxide by carbon. The presence or absence of a slag phase on the melt surface practically does not affect the occurrence probability of chemical transformations within the boundary of primary and secondary reaction zones. The additional secondary oxygen jets are characterized by oxidation of the oxide components of the slag and gas phases. Conclusions. During the research it was clarified the thermodynamical model of the oxidation processes in primary and secondary reaction zones, that were formed due to the interaction of 160-ton BOF bath with the supersonic and sonic oxygen jets flowing out of the separate groups of nozzles (of Laval and cylindrical shapes) of top three-level oxygen lance.

Abstract Decay patterns occurring in wood of hornbeam (Carpinus betulus) during natural decay in vivo were investigated and compared to decay in artificially inoculated wood in vitro. The fungal species causing decay was determined by morphological characterization and confirmed as Trametes versicolor using rDNA-ITS PCR and sequencing. T. versicolor caused degradation with properties of both simultaneous and selective white-rot. Chemical and FT-IR analyses suggested that T. versicolor caused severe reduction of lignin-carbohydrate complexes and guaiacyl lignin within the cell walls during natural decay. Under the light microscope, it was clear that decomposition of cell elements in the reaction zones of naturally decayed wood was greater than in inoculated wood. Histological analyses of inoculated wood blocks suggested that T. versicolor was able to switch from a typical simultaneous rot to selective delignification, with degradation of the middle lamella, and of lignin in cell corners. The results of our work demonstrated that test fungus able to attack the hornbeam tree by saprotrophic and parasitic life strategies. Highlight-IBB06 • Histological patterns of decayed hornbeam by T. versicolor indicated that cell decomposition in reaction zones was severe. • Chemical and FT-IR analyses showed that T. versicolor caused reduction of guaiacyl lignin in hornbeam in natural infection. • T. versicolor was able to switch from commonly rot to selective delignification by lignin degradation in ML and cell corner. [ABSTRACT FROM AUTHOR]

Abstract The leaching of phosphate ores in acid medium is widely practiced in the chemical fertilizers industry. Several processes can take place in the reactor and the quantitative modeling of the reaction kinetics or thermodynamics is essential for the design and dimensioning of the industrial equipments. The aim of the present study is to develop a mathematical model to describe the behavior of phosphate particles into acidic solution under certain conditions. A new formalism based on the Noyes-Whitney equation (NWE) is presented in this paper. In this approach, simplified Lucas-Washburn's equation (LWE) is incorporated to evaluate the progression of reaction zone into the mesoporous phosphate rock. The reliability and validity of this new approach are tested on a large database. Results show that the model is predictive in the case of a solid dissolution without ash film and non predictive in the case of solid leaching with formation of a rushed in the mesoporous area follows. Furthermore, the values and physical significance of the parameters of this model are also discussed in the present work. [ABSTRACT FROM AUTHOR]

The liquids produced by the pyrolysis process with biomass as the raw material are popularly called bio-oil. The reaction zone temperature in the pyrolysis process affects the liquid yield in a non-sweeping gas fixed-bed reactor. This research aims to obtain the effect of temperature in the reaction zone on the liquid yield. Camphor wood was fed into the reactor as raw material. An electric heater was controlled using the proportional integral differential (PID) controller to keep the reactor temperature constant at 500°C as an optimum decomposition temperature. To control the vapor temperature in the reaction zone, an electric heater was mounted on the wall of the reaction zone, which was equipped with a PID controller to keep the temperature constant. To convert the pyrolysis vapor into liquid, a double pipe condenser was used in the system. This study showed that the liquid yield increases as the vapor temperature increases. The rise in vapor temperature from an ambient temperature to 200°C increases the liquid yield 17.0 wt% with a low heating rate, 5 wt% with a heating rate of 8°C/minute and 4.5 wt% with a heating rate of 17°C/minute. Early condensation occurred due to the low temperature of the vapor at the reaction zone. [ABSTRACT FROM AUTHOR]

The interface reaction zone (RZ) in a unidirectional continuous carbon-coated SiC fibre reinforced Ti-17 titanium alloy composite is investigated. Micro-computed tomography (CT), scanning and transmission electron microscopy are employed to characterize the fibre/matrix interface. It is revealed that the interface RZ is a 400 nm thick titanium carbide (TiC) layer which is composed of two sublayers, a 60 nm thick fine-grained sublayer and an approximate 340 nm thick coarse-grained sublayer. The RZ is formed through chemical reaction between carbon coating on the SiC fibre surface and Ti, Zr and Sn in the alloy matrix. The reaction is controlled by atom diffusion occurring at the fibre/matrix interface. However, in the reaction process, Al, Cr and Mo in the matrix are rejected and piled up in front of the RZ on the matrix side. A structure model is proposed to describe the formation mechanism of the interface RZ. [ABSTRACT FROM AUTHOR]

The literature reports on the effect of liquid temperature on sonochemical degradation of hazardous substances are very controversial. Here, we show for the first time experimental evidence that the effect of liquid temperature at high frequency ultrasound is strongly dependent to the initial substrate concentration (C 0 ). Toluidine blue (TB) was taken as substrate model and experiments were conducted at 1700 kHz for a wide range of liquid temperature (25–70 °C) at various initial TB concentrations in the range of 0.5–20 mg L −1 . The obtained results showed that ultrasound at 1700 kHz efficiently degraded TB. For low initial TB concentrations, C 0  = 0.5 and 2 mg L −1 , the rise of the liquid temperature up to 60 °C had practically no significant impact on the degradation rate of the dye. For higher initial dye concentrations (>2 mg L −1 ), the degradation rate increased significantly with increasing liquid temperature up to 50 °C and decreased afterward. In this case, the higher the initial concentration of TB, the higher was the rate of the sono-oxidation. Computational analysis based on single bubble sonochemistry model as well as direct dosing of H 2 O 2 reveals that 50 °C gives the maximum sonochemical activity, OH yield, and thus, the obtained liquid temperature effect dependence of initial substrate concentration would be closely related to the difference in the reaction zone at low and high initial pollutants concentrations. [ABSTRACT FROM AUTHOR]

Abstract: Time- and space resolved selectivity in methanol conversion on zeolites has been investigated and exploited for insight about the reaction mechanism. Particular focus is directed to constraints on diffusion and reaction provided by the pore structure. 3 zeolites with well-ordered voids and channels of different size have been used comparatively. Novel experimental tools have been developed. Product composition is normalized, providing a deactivation pattern, which reflects the reaction mechanism, as changing with time and characterizing essential constraints. The higher product complexity, the more information is present about the mechanism. But in methanol conversion on zeolites, there are difficulties in making use this wealth of information—selectivity meaning a mixture of many compounds, ranging from gases to liquids and substances retained on the catalyst. As catalysts, zeolites with 8-, 10- and 12-ring channels and distinct void’s size have been used in a specifically designed fixed bed reactor, applying ampoule product sampling and advanced chromatography. On catalyst retained substances are taken in account and deactivation is elucidated profoundly. Progress about the mechanism of hydrocarbon formation concerns autocatalysis, constraints with zeolite topologies and changes with time when “C-Retained” accumulates in the pores or on surface of the zeolite crystallites. A surprising reanimation regime with zeolite HZSM5 has been observed and disclosed as thermodynamically controlled arene alkylation with olefins. At low temperature with HZSM5, a different reaction mechanism—as compared with application at high temperature—is noticed, with regimes of incubation, acceleration, and deactivation—at short catalyst live time. The novel experimental techniques allow revealing chemistry in the migrating reaction zone—and in the zones of deactivated catalyst behind, and of fresh catalyst in front. Comparing the results with the 3 zeolite topologies provides insight about controlling constraints.Graphical Abstract: [ABSTRACT FROM AUTHOR]

The oxygen-converter production of steel is determined by processes in the converter’s reaction zone, which consists of primary and secondary regions. The primary region is the crater formed by the collision of a supersonic gas jet with the molten-metal surface. It is filled with metal droplets (diameter 0.1-2 mm). The surrounding secondary region consists of melt with an enormous quantity of gas bubbles (diameter 0.2-4 mm). The total surface area of the droplets and bubbles is four orders of magnitude greater than the surface of the quiescent melt. That indicates the important role of processes at phase boundaries in steel production. The structure of the reaction zone and the corresponding temperature distribution are studied by hot simulation, when the molten metal is blown by oxygen in a transparent quartz crucible. The transparent walls permit photographic and video recording of the processes in the crucible. Besides the temperature distribution, the hydrodynamics of the bath may be studied directly in the injection zone. The most unexpected result of hot simulation is the motion of the bubbles in the secondary region. They move normal to the crater surface. In other words, their motion is almost horizontal, rather than vertical, as in cold simulation in water. This may be attributed to nonuniformity of the melt’s surface tension, resulting in motion of the bubbles toward higher temperatures. In liquid with a temperature gradient, the surface tension will be different ahead of and behind the bubbles. The forces pushing the bubbles from behind are greater than the forces at the front. Accordingly, they move toward the region of lower surface tension. The nonuniformity of the surface tension is due to the temperature gradient (up to 1200°C within the secondary region) and the change in concentration of the melt components, especially oxygen. The surface tension of the ferrocarbon melt changes in a complex manner with increase in temperature. The surface tension rises on heating to 1550°C, but begins to decrease beyond 1550-1600°C. With decrease in carbon content in the melt, the maximum value of the surface tension increases. The motion of gas bubbles and other phases toward lower surface tension begins at the 1550°C isotherm, which is therefore the external boundary of the secondary region, separating it from the remainder of the bath. Within this boundary, the resultant vector of the surface forces pushes the gas bubbles and slag particles, together with the molten metal, horizontally toward the crater, at increasing speed. This determines the hydrodynamics of the smelting bath and the associated redistribution of oxygen over different parts of the bath and hence the refining process as a whole. [ABSTRACT FROM AUTHOR]