High temperature oxidation of inoculated high Si/SiMo ductile cast irons in air and combustion atmospheres

The present work aims to investigate the effect of heating temperature(400,600 and 800°C)and inoculating elements(Ca,Ca-Ba,Ca-RE)on oxidation behavior of ductile irons containing 5.25%Si and 4.8%Si-2.3%Mo in dry air and combustion gas containing water vapour(natural gas burning).The oxidation is influenced by the gas atmosphere type,the iron alloying system,and the inoculating elements depending on the heating temperature.The weight gain increases from 0.001%-0.1%(400°C)to 0.05%-0.70%(600°C)and up to 0.10%-2.15%(800°C).No particular effects of the considered influencing factors are found when heating at 400°C,while at 600°C,mainly the oxidation gas atmosphere type shows a visible influence.At the highest heating temperature of 800°C,a limited increase of the weight gain is found for dry air atmosphere(up to 0.25%),but it drastically increases for combustion atmospheres(0.65%-2.15%).The water vapour presence in the combustion atmosphere is an important oxidising factor at 600-800°C.The alloying system appears to influence the oxidation behavior mainly at a heating temperature of 800°C in the combustion atmosphere,as evidenced by the lower weight gain in 5.25%silicon cast iron.Positive effects of inoculating elements increase with the heating temperature,with Ca and Ba-FeSi inoculation generally showing better performance.Irons inoculated with CaRE-FeSi exhibit a higher degree of oxidation.These results are in good relationship with the previous reported data:Ca-Ba-inoculation system appears to be better than simple Ca for improving the graphite parameters,while RE-bearing inoculant negatively affects the compactness degree of graphite particles in high-Si ductile irons.As the lower compactness degree is typical for graphite nodules in high-Si ductile irons,which negatively affects the oxidation resistance,it is necessary to employ specific metallurgical treatments to improve nodule quality.Inoculation,in particular,is a potential method to achieve this improvement.

Cultivation of aerobic granules for simultaneous nitrification and denitrification by seeding different inoculated sludge

Cultivation of aerobic granules for simultaneous nitrification and denitrification in two sequencing batch airlift bioreactors was studied. Conventional activated floc and anaerobic granules served as main two inoculated sludge in the systems. Morphological variations of sludge in the reactors were observed. It was found that the cultivation of aerobic granules was closely associated with the kind of inoculated sludge. Round and regular aerobic granules were prevailed in both reactors, and the physical characteristics of the aerobic granules in terms of settling ability, specific gravity, and ratio of water containing were distinct when the inoculate sludge was different. Aerobic granules formed by seeding activated floc are more excellent in simultaneous nitrification and denitrification than that by aerobic granules formed from anaerobic granules. It was concluded that inoculated sludge plays a crucial role in the cultivation of aerobic granules for simultaneous nitrification and denitrification.

Grain refinement of Mg-Al alloys inoculated by MgAl_(2)O_(4)powder

As a potent nucleating substrate forα-Mg grain,MgAl_(2)O_(4) powder was used to inoculate the Mg-Al melt in this study.The effects of MgAl_(2)O_(4)amount,holding time and Al content on the grain size and grain refining ratio of the inoculated Mg-Al alloys are systematically investigated.The results show that the minimum grain size of Mg-3Al alloy is achieved by adding 2wt.%MgAl_(2)O_(4)powder and this alloy exhibits higher grain refining ratio than Mg-5Al and Mg-8Al alloys.The crystallographic misfit calculation indicates the wellmatching and possible orientation relationships(ORs)betweenα-Mg and MgAl_(2)O_(4).Among these predicted ORs,[10–10]α−Mg//[110]MgAl2O4 in(0002)α−Mg//(1–13)MgAl2O4 possesses the smallest misfit,i.e.,2.34%(fr).Both results of the experiment and crystallographic calculation demonstrate that the grain refinement of Mg-Al alloys is attributed to the MgAl_(2)O_(4)particles acting as the heterogeneous nucleation substrates forα-Mg grains.

Comparison Study on Clinical and Neuropathological Characteristics of Hamsters Inoculated With Scrapie Strain 263K in Different Challenging Pathways

Objective To understand the infectious characteristics of a hamster-adapted scrapie strain 263K with five different routes of infection including intracerebral (i.e.), intraperitoneal (i.p.), intragastrical (i.g.), intracardiac and intramuscular (i.m.) approaches. Methods Hamsters were infected with crude- or fine-prepared brain extracts. The neuropathological changes, PrPSc deposits, and patterns of PK-resistant PrP were analyzed by HE stain, immunohistochemistry (IHC) assay and Western blot. Reactive gliosis and neuron loss were evaluated by glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) specific IHC. Results The animals inoculated in i.m. and Lp. ways with crude PrPSc extracts showed clinical signs at the average incubation of 69.212.8 and 65.5±3.9 days. Inoculation in i.c. and intracardiac ways with fine PrPSc extracts (0.00035 g) caused similar, but relative long incubation of around 90 days. Only one out of eight hamsters challenged in i.g way with low dosage (0.01 g) became ill after a much longer incubation (185 d), while all animals (4/4) with high dosage (0.04 g) developed clinical signs 105 days postinfection. The most remarkable spongiform degeneration and PrPSc deposits were found in brain stem among the five challenge groups generally. The number of GFAP-positive astrocytes increased distinctly in brain stems in all infection groups, while the number of NSE-positive cells decreased significantly in cerebrum, except i.c. group. The patterns of PK-resistant PrP in brains were basically identical among the five infection routes. Conclusion Typical TSE could be induced in hamsters by inoculating strain 263K in the five infection ways. The incubation periods in bioassays depend on infective dosage, administrating pathway and preparation of PrPSc. The neuropathological changes and PrPSc deposits seem to be related with regions and inoculating pathways.

Thermal analysis control of in-mould and ladle inoculated grey cast irons

The effect of addition of 0.05wt.% to 0.25 wt.% Ca,Zr,Al-FeSi alloy on in-ladle and in-mould inoculation of grey cast irons was investigated.In the present paper,the conclusions drawn are based on thermal analysis.For the solidification pattern,some specific cooling curves characteristics,such as the degree of undercooling at the beginning of eutectic solidif ication and at the end of solidifi cation,as well as the recalescence level,are identif ied to be more influenced by the inoculation technique.The degree of eutectic undercooling of the electrically melted base iron having 0.025% S,0.003% Al and 3.5% Ce is excessively high(39-40℃),generating a relatively high need for inoculation.Under these conditions,the in-mould inoculation has a more signif icant effect compared to ladle inoculation,especially at lower inoculant usage(less than 0.20 wt.%).Generally,the eff iciency of 0.05wt.% -0.15wt.% of alloy for in-mould inoculation is comparable to,or better than,that of 0.15wt.% -0.25wt.% addition in ladle inoculation procedures.In order to secure stable and controlled processes,representative thermal analysis parameters could be used,especially in thin wall grey iron castings production.

Assessment of solidification characteristics of carbon-inoculated Mg-3%Al melt by thermal analysis

The Mg-3%Al melt was inoculated by carbon with different holding time.The effect of holding time on grain refining efficiency was evaluated.The solidification characteristics of the carbon-inoculated Mg-3%Al melt with different holding time were assessed by computer-aided cooling curve analysis.The results showed that Mg-3%Al alloy could be effectively refined by carbon inoculation.Slight fading phenomenon occurred with increasing the holding time to 60 min.Carbon inoculation could significantly influence the shape of cooling curves of Mg-3%Al melt.The nucleation starting and minimum temperatures increased.The recalescence undercooling and duration decreased to almost zero after carbon inoculation.The grain refining efficiency of carbon inoculation could be assessed by the shape of the cooling curve and solidification characteristic parameters including nucleation starting and minimum temperatures,recalescence undercooling and duration.

Effect of Morphology of Instantaneous Inoculant on Inoculated Result of Melted Iron

The characteristics of some elements in inoculant were analyzed.The effect of the morphology of instantaneous inoculant on its melting velocity was studied.When the inoculants pass through the same sieve number,the volume and the ratio of surface area to volume are different.It is evident from the theoretical analysis and experiment under some conditions that the melting velocity of inoculant depends on the morphology of inoculant.The morphology of inoculant during production should be controlled carefully.

STUDY ON NUDE MICE INOCULATED WITH MYCOBACTERIUM LEPRAE BY MULTIPLE ROUTES

Immune-deficient nude mice were inoculated with nude mouse derived Mycobacteriurn leprae by multiple routes (intravenously. subcutaneously at the foot pads and ears). The results showed that these inoculated animals were capable of producing a great number of Mycobacterium leprae to a level 10(11-12) per gram of tissue. and were detected histopathologically to have heavy leproniatous lesions. The dissemination of the infection was found particularly in sites with lower body temperature.The organisms have a partiality to striated muscles and peripheral nerves. The authors suggest that experimental leprosy in nude mice is a very useful tool for leprosy resarch. especially in countries without armadillos. Compared with the single-route inoculation reported previously. multiple-route inoculation is more available.

Ruminal degradability of Guinea grass silage inoculated with Streptoccocus bovis isolated from bovine rumen combined or not with com wheat bran

This experiment aimed to evaluate the ruminal degradability in situ of the dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of Guinea grass silages. The experimental design was completely randomized with six treatments and six repetitions: Guinea grass silage, Guinea grass silage inoculated with 10% wheat bran, Guinea grass silage inoculated with 106 cfu/g of strains of Streptococcus bovis JB1;Guinea grass silage inoculated with 106 cfu/g of strains of Streptococcus bovis JB1 plus 10% of wheat bran;Guinea grass silage inoculated with 106 cfu/g of strains of Streptococcus bovis HC5;Guinea grass silage inoculated with 106 cfu/g of strains of Streptococcus bovis HC5 plus 10% of wheat bran. The silages inoculated with Streptococcus bovis and with added wheat bran resulted in higher values of ruminal degradability of DM, 32.76% and 32.17%, and of crude protein 38.28% and 37.89%. For the effective and potential degradability of DM, CP, NDF and ADF the highest values occurred for silages in these silages as well, in all passage rates. There is a similarity between the responses of Streptococcus bovis JB1 and the HC5, and the wheat bran enhanced the effectiveness of the microbial additive.

Strength Characteristics of Inoculated and Nodularised Thin Wall Ductile Iron Castings

Carbide precipitates in Thin Wall Ductile Iron (TWDI) used for automotive applications needs to be eliminated or reduced for improved strength, ductility, crack propagation resistance and good machinability. Ductile iron thin section profiles (≤3 mm) present danger of massive carbide precipitations in the as-cast sample. Precipitated carbide phase is brittle and negatively affects the mechanical properties of the iron matrix. The suppression of carbide formation is associated with the nucleating properties of the nodularizer and innoculant alloys. This treatment is vital in ensuring that carbide precipitation, flake graphite structure and non-nodular graphite phases are reduced or completely eliminated in the TWDI castings. Therefore, the temperature and technique of treatment would influence the yield of the process, and ultimately the mechanical properties. In this study, the effect of nodularization and inoculation treatment temperature on the microstructure and mechanical properties of TWDI castings is examined. The results indicate that good nodularity and nodule count with better percent elongations are achieved using low treatment temperatures in descending order of 1490°C, 1470°C and 1450°C, but have negative effect at lower treatment temperature of 1430°C. However, TWDI castings have superior properties in terms of nodule counts and nodularity at 1450°C. Treatment temperature does not produce significant influence on ultimate tensile strength (UTS) and hardness of TWDI castings. TWDI castings show poor nodularity, nodule count and ductility at higher inoculation treatment temperatures of 1550°C, 1530°C and 1510°C.

Effect of Cu-Ni and Cu-Ni-Mn on the Microstructural and Mechanical Behaviour of As-Cast Non-Inoculated Hypereutectic Grey Iron

The hypereutectic region of grey cast iron has received very little attention especially for designing cast products by researchers. Due to its high carbon equivalence, hypereutectic grey iron poses some challenges especially its tendency for grey to white transition (GWT) at this level of carbon content. However, hypereutectic grey iron possesses inherent properties that could be easily utilized for improved performance in automobile engines and brake pad system. Significantly, they could be modified for superior hardness, strength and toughness. This study presents the effect of microalloying on the mechanical behaviour of hypereutectic grey cast iron with carbon equivalence above 4.5. The first part of this work presented in this paper considers the addition of Cu-Ni and Cu-Ni-Mn to series of as-cast hypereutectic grey cast iron and their hardness and tensile strength were studied and compared. A total of 33 cast samples were obtained with the control sample. The examination of the micrographs revealed that graphite eutectics cells of Type A and A + D were obtained in the resulting microstructure. Results analyses showed that the ferrite forming tendency of silicon was suppressed due to the high carbon content of the as-cast hypereutectic grey iron coupled with the absence of inoculation which plays a great role in the graphite flake type, network, size and distribution. Cu-Ni microalloying was also confirmed to promote hardness with the hardening effect limit of nickel observed at 1.3% composition. For Cu-Mi-Mn addition, excess and free sulphur in the hyper- eutectic grey iron results in reverse effect of manganese on strength, hardness, reduced graphite flake size and shape.

Recorded Marked Changes in the Haematological and Immune Responses of Two Non-Transgenic Rodents Inoculated Orally and Intraperitoneally with <i>Trypanosoma brucei brucei</i>

Objectives: The digestive track of mice and humans has always been an integral part of the pathogenesis of the Trypanosomes but is constantly overlooked. This realization opens up completely new strategies for the development of trypanosomes vaccines, allowing approaches that parenteral delivery forms would not permit. The target of the study was to compare the haematological changes and immunological responses of trypanosomiasis model systems (mice and rats) inoculated orally and intraperitoneally and to observe the afterward effect of a controlled drug [Isometamidium chloride (ISM)] in the restoration of these initial parameters. Methods: To achieve this, a total of 40 rodents (20 rats and 20 mice) were purchased, then grouped into two [sixteen younger (1 - 5 weeks) and older (7 - 15 weeks) groups each]. They were further sub-grouped into five each. Body weights, Parasitaemia and Packed Cell Volume (PCV) were taken before, after inoculation and after treatment with ISM at 4 mg/kg. Results: Based on presumptive clinical diagnosis, all rodents inoculated intraperitoneally showed clinical signs of fluctuations in weight, PCV and parasitaemia levels before, after inoculations and after treatment compared to those inoculated orally with a significant difference (P < 0.05) observed. Both young and older rodents also responded differently to the inoculants and to the different methods of inoculation. But more deaths were recorded among the mice when compared to the rats. Conclusion: Although these non-transgenic models would not have offered a completely new methods to vaccine development, their differences in response to various methods of inoculations is an indication of an exciting research processes and could offer desired results, particularly where transgenic rodents are employed.

Biological soil crusts and their potential applications in the sand land over Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is now experiencing ecological degradation risks as a result of climate change and human activities.The alpine grassland ecology in permafrost zones is fragile and susceptible to deterioration due to its high altitude,low temperature,and limited oxygen,which complicates the repair of damaged land.Biological soil crusts(BSCs)are crucial for land restoration in plateau regions because they can thrive in harsh conditions and have environmentally beneficial traits.Inoculated biological soil crust(IBSC)has shown success in low-altitude desert regions,but may not be easily duplicated to the plateau environment.Therefore,it is essential to do a comprehensive and multifaceted analysis of the basic theoretical comprehension and practical application of BSCs on the Tibetan Plateau.This review article aims to provide a brief summary of the ecological significance and the mechanisms related to the creation,growth,and progression of BSCs.It discusses the techniques used for cultivating BSCs in laboratories and using them in the field,focusing on the Qinghai-Tibet Plateau circumstance.We thoroughly discussed the potential and the required paths for further studies.This study may be used as a basis for selecting suitable microbial strains and accompanying supplemental actions for implementing IBSCs in the Qinghai-Tibet Plateau.

Nanoparticles and their crosstalk with stress mitigators:A novel approach towards abiotic stress tolerance in agricultural systems

Plants are exposed to adverse environmental conditions,including cold,drought,heat,salinity,and heavy metals,which negatively impact plant growth and productivity of edible crops worldwide.Although the previous literature summarized the nanoparticle's involvement in abiotic stress mitigation,the interaction of nanoparticles with other stress mitigators to overcome abiotic stress from plants remains unclear.Currently,nanotechnology is considered a growing new field in agriculture for understanding plants'adapted stress tolerance mechanisms.Recent research has shown that nanoparticles can effectively mitigate abiotic stress by interacting synergistically with plant growth regulators.To address this,we comprehensively demonstrated the combined positive potential of nanoparticles in combination with plant growth regulators(signaling molecules,phytohormones,nanoparticles-nanoparticles interaction,fungi,plant growth promoting rhizobacteria and other metal salts)to improve plant growth and mitigate abiotic stresses.Their co-applications augment the plant's growth,nutrient uptake,antioxidant defense system,water absorption,cell viability,water use efficiency,and photosynthetic and biochemical attributes by reducing oxidative stressors under various abiotic stresses in different plant species.This review provides a comprehensive overview of the combined applications of nanoparticles and plant growth regulators,a novel strategy to reduce the harmful effects of abiotic stress on plants.It identifies research gaps and recommends future studies to overcome their phytotoxicity worldwide.

Inoculation Effects of Dendrobium officinale Mycorrhizal Fungi on Their Plantlets

[Objective] This study aimed to explore the inoculation effects of Dendrobium officinale mycorrhizal fungi on their plantlets. [Method] Endophytic strains Tj1, Tj2 and Tj3 were obtained by isolation and purification from mycorrhiza of wild Dendrobium officinale and inoculated on the root system of Dendrobium officinale for inoculation test. [Result] Under tissue-culture conditions, at early stage, Tj1 strain hadn＇t shown promotion effect on Dendrobium officinale, Tj2 strain had shown relatively strong promotion effects, and Tj3 strain had promoted the growth of roots; at late stage, Tj1 strain had shown relatively strong promotion effects, Tj2 strain had shown the best inoculation effects and the strongest promotion effects, while Tj3 strain had caused root and seedling rot problems of the plantlets; under outdoor conditions, after inoculation with Tj2 strain, the number of leaves and lateral buds were increased, the growth of lateral root and the increase of plant height were significant, the leaves of Dendrobium officinale plantlets were large and dark green and an obvious root enlargement phenomenon was observed. [Conclusion] The two inoculation methods both indicate that Tj2 strain has relatively strong promotion effects on the growth of Dendrobium officinale roots and shoots, the increase of plant number and plant height, and the germination of new shoots and roots, which proved the effective establishment of symbiotic relationship between Tj2 strain and Dendrobium officinale. Therefore, T2 strain has practical application values on the successful cultivation of Dendrobium officinale plantlets.

Grain refinement of pure aluminum by direct current pulsed magnetic field and inoculation

The combined effects of direct current pulsed magnetic field （DC-PMF） and inoculation on pure aluminum were investigated, the grain refinement behavior of DC-PMF and inoculation was discussed. The experimental results indicate that the solidification micro structure of pure aluminum can be greatly refined under DC-PMF. Refinement of pure aluminum is attributed to electromagnetic undercooling and forced convection caused by DC-PMF. With single DC-PMF, the grain size in the equiaxed zone is uneven. However, under DC-PMF, by adding 0.05% （mass fraction） Al5Ti-B, the grain size of the sample is smaller, and the size distribution is more uniform than that of single DC-PMF. Furthermore, under the combination of DC-PMF and inoculation, with the increase of output current, the grain size is further reduced. When the output current increases to 100 A, the average grain size can decrease to 113 μn.

Transient Expression of BYDV-MP in Nicotiana benthamiana

[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movement protein gene of barley yellow dwarf virus （BYDV） was cloned into potato virus X （PVX） viral vector of pGR107,and PVX-recombinant vector was obtained. After electroporation of Agrobacterium tumefaciens,PVX was inoculated into the lower leaves of tobacco by Agrobacterium infiltration assay to observe the infection of virus on tobacco. [Result]After infection for 7 days,upper non-inoculated leaves of tobacco infected by the PVX-recombinant vector showed the virus infection symptoms,while the control group had no viral infection phenomenon. Daily follow-up observations for two groups revealed that tobacco infected by PVX-recombinant vector had severe symptoms of virus infection and curling leaves,or even led to necrosis both in infiltrated and systemic leaves in late period. However,tobacco infected by PVX vector had only slight symptoms of virus infection and could recover from infection. RT-PCR of the infected tobacco indicated that exogenous gene BYDV-MP had a normal transcription and expression in tobacco. [Conclusion]As a determinant factor for viral disease,BYDV-MP promotes the systemic infection rate of PVX and its symptom. In addition,it is feasible to express exogenous MP gene in Nicotiana benthaminan via PVX expression vector.

Poisoning-free effect of calcium on grain refinement of Mg-3%Al alloy containing trace Fe by carbon inoculation

Mg-3%Al alloy was modified by combining Ca addition with carbon inoculation. The effects of Fe addition and addition sequence on the grain refinement were investigated. A higher grain refining efficiency could be obtained for the Mg-Al alloy modified by combining Ca addition with carbon inoculation. Fe addition and addition sequence had no obvious effect on the grain refinement. Ca addition could effectively avoid grain-coarsening resulting from Fe in the carbon-inoculated Mg-Al alloy. The Al-C-O particles, actually being Al4C3, should act as potent substrates for a-Mg grains in the sample treated by combining Ca addition with carbon inoculation. However, the duplex-phase particles of AI4C3 coated on Al-Fe or Al-C-Fe should be the potent substrates for a-Mg grains if Fe existed in the Mg-Al melt. Ca addition can contribute to the formation of the particles of Al4C3 coated on Al-Fe or Al-C-Fe, regardless of the Fe addition sequence. The poisoning effect of Fe was effectively inhibited in the carbon-inoculated of Mg-Al alloy due to Ca addition, namely, Ca has a poisoning-free effect.

HISTOCHEMICAL CHANGES OF HOST CELLS IN TISSUE CULTURE INOCULATED WITH RICKETTSIA TSUTSUGAMUSHI

Investigation of metabolic changes of host cells in tissue culture caused by Rickettsia tsutsugamushi helps to elucidate the pathogenesis and mechanism of immunity in scrub typhus. We used the histochemical methods for observing the changes of nucleic acids in the rabbit testicular monolayer tissue culture inoculated with R. tsutsugamushi. The method of preparation and inoculation of the tissue culture was the same as already reported. In the present experiment a glass slide was first inserted into the tube. before introduction of tissue cells. Examination was made once every 4 days after the cells had been inoculated with rickettsia. On the days

Optimization of Fermentation Process for the Production of Bacteriocins from Lactic Acid Bacteria

[Objective]This study aimed to improve the yield of bacteriocins from lactic acid bacteria by optimizing the fermentation process for production of bacteriocins from lactic acid bacteria.[Method]By single-factor analysis,fermentation temperature,seed age,inoculation volume,fermentation duration and fermentation media p H were optimized to determine the best fermentation process.The inhibitory zone of bacteriocins from lactic acid bacteria was analyzed with oxford cup method,based on which the fermentation process was evaluated.[Result]The optimal fermentation process was optimized：fermentation temperature 37℃,seed age 14 h,inoculation volume 2%,fermentation duration 48 h,fermentation media p H 5.0.[Conclusion]Under the optimized fermentation conditions,the yield of bacteriocins from lactic acid bacteria was improved significantly.