Papers by Keyword: Inoculant

Abstract: Agarwood has been used for its fragrance and medicinal properties in Asian culture for centuries. In recent years, agarwood gains its popularity in the west due to its usage in perfume formulation. Unfortunately its supply not meets the augmentation market demand. This is mostly because of depleting nature agarwood reservoir and lack of induction technique that can produce agarwood consistently in the plantation. In this study, we look into a case where artificial inducing technique successfully produced high quality agarwood. To assure its quality, agarwood chip was analysed by Gas Chromatography for its chemical profiles. Discovered compounds were identified as sesquiterpene group which also had been characterized as major agarwood compound listed on previous studies. Few compounds that are detected such as δ-cadinene (0.20%), jinkoh-eremol (22.09%), epi-α-cadinol (4.74%), agarospirol (3.75%) and others. Soil condition that contributes into this agarwood formation; soil analysis on physical properties, chemical properties and nutrients content of the soil have been analyzed. Based on the findings, soil condition is an important factor to successfully induced high quality agarwood.

Abstract: Nucleation mechanisms and the effect of minor elements added with the inoculants are still a subject of extensive research in ductile iron. Oxides, sulfides, silicates and nitrides have been reported to be nuclei for graphite precipitation. Those compounds originate both from the nodulizing treatment and the inoculation process. Previous research works have shown that titanium nitrides or carbonitrides play an active role in graphite nucleation. In order to determine the efficiency and nature of nitrides that can act as nuclei for graphite, and the possible effect of the trace elements added with the inoculant, melts with titanium contents ranging from 0.007% to 0.036% were produced and poured into standard thermal analysis cups, with and without inoculation. Different inoculants rich in titanium, cerium, aluminum or zirconium were used. Two cups were produced with each inoculant, one cooled down to room temperature, and the other quenched in brine immediately after pouring. Nucleation sites were characterized through detector, spectrum, mapping and line scans of a FEG-SEM equipment. Most of the analyzed nuclei exhibited two or three different inclusions: magnesium sulfides or Mg-Ca oxy-sulfides, Mg or Al oxides, and Ti carbo-nitrides or Mg-Si-Al nitrides. The appearance of each type of nitrides is directly related to the titanium content in the base melt. When titanium was added in the inoculant, no titanium nitrides were noticeable. The zirconium added with the inoculant promoted more complex nitrides that appeared in higher amount. Cerium appears occasionally forming sulfides. Aluminum stimulates the formation of complex nitrides. No differences in the nature of the nuclei were observed between the samples quenched and the ones obtained at room temperature, which assures the methodology approach.

Abstract: It is proposed to use waste slags of copper, nickel and titanium production at mining and metallurgical enterprises for their full recycling in graphite iron castings as a charge component, as well as an active additive in ladle and furnace inoculation of iron melt.

Abstract: This paper investigated the effect of inoculant, Al-5Ti-1B in conventional and semi-solid casting A356 aluminium alloy. A356 aluminium alloy was melted at 850 oC and poured at 680 °C directly into the steel mould and on the inclined slope into steel mould. Inoculant was added in various percentages of 1 wt.%, 2 wt.%, 3 wt.% and 3.5 wt.% in A356 aluminium alloy melt. Microstructure and microhardness were characterized using optical microscope and Vicker’s microhardness tester. The addition of master alloy up 3.5 wt.% Al-5Ti-1B in conventional casting refined dendritic structure with average grain size of 33.41 μm. The microstructures of semi-solid A356 aluminium alloy with addition of Al-5Ti-1B consist of equiaxed structure of α-Al. Further addition of Al-5Ti-1B refined the globular structure of α-Al. The higher hardness was achieved for A356 alloy prepared using semi-solid with addition of 3.5 wt.% of Al-5Ti-1B.

Abstract: 1-level anaerobic and 2-level aerobic bio-film treatment process is adopted in the test. Complex microbial inoculants are added to the system to make sure the system has abundant bio-phase and stable biomass. The paper has discussed the startup and stable operation conditions of the system and analyzed the degradation effect of microorganisms in each reaction tank within the wastewater treatment cycle. The result indicated the effect of treatment of wastewater generated from natural rubber processing is favorable and the effluent quality is stable. Besides, Discharge standard of wastewater pollution for natural rubber processing NY687-2003-Grade I can be reached. The removal of pollutants is mainly completed in 1-level anaerobic pool and 2-level aerobic pool.

Abstract: The aim of this study was to evaluate the effect of Ampicillin as bacteriostats on the number of P solubilizing and antibiotic-anti- Rhizobium. meliloti cells and contamination in inoculants during one year storage, and plant promotion ability of subgeneration cells of antibiotic-resistant phosphate-solubilizing R. meliloti strain LW107 growth on YMA plates containing different concentrations of ampicillin were also investigated. In the first experiment, 100 mg liter-1 ampicillin was added in inoculants, number of R. meliloti cells and contamination in inoculants were investigated at two temperatures, using both liquid and peat based solid inoculants in experiment. Statistical design was a complete randomized block in a factorial 2×2×2 experimental arrangement with 4 replicates. Results show that there are various viable cells and contamination levels in inoculants. The ampicillin increased R. meliloti LW107 viable cells and inoculants stored at low temperature with lesser contamination when ampicillin been added. To clarify whether ampicillin affect the main character of R. _meliloti LW107 cells, the ability of calcium phosphate solubilization and IAA production in ampicillin-containing conditions was determined. Results indicated that the ability of calcium phosphate solubilization and IAA production have no significant difference on 6th generation cells of R. meliloti LW107 between the growth plates and the lack of ampicillin. In the third experiment, the plant growth promotion of the ampicillin-containing inoculants on alfalfa seedlings was determined in sterile sand conditions in a temperature-controlled growth chamber at 20 -25°C for 35 days. We also found that no significant difference on nodule numbers between diluted liquids ampicillin-containing inoculants and the common liquid inoculants containing no ampicillin, but plant growth and efficiency of nitrogen-fixing responded to undiluted liquids inoculants containing ampicillin with a decrease in biomass and nitrogenase activity indicating that the five-fold dilutions of the ampicillin-containing inoculants are necessary for applications.

Abstract: The effects of rotating electromagnetic stirring and inoculants on the solidification structures and properties of IN100 superalloy vacuum investment casting was studied with XRD, SEM and optical microscope. The results show that by initiating the 50Hz, 150A rotating electromagnetic stirring as soon as the molten metal was poured into the mould, which was coated with inoculant CoAl₂O₄, the average equiaxed grain size of IN100 superalloy vacuum investment casting can be refined to 95μm and the fraction of equiaxed grains can be increased to 99 %. On condition that the grain size of K417 superalloy vacuum investment casting were refined to 95μm, the tensile properties at room temperature, the morphology of （γ＋γ′）eutectic and the morphology of dendrites can be greatly improved.

Abstract: The main purpose with this paper is to show the effect of nitrogen and inoculation on the tensile properties and microstructure of cast iron with lamellar graphite. Casting experiments were performed with the main composition: 3.4 % C, 2.0 % Si, 0.7 % Mn, 0.5 % Cu. The nitrogen content was varied between 90-180 ppm and inoculant was added as 0, 0.2 or 0.4 % by weight. The addition of inoculant changed the graphite structure from distribution D/B/A to distribution A, according to ISO 945. The eutectic cell size decreased significantly. The addition of inoculant had no influence on the hardness. The addition of nitrogen shortened the graphite flakes and increased the hardness. The influence on the eutectic cell size was low and there was no significant effect on the graphite distribution. Tensile test samples were analysed by true stress – true plastic strain in terms of the flow relationships proposed by Hollomon, , and Ludwigson, . The stress-strain curves were fitted to polynomial functions of the 6:th to 8:th order before evaluating the constants in order to eliminate noise from the measurements. This approach also enabled the slope of the stress-strain curve to be evaluated at zero stress (Young’s modulus), resulting in plastic strain from stress levels close to zero. The Hollomon flow relationship failed to describe the deformation behaviour for the whole range of the stress-strain curve. The correction terms in the Ludwigson flow relationship resulted in a better fit. The addition of inoculant mainly affected the strength coefficient, . The addition of nitrogen also affected the constant. The main reason for this was that the addition of inoculant influenced the last part of the stress-strain curve while the addition of nitrogen had an effect over the whole range of the curve. The addition of nitrogen and inoculant increased the tensile strength from 288 MPa to 393 MPa and the total elongation at fracture from 0.8 % to 1.6 %.

Abstract: As the most commonly used carrier for commercial inoculants, the development of peat has been limited because peat is a material of nonrenewable resource. Many other materials have been evaluated as alternatives to peat as carriers of rhizobia, yet seldom have been included in inoculants of phosphate dissolving rhizobia. As accessible and inexpensive carriers for rhizobial inoculants, corn stalk powder, loessal soil and vermiculite powder were used in the study to compare with peat carrier on the capacities of rhizobial solution absorption, pH value maintaining of microenvironment, viable rhizobial cells maintaining and the control of contamination. Completely randomized design and 4 replicates were used in the experiment. Twelve different compositions of selected inoculant carrier with different absorption volumes of rhizobial suspension, and were evaluated the ability of maintaining viable rhizobial cells and undesired microbes during the period of 120 days at room temperature. Thereafter, pH value, viable rhizobial cell number and undesired microbes of inoculants with selected absorption volume of rhizobial suspension that stored at 4 and room temperature respectively, after 1a storage, were evaluated. Viable rhizobial cells in inoculants were examined after 120d and 1a storage by plate counting method, and ratio of undesirable microbes was examined by antibiotic-carrying and normal plates counting method. The result indicated that: for a period of 120days at room temperature, maximum viable rhizobial cells were found in peat, vermiculite powder, corn stalk powder and loessal soil based inoculants when the absorption volume of rhizobial suspension of inoculants were 450, 500, 1000 and 200ml/kg, respectively; viable rhizobial cell numbers were better maintained in corn stalk powder than in peat, loessal soil and vermiculite, but undesired microbes contamination was a severe problem. In the study, viable rhizobial cell numbers in loessal soil was found the highest, followed by peat, while the most serious contamination was found in peat inoculants; corn stalk powder and vermiculite could not be used as inoculant carrier because fewer viable rhizobial cells existed in these inoculants. The greatest pH change was found in peat and loessal soil based inoculants during 1a storage because of enhanced acidification caused by metabolism of phosphate dissolving rhizobia; more viable rhizobial cells were found in the 4 carriers that stored at 4 than at room temperature after 1a storage. As carriers of phosphate dissolving Rhizobium inoculants, viable rhizobial cells of corn stalk powder after short time storage (120d) and of loessal soil after long time storage (1a) were found better than that of peat, and was also found more cost effective compared with peat, commercially. Both of the two carriers could be used as inoculant carriers at room temperature, but corn stalk powder could only be used as carrier with short shelf life.