Duration Of Induction Period Research Articles

Effect of CSN3 Gene Polymorphism on the Formation of Milk Gels Induced by Physical, Chemical, and Biotechnological Factors.

During the last decade, research into genetic markers in the casein gene cluster has been actively introduced in cattle breeding programs. A special interest has been paid to the polymorphism of the CSN3 gene, responsible for the expression of the k-casein, playing a key role in protein coagulation, interaction with whey proteins, stabilization, and aggregation of casein micelles. This paper aimed to determine the effect of CSN3 genetic polymorphism on acid; rennet; acid-rennet; heat- and acid-induced as well as heat- and calcium-induced coagulation in skimmed milk; and protein-standardized milk systems (UF, NF, RO, VE). The influence of polymorphic variants of the CSN3 gene on the coagulation ability of milk proteins was assessed by the particle size of casein micelles, protein retention factor in the clot, and coagulation ability (duration of induction period, mass coagulation period, dynamic viscosity in gel point). The correlation between CSN3 gene polymorphism and protein coagulation was revealed. Milk systems obtained from CSN3 BB milk were found to have the shortest duration of coagulation, formation of better gel strength values, and increased yield compared to CSN3 AA. This study will improve the efficiency of milk processing and optimize the technology of dairy product production.

Synthesis of nanoparticles from slag and their enhancement effect on hydration properties of CaO/CaSO4-activated slag binder

Developing a low-cost and eco-friendly alternative to cement is of great significance for reducing the CO2 emissions. CaO/CaSO4-activated slag binder may only be served as a promising cementitious material when the severe defect in the early strength is overcame. In this study, gel-like nanoparticles with an average size of ∼ 328 nm were prepared from the slag through dissolution at room temperature and reprecipitation at 50 °C. Subsequently, synthetic nanoparticles (SNPs) were added as a supplementary additive to enhance the strength of CaO/CaSO4-activated slag binder. The effects of SNPs on the strength development, hydration kinetics, hydration products, and microstructure of the slag binders were investigated. The results indicated that the addition of moderate SNPs shortened the duration of induction period and improved the reaction rate in the acceleration period of the slag binders. As a result, large amounts of calcium aluminosilicate hydrate (C-A-S-H) gel was generated at early hydration ages. Meanwhile, SNPs increased the polymerization degree of this gel through the nucleation effect. Gel products’ well-filled the pore spaces between slag particles and yielded a compact microstructure, consequently enhancing the binder strength. The sample with adding 1.5 wt% SNPs exhibited the optimum strengths of 7.78 and 39.86 MPa after 1 and 28 days.

The Effect of Various Grinding Aids on the Properties of Cement and Its Compatibility with Acrylate-Based Superplasticizer.

The influence of grinding aids (pure triethanolamine and ethylene glycol) on the properties of cements, their compatibility with an acrylate-based superplasticizer and the rheological parameters of mortars were investigated. The presence of surfactants influences the standard properties of cements and the effectiveness of the superplasticizer. The results of the heat of hydration and setting time measurements indicate a delay in the hydration process and an increase in the induction period duration of the surfactant-doped pastes, in relation to the reference sample without grinding aids. Triethanolamine increases early-age compressive strength; the effect was observed for both standard and superplasticizer-containing mortars. The presence of grinding aids decreases the slump flow of mortars and increases rheological parameters such as yield stress (τ0) and viscosity (η).

New insights into the reaction of tricalcium silicate (C3S) with solutions to the end of the induction period

Although dissolution theory is widely used, in certain circumstance, it seems to be unable to explain the hydration of C3S. In this article, more attention is paid to the nucleation of hydration products. We find that the precipitation of C-S-H is a nonclassical nucleation process. It starts with nucleation of primary particles and then grows by particle attachment. A sharp increase in the reaction rate after induction period may come from the accelerating growth rate of C-S-H instead of dissolution of etch pits. The duration of induction period relates to the size of primary floc. Potassium salts influence the primary globule floc size and mitigate the effect from Al. The pH impacts ion species in solution to affect the dissolution and precipitation. A hypothesis regarding the dissolution of C3S and nucleation of C-S-H within the near-surface region may narrow the gap between dissolution theory and protective layer theory.

Additives to Coal-Based Fuel Pellets for the Intensification of Combustion and Reduction in Anthropogenic Gas Emissions

Cylinder-shaped fuel pellets that were 3 mm in diameter and 3 mm in height, with a mass of 20 mg, were produced by compressing dry coal processing waste under the pressure of 5 MPa. The first group of pellets from coal dust with a particle size less than 140 µm did not contain any additives. The pellets of the second group of fuel compositions contained an oil-impregnated porous polymer material particle with a size of 0.5 mm in the central part of the experimental sample. The particle was surrounded by coal dust from all sides. The ratio of components was 90:10% for coal dust: polymer particle. The latter value almost completely corresponds to the fraction of oil in the fuel composition, since the mass of a porous polymer material particle is negligible. The third group of compositions was a 70:30% mixture of coal dust with wood sawdust with a particle size less than 45 µm, or 45–100, 100–200 and 200–500 µm. The ignition and combustion of single fuel pellets were studied under radiant heating in an air medium while varying the temperature from 800 to 1000 °C. The processes during the fuel combustion were recorded by a high-speed video camera, and the concentrations of the main anthropogenic emissions in flue gases were measured by a gas analyzer. The main characteristics were established—ignition delay times (2–8 s) and duration of burnout (40–90 s)—at different heating temperatures. A difference was established in the combustion mechanisms of the pellets, when adding various components to the fuel mixture composition. This has a direct influence on the induction period duration and combustion time, other conditions being equal, as well as on the concentration of nitrogen and sulfur oxides in the flue gases. Adding an oil-impregnated porous polymer particle to the fuel composition intensifies ignition and combustion, since the times of ignition delay and complete burnout of fuel pellets under threshold conditions decrease by 70%, whereas adding wood sawdust reduces the content of nitrogen and sulfur oxides in the flue gases by 30% and 25%, respectively.

Effect of Antioxidants on High-Temperature Stability of Renewable Bio-Oils Revealed by an Innovative Method for the Determination of Kinetic Parameters of Oxidative Reactions.

Bio-oils employed for various industrial purposes, such as biodiesel production, undergo extensive oxidation and degradation during transformation processes. Therefore, it is extremely important to predict their stability at high temperature. We report herein a new procedure based on the optically detected profile of headspace O2 concentration during isotherms at 130 °C for evaluating the oxidation kinetic parameters of several bio-oil feedstocks. The slope of O2 consumption and the induction period duration were related to the oil characteristics (molecular structure, acidity, and presence of intrinsic antioxidants or metals). The increase of the induction time caused by a standardized propyl gallate addition yielded a semiquantitative value of radical generation rate. Investigated oils included used cooking oils; mono-, di-, and triglycerides from natural sources; free fatty acids; transesterified oils; and their blends. With respect to other methods, this characterization presents the advantage of disentangling and evaluating the role of both fatty acids composition and naturally occurring antioxidants, and allows the development of rational strategies for antioxidant protection of oils and of their blends.

The role of sulfate ions in tricalcium aluminate hydration: New insights

As a major mineral of Portland cement, the hydration of tricalcium aluminate (C3A) has a significant impact on various properties of cement-based materials. However, there is little consensus on its mechanism, especially the interaction between C3A and gypsum which usually co-exist in cement systems. Recent researches have shown that sulfate ions play an important role in the kinetics of C3A hydration, which may provide more promising alternatives on controlling cement hydration besides the present solution on adjusting gypsum contents. In this study, effects of different kinds of solid sulfates (gypsum, Na2SO4, MgSO4) on the heat released during the early age of C3A hydration as well as hydration products were investigated first by isothermal calorimetry, SEM, XRD and thermal analysis. Retardation was observed in all the three systems (C3A-gypsum, C3A-Na2SO4 and C3A-MgSO4). But the duration of induction period varied with cations. Then barium nitrate (Ba(NO3)2) aiming to remove the sulfate ions was innovatively employed to highlight the role of sulfate ions. Interestingly, the renewed hydration of C3A occurred immediately after Ba(NO3)2 solution was added into the three systems with different amount of AFt remained. According to the characterization of hydration products, little monosulphoaluminate (s-AFm) was detected in the induction period of C3A-gypsum hydration and a large amount of h-AFm was found to cover the surface of C3A particles after adding Ba(NO3)2 solution. It is concluded that the coexistence of calcium and sulfate ions absorbed at C3A surface is more likely to dominate the retardation of C3A hydration in the presence of gypsum, rather than the alleged physical barrier mechanism caused by the precipitation of hydration products.

Interaction between aromatics and n-alkane for in-situ combustion process

In this research, the effect of p-quaterphenyl and cumene hydroperoxide on tetracosane combustion was investigated using accelerating rate calorimetry (ARC). Two obvious reaction processes were identified as induction period and ignition period for tetracosane combustion. p-Quaterphenyl showed a strong suppression on tetracosane combustion: prolonged induction period, suppressed the reaction rate of intense exothermic reaction, and delayed the occurrence of ignition period. Cumene hydroperoxide also exhibited a delay effect in ignition period, but it can slightly promote the exothermic reaction in reduction period and shortened the duration of induction period due to the presence of hydroperoxide group. We find that the Arrhenius zero-order kinetic model (lnk∗=lnA−EaR1T) fitted experimental data reasonably well in induction period, while nth-order reaction model (dαdt=A∗f(α)∗exp(−EaR∗T), where f(α)=(1−α)n) is more suitable for estimating kinetics in the ignition period as the intense exothermic process is dependent of both hydrocarbons and oxygen concentration. However, when there is a strong interaction between tetracosane and p-quaterphenyl during their co-combustion, nth-order reaction model cannot be applied well for ignition period, instead, Ginstling-Brounshtein diffusion model (1.5/((1−α)1/3−1)) fitted much better with experimental data, indicating that diffusion might play an important role in ignition period. This means that the interaction between components should be considered when simulating crude oil combustion in in-situ combustion (ISC) process, and coupling diffusion to reaction-kinetic model to control mass transfer might be necessary and helpful for its precise simulation.

Characterization and performance of high volume recycled waste glass and ground granulated blast furnace slag or fly ash blended mortars

The application of recycled waste glass powder in high volume (60%) of ground granulated blast furnace slag (GGBS) or fly ash blended cement binder is shown in this study. The hydration kinetics, hydration products of different binder systems were studied by calorimetric and X-ray diffraction test. To investigate the microstructure properties of bended binders modified by glass powder, the mercury intrusion porosimetry test and scanning electron microscopy were conducted. The resistance to chloride penetration was evaluated by the rapid chloride migration test. The incorporation of recycled waste glass in slag or fly ash blended cement improves the reaction intensity while decreases the duration of induction period. The calcium hydroxide content of blended samples (91 days) was decreased after the incorporation of waste glass powder, while a densification effect on the capillary pores (10–100 nm) and lowers the total porosity of waste glass containing ternary binders were observed. From the SEM analysis, a dense microstructure and inter transition zone can be found in recycled waste glass blended samples. The waste glass powder modified slag or fly ash blended mortars exhibit a significant enhancement of resistance to chloride migration. Furthermore, a synergistic effect on the mechanical performance of large volume GGBS blended mortars containing recycled waste glass was identified, which presented the highest compressive strength among all waste blended samples.

Unusual Regularities of Propylene Carbonate Obtained by Propylene Oxide Carboxylation in the Presence of ZnBr2/Et4N+Br− System

The aim of the work was to study the unusual regularities of propylene carbonate prepared by carboxylation of propylene oxide in the presence of the catalytic system ZnBr2/Et4N+Br−. Using the kinetic method, a long induction period was detected, followed by the rapid formation of propylene carbonate in a quantitative yield, where the maximum turnover frequency (TOF) values reached 21,658 h−1. The regularities of the influence of the main process parameters on the induction period duration and the reaction rate were established. Based on the results obtained and considering the literature, assumptions about the mechanism of the process were proposed and ways for its further study were outlined.

Synthesis of nickel nanopowders in water/ethylene glycol solutions. The influence of precursor concentration and temperature on the particles’ size

Heterogeneous reaction of reduction of freshly prepared nickel hydroxide by hydrazine hydrate in water/ethylene glycol solutions have been investigated. The effect of the initial concentration of nickel hydroxide and temperature on duration of induction period and the total duration of the reaction and zero formal orders of nucleation and growth processes for nickel hydroxide were found as well as were observed that the activation energies of these processes are close. The size and composition of the formed nickel nanoparticles have been investigated using scanning electron microscopy. It was found that the obtained nickel particles are characterized by near-spherical shape and an average diameter of 120–140 nm and narrow size distribution. With the use of powder diffraction method it was found that obtained nickel nanopowders does not contain nickel oxide or hydroxide and consist of crystallites with a size 10–14 nm. Using Uv-vis spectroscopy the dissolution of nickel hydroxide and formation of complex [Ni(N 2 H 4 ) 3 ](OH) 2 in reaction mixture after adding of hydrazine was observed and the dependence of its solubility on ethylene glycol concentration in reaction mixture was investigated. Tentative multistage scheme of formation of nickel nanoparticles at heterogeneous conditions in water/ethylene glycol media was proposed. This scheme include 1) partial dissolution of nickel hydroxide and formation of nickel-hydrazine complex; 2) the decay of formed nickel-hydrazine complex on the nickel hydroxide surface and formation of nuclei of nickel nanoparticles; 3) growth of nickel nuclei via the reaction with dissolved nickel-hydrazine complex; 4) coagulation of small nickel particles; 5) growth of nickel nanoparticles from the surface. Keywords: nickel nanopowders, ethylene glycol, hydrazine, kinetics.

Sustainable Catalytic Activity of Ag-Coated Chitosan-Capped γ-Fe2O3 Superparamagnetic Binary Nanohybrids (Ag-γ-Fe2O3@CS) for the Reduction of Environmentally Hazardous Dyes-A Kinetic Study of the Operating Mechanism Analyzing Methyl Orange Reduction.

The formation of binary nanohybrids consisting of environmentally benign components, γ-Fe2O3, chitosan (CS), and Ag (Ag-γ-Fe2O3@CS) (CSIOAg), containing very low concentration of Ag NPs (≤1.2 μM), has been reported. In the as-synthesized nanohybrids, the presence of γ-Fe2O3 (8.5 ± 0.8 nm) and Ag (5.9 ± 0.5 nm) are revealed by optical, XRD, TEM, and XPS analyses, and their presence in cubic phase is determined by XRD and SAED measurements. The catalytic activity of CSIOAg has been analyzed by performing the reduction of certain toxic dyes. Under all kinetic conditions, the reaction is attended by an induction period, which is reduced upon increasing [Ag] and [Dye] in a specific concentration range, as well as temperature, suggesting restructuring of the surface prior to reduction. In case of methyl orange (MO), the reduction results in its cleavage to produce N,N-dimethyl-1,4-phenylenediamine and sodium sulfanilate in a significantly higher (>97%) yield in a bimolecular reaction between MO and BH4–. The duration of induction period is regularly decreased and the rate of reduction (kapp) increases linearly with increasing Ag in the wide concentration range (0.03–2.4 μM). The reduction takes place with a second-order rate constant of 2.7 × 104 dm3 mol–1 s–1, which is >3.5-fold higher than that in the absence of chitosan (IOAg) under identical experimental conditions. The kinetics of reduction of MO is controlled by the nature and extent of its adsorption on the catalyst surface. The weaker binding between MO and Ag catalyst only allows its effective reduction. The XPS analysis of CSIOAg and IOAg containing the same amount of Ag (1.2 μM) showed its higher amount on the surface of CSIOAg (0.12%) as compared to that of IOAg (0.09%). Detailed kinetic analysis of MO reduction, performed under pseudo-kinetic conditions for both the nanohybrids revealed them to follow Langmuir–Hinshelwood kinetic model and exhibited the recyclability up to 10 cycles with fairly high reaction efficiency and TOF, suggesting it to be a sustainable green nanosystem.

Effect of graphite nanoplatelets and carbon nanofibers on rheology, hydration, shrinkage, mechanical properties, and microstructure of UHPC

This study evaluates the effects of two types of graphite nanoplatelet (GNP-C and GNP-M) and one type of carbon nanofiber (CNF) on rheological properties, hydration kinetics, autogenous shrinkage, and pore structure of ultra-high-performance concrete (UHPC). The dispersion method was optimized to secure uniform dispersion of the nanomaterials in the UHPC. The plastic viscosity decreased with the nanomaterials content as the content was increased from 0 to 0.05%. As the nanomaterials content increased from 0 to 0.3%, the duration of induction period was extended by the addition of CNF, but shortened by use of GNP-C or GNP-M; cumulative hydration heat release was increased by introduction of nanomaterials; the autogenous shrinkage of UHPC with CNF, GNP-C, and GNP-M was increased by 30%, 20%, and 20%, respectively. The use of 0.3% CNFs reduced the total porosity of the UHPC by approximately 35%, indicating that the presence of CNFs refined the microstructure of UHPC.

Acidic and Catalytic Properties of Mo-Containing Zeolite Catalysts for Non-Oxidative Methane Conversion

<p>The conversion of methane into benzene, toluene and naphthalene at the reaction temperature of 750 °C and gas hourly space velocity (GHSV) of 500-1500 h<sup>-1</sup> over zeolites modified via impregnation with ammonium heptamolybdate and mechanical mixing with Mo oxide and nanopowder is studied under non-oxidative conditions. It has been established that the highest methane conversion per one run and maximal yield of aromatic hydrocarbons are reached for the sample containing 4.0 mass.% the Mo nanopowder. The stability of Mo-containing zeolite catalysts in the process of methane dehydroaromatization at different GHSV has been studied and a characteristic presence of the induction period caused by the formation of active Mo forms both on the external surface and into the zeolite channels has been established. Both the duration of induction period and stable catalyst operation are decreasing with increasing of GHSV. It was demonstrated that acidic properties of a Mo-containing zeolite catalyst depend on the Mo concentration and method of its introduction.</p>

Investigation of nickel chemical precipitation kinetics

The results of investigation of nickel hypophosphite reduction reaction kinetics in the bulk solution depending on the pH, temperature, oxidant content, nature and concentration of the activator, the presence of water-soluble polymer - polyvinylpyrrolidone are presented.The main objective of the study was to investigate the kinetics and establish optimum conditions for nickel chemical precipitation in the bulk solution. It is found that the process of chemical precipitation of the metal in the alkalescent environment is characterized by the high rate and small induction period at a temperature of 60–70 oС. The presence of polyvinylpyrrolidone in the solution affects the induction period duration and the reduction reaction rate. The nature of the polyvinylpyrrolidone effect depends strongly on the pH. It is proved that using preformed nickel hydrosols as the activator makes it possible to significantly shorten the induction period of the reduction reaction at low temperatures.The results are used in the development of technology and substantiation of the process parameters of synthesis of composite metal-filled polyvinylpyrrolidone copolymers with (meth) acrylates and hydrogel materials on their basis by a combination of metal polymerization and reduction processes.

Electroless Co-B Deposition Using Dimethylamine Borane as Reducing Agent in the Presence of Different Amines

The therm “electroless plating” was originally adopted by A. Brenner and G. Riddell [1, 2] to describe a method of plating metal substrates with cobalt or nickel alloys without the benefit of an external source of electric current [3].Electroless metal deposition processes are recognized to be electrochemical by nature and to result from the coupling of two partial electrochemical reactions – the cathodic reduction of metal ions and the anodic oxidation of the reducing agent [4]. Electroless cobalt deposition process is consisting of anodic oxidation of proper reducing agent and cathodic reduction of Co(II) ions occurring simultaneously on the same cobalt surface; the electrons appeared in anodic oxidation of reducing agent are transferred through the metallic surface to adsorbed Co(II) ions, and the autocatalytic deposition of Co takes place. It is noteworthy the fact, that pure cobalt coatings are obtained seldom. In most cases cobalt alloys containing boron or/and phosphorus are formed – phosphorus and boron are originated from reducing agents.When comparing the action of amines on duration of induction period it is seen that in the case of amines with the shorter chain (propylenediamine (prop), diethylenetriamine (dien), triethylenetetraamine (trien)) the induction period is very short and the mixed potential of electrode becomes most negative values also very rapidly. The situation changes dramatically, when using ammines with longer chains and containing more amine-groups (pentaethylenehexaamine (pnten), tetraethylenepentaamine (ttren) ) – the induction period becomes longer: ca. 3 min in the case of pentaethylenehexaamine and more than 6 minutes using tetraethylenepentaamine. The prolongation of induction period is connected with changes in electrode mixed potential values: electroless cobalt deposition begins only when negative enough value of mixed potential is established. It can be noted, that after leveling of quasy-stationary plating conditions, the electroless cobalt deposition rate is practically the same for all amines investigated.Therefore, on the basis of EQCM experiments, we can conclude that the optimum operating conditions (rational low induction period, high enough plating rate and moderate temperature) are as follows: 0.05 M CoSO4, 0.2 M DMAB, amine (preferably diethylenetriamine), pH ca. 6 and temperature of 50 °C. Acknowledgement The work was carried out within the project VP1-3.1-ŠMM-08-K-01-009 that is partly supported by the National Programme “An Improvement of the Skills of Researchers” launched by the Lithuanian Ministry of Education and Science.

Quantitative and qualitative analysis of high molecular compounds in vegetable oils formed under high temperatures in the absence of oxygen

Conditions of deodorization/physical refining of sunflower oil were simulated by high temperature heating in laboratory at 240, 250, and 260 °C. Oxygen atmosphere was excluded by argon atmosphere. Influence of temperature, initial oxidation of incoming oil (peroxide value 2–30 mmol ½ O2/kg) on geometrical, positional isomerization, and polymerization was measured. The level of initial oxidation of the oil has a significant influence on rate of isomerization, polymerization, and duration of induction period of polymerization reactions. Induction period of polymerization is dependent linearly on temperature at constant hydroperoxide content and is extended with decreasing temperature and lower peroxide value of oil. Significant conjugation took place with geometrical isomerization and resulted in all-trans diene formation. All-trans dienes are incoming reactants for polymerization according to the Diels–Alder mechanism. Suggested “propagation” phase of polymerization took place later. Induction period was observed only in the case of polymerization reactions of triacylglycerols. This is the confirmation of the hypothesis that the cis/trans isomerization, positional isomerization, and polymerization are consecutive reactions in ascending order. Identification of molecular peaks and confirmation of fragments were possible by connecting HPSEC with APCI-MS. Dimers of triacylglycerols (TAG) dominated in studied system. Remaining compounds may have been formed from di-, monoacylglycerols, and other minor constituents of sunflower oil.

Rate constants of oxidation of unsaturated fatty esters studied by chemiluminescence

This study deals with oxidation kinetics of three unsaturated fatty esters: methyl oleate, methyl linoleate and methyl linolenate at temperatures ranging from 90 to 150°C. The reaction was monitored by chemiluminescence. A kinetic model was derived from a simple mechanistic scheme, in which initiation is due to hydroperoxides decomposition, whereas propagation results from the abstraction of the most labile hydrogen and termination results only from the bimolecular combination of peroxyl radicals. Analysis of induction period duration indicated that hydroperoxides mainly decompose by a bimolecular process. The model well predicts the main features of the experimental chemiluminescence curves. Kinetic parameters of the three unsaturated fatty esters were assessed from inverse method and discussed.

Polypropylene stabilization by hindered phenols – Kinetic aspects

This article deals with polypropylene stabilization by hindered 2,6-di-tert-butylphenols. Two aspects are mainly considered: the influence of stabilizer structure, of its concentration and temperature on induction period duration through a literature compilation completed by results obtained on PP samples stabilized by Irganox 1010 in conditions in which physical loss was negligible. Results show that the induction period duration is almost proportional to the phenol concentration and that the proportionality ratio is almost independent of the stabilizer structure in the investigated phenol family. A unique set of kinetic parameters can be therefore used to model the kinetic behaviour of all the family members. The kinetic approach can be more or less complex depending on the number of secondary processes taken into account. The results of simulations indicate that a two steps process allows generation of a kinetic behaviour in good agreement with experimental trends regarding effects of both stabilizer concentration and temperature on induction time.

Growth Optimization and Organogenesis of Gerbera jamesonii Bolus ex. Hook f. in vitro

Regeneration potentials in Gerbera jamesonii Bolus ex. Hook f. from tissues culture system was studied using leaf, petiole and root explants. In vitro regeneration, callus induction and root formation were optimized by manipulation of growth regulators during organogenesis. Various kinds of plant growth regulators such as 6-Benzylaminopurine (BAP), alpha-Naphthalene acetic acid (NAA), 2, 4-Dichlorophenoxyacetic acid (2,4-D), Indole-3-acetic acid (IAA), Indole-3-Butyric acid (IBA), N6-[2-Isopentenyl]adenine (2iP), Kinetin and Zeatin were used to initiate cultures. These plant growth regulators were added to Murashige and Skoog medium in different combinations and concentrations. Adventitious shoots were obtained from petiole explants cultured on Murashige and Skoog (MS) medium supplemented with 2.0 mg L(-1) BAP and 0.5 mg L(-1) NAA. Effectiveness of shoot regeneration medium, type of growth regulator used and duration of induction period were investigated. Leaf explants cultured on MS medium supplemented with 1.0 mg L(-1) BAP and 2.0 mg L(-1) 2, 4-D showed the best results for callus induction. Root explants were found to be non-regenerative in all experiments conducted. Petiole segment was identified as the best explant for regeneration of this species. Regenerated plants were rooted on Murashige and Skoog basal medium. Plantlets were then transferred to field with 75% survival rate.