Hot Sulfuric Acid Research Articles

Tunable Chirality-Dependent Nonlinear Electrical Responses in 2D Tellurium.

Tellurium (Te) is an elemental semiconductor with a simple chiral crystal structure. Te in a two-dimensional (2D) form synthesized by a solution-based method shows excellent electrical, optical, and thermal properties. In this work, the chirality of hydrothermally grown 2D Te is identified and analyzed by hot sulfuric acid etching and high-angle tilted high-resolution scanning transmission electron microscopy. The gate-tunable nonlinear electrical responses, including the nonreciprocal electrical transport in the longitudinal direction and the nonlinear planar Hall effect in the transverse direction, are observed in 2D Te under a magnetic field. Moreover, the nonlinear electrical responses have opposite signs in left- and right-handed 2D Te due to the opposite spin polarizations ensured by the chiral symmetry. The fundamental relationship between the spin-orbit coupling and the crystal symmetry in two enantiomers provides a viable platform for realizing chirality-based electronic devices by introducing the degree of freedom of chirality into electron transport.

An In Vitro Surface Characterization and Energy Dispersive X-ray Spectroscopy Analysis to Examine the Impact of Y-TZP Ceramic Pretreatment with Hot H2SO4, Nd: YAP Laser, and Al2O3 on Both Surface Texture and Bond Integrity

Aim: Pretreatment techniques i.e., Hydrofluoric acid (HF) acid, hot Sulfuric acid (H2SO4), and Nd: YAP laser on the surface roughness (Ra) and shear bond strength (SBS) of Y-TZP ceramics. Materials and Methods: Eighty Y-TZP ceramic discs were allocated into four different groups based on the conditioning (n = 20) Group 1: SB, Group 2:40% HF acid, Group 3: Hot H2SO4 and Group 4: Nd: YAP laser. Forty discs (n = 10 each) were subjected to Ra measurements using a profilometer. The dual-cure resin cement was applied to forty conditioned zirconia discs (10 from each group) for SBS. SBS and failure mode were assessed utilizing a universal testing machine (UTM) and stereomicroscope. To analyze the average values of Ra and SBS among the different groups, one-way ANOVA and post hoc Tukey test were used. Results: The maximum Ra scores and SBS were displayed by Group 3 samples. Group 2 specimens in which HF acid was used as a Y-TZP ceramics conditioner displayed minimum Ra and bond integrity. Comparison among different tested groups exhibited that Group 1, Group 4, and Group 3 displayed comparable outcomes of Ra and bond strength. Conclusions: Hot H2SO4 and Nd: YAP laser can be used as a suitable alternative to sandblasting as a surface pretreatment regime for Y-TZP ceramics.

STUDY ON POLYMER CONCRETE DEFORMATIONS IN DIFFERENT ENVIRONMENTS AT HIGH TEMPERATURE

Problem statement. High stability composite materials, such as polymer concrete, play a significant role in modern practice. Due to a continuing demand for the use of building materials resistant to aggressive environments both in Ukraine and globally, as well as their prospective use in construction, metallurgy, and chemical industry, the investigation deals with deformations of polymer concrete in various types of environment at high temperature. The purpose of the research is to find mechanisms to increase the stability of polymer concrete in aggressive environment. The object of the study is polymer concrete based on modified furan resins. The subject of the study is deformation characteristics (namely creep) of polymer concrete in different environments (water, sulfuric acid) at different temperatures. Results. In the course of research of the deformation parameters of polymer concrete in various environments were identified. Conclusions. The deformation parameters of polymer concrete on modified furan resins in hot sulfuric acid solutions were determined. It has been proved that the decrease in strength and deformation properties also depends on the hygroscopicity of benzosulfonic acid. It is shown that under simultaneous influence of aggressive environment and temperature in a stressed state the phenomenon of creep is more intensive and the polymer concrete is destroyed in a short time.

Pelleting of Physical Dormancy Small-Seeded Species in Astragalus sikokianus Nakai

Astragalus sikokianus is a rare Japanese perennial of the seashore that was reported to be extinct in the wild. The small seed size and deep dormancy of A. sikokianus make it difficult for direct seeding restoration in aspects of seed handling, transport, planting, and seedling establishment. For the large-scale economic restoration of dormant small-seeded species, seed pelleting combined with the breaking of dormancy was studied. Physiological (prechilling and plant hormones) and physical (hot water, hydrochloric acid, and sulfuric acid) seed dormancy break treatments were evaluated. The dormant broken seeds were used for pelleting. The effects of the substrate, pellet sizes, and their interactions on germination were measured. The scarification of five rubs of seeds placed between sandpapers completely broke the physical dormancy of A. sikokianus. Seed coat impermeability inhibited germination. Pelleted seeds ranging from 2.0 to 4.0 mm in diameter showed more than 90% germination on filter paper. The germination of the pelleted seeds was measured in commercial, field, and sand soil conditions. The highest germination was shown in sand (70–74% GP), regardless of the pellet size, whereas unpelleted scarified seeds germinated only 48%. These results suggest that small-seeded species with physical dormancy can be used for seed-based restoration after seed pelleting.

ВОЗМОЖНОСТь ХИМИЧЕСКОГО ИЗВЛЕЧЕНИЯ ВАНАДИЯ И ТИТАНА ИЗ ЖЕЛЕЗНОГО КОНЦЕНТРАТА ТИТАНОМАГНЕТИТОВОЙ РУДЫ

The metallurgical industry is experiencing certain difficulties in the raw material segment of ferrous metals due to the depletion of highly liquid target iron ores reserves, the alternative of which are titanomagnetites. In addition, the demand for vanadium and titanium is increasing on the world market, the absolute part of the world stock of which also falls on titanomagnetite ore. Complex processing of titanomagnetite ores provides for production of not only iron concentrate, but also vanadium and titanium present in it. In this regard, the relevance of research lies in the need for deep complex processing of titanomagnetites and their enrichment products. The object of the study was iron concentrate of titanomagnetite ore from the Volkovsky deposit. Due to the isomorphism of vanadium with iron and the extremely thin integration of titanium into magnetite grains, the purpose of this investigate was to study the possibility of vanadium and titanium chemical extraction from titanomagnetite ore iron concentrate. The authors have analyzed the features of the chemical and mineralogical composition of iron concentrate. Granulometric, X-ray diffraction, X-ray fluorescence analyses are used in the work. The feasibility of complex processing of iron concentrate in order to extract not only iron from it, but also such valuable components as vanadium and titanium by acid leaching has been proved. It has been experimentally established that it is possible to extract vanadium into solution and concentrate titanium in the cake by acid leaching of iron concentrate. The highest percentage of vanadium extraction (68.31%) is achieved by leaching with 30% hydrochloric acid at a temperature of 92-98 °C. It has been established that titanium is not extracted into the solution, but is concentrated in the cake, however, titanium dioxide is partially dissolved when hot sulfuric acid is used. Thus, it was proved that, it is preferable to use solutions of hydrochloric acid, rather than sulfuric acid for the selective separation of titanium and vanadium, due to the dissolution of titanium dioxide in hot sulfuric acid

Dormancy in native fruit seeds of the Brazilian South Region

The aim of the present study was to investigate whether seeds from six native fruit species ofthe South Brazilian regionhad any type of dormancy, as well as, to verify if they havephotoblastism. The work was carried out at the Plant Physiology Laboratoryofthe Federal Technological University of Paraná –Câmpus Dois Vizinhos, Paraná State, Brazil. The influence of photoperiod factors and techniques for overcoming dormancy were tested on the germination of Eugenia uniflora L.(Surinan cherry), Plinia peruviana(native jabuticaba), Plinia cauliflora(hybrid jabuticaba), Eugenia involucrataDC. (Rio Grande cherry), Myrcianthes pungens(guabiju) and Campomanesia guazumifolia(sete capoteiro). The seeds were exposed in a condition of total darkness or photoperiod of 24 hours, being the levels of one of factors tested. The techniques for breaking dormancy tested werethe immersion in gibberellic acid solution (200 mg L-1); stratification at 5°C for 30 days; immersion in water at room temperature for 24 hours; immersion in hot water (80°C) for five minutes; immersion in sulfuric acid solution (96%) for five minutes; and manual physical scarification with 120 grit sandpaper. The seeds were also tested without using any technique, making up the controlstreatments with or without light. The experimental design was completely randomized, in a 2 x 7 factorial scheme (luminosity x treatment for breaking dormancy), with four replications of 100 seeds. After 60 days, germination (%), percentage of accumulated germination, germination speed index and average germination time were analyzed. The seeds of most of the studied native species do not present dormancy or the effect of photoblastism, except for “sete capoteiro”seedswho are supposed to have morphophysiological dormancy, with negative photoblastism. The use of hot water or sulfuric acid in the seeds of native fruit trees is not recommended.

Evaluation of surface properties and shear bond strength of zirconia substructure after sandblasting and acid etching

To compare the effects of different surface treatment methods on the surface characteristics of yttria-stabilized tetragonal zirconia (Y-TZP) and relevant shear bond strength (SBS) between zirconia and composite resin. Forty-eight Y-TZP ceramics were randomly divided into four groups based on the specific surface treatments: Group C (blank treatment), Group Sand (sandblasting with 80 μm Al2O3 particles), Group HF (etched with 40% hydrofluoric acid for 10 min), and Group H2SO4 (etched with hot sulfuric acid for 10 min). Surface characteristics of the treated specimens, including morphology, roughness, wettability, chemical composition and crystalline structure were analyzed. SBS was tested by bonding ceramics to resin cement in the same group. Kruskal-Wallis test followed by pair wise comparison was conducted for statistical processing. A significance level of α = 0.05 was set. Three kinds of surface structures with different widths and heights in roughness were obtained, including micron-scale pit/peak size by sandblasting, nano-scale pit/peak size by hydrofluoric acid etching and middle submicron-scale pit/peak size by hot sulfuric acid etching. By comparison, the specimens of Group HF showed the most favorable wettability, the highest SBS and the lowest phase transformation than those of other groups. Therefore, HF etching was considered as a promising surface treatment to promote resin–zirconia bonding without excessive surface damage. The height, width, frequency and regularity of roughness altogether affected the shear strength.

Hot Water and Sulfuric Acid Solution for Increasing The Viability and Vigor of Indigofera (Indigofera zollingeriana)

Indigofera (Indigofera zollingeriana) is a multi-benefit plant, two of them are for natural dyes and livestock feed supplement. Indigofera seeds are hard and thick-coated so that the germination percentage is low and not grow in simultaneously. This study aimed to obtain an effective and practical method of increasing seed viability and vigor was carried out from March to May 2019 at the BBTP Central Java. The research used a completely randomized design, consisted 9 treatments(control, soaked in hot water by 80 and 100°C then leave it for 24 hours, and soaked in a solution of H2SO4 95% for 10, 20, 30, 40, 50 and 60 minutes) and 4 replications. The germination method used the top of paper with filter paper media. The results showed that soaking the seeds in hot water and sulfuric acid solutions significantly increased germination, maximum growth potential, vigor index, and growth rate. Soaking seeds in a 95% H2SO4 solution for 10 minutes increased the germination of the seeds (84%), maximum growth potential (91%), vigor index (69%), and growth rate by (13.81% etmal−1). The finding concludes that the best treatment was soaking seed in H2SO4 solution for 10 minutes, and longer soaking time (> 50 minutes) will decrease all parameters.

Visual binary testing of methanol contained in ethyl alcohol

A method for control of methanol traces in rectified ethyl alcohol and alcoholic drinks based on visual binary testing using one reference sample was proposed. An indicator reaction of formaldehyde interaction (product of methanol oxidation) with chromotropic acid disodium salt was chosen for methanol screening. The conditions of indicator reaction proceeding are analogous as for the spectrophotometric technique of methanol determination: methanol was oxidized to formaldehyde with potassium permanganate in an acidic medium; the formaldehyde then reacts with chromotropic acid in the presence of hot concentrated sulfuric acid and forms a violet product (color of this product is stable for 12 hours). It was established that the absorption spectrum of the reaction product does not change on going from 96% ethanol to aqueous-ethanol solutions with a volume fraction of 40% ethanol. The maximum light absorption of the reaction product corresponded to 570 nm. All further studies were carried out in water-ethanol solutions with a volume fraction of ethanol of 40%. According to regulatory documents the normalized limiting content of methanol (clim) in ethyl alcohol of the “Lux” grade (the most common in the alcoholic industry) and alcoholic beverages is 0.01% by by volume counted upon anhydrous alcohol. The comparison sample (the solution of colored reaction product of indicator reaction) had to be less than the normilized level on the value which providing the risk of false-negative test result not more than 5%. To determination the threshold concentration of methanol in the comparison sample was applied the statistics of observation. For the aim the solution of colored product corresponding to the normalized limiting methanol concentration clim = 0.01% by volume was prepared and comparison samples with lower methanol concentrations were also prepared. The interval of unreliability was discovered with the help of observers. The frequency of detecting of the difference in the color of comparison samples and normalized sample (P(c)) changed from 0 to 1 in this interval. The value of methanol concentration 0.0072% by volume counted upon anhydrous alcohol was taken for the lower boundary of the interval and the value of methanol concentration 0.01% by volume counted upon anhydrous alcohol was chosen the upper border of the interval. This interval was divided on eight concentrations with step Dс = 0.0004% by volume. Three parallel series of solutions were prepared and 48 observations for each concentration were received. The experimental efficiency curve obtained was checked for compliance with the mathematical functions of the known distributions: normal, logistic, lognormal, exponential and Weibull distribution function using the statistical criterions c2 and Kolmogorov-Smirnov λ. The efficiency curve was described by the theoretical functions of the lognormal and Weibull distributions. Calculated at a confidence level of 0.95 estimation of the threshold concentration for the comparison sample was 0.0073% by volume fraction corresponding to anhydrous alcohol. The visual binary testing of methanol trace in alcoholic drinks was carried out. The accuracy of visual binary testing of methanol was confirmed by gas chromatography.

Ion-Implanted Photoresist Stripping by Using Organic Solvents

In the ion implantation process, accelerated ions attack not only target materials but also photoresist, causing deformation of the molecular structure of the photoresist. It is difficult to remove crust layer formed by ion implantation in the standard photoresist removal methods. A typical method of removing high-dose ion-implanted photoresist is to use plasma ashing followed by the treatment in the mixture of hot sulfuric acid and hydrogen peroxide [1]. However, this process etches III-V semiconductors and dielectric materials [2]. Therefore, in this study, organic solvent-based mixtures were developed to remove high-dose ion-implanted photoresist without damaging the substrate. Trench-patterned GaAs was used as a substrate and KrF photoresist was coated on trench patterned GaAs. Then, P+ ion implantation with a dose of 5×1015 ions/cm2 was conducted on the photoresist. A mixed solution of dimethyl sulfoxide (DMSO) and acetonitrile (AcN) (DMSO: AcN = 6: 4) was used to remove the ion-implanted photoresist and 1 vol% HCl or HF was used as an additive. Photoresist removal was measured using an optical microscope and in-situ MIR-FTIR. When a mixed solvent of DMSO and AcN was used to remove ion-implanted photoresist, the photoresist was not completely removed and the residue and crust remained on the trench-pattern (Fig. 1). In order to improve the removal efficiency of ion-implanted photoresist, 1 % HCl or HF was added to DMSO+AcN solution. When 1 % HCl was added to the DMSO+AcN solution, the ion-implanted photoresist with an implantation energy of 30 and 50 keV was completely removed without residue. However, when the ion implantation energy was 70 keV, the photoresist crust was not removed in DMSO+AcN+HCl solution. When 1 % HF was added to DMSO+AcN solution, the ion-implanted photoresists was completely removed regardless of the ion implantation energy. Removal performance was quantitatively analyzed by in-situ MIR-FTIR as shown in Fig. 2. First, the ion-implanted photoresist was not removed more than 40 % for 10 min in DMSO. In DMSO+AcN solution, most of the photoresist was removed in 6 min, and all photoresist was removed in 4 min when DMSO+AcN+HCl was used. In the case of DMSO+AcN+HF, all of the ion-implanted photoresists were completely removed in 2 min and 30 s. Therefore, it is confirmed that DMSO+AcN+HF solution removes ion-implanted photoresist more quickly and effectively than other solutions used in this study. In addition, it is suggested that the largest interaction energy between DMSO+AcN+HF and the ion-implanted photoresist resulted in improvement of the removal efficiency of the photoresist.

Chlorinated holey double-walled carbon nanotubes for relative humidity sensors

A chemical procedure for modification of double-walled carbon nanotubes (DWCNTs) to enhance their response to humidity was developed. The DWCNTs walls were etched by hot concentrated sulfuric acid, after what the edge carbon sites were saturated by chlorine via reaction with CCl4 vapor. This treatment increases the dispersibility of DWCNTs in solvents, removes oxygen groups, and produces chlorine-decorated holes in the outer walls. Networks of chlorinated holey DWCNTs showed a high repeatable response to humid environment and a good reversible behavior after the sensor purging by dry air. The density functional theory calculations predict enhanced polarization of the DWCNTs when they contain chlorine-decorated holes in the outer walls and physisorption of H2O molecules near chlorine atoms. These two effects are the cause of an intense low-noise signal to gaseous H2O and easy sensor recovery.

Влияние некоторых факторов на коррозионно-эрозионное поведение литой высокоуглеродистой высокохромистой стали в горячей водной сернокислотной пульпе

Влияние некоторых факторов на коррозионно-эрозионное поведение литой высокоуглеродистой высокохромистой стали в горячей водной сернокислотной пульпе

Hot-injection strategy for 1-min synthesis of carbon dots from oxygen-containing organic solvents: Toward fluorescence sensing of hemoglobin

Here, we present a rapid and general fabrication methodology for fluorescent carbon dots (CDs) via injecting various oxygen-containing organic solvents including acetone, ethanol, ethyl acetate, tetrahydrofuran, and diethyl ether into hot concentrated sulfuric acid. All these small organic molecules are recognized as common, cheap, and abundant carbon precursors, which can convert into CDs just in 1 min through protonation, polymerization and aromatization. The as-prepared CDs with disordered amorphous cores and plentiful oxygenous groups show fascinating photoluminescence features, that can be used for sensitive and selective detection of hemoglobin (Hb) based on fluorescence quenching. The linear detection range is estimated to be 2–360 nM and the limit of detection is as low as 0.79 nM. After careful investigations, the inner filter effect is proposed to explain the sensing mechanism because the absorption band of Hb fully covers the emission spectrum of CDs and the fluorescence lifetime of CDs remains nearly constant after addition of Hb. The sensor is successfully applied for Hb detection in human blood samples, exhibiting a great potential for quantitative analysis of Hb in complex biological matrices.

DORMANCY BREAKING, GERMINATION, AND PRODUCTION OF MIMOSA BIMUCRONATA (DC.) KUNTZE SEEDLINGS

ABSTRACT Mimosa bimucronata is a pioneer, easily adapted, fast-growing species used in restoration programs. The objectives of this study were to experimentally compare (1) methods for dormancy breaking; (2) suitable temperature and substrate for germination; and (3) suitable light intensity and substrate volume for seedling production of M. bimucronata. In the first two experiments, the variables percentage of germination, speed of germination and germination mean time were analyzed. In dormancy test, seeds were submitted to ten methods divided into three groups: hot water, sulfuric acid, and control. In the second experiment, effects of five different temperatures and four substrates were evaluated. In the third experiment, morphometric and biomass variables of seedlings were evaluated in two substrate volumes and two light intensities. The most effective method for breaking dormancy was hot water at 80 °C for one minute with post-treatment immersion in water at room temperature for 24 hours. This finding contrasted with the recommended method for dormancy breaking in the Brazilian Rules for Seed Analysis. The most suitable substrates and temperatures for germination were germitest paper at alternating temperatures of 25-35 °C and sand at constant temperature of 30 °C. The most adequate volume of substrate for seedling production was 280 cm3 in both shaded and full sunlight conditions.

Energy-efficient and simultaneous extraction of lithium, rubidium and cesium from lepidolite concentrate via sulfuric acid baking and water leaching

Lepidolite is a valuable mineral resources of lithium, rubidium and cesium. However, most researches only focused on the lithium extraction without recovery of rubidium and cesium, and most of these processes involved energy-intensive high-temperature roasting and/or mechanical activation. In this study, simultaneous extractions of lithium, rubidium and cesium from a lepidolite concentrate were conducted through a low-temperature sulfuric acid baking and water leaching route. The influence of the extraction process parameters were systematically investigated. An optimized baking and leaching condition was determined as follows: H2SO4 concentration 85 wt%, baking temperature 200 °C, acid-to-concentrate mass ratio 1.7:1, baking time 4 h, 88% concentrate particles <74 μm, and water leaching temperature 85 °C. Under the optimal condition, the maximum extractions of Li, Rb and Cs reached 97.1%, 96.0% and 95.1%, respectively. Besides, the chemical formula of the lepidolite mineral in the concentrate was determined as KLi1.6Al2.2Si3.2O10FOH via AMICS characterization. During the baking process, the lepidolite reacted with hot sulfuric acid to generate water-soluble but acid-insoluble sulfates, KAl(SO4)2, Al(SO4)OH·5H2O and Li2SO4, while the rubidium and cesium might be converted to RbAl(SO4)2 and CsAl(SO4)2 existing in the form of isomorphism in KAl(SO4)2.

Chemical resistance of TiO2 and Al2O3 single-layer and multilayer coatings atomic layer deposited from hydrogen-free precursors on silicon and stainless steel

Chemical resistance of TiO2 and Al2O3 single-layer and multilayer coatings deposited in TiCl4O3 and AlCl3O3 atomic layer deposition processes on Si(100) and AISI 310 stainless steel was studied. Etching of coatings in hot sulfuric acid revealed marked dependence of the etching rate on the deposition temperature. The dependence was in correlation with changes in chlorine concentration and with the density of Al2O3 films, and with the development of preferential orientation of anatase phase in TiO2. The TiO2 coatings studied markedly reduced the mass loss of AISI 310 samples in etching tests.

Porous graphite sheet spray ionization ion mobility spectrometry.

In this work, a porous graphite sheet is introduced as the substrate in a spray ionization source for ion mobility spectrometry (PGSI-IMS) for the first time. This ionization source has some important advantages in comparison with the hollow needle, which is conventionally used in electrospray ionization. In order to prepare the hydrophilic surface needed to load samples on a graphite substrate, the graphite sheet was treated with hot sulfuric acid solution for 2hours. Some parameters affecting the ionization efficiency were studied, and the optimized conditions were found to be 3.5-kV graphite voltage, 24-μL methanol flow rate, 500mLmin-1 the gas flow rate, and graphite sheet with a 60° tip angle and 3-mm distance from the counter electrode. Finally, analyses of some test compounds (imipramine, diclofenac, codeine, morphine, and ethion) were conducted to evaluate the capability of the new ionization source in the positive and negative modes. The satisfactory results proved the capability of the graphite sheet spray ionization, to be conveniently used for routine analysis of chemical compounds by IMS.

Electrodeposition of a Pd-Ni/TiO2 Composite Coating on 316L SS and Its Corrosion Behavior in Hot Sulfuric Acid Solution

Pd-Ni/TiO2 composite coatings were elaborated on 316L stainless steel by an electrodeposition method. The specimens were obtained from an electrolytic bath that contained various contents (5, 10, and 15 g L−1) of nanosized TiO2 particles. X-ray diffraction (XRD) characterization showed that increasing the TiO2 content in the coatings can decrease the crystal grain size. The surface morphology and chemical composition of the composite coatings were modified by the addition of TiO2 particles in the electrolyte, as shown by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) methods, respectively. The TiO2 content also significantly affected the mechanical and electrochemical properties of the Pd-Ni/TiO2 composite coatings. The microhardness of the Pd-Ni/TiO2 composite coatings can be enhanced by increasing the TiO2 content in the coatings. With the addition of 5 g L−1 TiO2 particles to the electrolyte, the deposited Pd-Ni/TiO2 composite coating presented a remarkably increased corrosion resistance when exposed to a sulfuric acid solution at 60 °C compared with that of the Pd-Ni alloy coating. Nevertheless, the further addition of TiO2 particles into the electrolytic bath did not further improve the corrosion resistance of the composite coating.

ChroSiMol: A Completely Different Coating Against Corrosion and Wear

The paper deals with new layers of the systems Cr-Mo-Ni-Si and Cr-Mo-Co-Si bearing the common name "ChroSiMol". These layers are applied by means of atmospheric plasma spraying on metallic substrates of iron, nickel, cobalt, and titanium-based alloys and serve as corrosion, oxidation and wear protection for these metals at temperatures up to max. 900°C. The layer ChroSiMol is an acid-resistant layer and provides for its substrates a perfect protection against hot sulfuric acid and phosphoric acid in all concentrations. With a hardness of approx. 900 HV and very good anti-friction properties of the molybdenum-containing surface, these layers are optimally suited for use with friction pairs with corrosive loads.

Effect of Gibberellic Acid Treatment on Seed Germination of Kantakari (Solanum virginianum L.)

Aim: Solanum virginianum L., an important medicinal plant used in Dashmoolarishtha, belongs to the Laghoopanchamoola group. It is also used in various Ayurvedic formulations. It is reported as rare and endangered species in some parts of India. To fulfil the raw drug demand of the market, it is necessary to increase its production on a large scale. Materials and methods: Mature plants were collected, identified, authenticated and herbarium specimens preserved in herbarium section of the institute. Mature seeds were subjected to various treatments like hot water, sulfuric acid (H2SO4), and different concentrations of gibberellic acid (GA3). Result: Data obtained from the experiments indicated that the pre-sowing treatment with GA3 was effective in breaking seed dormancy as compared to the treatments with hot water and conc. sulfuric acid. Conclusion: Seed germination of S. virginianum L. could be achieved irrespective of the season by treating seeds with GA3.