This paper seeks to identify the criteria that influence the performance of high-tech new ventures. Twenty-seven venture capitalists who experienced both failure and success in high-tech ventures ...were asked to rate one of their most successful ventures and one of the least successful or failed ventures on 38 criteria identified under six groups: entrepreneur quality, resource-based capability, competitive strategy, product characteristics, market characteristics and financial criteria. The venture capitalists were subsequently interviewed to overcome biased or forced results and to know more about success criteria.
The study reveals that entrepreneur quality, resource-based capability, and competitive strategy are the critical determinants of the firm’s viability and achievement. It is seen from cluster analysis that successful entrepreneurs develop multiple resource-based capabilities to backup multiple-strategies to push their products through market. Furthermore, it is concluded that it is not the unique products relative to competitors that brings success rather it is the firm’s ability to meet the unique requirements of customers that bring success.
This article reports the synthesis of tungsten nanoparticles predominantly in α-W phase by a single step plasma expansion technique. The oxidation of the metal and contribution from the β-W phase in ...the nanomaterial samples was observed to decrease with the increase of both the pressure in the sample collection chamber and the plasma power. We had observed production of faceted, lightly sintered particles with up to 300 nm individual sizes during high plasma current/high pressure synthesis conditions, which were measured to have the highest specific surface area of 35 m2/g. Condensation of this high temperature material at low saturation ratio and the high collisional regime had led to the synthesis of relatively bigger particle sizes in this experiment. Cauliflower like particle morphologies was observed during low pressure synthesis conditions, which is considered to have formed through spherulitic growth processes. Transmission Electron Microscopy (TEM) micrographs show very small crystallites remaining dispersed in an amorphous moss like the background, which was confirmed to be a mixture of tungsten and its oxides.
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•Controlled synthesis of α-tungsten nanoparticles by a plasma expansion technique.•Oxides and β-W decrease with increase in plasma power and pressure in the chamber.•High power/pressure gives faceted particles mixed with mesocrystal like aggregates.•Under low-pressure cauliflower like particles grow through spherulitic processes.•Moss like almost amorphous particle background consists of tungsten and its oxides.
During last two decades a large number of transport sector projects have been executed through the Public Private Partnership (PPP) mode in India. Since the period of execution and operations of ...these infrastructure projects are usually long enough, their intricacies are also much more. This is more so in a country like India where culture of PPP projects had just started in late 1990s. The vague nature of criticalities associated with these projects compound with inexperienced project management has compelled many researchers to go for finding better path of managing these projects by applying methods like AHP, Fuzzy logic and neural networks. In this paper five simple representative fuzzy logic modules have been framed for determining probabilities of some critical events, results from which have been further refined with the Delphi process. For convergence of crisp value in Delphi process ‘10% + Mode value’ has been considered as the criteria. Validation of the developed modules have been done with data collected through questionnaires survey as part of the research. Analysis of data from some surveyed case study projects through our developed modules shows that in India managing the “O & M risk” is most vulnerable as of now.
This paper demonstrates fine size-controlled synthesis of superparamagnetic carbon-encapsulated iron nanoparticles, by a supersonic plasma jet assisted rapid, bulk-production process, by manipulation ...of the pressure in the sample collection chamber. Transmission electron microscopy and small angle x-ray scattering measurements confirmed the formation of single-crystals with a narrow size distribution, having core average size of 5.0 nm and encapsulated by an ultrathin carbon coating, for sub-mbar pressure. VSM and Mossbauer characterization established the nanocrystallites to be superparamagnetic in nature, with saturation magnetization 67 emu/g and coercive field 7.4 Oe. Controlled plasma heating during synthesis led to the burning down of extra carbon that resulted in further enhancement of the magnetization of the product. Graphitization of the encapsulating layers also enhanced, which could successfully protect the metallic core from oxidation, as well as improved its cyto-compatibility. This purified sample could be ideal for targeted drugs delivery and water treatment applications. Another sample was processed through controlled reaction with oxygen, the as-synthesized sample having magnetic properties approaching that of the first sample, which may be more attractive especially for water treatment processes because of the simpler single-step processing of the material.
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•Controlled plasma synthesis of C encapsulated superparamagnetic nanoparticles.•Small angle X-ray scattering confirms 5 nm size and ultrathin carbon coating.•VSM measures 67 emu/g saturation magnetization and 7.4 Oe coercive field.•Controlled plasma heating at low pressure burns-off extra carbon.•Nanomaterials likely to be ideal for biomedical and environmental applications.
The paper reports studies on supersonic thermal plasma expansion process for rapid, controlled synthesis of titanium nitride nanoparticles with enhanced particle characteristics, by injecting TiCl4 ...and NH3 at two different reaction zones, namely hot zone and colder tail zone of a thermal plasma jet assisted chemical reactor. Two different chamber pressures of 30mbar and 10mbar were maintained to investigate the effect of pressure on the characteristics of the product particles. The nanoparticles synthesized by injecting reactants to the colder tail zone at 10mbar chamber pressure show sub-10 nanometer average sizes with cubic shapes. On the other hand, particles synthesized by injecting the reactants to the hot zone shows better crystal structure and bigger size. The optical spectrums obtained from the injection zone indicate the presence of both atomic and ionic species in the plasma which are the growth precursors for the synthesis of titanium nitride particles. Plasma temperature at the injection zone was estimated from the plasma emission spectra by Atomic Boltzmann Plot method.
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•Nanoparticles of TiN synthesized by a supersonic plasma expansion process.•Plasma zone isolated from particle growth zone through a supersonic nozzle.•Control demonstrated by chamber pressure and reactant injection location.•Low pressure, colder tail zone injection produces sub-10nm, mono-crystals.•Plasma precursor chemistry studied with optical emission spectroscopy.
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•Alternative bulk production of fusion relevant tungsten dusts by plasma techniques.•Polyhedral and nonequilibrium spherulitic W-crystals from nano to micrometer sizes.•NRRA measures ...orders of magnitude higher H retention compared to the bulk tungsten.•Porosity and enhanced surface of the nonequilibrium dusts led to higher absorption.
In this communication, we identify some thermal-plasma assisted synthesis techniques for the alternative production of fusion relevant tungsten dust particles in bulk amounts, to allow for the statistically meaningful study of their hydrogen absorption properties. Fast, single step synthesis of fine particles in the α-tungsten phase was demonstrated, using a high heat flux device for sizes in the micrometer region and an experimental nanoparticle reactor for dust with nanometer sizes. Production of both equilibrium polyhedral and nonequilibrium spherulitic crystal shapes was demonstrated, dust morphologies similar to which were identified before in existing tokamaks and divertor simulator systems. Their hydrogen retention characteristics were measured by the Nuclear Resonance Reaction Analysis technique, which was found to be orders of magnitude higher compared to the same metal in the bulk form. The mesoporous crystals generated during high power, high pressure synthesis conditions were assumed to be responsible for the unusually high gas retention of the nanoparticle sample. It was concluded that non-equilibrium tungsten dust morphologies would be dominant in the high power fusion machines in the future, which may aggravate the hydrogen isotope retention issues further.
This paper reports rapid, continuous and carbon-nanotube free synthesis of carbon encapsulated magnetic nanoparticles by thermal-plasma expansion technique, which combines the typical advantages of ...high-temperature plasma assisted synthesis method with efficient particle-size control. Core nanocrystals were encapsulated with few layers of graphitized carbon, which could provide protection against both oxidation and intense chemical treatment. The average iron/iron-carbide nanoparticle diameter (7.7, 9 and 10nm) and the width of the size distribution increased with pressure in the sample collection chamber, as a result of the decreasing quenching rate of the plasma jet. This also resulted in the smaller particles remaining frozen predominantly in the high-temperature γ-Fe phases, part of which was oxidized subsequently and eliminated preferentially during the purification process. All samples could be correlated with smooth variation of magnetic properties; saturation magnetization, remnant magnetization and coercive-field enhancing with increasing chamber pressure or average particle size. The low pressure synthesized sample with smallest average particle size approached super-paramagnetic behavior (saturation magnetization=51.8emu/g, ratio of remnant to saturation magnetization=4.9 and coercive field=52Oe), which may be ideal for biomedical applications. High-pressure samples on the other hand have a higher saturation magnetization (76.3emu/g) and coercive fields (123Oe).
•ZnO/α-Fe2O3 composite deposited on plasma chamber wall (ZF-W) are investigated.•ZF-W is compared with plasma treated mixture deposited on target substrate (ZF-S).•Structural studies are conducted by ...XRD, TEM, PL, Raman and Mossbauer spectroscopy.•Cationic arrangement and oxygen vacancy defects play a role in structural variations.•ZF-W shows excellent methyl blue adsorption without any external light sources.
While conventional cleaning to remove the coating from plasma chamber walls becomes essential to reproduce the desired materials on the target substrate for widespread applications, an attention towards wall-deposited materials is scarce. Recycling those waste materials to value-added product is of great importance for sustainable progress of our modern society. Herein, we investigated the materials deposited on the wall of plasma chamber, explored their promising features and compared them with conventionally grown materials. A mixture of ZnO and α-Fe2O3 (ZF) exposed to high energy plasma was collected from the wall (ZF-W) and also from the substrate (ZF-S) to check the feasibility of providing same quality products. With same lattice constant of hematite, magnetite and zinc ferrites, ZF-W differs from ZF-S in coercivity, saturation magnetization, ferromagnetic stoichiometry and defects. In addition, degradation of Methyl Blue (MB) dye in ZF-W without use of any external light sources are comparable, more stable and durable in comparison to ZF-S. The slight differences obtained in the property-performances between ZF-W and ZF-S are attributed to the cationic arrangement and the oxygen vacancy defects present in the structure. The study reflects the potentiality of ZF-W as a promising active material for wastewater treatment just as one can use ZF-S. These findings clearly depict that the unused products with altered intrinsic properties obtained after plasma treatment has similar or even better potential to its actual targeted product and thus can be utilized properly thereby saving cost and time and, hence generates an unexplored direction for the materials science community.
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While conventional cleaning to remove the coating from plasma chamber walls becomes essential to reproduce the desired materials on the target substrate for widespread applications, an attention ...towards wall-deposited materials is scarce. Recycling those waste materials to value-added product is of great importance for sustainable progress of our modern society. Herein, we investigated the materials deposited on the wall of plasma chamber, explored their promising features and compared them with conventionally grown materials. A mixture of ZnO and α-Fe2O3 (ZF) exposed to high energy plasma was collected from the wall (ZF-W) and also from the substrate (ZF-S) to check the feasibility of providing same quality products. With same lattice constant of hematite, magnetite and zinc ferrites, ZF-W differs from ZF-S in coercivity, saturation magnetization, ferromagnetic stoichiometry and defects. In addition, degradation of Methyl Blue (MB) dye in ZF-W without use of any external light sources are comparable, more stable and durable in comparison to ZF-S. The slight differences obtained in the property-performances between ZF-W and ZF-S are attributed to the cationic arrangement and the oxygen vacancy defects present in the structure. The study reflects the potentiality of ZF-W as a promising active material for wastewater treatment just as one can use ZF-S. These findings clearly depict that the unused products with altered intrinsic properties obtained after plasma treatment has similar or even better potential to its actual targeted product and thus can be utilized properly thereby saving cost and time and, hence generates an unexplored direction for the materials science community.
In this communication, we are numerically investigating the nucleation and growth of nanoparticles in the context of a supersonically expanded thermal plasma assisted process, using the Nodal General ...Dynamic Equations (NGDE) model. The dependence of particle size distribution on reactant injection rate and sample collection chamber pressure is investigated. The possible effect of particle charging in the plasma environment on nucleation and growth of particle sizes is also studied. Results are compared with findings from an actual experimental reactor system in the laboratory of the authors.
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