Search results

To discuss synthesis and evaluation of organo‐metallic chalcones as second‐order nonlinear optical (SONLO) materials.

The new chalcones have been synthesised via Knovoenagel reactions of ferrocen carboxaldehyde with two active methylene compounds.

The ferrocenyl chalcones prepared have shown bathochromic shift and thermal stability in polymeric film. On heating the dye films up to 80°C the extent of degradation reached up to 12 per cent and very small amount of degradation was observed at 43 and 60°C.

The paper shows that these compounds have UV‐Vis bathochromic shift, enabling them to be used as SONLO materials in the blue domain as well as dyes.

Hydroelectric power is widely used because it is environmental friendly, renewable and green. The cavitation is an inevitable phenomenon during the operation of hydro turbine, which is related to the efficiency and service life of the unit. This paper aims to discriminate the phenomenon of the incipient cavitation, prevent the early destruction and avoid the irreversible damage to hydro turbine.

The paper tries to find out the characteristics of cavitation entirely through a variety of features. The method comprises collection of the signals using a hydrophone, acceleration sensor and acoustic emission sensor; analyzing cavitation signal by using the way of wavelet time-frequency, peak factor and power spectral density; and comparing the different wavelet basis for analyzing signals and find the most suitable one.

The analyzed results show that the wavelet basis of morlet is more suitable for the cavitation signals. The hydrophone can distinguish the different operating conditions and discriminate the difference between the phenomenon of incipient cavitation and the other state of cavitation. The results show that when the hydrophone and acceleration sensors are used, the accuracy rate goes up to 75 per cent, which meets the requirements for the detection for incipient cavitation.

This paper focuses on finding the best sensor to discriminate the operating state of incipient cavitation to prevent early destruction.

Given the critical mass of literature on entrepreneurial risk-taking, the purpose of this paper is to assess the contribution to the knowledge so far by exploring important themes in the literature on entrepreneurial risk-taking.

The review is organized around four themes: nature of entrepreneurial risk-taking; antecedents of entrepreneurial risk-taking; context of entrepreneurial risk-taking; and outcomes of entrepreneurial risk-taking. The author critically evaluates the literature on each theme and presents the pointers for future research.

Literature does provide a holistic view encapsulating different dimensions of entrepreneurial risk-taking, but it has produced largely inconsistent findings in terms of risk and gender, risk propensity of entrepreneurs in comparison to non-entrepreneurs and the outcomes of entrepreneurial risk-taking. Organizational antecedents, non-financial measures and ethical- and health-related consequences of entrepreneurial risk are underexplored. Inconclusive literature also implies that the risk may not be a distinguishing or important factor for undertaking an entrepreneurial endeavor. Therefore, it is pertinent to explore the critical factors entrepreneurs consider (or not consider) while marshalling their resources to embark on an entrepreneurial journey. This posits the need to explore an entrepreneur’s informal approach toward risk-taking.

Suggested pointers of future research will potentially enhance the theoretical understanding of entrepreneurial risk-taking.