In vitro enzyme catalyzed synthesis of polyesters is a new technique of polymer synthesis and is an eco-friendly process having several benefits over conventional chemical polymerization. In this ...article lipase-catalyzed ring-opening polymerization of lactones, lactides and macrolides, cyclic carbonates, cyclic phosphates, cyclic depsipeptides and copolymerization of oxiranes with dicarboxylic acid anhydrides leading to the formation of polyesters, polycarbonates, polyphosphates and poly(ester-amides) has been reviewed in detail. The effect of reaction parameters, i.e. solvent, temperature, enzyme and monomer concentration, on the rate and molecular weight of the polymers is discussed. Synthesis of polyesters by step-growth polycondensation reactions using simple diacids and diols, hydroxy acids or transesterification reaction of simple or activated diesters with diols has also been surveyed. The general mechanisms of ring-opening and step-growth polymerization have also been considered. Lipase hydrolyzes the ester bonds of polyesters in an aqueous medium and recombines the cleaved moiety in non-aqueous medium. The possibility of utilizing such reactions for the repetitive recycling of biodegradable polyesters has been highlighted.
A study is done to compare the effect of film or sport celebrity or mascot usage in advertising on educated, well -informed consumers through the application of Meaning Transfer theory and the ...elaboration likelihood model (ELM) of persuasion theories. Film or sport or Mascot advertising of global brands of the FMCG category has no role in improving purchase intentions and expertise, gender and controversy of the celebrity does not influence "educated working consumers "with graduate and post graduate degree in the present study. The study helps to resolve the dilemma for global brands on usage of Celebrity and Mascot in advertising for a global brand in emerging markets like India which is a destination for many global brands. Moreover, if the content is good and celebrity with "expertise image" is used to promote the global brands in FMCG category, brand parameters are positively influenced for educated working consumers who are under 35 years.
Purpose
This study aims to explore consumer motivations to mitigate the contagion effect in access-based consumption after instances of prior customer misbehavior. Reverse contagion, demonstrated ...through customer citizenship behavior, entails using both firm-provided and personal resources to cocreate value, even in the presence of norm violations by others. The research delves into the influence of empathy, narrative appeal and past misbehavior severity on customer behavior, specifically in the context of reverse contagion.
Design/methodology/approach
Two scenario-based studies and a field study were used within the context of scooter-sharing to assess the conceptual model. Study 1 (n = 156) and Study 2 (n = 97) were conducted through surveys. Study 3 (n = 54) was a field study.
Findings
The results emphasize the crucial role of empathy in breaking the cycle of misbehavior contagion. Specifically, the findings suggest that narrative appeals have the potential foster greater empathy, encouraging customers to counteract the contagion. However, the intensity of prior misbehavior lessens the efficacy of narrative appeals in triggering reverse contagion, thereby moderating the mediating effect of empathy.
Originality/value
This study investigates reverse contagion stemming from customer misbehavior in accessed-based consumption. It delves into the impact of empathy, narrative appeal and previous misbehavior on the dynamics of value codestruction and cocreation. This comprehensive examination of these factors within a unified framework represents a new contribution to the literature. The results illuminate this intricate phenomenon, offering valuable insights for managers to address adverse customer behavior and harness the positive aspects of reverse contagion.
Detailed electron-impact excitation cross-section results for xenon in the wide range of incident energy from threshold to 1000 eV are calculated using relativistic distorted wave theory. Various ...transitions from the ground 5p6 state to the excited 5p56s, 5p56p, 5p55d, 5p57s and 5p57p as well as among these excited states are considered. The relativistic Dirac-Fock multi-configuration wave functions for the ground and excited states of Xe are obtained and used in the calculations. Where available, our cross-section results are compared with previously reported measurements and calculations. We have also fitted the calculated cross-sections through analytical formulae for plasma modeling purposes. As an application, using the obtained cross-sections, a collisional-radiative (C-R) model coupled with an optical emission measurement from the inductively coupled Xe plasma is developed and the extracted plasma parameters are reported.
Friction and wear remain the primary cause of mechanical energy dissipation and system failure. Recent studies reveal graphene as a powerful solid lubricant to combat friction and wear. Most of these ...studies have focused on nanoscale tribology and have been limited to a few specific surfaces. Here, we uncover many unknown aspects of graphene’s contact-sliding at micro- and macroscopic tribo-scales over a broader range of surfaces. We discover that graphene’s performance reduces for surfaces with increasing roughness. To overcome this, we introduce a new type of graphene/silicon nitride (SiN x , 3 nm) bilayer overcoats that exhibit superior performance compared to native graphene sheets (mono and bilayer), that is, display the lowest microscale friction and wear on a range of tribologically poor flat surfaces. More importantly, two-layer graphene/SiN x bilayer lubricant (<4 nm in total thickness) shows the highest macroscale wear durability on tape-head (topologically variant surface) that exceeds most previous thicker (∼7–100 nm) overcoats. Detailed nanoscale characterization and atomistic simulations explain the origin of the reduced friction and wear arising from these nanoscale coatings. Overall, this study demonstrates that engineered graphene-based coatings can outperform conventional coatings in a number of technologies.
Effects of long term, medium level (electrical conductivity of extract (ECe)=6.85 dS m
−1) sodium chloride (NaCl) salinity were studied in tolerant (Kharchia 65) and susceptible (HD 2687) wheat ...genotypes. NaCl salinity caused decrease in relative water content (RWC), chlorophyll (CHL), membrane stability index (MSI) and ascorbic acid (AA) content, and increased the contents of hydrogen peroxide (H
2O
2), thiobarbituric acid reactive substances (TBARS) (measure of lipid peroxidation) and activities of superoxide dismutase (SOD), its various isozymes, ascorbate peroxidase (APOX) and glutathione reductase (GR) in wheat genotypes Kharchia 65 (tolerant) and HD 2687 (susceptible). Salinity tolerant wheat cv. Kharchia 65 showed less decline in RWC, CHL, MSI estimated in whole tissue than salt sensitive HD 2687. Kharchia 65 also exhibited less decrease in AA content, less increase in H
2O
2, TBARS contents and higher increase in SOD and its isozymes, APOX and GR in all sub-cellular fractions than salt sensitive HD 2687. H
2O
2, TBARS contents and AA contents were higher in chloroplastic fraction. Chloroplastic fraction showed higher total SOD, APOX and GR activity, followed by mitochondrial fraction in case of total SOD and GR, while cytosolic fraction was in second place in case of APOX activity. Though Mn–SOD activity was highest in mitochondrial fraction, but residual activity was also observed in cytosolic fraction. Cu/Zn–SOD and Fe–SOD were observed in all the sub-cellular fractions, however, the activities were higher in chloroplastic fraction for both the isoforms. Total Cu/Zn–SOD activity, sum of activity observed in all the fractions, was higher than other SOD isoforms. Susceptibility of HD 2687 to long-term salinity stress seems to be due to relatively less induction of SOD isozymes, no induction in chloroplastic and mitochondrial APOX and cytosolic GR and decrease in chloroplastic GR under salt stress resulting in higher oxidative stress in the form of H
2O
2 and TBARS contents and decrease in MSI and CHL.
A new current-mode fractional-power CMOS circuit such as cube-root and squared-cube-root configurations that give output signal in four quadrants has been presented for the first time. MOSFETs ...utilized in the design exploit translinear principle in weak-inversion region. The second-order effects on the circuit proposition have been analysed. The implementation justification has been validated by post-layout simulation on Virtuoso-SPECTRE tool with 180 nm GPDK CMOS process parameters. It has been found that using ± 0.5 V supply voltage, the realized cube-root and squared-cube-root circuits work for an input range of ± 30 µA while consuming few hundred nano-watts of static power and exhibit a maximum of ± 1 dB error over a wide input range of ± 1.5 µA to ± 30 µA in all four quadrants. Utility of the proposed circuits, as companding and gamma corrector, has also been elaborated.
An efficient, low-energy technique named solution-combustion synthesis was taken into use to generate a sequence of BaY
(1−
x
)
Zn
3
AlO
7
:
x
Tb
3+
(
x
= 0.01–0.10) nanophosphor. The powder X-ray ...diffraction patterns braced by Rietveld refinement established the sustenance of BaYZn
3
AlO
7
lattice having hexagonal phase with space group P63mc (186). The most bulging peak in emanation spectra of the nanostructure at 543 nm was due to
5
D
0
→
7
F
2
electronic transition resulting in a green emission when excited by a near-UV light source (
λ
max
= 278 nm). The quantum efficiency for the optimized sample was found out to be 78%. The synthesized nanophosphor with an optimum concentration of Tb
3+
, i.e., BaY
0.95
Tb
0.05
Zn
3
AlO
7
, and the standard host were characterized by DRS (diffuse reflectance spectroscopy), and bandgaps were evaluated which were found to be 4.63eV and 4.67eV respectively. The color coordinates also existed in the greenish section of the chromaticity diagram (
x
= 0.221 and
y
= 0.46). The CCT (correlated color temperature) was also evaluated for whole series of nanophosphors and found to be 1714 K for the optimized one that confirmed its applications in warm LED’s fabrication.
In this article, we prove that a cone is a Heisenberg uniqueness pair corresponding to sphere as long as the cone does not completely recline on the level surface of any homogeneous harmonic ...polynomial on Rn. We derive that S2,paraboloid and S2,geodesic ofSr(o) are Heisenberg uniqueness pairs for a class of certain symmetric finite Borel measures in R3. Further, we correlate the problem of Heisenberg uniqueness pairs to the sets of injectivity for the spherical mean operator.
This paper presents the design aspects and thermal characteristics of single-sided linear induction motor (SLIM) for Electromagnetic launchers. It is designed to accelerate a 50 kg mass through a ...distance of 3 meters within a minuscule time to an exit velocity of 50 m/s. A study of the motor's parametric variation based on the launching requirement has been performed. Its performance characteristics are obtained using 3D FEM and verified analytically using Parseval's method. The FEM, analytical and experimental verification of the thrust characteristics of different secondary conductive sheet materials namely, aluminum, Beryllium copper and German silver shows that, the latter exhibits superior characteristics than the former two, because its thrust-velocity curve is close to inverse linear relationship (stable region of operation of LIM), which significantly reduces the accelerating time during the launch. The designed SLIM is assessed for its thermal performance with materials having temperature-dependent electrical properties by carrying out a coupled-field FEM simulation. The conclusions demonstrate that the electromagnetic and thermal assessments are in tandem with each other as required for launching.
