Women Engineers’ Self-Efficacy And Career Persistence: The Mediating Roles Of Job Crafting And Subjective Career Success

Engineering is one of the fields considered male-dominated and a non-traditional profession for women. Hence, many studies have focused on barriers that prevent women’s progress in engineering education and career domain. Little attention has been directed to those women engineers who persist despite the barriers. Guided by the human agency approach and drawing on social cognitive career theory and job demands-resources theory, this study focuses on two individual factors; job crafting behaviour and subjective career success (career satisfaction and satisfaction with work-life balance) as the influential variables explaining women engineers’ career persistence. A serial multiple mediator model was developed to examine the roles of job crafting and subjective career success as the underlying mechanism linking self-efficacy to career persistence. The research hypotheses were assessed using partial least squares structural equation modelling (PLS-SEM) with bootstrapping. Using a purposive sampling technique, data were collected through a survey method from a sample of women engineers employed in manufacturing organisations in Malaysia. A total of 156 data were analysed using PLS-SEM. The results of the study indicate that job crafting and subjective career success (career satisfaction and satisfaction with work-life balance) fully mediate the effect of self-efficacy on career persistence. Overall, this study contributes to the utility of the social cognitive career theory and job demands-resources theory among a sample of women engineers

Intermolecular ligand exchange in alkyltin trihalides: semiempirical and density functional theory calculations

The mechanism of intermolecular exchange of methyl and ethyl groups for chlorine in CH3SnCl3 and C2H5SnCl3, respectively, has been probed through semiempirical (PM3) and density functional theory (B3PW91 and B3LYP) calculations. The reaction is explained by a mechanism involving the formation of the transition state comprising bridging alkyl and chloro groups. The PM3 calculated activation energies are 37.5 and 36.4 kcal mol-1 while the B3LYP/LANL2DZ calculated activation energies are 50.4 and 41.3 kcal mol-1 for the methyl and ethyl analogues, respectively. The rate constants calculated at the DFT level are in close agreement with the corresponding experimental values

Supramolecular Gel Formation Based on Glycolipids Derived from Renewable Resources

The potential applications of self-assembled supramolecular gels based on natural molecules encouraged the researchers to develop a versatile synthetic method for their structural analogues. Herein, we report a facile synthesis of glycolipid from renewable resources, cashew nut shell liquid,d and d-glucose in good yield. Gelation behavior of these glycolipids were studied in a wide range of solvents and oils. To our delight, compound 5b formed a hydrogel with Critical gelator concentration (CGC) of 0.29% w/v. Morphological analysis of the hydrogel depicts the formation of twisted fibers with an entangled network. Formation of a twisted fibrous structure was further identified by CD spectral studies with respect to temperature. The molecular self-assembly assisted by hydrogen bonding, hydrophobic, and π–π stacking interactions were identified by X-ray diffraction (XRD) and FTIR studies. Rheological analysis depicted the mechanical strength and stability of the hydrogel, which is crucial in predicting the practical applications of supramolecular soft materials

Multiwalled Carbon Nanotube Oxygen Sensor: Enhanced Oxygen Sensitivity at Room Temperature and Mechanism of Sensing

A pyrolysis assisted method was applied for the synthesis of defect controlled carbon nanotubes (CNTs) by varying different growth temperatures. The fabricated resistive devices containing a random network of CNTs were tested for oxygen sensing under standard room-temperature and pressure conditions. Nanotubes grown at moderate growth temperatures (870 °C), when exposed to different concentrations of oxygen, displayed a higher sensitivity (3.6%), with fast response and recovery times of about 60 and 180 s, respectively, compared to nanotubes grown at higher and lower temperatures. A room-temperature oxygen detection concentration as low as 0.3% is achieved. The fast response and recovery of CNTs are explained in terms of physisorption of oxygen molecules at (i) carboxyl functional sites and (ii) graphitic carbon sites (pristine CNT) rather than chemisorption at (iii) defected sites. Interestingly, the density functional theory simulated interaction energies (<i>E</i>_ads) of oxygen molecules with defected CNTs (−3.381 eV) and pristine CNTs (−0.753 eV) are higher than that of the carboxyl functional sites (−0.551 eV) and are well correlated with the observed sensing response and recovery times of CNT sensors. Our results show that the carboxyl sites provide lower activation energy or shorter time for desorption of oxygen molecules to yield higher response and fast recovery of the CNT sensors

Intrinsic Hydrophobic Antibacterial Thin Film from Renewable Resources: Application in the Development of Anti-Biofilm Urinary Catheters

The use of renewable resources to develop functional materials is increasing in order to meet the sustainability challenges. In an era of inexorable evolution of antimicrobial resistance, there is a substantial increase in demand for the development of efficient antimicrobial thin film coating from renewable resources for public bacterial threats, food, biomedical, and industrial applications. In the present investigation, we have used cardanol, a phenolic compound having unsaturated hydrophobic tail isolated from cashew fruits, and linseed oil, a vegetable oil and an important biobased building block, which are cheap and easy to regenerate. This study reports the synthesis of cardanol based metal complexes having unsaturated hydrophobic unit and acrylated epoxidized linseed oil (AELO) prepared via epoxidation of double bonds followed by acrylation. The double bond present in the metal complexes and AELO is prone to form assembled thin film under atmospheric conditions, without the need of any initiators. Assembled thin film is one of the important aspects of nanotechnology holding a wide range of applications. ¹H NMR and FT-IR analysis revealed the existence of a strong interaction between ligand and metal, which paves a way to develop a nonleachable metal based thin film coating. The leaching behavior of thin film coating was investigated under various aggressive conditions with the aid of UV–vis spectroscopy. The mechanical properties of assembled thin film coating material composed of cardanol-based metal complex and AELO are described using oscillatory rheology. Morphological and SAXD analysis clearly revealed the formation of the assembled structure in thin films. Thermal response of these materials has been investigated using TGA and DSC measurements. Intrinsic hydrophobic character was identified by contact angle measurement. Antimicrobial and biofilm inhibitory behavior of synthesized compounds and thin films were investigated against various human pathogenic bacterial strains. The assembled thin film coated catheter tube completely inhibits the biofilm formation of uropathogenic Escherichia coli (UPEC). Thus, the developed thin film coating material holds promise to be used as metal enabled, nonleachable coating materials for public bacterial threats, and food and biomedical applications. In particular, this material can be potentially used for developing urinary catheter tubes with antibacterial properties

Disassembly of Bacterial Biofilms by the Self-Assembled Glycolipids Derived from Renewable Resources

More than 80% of chronic infections of bacteria are caused by biofilms. It is also a long-term survival strategy of the pathogens in a nonhost environment. Several amphiphilic molecules have been used in the past to potentially disrupt biofilms; however, the involvement of multistep synthesis, complicated purification and poor yield still remains a major problem. Herein, we report a facile synthesis of glycolipid based surfactant from renewable feedstocks in good yield. The nature of carbohydrate unit present in glycolipid influence the ring chain tautomerism, which resulted in the existence of either cyclic structure or both cyclic and acyclic structures. Interestingly, these glycolipids self-assemble into gel in highly hydrophobic solvents and vegetable oils, and displayed foam formation in water. The potential application of these self-assembled glycolipids to disrupt preformed biofilm was examined against various pathogens. It was observed that glycolipid <b>6a</b> disrupts <i>Staphylococcus aureus</i> and <i>Listeria monocytogenes</i> biofilm, while the compound <b>6c</b> was effective in disassembling uropathogenic <i>E. coli</i> and <i>Salmonella enterica</i> Typhimurium biofilms. Altogether, the supramolecular self-assembled materials, either as gel or as surfactant solution could be potentially used for surface cleansing in hospital environments or the food processing industries to effectively reduce pathogenic biofilms