When daily planning improves employee performance: the importance of planning type, engagement, and interruptions

Does planning for a particular workday help employees perform better than on other days they fail to plan? We investigate this question by identifying two distinct types of daily work planning to explain why and when planning improves employees’ daily performance. The first type is time management planning (TMP)—creating task lists, prioritizing tasks, and determining how and when to perform them. We propose that TMP enhances employees’ performance by increasing their work engagement, but that these positive effects are weakened when employees face many interruptions in their day. The second type is contingent planning (CP) in which employees anticipate possible interruptions in their work and plan for them. We propose that CP helps employees stay engaged and perform well despite frequent interruptions. We investigate these hypotheses using a two-week experience-sampling study. Our findings indicate that TMP’s positive effects are conditioned upon the amount of interruptions, but CP has positive effects that are not influenced by the level of interruptions. Through this study, we help inform workers of the different planning methods they can use to increase their daily motivation and performance in dynamic work environments

Applicability of Semi-Tension Fields to the Back Panel of a Pick-Up Truck

The study and design of light-weight automobiles has emerged as an important area of interest in the government, academia, and the manufacturing industry. Significant advances in vehicle weight reduction technologies have taken place in almost all fields of transportation. Weight reduction is identified as a key factor to achieving fuel-economy, energy efficiency and environmental safety. The main objective of this thesis is to investigate cost effective design methodologies that enable fabrication of light weight structures, which subsequently result in a fuel saving. A few important techniques and trends of weight reduction in the automotive industry over the past few years are studied as part of the thesis. A summary from the survey of various approaches to weight reduction is presented in the literature review. This thesis is based on the theory of semi-tension fields, which was originally applied towards the design of structures in the aircraft industry. A semi-tension field is a post buckling phenomenon in which the load is continued to be carried even after the web has buckled. The advantage of semi-tension fields is twoold: first, by using this theory the structural stability of the original structure is retained; and secondly, its application replaces a comparatively heavy-weight shear resistant web with a thin web, potentially resulting in reduced weight. The semi-tension field theory is applied to the redesign of back panel of a prototype Ford F-150 pick up truck, which was modeled and analyzed using IDEAS Master Series 8 FEA software. The literature review also consists of the survey of several advances in the Semi-tension fields theory, and the corresponding trends in weight reduction. Analytical theories related to semi-tension field-based design and the respective mathematical formulations have also been described. Finite element analyses of the design that resulted from the application of the theory were carried out and results were validated using analytical theories. A technical paper demonstrating the redesign of a door beam was also studied and results are presented as an appendix

Computational models of particle size effects on brittle oxide scale erosion

Metals and alloys designed for machines at elevated temperatures have microstructures and chemistries optimized to provide strength and resistance to oxidation. The majority of the commercial high temperatures metal or alloys intended to use at temperatures below 850°C or so rely on the formation of a continuous surface layer of essentially oxide scale for further oxidation resistance. Erosion of these machine parts by the small solid particle entrained in the liquid or gaseous working environment is a serious problem in many industrial applications. Numerous experiments have been conducted to obtain empirical relations for predicting material loss during erosion and to arrive at an appropriate material for a particular working environment. Arrival of many new materials and surface coatings being used for different applications demand analytical models that are more generic in applying and predicting the volume loss due to erosion. The current thesis work is focused on finite element modeling that takes into account various boundary conditions and predicts the loss of material due to erosion.;Two models, aluminum oxide model and iron/iron-oxide model were developed using IDEAS and analyzed using LS-DYNA3D. The aluminum oxide model was used to validate the computational model with the experimental work of Allan Levy. The results indicated the correlation with the experimental observations. The same procedure is extended to estimate the material loss for iron/iron-oxide model. Several parameters such as size of the erodent, temperature, velocity of the erodent, angle of attack were varied and the influence on volume loss of oxide layer was studied. The results were presented in the form of stress contours and the graphs between the volume loss in mm3 and the parameter affecting erosion

Effects of aircraft operating fluids and environmental thermal fatigue on fly ash and steel slag based cementitious composites.

This paper investigates the performance of concrete incorporating high-volume fly ash (HVFA) and steel slag aggregates against the detrimental effects of combined cycles of environmental thermal fatigue and exposure to leaked aircraft fluids. A total of 128 cubes and 90 prisms were cast for five mixes and exposed to 60, 120, 180, 240 and 300 combined cycles. The results demonstrate the positive effect of utilization of HVFA which reduces the total amount of portlandite available in the system. The SS aggregates demonstrate a strong interlocking with the surrounding matrix and supply the necessary portlandite for continued pozzolanic reaction. However, their reaction with aircraft fluids causes significant degradation to flexural strength initially, which is redeemed by pozzolanic reaction at a later stage. Hybrid basalt and polypropylene fibres were successful in enhancing the flexural strength and reducing the cracking. The mercury intrusion porosimetry revealed a reduction in pore volume because of HVFA. Scanning electron microscopy and differential scanning calorimetry were also employed to uncover the underlying mechanisms of damage and assess the performance of the cementitious composite

Cysteamine inhibits lysosomal oxidation of low density lipoprotein in human macrophages and reduces atherosclerosis in mice

Background and aims: We have shown previously that low density lipoprotein (LDL) aggregated by vortexing is internalised by macrophages and oxidised by iron in lysosomes to form the advanced lipid/protein oxidation product ceroid. We have now used sphingomyelinase-aggregated LDL, a more pathophysiological form of aggregated LDL, to study lysosomal oxidation of LDL and its inhibition by antioxidants, including cysteamine (2-aminoethanethiol) which concentrates in lysosomes by several orders of magnitude. We have also investigated the effect of cysteamine on atherosclerosis in mice. Methods: LDL was incubated with sphingomyelinase, which increased its average particle diameter from 26 to 170 nm, and was then incubated for up to 7 days with human monocyte-derived macrophages. LDL receptor-deficient mice were fed a Western diet (19-22 per group) and some given cysteamine in their drinking water at a dose equivalent to that used in cystinosis patients. The extent of atherosclerosis in the aortic root and the rest of the aorta was measured. Results: Confocal microscopy revealed lipid accumulation in lysosomes in the cultured macrophages. Large amounts of ceroid were produced, which colocalised with the lysosomal marker LAMP2. The antioxidants cysteamine, butylated hydroxytoluene, amifostine and its active metabolite WR-1065, inhibited the production of ceroid. Cysteamine at concentrations well below those expected to be present in lysosomes inhibited the oxidation of LDL by iron ions at lysosomal pH (pH 4.5) for prolonged periods. Finally, we showed that the extent of atherosclerotic lesions in the aortic root and arch of mice was significantly reduced by cysteamine. Conclusions: These results support our hypothesis that lysosomal oxidation of LDL is important in atherosclerosis and hence antioxidant drugs that concentrate in lysosomes might provide a novel therapy for this disease

Sliding Mode Controller For Unstable Systems

The method proposed by Rojas et al.1 for the design of sliding mode controllers (SMC) for un-stable first order plus time delay systems, is extended for delay-time constant ratio () up to 1.8. The SMC settings obtained for various are fitted by simple equations. Up to = 1.2, the method is found to be more robust than that of latest PID Controller proposed by Padmasree et al.2 There is no method available in literature to stabilize unstable systems using PID controller for > 1.2. Simulation results are also given for a nonlinear bioreactor control proble

Development and characterization of water-in-water emulsion using pea protein and different gums

Water-in-water (W/W) emulsions are gaining attention for their potential applications in food and nutrition due to their unique properties, including biocompatibility and stability. However, achieving stable W/W emulsions remains challenging, requiring a careful combination of biopolymers. The present study aimed to formulate W/W emulsion using a combination of protein and polysaccharide phases. Pea protein (P) was considered for the protein phase, and locust bean gum (LBG), guar gum (GG), xanthan gum (XG) were considered for the polysaccharide phase. The protein-polysaccharide phases were mixed in 10:90, 20:80, 80:20, and 90:10 ratios to create nine W/W emulsion combinations for Pea protein-Locust bean gum (PL), Pea protein-Guar gum (PG), and Pea protein-Xanthan gum (PX) each. These 27 emulsion combinations were then characterized based on their particle size, interfacial tension, phase separation, microstructure, and rheological properties. PL-6 (60:40 ratio) exhibited the smallest particle size (0.1891 ± 0.0113 μm), lowest interfacial tensions (1.78 ± 0.071 mN/m), and superior rheological properties. The emulsion phase separation study showed that the process followed the Exponential decay model, with PL-6 having the lowest decay rate constants (k = 17.640 s⁻¹). The microstructure of the emulsions was revealed through Confocal laser scanning microscopy analysis. The results concluded that PL-6 emulsion proved highly effective for formulating a stable W/W emulsion. This research opens new possibilities for using such emulsions in various applications, particularly in food and nutritional security.

Physical Analysis of VO2 Films Grown by Atomic Layer Deposition and RF Magnetron Sputtering

Among the many vanadium suboxides and different stoichiometries, VO2 has received considerable attention due to its remarkable metal-insulator transition (MIT) behavior, which causes a significant reversible change in its electrical and optical properties occurring across the phase transition at 67°C. The initially amorphous VO2 thin films were fabricated by the emerging, Atomic Layer Deposition (ALD) technique with (tetrakis[ethylmethylamino]vanadium) {V(NEtMe)4} as precursor and H2O vapor as oxidation agent. For benchmarking we have also used the RF Magnetron Sputtering technique to deposit metallic vanadium thin films, which were later oxidized during furnace annealing. Post annealing of the as-deposited ALD films was performed in order to obtain the technologically important form of crystallized VO2 thin films using furnace annealing. All film depositions were carried out on native oxide covered (100) Si substrates. The conditions for successful furnace annealing are reported in terms of temperature and annealing gas composition and the physical characterization results are presented. (C) The Author(s) 2014. Published by ECS