Highly compatible wood thermoplastic composites from lignocellulosic material modified in ionic liquids: Preparation and thermal properties

A study of converting chemically modified wood into thermoplastic materials was undertaken to develop a new technology platform for the effective utilization of wood‐based lignocellulosic materials. Highly substituted benzoylated spruce thermomechanical pulp (TMP) and lauroylated spruce TMP were used as components for thermoplastic composites of poly(styrene) and poly(propylene). Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA) were used to characterize the interfacial morphology and thermal properties of the resultant composite filaments. The coupling of the interfacial morphology effort and that of torque analysis applied during processing indicated that the thorough modification of wood fibers by benzoylation and/or lauroylation reactions can improve the compatibility between the wood‐based lignocellulosic materials and poly(styrene) and poly(propylene). Thermal analysis showed that, with the addition of wood derivatives into poly(styrene) and poly(propylene) matrices, a slight decrease in their T_gs was observed. Furthermore, all of the prepared composites showed improved thermal stability, as revealed by TGA. The resultant thermoplastic wood composites exhibited good melting properties and were readily extruded into filaments or sheets. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Energy harvesting with a cymbal type piezoelectric transducer from low frequency compression

In this paper a piezoelectric energy harvester based on a Cymbal type structure is presented. A piezoelectric disc ?35?mm was confined between two convex steel discs ?35?mm acting as a force amplifier delivering stress to the PZT and protecting the harvester. Optimization was performed and generated voltage and power of the harvester were measured as functions of resistive load and applied force. At 1.19?Hz compression frequency with 24.8?N force a Cymbal type harvester with 250?μm thick steel discs delivered an average power of 0.66?mW. Maximum power densities of 1.37?mW/cm³ and 0.31?mW/cm³ were measured for the piezo element and the whole component, respectively. The measured power levels reported in this article are able to satisfy the demands of some monitoring electronics or extend the battery life of a portable device.     

Experimental compaction characterization of unidirectional stitched noncrimp fabrics in the vacuum infusion process

In this study, experimental test equipment developed in‐house was used to study the compaction behavior of stitched quasi‐unidirectional (UD) non‐crimp fabrics (NCF) during the pre‐filling, filling, and post‐filling stages of the vacuum infusion (VI) process. The effects of the stitch pattern, stitch tension, and fiber sizing of reinforcements, as well as the effect of nesting of fiber bundles in neighboring layers, were studied. Moreover, the effects of cyclic compaction, resin viscosity, and different post‐filling strategies were studied. The developed experimental test equipment provided an applicable measuring method for characterizing the compaction behavior of both the dry and resin‐impregnated reinforcements. The effects of the stitching parameters and fiber nesting of reinforcements were found. The stitch pattern and post‐filling strategies were noted to have an effect on the preform and laminate thickness. POLYM. COMPOS., 37:2692–2704, 2016. © 2015 Society of Plastics Engineers     

Study on process parameters in metallocene polymerizations,I. Apparent viscosity and macro-scale mass transfer

A heat balance reaction calorimeter was used to obtain information about the most informative process parameters in polymerizations carried out with Et[Ind]₂ZrCl₂-methylaluminoxane catalyst. The viscosity of the reaction mixture was found to increase dramatically during the homopolymerization of ethylene, but it could be controlled through appropriate selection of the reaction mixture medium. The mass transfer between the gas and liquid phases was the rate-determining step for the polymerization when the reaction mixture-based Reynolds number was below 2.500. The limited mass transfer between the gas and liquid phases was caused by the intensive activity of the metallocene catalyst and the increased viscosity of the reaction mixture.     

Bioavailability Studies and in vitro Profiling of the Selective Excitatory Amino Acid Transporter Subtype 1 (EAAT1) Inhibitor UCPH‐102

Although the selective excitatory amino acid transporter subtype 1 (EAAT1) inhibitor UCPH‐101 has become a standard pharmacological tool compound for in vitro and ex vivo studies in the EAAT research field, its inability to penetrate the blood–brain barrier makes it unsuitable for in vivo studies. In the present study, per os (p.o.) administration (40 mg kg^?1) of the closely related analogue UCPH‐102 in rats yielded respective plasma and brain concentrations of 10.5 and 6.67 μm after 1 h. Three analogue series were designed and synthesized to improve the bioavailability profile of UCPH‐102, but none displayed substantially improved properties in this respect. In vitro profiling of UCPH‐102 (10 μm ) at 51 central nervous system targets in radioligand binding assays strongly suggests that the compound is completely selective for EAAT1. Finally, in a rodent locomotor model, p.o. administration of UCPH‐102 (20 mg kg^?1) did not induce acute effects or any visible changes in behavior.     

Keeping secure to the end: a long-term perspective to understand employees’ consequence-delayed information security violation

Employees’ violation of information security policies is a major threat to an organisation. Some violations such as using an easy-to-guess password or storing confidential data on personal unencrypted flash drives usually do not cause immediate harm; instead, these actions create security flaws that can be attacked in the future and cause delayed consequences. We call such behaviour consequence-delayed information security violation (CDISV). The ignorance or denial of the possible delayed consequences is the main reason employees engage in such insecure behaviour. Due to the delay between the action and the consequence, a long-term mindset could play an important role in employees’ current decision-making. Specifically, in this study, we propose that long-term orientation is an influential factor in decreasing CDISV. The long-term orientation includes three dimensions: continuity, futurity, and perseverance. In addition, based on the stewardship theory and the needs theory, we further propose that value identification and the fulfilment of higher-order needs (trusted relationship and growth) are important drivers for employees to have a long-term orientation. We collected survey data using the 170 responses we received from a global company’s employees. The empirical results support our arguments. Our findings provide implications to organisations to encourage employees’ information security behaviours.     

Dynamical modelling of peak-current-mode-controlled converter in continuous conduction mode

Peak-current-mode (PCM) control has been a popular control method of switched-mode converters since its publication in late 1970s due to the inherent features it provides especially in buck derived converters such as high input-noise attenuation, first-order control dynamics as well as cycle-by-cycle current limiting. Its main disadvantages are considered to be the limited duty ratio, increased output impedance, and noise sensitivity due to the fast feedback-current loop. The observed peculiar dynamical behaviour associate to the PCM control has attracted the researchers for tens of years yielding multitude of dynamical modelling approaches. Application of sampling effect as the basis for the modelling has been considered to producing most accurate dynamical models as well as explanations for the observed phenomena. A consistent and easy-to-apply modelling approach is presented in this paper, which explains the observed dynamical phenomena, provides accurate dynamical power-stage models as well as comply with the other methods proposing the existence of an infinite small-signal duty-ratio gain leading to the observed behaviour. Experimental evidence is provided based on second and fourth-order buck converters.     

The movement patterns and the experiential components of virtual environments

Human movement in virtual environments (VEs) is a largely unstudied area, and there are no well-established methods of measuring it in VEs. Consequently, it is unclear how movement affects the experiential side of VEs. We introduce a novel method of measuring and modelling human movement. A specific information entropy-based modelling method enabled us to identify different movement patterns and analyse the experiential components related to them. The data was collected by registering the movement patterns of 68 participants who were in a virtual house doing a search task. The experiential side of the VE was measured with the Experimental Virtual Environment Questionnaire (EVEQ). Four movement patterns were identified. In addition, fluent movement in VEs was related to a high sense of presence. Moreover, the participants who moved fluently in the environment assessed their skills high. The results show how movement is related the way in which people experience the VE. The movement analysis method introduced here is applicable to other related research areas as well.     

What levels of moral reasoning and values explain adherence to information security rules? An empirical study

It is widely agreed that employee non-adherence to information security policies poses a major problem for organizations. Previous research has pointed to the potential of theories of moral reasoning to better understand this problem. However, we find no empirical studies that examine the influence of moral reasoning on compliance with information security policies. We address this research gap by proposing a theoretical model that explains non-compliance in terms of moral reasoning and values. The model integrates two well-known psychological theories: the Theory of Cognitive Moral Development by Kohlberg and the Theory of Motivational Types of Values by Schwartz. Our empirical findings largely support the proposed model and suggest implications for practice and research on how to improve information security policy compliance.     

Mixed preconditioners for harmonic balance Jacobians

Preconditioning is crucial for the convergence of GMRES iteration in the Harmonic Balance analysis of RF and microwave circuits. In this article, mixed frequency/time‐domain preconditioners for harmonic balance Jacobians are presented. The efficiency of mixed preconditioners is demonstrated with realistic simulation examples. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.