Delignification kinetics of empty fruit bunch (EFB): a sustainable and green pretreatment approach using malic acid-based solvents

Recently, the development of efficient and environmentally benign solvents has received great attention to replace current harsh organic solvents. In this context, low-transition-temperature mixtures (LTTMs) have emerged as favorable green solvents for biomass delignification. Palm oil biomass, empty fruit bunch (EFB) was pretreated with commercial l-malic acid and microwave hydrothermally extracted cactus malic acid-derived LTTMs at 60, 80, and 100 °C. The LTTMs applied in this study were derived from malic acid–choline chloride–water and malic acid–monosodium glutamate–water with a molar ratio of 2:4:2 and 3:1:5, respectively. Three first-order reactions were used to express the delignification kinetic model of EFB. The first term was based on the initial stage and assigned as infinite due to the fast rate of delignification which could not be detected. The second and third terms were proportional to bulk and residual delignification stages. A good agreement was obtained between the kinetic model and the experimental data obtained in this study with R²?≥?0.91. The activation energies for the delignification reactions using l-malic acid and cactus malic acid-based LTTMs in the bulk and residual stages were approximated as 36–56 and 19–26 kJ/mol and 34–90 and 47–87 kJ/mol, respectively.     

Structural Studies of DNA–Cationic Lipid Complexes Confined in Lithographically Patterned Microchannel Arrays

We have used lithographically patterned microchannel arrays with channel widths ranging from 1 to 20 m, fabricated using electron beam lithography and reactive ion etching, in structural studies of DNA–cationic lipid complexes in confinement. Various techniques have been developed for loading these DNA–membrane complexes into the microchannels or to form the complexes in situ by sequentially depositing DNA and lipid solutions into the microchannels. Optical microscopy studies indicate that such complex formation is strongly influenced by the periodic channel structure even at channel widths much larger than the persistent length of the DNA molecules. Preliminary x-ray diffraction experiments conducted at Stanford Synchrotron Radiation Laboratory (SSRL) yielded only a weak signal from the lipid bilayers in the complexes. The use of a microfocused x-ray beam produced by the newly developed Bragg–Fresnel optics at a third-generation synchrotron facility may dramatically increase the signal-to-noise ratio and allow observation of orientational as well as positional ordering of DNA molecules induced by the microchannels. Structural control of the DNA–membrane complexes has a broad range of potential applications in gene probe technology and as mesoscopic biomolecular composites.     

A novel polymer microneedle fabrication process for active fluidic delivery

In this article, we explore a new fabrication process for a flexible, all polymer, active fluidic delivery system, incorporating a fusion of laser micromachining and microfabrication techniques as well as rapid prototyping technology. Here, we show selective fluidic delivery from isolated microchannels through an electrochemically driven pumping reaction, demonstrate the dispensing of dose volumes up to 5.5 μl, and evaluate the device’s performance in terms of its delivery speed and ejection efficiency. Finally, we move this work toward an implantable microfluidic drug delivery device by investigating the device’s biocompatibility through a statistical approach that overviews the viability of bovine aortic endothelial cells on polyimide and silicon substrates.     

Organizational impact of system quality,information quality,and service quality

Increased organizational dependence on information systems drives management attention towards improving information systems’ quality. A recent survey shows that “Improve IT quality” is one of the top concerns facing IT executives. As IT quality is a multidimensional measure, it is important to determine what aspects of IT quality are critical to organizations to help Chief Information Officers (CIOs) to devise effective IT quality improvement strategies. In this research, we model the relationship between information systems’ (IS) quality and organizational impact. We hypothesize greater organizational impact in situations in which system quality, information quality and service quality are high. We also hypothesize a positive relationship between system quality and information quality. We test our hypotheses using survey data. Our structural equation model exhibits a good fit with the observed data. Our results show that IS service quality is the most influential variable in this model (followed by information quality and system quality), thus highlighting the importance of IS service quality for organizational performance. This paper contributes theoretically to IS success models through the system quality-to-information quality and IS quality-to-organizational impact links. Implications of our results for practice and research are discussed.     

Assessment of working conditions in two different semiconductor manufacturing lines: Effective ergonomics interventions

This article examines two manufacturing lines producing semiconductors using different technology concepts, namely Conventional Line (CL) and Lean Production Line (LPL). Both lines manufacturing the same products were compared using various factors, including working conditions, task risks and dangers of the job, and physical body stress. Ergonomic approaches were adopted in the investigation of the two lines. Survey questionnaires were administered to 30% of the workers, and multiple statistical tests were used to determine crucial predictors and to investigate the interactions between the factors. This research has shown that improved ergonomics factors will lead to better working conditions and thus increased job satisfaction. The observed ergonomic differences of these two production lines are compared, and appropriate managerial remedial action is recommended. The interventions to both the lines should reduce accident rates, minimize waste of resources, improve work effectiveness, and provide a better working environment that enhances employees' morale and maximizes productivity and profits. © 2010 Wiley Periodicals, Inc.     

Autonomous topological modeling of a home environment and topological localization using a sonar grid map

This paper presents a method of autonomous topological modeling and localization in a home environment using only low-cost sonar sensors. The topological model is extracted from a grid map using cell decomposition and normalized graph cut. The autonomous topological modeling involves the incremental extraction of a subregion without predefining the number of subregions. A method of topological localization based on this topological model is proposed wherein a current local grid map is compared with the original grid map. The localization is accomplished by obtaining a node probability from a relative motion model and rotational invariant grid-map matching. The proposed method extracts a well-structured topological model of the environment, and the localization provides reliable node probability even when presented with sparse and uncertain sonar data. Experimental results demonstrate the performance of the proposed topological modeling and localization in a real home environment.     

Case-based expert system using wavelet packet transform and kernel-based feature manipulation for engine ignition system diagnosis

Whenever there is any fault in an automotive engine ignition system or changes of an engine condition, an automotive mechanic can conventionally perform an analysis on the ignition pattern of the engine to examine symptoms, based on specific domain knowledge (domain features of an ignition pattern). In this paper, case-based reasoning (CBR) approach is presented to help solve human diagnosis problem using not only the domain features but also the extracted features of signals captured using a computer-linked automotive scope meter. CBR expert system has the advantage that it provides user with multiple possible diagnoses, instead of a single most probable diagnosis provided by traditional network-based classifiers such as multi-layer perceptions (MLP) and support vector machines (SVM). In addition, CBR overcomes the problem of incremental and decremental knowledge update as required by both MLP and SVM. Although CBR is effective, its application for high dimensional domains is inefficient because every instance in a case library must be compared during reasoning. To overcome this inefficiency, a combination of preprocessing methods, such as wavelet packet transforms (WPT), kernel principal component analysis (KPCA) and kernel K-means (KKM) is proposed. Considering the ignition signals captured by a scope meter are very similar, WPT is used for feature extraction so that the ignition signals can be compared with the extracted features. However, there exist many redundant points in the extracted features, which may degrade the diagnosis performance. Therefore, KPCA is employed to perform a dimension reduction. In addition, the number of cases in a case library can be controlled through clustering; KKM is adopted for this purpose. In this paper, several diagnosis methods are also used for comparison including MLP, SVM and CBR. Experimental results showed that CBR using WPT and KKM generated the highest accuracy and fitted better the requirements of the expert system.     

Qualitative findings of students’ perception on practice of self-regulated strategies in online community discussion

With rapid emergence to the birth of the knowledge era, an active and interactive learning environment is fundamental to any teaching and learning process. Over time, negative implications of traditional learning environment are mounting, and measures must be taken to challenge it. With extensive research on available learning tools, it has become more feasible to provide our students with better learning opportunities. Such was the anticipation in the Malaysian educational context. Hence, this paper aims to address qualitative findings of a study on self-regulated learning strategies conveyed through the proposed interactive e-learning community (iELC). In duration of eight weeks, students (n = 50) from regular national secondary schools were subjected to online learning tasks aimed to advance strategies on self-regulated learning. To date, strategies of self-regulated learning have been perceived as key to learner to succeed academically and after the schooling years. By means of semi-structured interview, data were collected from small group and one-to-one perception. Results were directed at the overall development of self-regulated learning strategies and its diffusion in the iELC discussion platform. Conclusively, these findings add significantly to the understanding of self-regulated learning strategies in an online learning environment.