Drying behaviour of Andrographis paniculata in vacuum drying

Hempedu bumi (Andrographis paniculata, AP), also known as the king of bitters, is an herb commonly found in Asian communities for medicinal usage. The drying behaviour of AP at temperatures of 40, 50, and 60°C with vacuum pressures of 10 and 30 kPa was investigated in this study. The data were then fitted with semi-theoretical and theoretical thin-layer drying models. The results reveal that the drying time is significantly (p<0.05) affected by temperature and pressure. A two-term, thin-layer model was determined as the most suitable model to fit the drying behaviour of AP. The effective diffusivity and active energy for moisture diffusion were 10-13 m2/s and 33.4 kJ/mol, respectively

Service-Driven Growth Pattern In IT Industries And Contributing Factors:A New Pattern In The Korean Industrial Development Perspective

This paper examines the pattern behind rapidly growing Korea’s IT industries. Korea has characterized economic growth based on export demand rather than domestic demand at the traditional industries such as automobile, electronics, steel, and shipbuilding etc. However, the recent development of IT industry is indicating a different aspect from traditional sectors. The rapid growth in service demand is becoming a key factor in the rapid growth and high competitiveness of IT industry. A statistical estimation testing relationship between mobile telecommunication, Internet service, and wireless equipment, computer, strongly supports service-driven growth pattern of IT industry. Strong network externalities in demand side, government’s demand promotion policies, residential environment, and users’ preferences, are main contributing factors to this new growth pattern

Modeling Multilevel Structures of Information Technology Acceptance: An Investigation of Group Level Effects on Individual Usage of Web-Based Systems

Despite the sizable and continually increasing amount of investment in information technology (IT), IT often falls short of realizing its expected benefits due to inadequate user acceptance. Understanding the key factors that facilitate user acceptance of IT is an issue that has considerable practical implications. While much research effort has been directed to investigating the effects of various variables operating at the individual level, little effort has been made to modeling and assessing the effects of group level variables on individual usage behavior. Our study addresses this issue by proposing a multilevel model composed of individual level variables and group level variables, integrating the Unified Theory of Acceptance and Use of Technology model with Resource-Based Theory. Research hypotheses derived from this integrative model will be empirically validated in a field study setting involving college students who use a Web-based system over a 12-week period. The proposed model will be tested using a hierarchical linear modeling approach, which is specifically designed to examine multilevel data structures. The findings are expected to provide important insights into the dynamic interplay between individual level variables and group level variables and their joint effects on individual acceptance of IT

Verifying Empirical Predictive Modeling of Societal Vulnerability to Hazardous Events: A Monte Carlo Experimental Approach

With the emergence of large amounts of historical records on adverse impacts of hazardous events, empirical predictive modeling has been revived as a foundational paradigm for quantifying disaster vulnerability of societal systems. This paradigm models societal vulnerability to hazardous events as a vulnerability curve indicating an expected loss rate of a societal system with respect to a possible spectrum of intensity measure (IM) of an event. Although the empirical predictive models (EPMs) of societal vulnerability are calibrated on historical data, they should not be experimentally tested with data derived from field experiments on any societal system. Alternatively, in this paper, we propose a Monte Carlo simulation-based approach to experimentally test EPMs of societal vulnerability. Our study applied an eigenvalue-based method to generate data on societal experiences of IM and pre-event vulnerability indicators. True models were designed to simulate event loss data. Supervised machine learning (ML) models were then trained on simulated data and were found to provide similar predictive performances as the true models. Our results suggested that the calibrated ML-EPMs could effectively quantify societal vulnerability given a normally experienced IM. To extrapolate a vulnerability curve for large IMs, however, simple models should be preferred

High temperature, gate-free quantum anomalous Hall effect with an active capping layer

Quantum anomalous Hall effect (QAHE) was discovered a decade ago, but is still not utilized beyond a handful of research groups, due to numerous limitations such as extremely low temperature, electric field-effect gating requirement, small sample sizes and environmental aging effect. Here, we present a robust platform that provides effective solutions to these problems. Specifically, on this platform, we observe QAH signatures at record high temperatures, with the Hall conductance of 1.00 e2/h at 2.0 K, 0.98 e2/h at 4.2 K, and 0.92 e2/h at 10 K, on centimeter-scale substrates, without electric-field-effect gating. The key ingredient is an active CrOx capping layer, which substantially boosts the ferromagnetism while suppressing environmental degradation. With this development, QAHE will now be accessible to much broader applications than before.Comment: 20 pages, 8 figures, Accepted for publication in Nano Letters, https://pubs.acs.org/doi/full/10.1021/acs.nanolett.3c0131

Second harmonic optical coherence tomography

Second harmonic optical coherence tomography, which uses coherence gating of second-order nonlinear optical response of biological tissues for imaging, is described and demonstrated. Femtosecond laser pulses were used to excite second harmonic waves from collagen harvested from rat tail tendon and a reference nonlinear crystal. Second harmonic interference fringe signals were detected and used for image construction. Because of the strong dependence of second harmonic generation on molecular and tissue structures, this technique offers contrast and resolution enhancement to conventional optical coherence tomography.Comment: 3 pages, 5 figures. Submitted on November 8, 2003, this paper has recently been accepted by Optics Letter

Current Advances in Retroviral Gene Therapy

There have been major changes since the incidents of leukemia development in X-SCID patients after the treatments using retroviral gene therapy. Due to the risk of oncogenesis caused by retroviral insertional activation of host genes, most of the efforts focused on the lentiviral therapies. However, a relative clonal dominance was detected in a patient with β-thalassemia Major, two years after the subject received genetically modified hematopoietic stem cells using lentiviral vectors. This disappointing result of the recent clinical trial using lentiviral vector tells us that the current and most advanced vector systems does not have enough safety. In this review, various safety features that have been tried for the retroviral gene therapy are introduced and the possible new ways of improvements are discussed. Additional feature of chromatin insulators, co-transduction of a suicidal gene under the control of an inducible promoter, conditional expression of the transgene only in appropriate target cells, targeted transduction, cell type-specific expression, targeted local administration, splitting of the viral genome, and site specific insertion of retroviral vector are discussed here

Toward an Integrative Understanding of Information Technology Training Research across Information Systems and Human-Computer Interaction: A Comprehensive Review

Researchers investigating issues in the domain of training and human-computer interaction share a common interest in ensuring that users are skilled in the use of Information Technologies (IT). When users have the necessary skills, they can utilize IT productively and also have a pleasant human-to-computer interaction. Over the past three decades, Information System (IS) researchers have made considerable efforts in identifying the most effective ways to develop users’ IT skills. However, at this point in time, there are many changes taking place in the IT environment and organizations find it challenging to keep their employees trained and updated on IT skills. Hence, it is important for the IS community to respond by taking the lead in identifying and conducting research that can help organizations effectively address these challenges. We take the first step in conducting a comprehensive review of training research published in major IS and HCI journals over the past three decades so as to synthesize IT training research, provide an integrative understanding of findings, and propose directions for future research. Our study indicates that while IS research on training has made steady progress in advancing our understanding of alternative IT training methods and cognitive learning processes, it also has several shortcomings. Past research has: a) focused primarily on the training program without sufficient attention to activities prior to and after the program, b) used a small set of theoretical foundations, and c) focused on a few topics and on single-user systems rather than integrated enterprise systems. Critical issues such as improving user motivations prior to training, transfer of training skills to the workplace, assessment of training, and supporting user learning that occurs after training have not been given adequate attention. We identify several research opportunities by tapping into relatively unexplored theories and urge researchers to continue research to address the gaps identified in this comprehensive review as well as to develop innovative methods to help employees learn through newer channels, such as e-learning and social media