Laboratory study of sonic booms and their scaling laws

This program undertook to seek a basic understanding of non-linear effects associated with caustics, through laboratory simulation experiments of sonic booms in a ballistic range and a coordinated theoretical study of scaling laws. Two cases of superbooms or enhanced sonic booms at caustics have been studied. The first case, referred to as acceleration superbooms, is related to the enhanced sonic booms generated during the acceleration maneuvers of supersonic aircrafts. The second case, referred to as refraction superbooms, involves the superbooms that are generated as a result of atmospheric refraction. Important theoretical and experimental results are briefly reported

Understanding the Thermal Stability and Environmental Sensitivity of Phycocyanin using Spectroscopic and Modelling Tools

Phycocyanin (PC), a pigment-protein conjugate from Arthrospira platensis, is increasingly used in foods as a natural alternative to artificial blue dyes. Although PC has been classified as a color additive exempt from certification by the Food and Drug Administration, its limited stability has hindered its widespread application in food products. The objectives of this study were: a) to evaluate the photophysical properties of PC and their sensitivity to temperature, viscosity, and water activity, b) to monitor PC’s thermal degradation based on changes in the optical properties of its intrinsic fluorophores, namely its chromophores and aromatic amino acids, and c) to extract PC’s thermal degradation kinetics parameters from non-isothermal degradation profiles and validate their predictive ability. PC’s photophysical properties were monitored in solutions with viscosities from 1 to8000 mPa s and water activities, aw, from about 0 to 1. PC’s emission intensity showed high sensitivity to aw above 0.8 and mild sensitivity to the viscosity of its local environment. The effect of temperature on PC’s photophysical properties was tested in aqueous PC solutions (0.5 mM, pH: 6.1) subjected to non-isothermal temperature profiles with target temperatures from 42.5 to 80°C. The stability of PC was monitored in terms of its photophysical properties, i.e., fluorescence emission intensity, energy, and anisotropy (r) of its chromophore at set time intervals. Additionally, the photophysical properties of PC’s aromatic amino acids (AAs) tyrosine and tryptophan (lexc: 280 and 295 nm) were recorded. The thermal degradation kinetics of PC was assumed to follow a Weibullian model, and the temperature dependence of the degradation rate parameter, b(T), a logarithmic exponential model. Changes of PC fluorescence intensity under dynamic conditions were used to extract the degradation kinetics parameters using the endpoints method. Deviations between the estimated and experimental values were less than 10% for all temperature profiles. During thermal treatments, hypsochromic shifts of AAs’ emission spectra (from 340 to 315 nm) and significant increases in fluorescence anisotropy revealed that color losses were not solely associated with an alteration of the chromophore but with conformational changes and possible aggregation of the protein subunits. An increase in viscosity of the surrounding media provided a protected effect on discoloration during heating. Adequate modeling approaches and molecular spectroscopic techniques can help to develop effective strategies to enhance thermal stability, expand its use as a color and functional ingredient and operationalize it as an endogenous sensor of food quality

Institutional Repositories in the Indonesian Higher Education Sector: Current State and Future Prospect

This research aims to provide the first detailed survey of various aspects of institutional repositories serving Indonesia’s higher education sector. This includes establishing the current state of implementation of repositories and their major characteristics, and assessing their future potential. The study adopts a mixed-methods research strategy. Methods employed are: 1) a longitudinal content analysis of university repository websites; 2) an online survey of Indonesian academics; and 3) interviews with stakeholders in three Indonesian universities

Interpretation of atmospheric emission spectra near 1-cm wavelength

Passive microwave meteorology techniques for measuring water vapor densities and cloud water conten

Assessment of BioPattern in Novel Idea Generation for Bio-Inspired Design

BioPattern is a novel ideation tool for Bio-Inspired Design, built based on TRIZ, SAPPhIRE, and pattern language. It consists of an ontology, known as pattern-based ontology, and a sustainability evaluation, known as Ideal Windows. However, this framework has not been tested yet. Therefore, this article is to present the results and analysis of the case study conducted to assess this biomimicry framework. Two different groups of students, Creative & Innovation class (controlled group) and Integrated Engineering Design class (experimental group), are asked to generate innovative ideas where the experimental group employed BioPattern as the ideation tool. It is found that the level of innovation for the inventive ideas generated by the experimental group is much higher compared to that of the controlled group. Based on the inventive ideas produced by the experimental group, BioPattern is found to be efficient in ideation, able to generate effective solution, the problem-solution pairs of the ontology are adequate, and the biological solutions suggested are transferable as technological solutions. It can be concluded that BioPattern is able to bridge the biology-engineering gap

Replication of a Malaysian Strain Avian Influenza A Virus H5N1 in Madin-Darby Canine Kidney and African Green Monkey Kidney cells

The use of cell lines such as Madin-Darby Canine Kidney (MDCK) and African Green Monkey Kidney (Vero) cells in influenza vaccine production is much advocated presently as a safer alternative to chicken embryonated eggs. It is thus essential to understand the influenza virus replication patterns in these cell lines prior to utilizing them in vaccine production. The infectivity of avian influenza A virus (A/Chicken/Malaysia/5858/2004) H5N1 in MDCK and Vero cell lines was first assessed by comparing the cytopathic effect (CPE) caused by the virus infection. The viral loads in both of the infected media and cells were also compared. The results showed that both of the MDCK and Vero cells began to exhibit significant CPE (p<0.05) after 48 h post-infection (h p.i). The MDCK cell line was more susceptible to the virus infection compared to Vero cell line throughout the incubation period. A higher viral load was also detected in the host cells compared to their respective culturing media. Interestingly, after reaching its maximum titer at 48 h p.i, the viral load in MDCK cells declined meanwhile the viral load in Vero cells increased gradually and peaked at 120 h p.i. Overall, both cell lines support efficient H5N1 virus replication. While the peak viral loads measured in the two cell lines did not differ much, a more rapid replication was observed in the infected MDCK samples. The finding showed that MDCK cell line might serve as a more time-saving and cost-effective cell culture-based system compared to Vero cell line for influenza vaccine production

A study of best management practices for enhancing productivity in building projects: construction methods perspectives

This research investigates management practices that have the potential to enhance productivity in building projects by focusing on construction methods. In phase 1 of the study, face-to-face interviews with nineteen experts were conducted to identify the best management practices for construction methods. The qualitative data analysis reached saturation and resulted in a list of best practices for construction methods that are relevant to the local industry. The second phase used an industry-wide survey to prioritize the best practices. Accordingly, project start-up plan, traffic control plan, machinery positioning strategy, project completion plan, and dynamic site layout plan were shown to be the top five best practices for construction methods. The study also revealed that high levels of implementation of best practices are associated with low levels of project delays. The use of best practices also varied according to the project costs. There were no discernible differences between the top five best practices. The authors suggest that they should be implemented jointly to improve productivity in building projects. Contractors could use the logistic regression model developed, to predict the probability of exceeding a baseline productivity factor and, on that basis, implement corrective actions to achieve the desired level of productivity

Clearing the complexity: immune complexes and their treatment in lupus nephritis

Systemic lupus erythematosus (SLE) is a classic antibody-mediated systemic autoimmune disease characterised by the development of autoantibodies to ubiquitous self-antigens (such as antinuclear antibodies and antidouble-stranded DNA antibodies) and widespread deposition of immune complexes in affected tissues. Deposition of immune complexes in the kidney results in glomerular damage and occurs in all forms of lupus nephritis. The development of nephritis carries a poor prognosis and high risk of developing end-stage renal failure despite recent therapeutic advances. Here we review the role of DNA-anti-DNA immune complexes in the pathogenesis of lupus nephritis and possible new treatment strategies aimed at their control