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Statistical medium optimization for enhancing high biomass production of Lactobacillus reuteri using response surface methodology
No full textThe high cell mass production of probiotic lactic acid bacteria using low-cost substrate is critical for successful large-scale production. Lactobacillus reuteri DSM20016T is a heterofermentative lactic acid bacterium that is well recognized for its probiotic properties. Defining an optimal cultivation medium could enhance the yield and reduce the production cost as well. In this paper, seven media reported in the literature were reviewed and assessed for their capability to be used as a growth medium of L. reuteri. The most appropriate cultivation medium for L. reuteri, which has reached the best cell mass yield, annotated M5, was selected. The selected medium from the screening stage was optimized using response surface methodology (RSM). The optimized medium composition was (gL-1): sucrose (55), yeast extract (44), sodium acetate (2.6), tri-ammonium citrate (0.2), KH2PO4 (0.2), Mg SO4 (0.2), Mn SO4 (0.05), and NaCl (0.01). The comparative study showed 28% increase was achieved in the optimized medium with the yield of 3.31 gL-1 compared to the cell mass production in the unoptimized medium that was 2.59 gL-1. A significant cell mass growth rate accompanied the achieved increment. Finally, an optimum medium was proposed for enhanced cell mass production
Metal based passive saturable absorber embedded in chitin host polymer
Get PDFPulse fiber laser is used in many applications such as those in high-speed communication, optical imaging, laser machining and fiber optic sensing. This is due to its simple setup, compact geometry, zero alignment configuration and cost-saving nature. Passive Q-switching is a technique to produce pulse fiber laser. Saturable absorbers play important roles in passive Q-switching technique. Research works on materials for saturable absorbers (SAs) have been conducted for decades. Saturable absorbers began with dyes or coloured glasses. Currently, Two-Dimensional (2D) materials are employed as the SA for the Q-switching. Metal-based SAs like gold, silver and copper are reported to exhibit excellent optical properties. However, reports on copper-based SA are still scarce despite their ultrafast response time, broad operation spectrum, and large third-order nonlinearity. Previously, researchers employed physical vapor deposition and chemical reduction that had drawbacks like using expensive methods, generating low volume of materials, and having issues such as toxicity, high cost, and impurities with reducing agents. Therefore, this study used three types of metal which were copper, aluminium, and brass. Three-dimensional filament was used to simplify the fabrication process of these metals. To do this, bio-compatible host polymer, materials characterisation, and the implementation in pulse fiber laser within a 1.5 μm region were employed. The three-dimensional metal filament was combined with metal: chitin as the bio compatible host polymer with a ratio of 1:4, 1:1.5 and 1:1. Regarding the performance of the SAs, the lowest threshold pump power for the passive Q-switching technique was obtained by copper-chitin 1:1 with 38.7mW. Meanwhile, the highest repetition rate and the lowest pulse width was by brass-chitin 1:4 with 165.60 kHz and 3.46 μs respectively. Besides, the highest signal to noise ratio (SNR) was 80.18 dB by copper-chitin 1:1. Finally, the SAs utilised were stable to produce pulse lasers through passive Q-switching, with the lowest SNR value of 64 dB
Effect of span length on the seismic design modification factors of steel frames with high ductility
Get PDFSeismic design modification factors (SDMFs) control the estimated force and displacement to structures during seismic events. Seismic design codes recommend similar SDMFs for short andlong-span structures. Therefore, this study investigated the effect of span length on the SDMFs of steel frames with high ductility. For this purpose, nine steel frames with three different span lengths of 5, 10, and 15 m were selected and designed according to the specifications of ASCE/SEI 7-16. The designed structures were single, double, and three-story frames. The obtained results showed that the values of response modification factor (R), overstrength factor (O), and deflection amplification factor (Cd) were increased as the span length was increased. Besides, an increase in the number of stories decreased the value of R and O-factors. It was concluded that the inelastic displacement of long-span steel frames might be underestimated if the given Cdvalues in the seismic design code were used
CMAR: A conceptual framework for designing mobile augmented reality learning module for construction measurement
No full textAugmented Reality (AR) is a technology that allows two- or three-dimensional computer-generated graphics, objects, and information to be displayed as an overlay onto the real environment. With the advancement of mobile devices in term of their sensors (gyroscope, barometer, accelerometer, proximity sensor, camera module), displays and processing power, the potential of using mobile AR in teaching and learning (T&L) is becoming clearer. Construction measurement subject is considered the core subject for a quantity surveying student to master. However, some of the measured elements are difficult for students with low spatial skills to visualize the construction sequence and understand. Therefore, the use of AR would help in enhancing the T&L experience of construction measurement for the students. This paper aims to propose a conceptual framework for designing a mobile AR learning module for construction measurement subject. The Construction Measurement Augmented Reality (CMAR) framework consist of the learning theory, learning content, features and learning outcome
Architectural value in tanggam System on the traditional Malay house
No full textIn to preserve this great heritage, the Centre for the Study of Built Environment in the Malay World (KALAM) has collected more than 600 buildings, mostly using the tanggam system. Malay house construction has an architectural value especially on the system used. Besides, features of traditional Malay houses can be refined from their spatial structure, function rooms that make up the various rituals and customs as well as artistic carvings on them. Interestingly, the construction of the traditional Malay house is measured using the human body scale. In general, the height of the housing is according to the size of the man’s body (husband) while the area and size of the house are preferred by the size of the woman’s (wife) hand. Other than that, construction of Malay traditional houses according to local customs. Most of the traditional Malay houses using wood in construction with the unique method by applying the tanggam. ‘Tanggam’ system is a method of joining woods (Sabil and Uterberta in Adv Mater Res 984–987, 2011). According to the understanding of Malays, tanggam means wooden building frame assembly in the experimental stage. The full pronunciation is ‘tanggam-menanggam’, while the tanggam means insert and match. The function of the use of tanggam is notched wood joints so close and sturdy (DBP in https://prpm.dbp.gov.my/cari1?keyword=tanggam ). This system is shown the least exposed and documented as a reference in the construction of Malay traditional houses. Based on the material in KALAM, this study will provide exposure related to the types of tanggam as well as their installation methods. The purpose of the tanggam is to connect wooden structures, strengthen the construction, maintain the aesthetic nature of the building and it makes it easier for craftsmen to sew and remove the construction because no nails are used. The researchers will share about the construction of traditional houses belong to Daeng Haddadek bin Kafitang Wallingah located in Johor, Malaysia. The original study of this house was from a group of Universiti Teknologi Malaysia researchers to study and record information related to this architecture in the year 2011. The study began with a qualitative method that is by observation of the house. Then, a group of researchers obtained information by conducting interview sessions with owners, local communities, and local authorities. Next, they prepared a measurable drawing of the building. Therefore, the study was continued by a group of new researchers who have expertise in the field of architectural structure as well as evaluating its architectural value in this paper at the same time sharing the available data as a reference to government agencies, private agencies, stakeholder, researchers and others
Interactive distance learning for virtual capacity building development intra-pandemic experiences: A case of Mooc UTM-PORSEC
No full textIn the wake of the current COVID-19 pandemic, most face-to-face activities have been restricted including the scientific program such as capacity building. This, in turn, requires rapid redesign of capacity building implementation during the pandemic period. Hence, this study aims at organizing a virtual capacity building for early-career scientists as an alternative to traditional setting which requires face-to-face interaction. This virtual capacity building focuses on the use of remote sensing for effective monitoring of ocean climate resilience. This program was developed using Massive Open Online Course (MOOC) under UTM Open Learning platform which is known as MOOC on Ocean Remote Sensing towards Climate Resilience. A total of 26 international participants successfully participated in this MOOC UTM-PORSEC. This virtual program contains 14 modules that were conducted by experienced instructors in the field of ocean remote sensing. The program evaluation has shown that the overall Programme Learning Outcomes have scored above 70%. Furthermore, 88% of the MOOC-PORSEC participants have completed all the course content, assignments and quizzes. The developed virtual capacity building has provided a new digital learning experience as well as it saves the cost of travelling and time at the expense of physical interaction
Spatio-temporal wave pattern using multi-dimensional clustering method for exploring ocean energy potential
Get PDFWave is formed from the movement of air caused by pressure variations that make airflow move from high pressure toward places of low pressure. Understanding the wave patterns is challenging since it is highly changeable in space as they travel in variety of directions and heights. Wave are also changing over time especially during the monsoon seasons. Hence, to extract significant information from this highly changeable behaviour of wave this study has utilized a multi-dimensional clustering technique called co-clustering. This technique is able to cluster spatio-temporal data with similar behavior into spatial and temporal components simultaneously. To reveal the spatial and temporal patterns, an algorithm called Bregman Block Average co-clustering with I-divergence (BBAC_I) has been implemented for extracting wave patterns. In order to discover the wave behaviour, the extracted wave patterns were visualized in the form of heatmap that contain information of co-clusters; spatial clusters and temporal clusters dimensions. Then, both spatial and temporal clusters from the heatmap were transformed into geographical maps to depict the variation of wave patterns based on their individual dimension. From these maps, we could observe the distribution of 8 different group of clusters that representing the spatial wave patterns. Furthermore, 5 individual maps have been produced to depict the temporal wave patterns across the study area. Finally, the obtained maps were interpreted in the form of wave height which were found to be within 0.4 to 1.4 m heights. The wave height information can be used for identifying their potential for ocean energy harvesting along the coastal area. In generally, the generated spatio-temporal wave patterns from this study could aid Malaysian marine agencies to provide strategic planning for proposing future ocean energy in Malaysian coastal area
Instantaneous tropical cyclone wind characterization from JASON-3 satellite altimeter
No full textThe sea surface wind (U10) is one of the vital variables needed to monitor the tropical cyclone development stages. Since the previous operational altimeter U10 product despair significantly inside extreme tropical cyclone conditions, the least attention is given to understand the tropical cyclone. With the latest improvement of high U10 accuracy estimates inside the tropical cyclone environment developed for altimeter satellite, tropical cyclone wind characterizations can be anticipated. This study aims to derive prominent tropical cyclone wind characteristics namely the centre and the radial extends threshold used by the agency in describing the tropical cyclone. The results demonstrated that the objectively derived characteristics from the Jason-3 altimeter for Typhoon Jebi 2018 were in good agreement with the best-track reported. This study draws new perspective of instantaneous observation for tropical cyclones characterisation from the altimeter satellite which can be vital complement of operational analysis
Mobile parenting training program based on a ubiquitous learning context to improve parenting skill: the moderating role parental locus of control
Get PDFThe lack of knowledge about parenting has led to several cases of violence against children. Providing training on parenting skills is a possible solution. This study was presented with the aim of knowing the effectiveness of a mobile parenting training program based on ubiquitous learning to improve parenting skills moderated by parental locus of control. This study used a quasi-experimental design with control and experimental groups. Sampling in this study used purposive sampling with the following criteria for parents: 1) Having children aged 3–6 years, 2) Parents experiencing parenting problems, 3) Children experiencing developmental delays, 4) Willing to participate in the training program to completion. The tests used in this study include testing the validity and reliability of the instrument, classical assumption test, homogeneity test, and hypothesis testing using Two Way Anova parametric statistics. The results of this study can be concluded that a mobile parenting training program based on unbiquitous learning moderated by a good parental locus of control can improve parenting skills in parents
Mobile learning by English literature students: the role of user satisfaction
Get PDFThe purpose of this study is to determine the predictors of using mobile learning (ML) among English literature students in Iraq. This study assumes that variables of UTAUT such as effort expectacny (EE) and performance expectancy (PE) as well as the subjective norms (SN) from theory of planned behavior (TPB) will affect the behavioral intention (BI) to use ML. BI and availability (FC) will affect the actual use (AU). In addition, user satisfaction is proposed as a mediating variable between PE, EE, and SN with BI. Data of this study was collected using a questionnaire from 240 undergraduate students. The data was analyzed using PLS. The findings showed that PE, EE and SN are important factors for the BI of ML. BI and FC significantly affected the AU. User satisfaction mediated only the effect of PE and EE on BI. Easier processes and instruction must be provided by univeristies to enhance the adoption of ML among English literature students