19672 research outputs found
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Pellet diameter and morphology of European Ganoderma pfeifferi in a repeated-batch fermentation for exopolysaccharide production
No full textThe pellet diameter and morphology of an underutilized European Ganoderma pfeifferi (EGP) mycelium was studied in a repeated-batch fermentation (RBF) for exopolysaccharide (EPS) production. In preliminary fermentation, growth screening was performed for initial pH, glucose concentration, and agitation speed. At 30 °C, the favourable conditions for EPS production (0.58 g/L) and EPS productivity (0.058 g/L day −1 ) were 15 g/L glucose, initial pH 6, and 100 rpm, while the highest dry cell weight (DCW; 3.63 g/L) was achieved at 9 g/L glucose, initial pH 4, and 120 rpm. Morphologically verified, large, compact pellets (diameter: 40 μm < d < 40.67 μm) were associated with high DCW while small dispersed pellets (diameter: 11.67 μm < d < 14.67 μm) were associated with high EPS production. In RBF, EGP mycelium exhibited the ability to self-immobilize and high stability for repeated use with increasing smooth pellet diameter from RBF1 (7.33 μm < d < 7.67 μm) to RBF4 (16.67 μm < d < 18.33 μm). The fermentation period was subsequently shortened from 48 (batch) to 24 days in four consecutive cycles of RBF, and the productivity of EPS increased from 0.053 g/L day −1 to 0.108 g/L day −1 . In an FTIR analysis, crude EPS of EGP showed the presence of β-glucan characteristics at 1075 cm −1 and 891 cm −1 wavelengths, similar with European G. lucidum BCCM 31549. In addition, 1 H NMR showed similar β-glycosidic linkages when compared with laminarin standard. The proposed strategy demonstrated that G. pfeifferi pellet morphology can withstand extended fermentation cycles for efficient EPS production. © 2019 Elsevier Lt
Improved Image Splicing Forgery Detection by Combination of Conformable Focus Measures and Focus Measure Operators Applied on Obtained Redundant Discrete Wavelet Transform Coefficients
No full textThe image is the best information carrier in the current digital era and the easiest to manipulate. Image manipulation causes the integrity of this information carrier to be ambiguous. The image splicing technique is commonly used to manipulate images by fusing different regions in one image. Over the last decade, it has been confirmed that various structures in science and engineering can be demonstrated more precisely by fractional calculus using integrals or derivative operators. Many fractional-order-based techniques have been used in the image-processing field. Recently, a new specific fractional calculus, called conformable calculus, was delivered. Herein, we employ the combination of conformable focus measures (CFMs), and focus measure operators (FMOs) in obtaining redundant discrete wavelet transform (RDWT) coefficients for improving the image splicing forgery detection. The process of image splicing disorders the content of tampered image and causes abnormality in the image features. The spliced region's boundaries are usually blurring to avoid detection. To make use of the blurred information, both CFMs and FMOs are used to calculate the degree of blurring of the tampered region's boundaries for image splicing detection. The two public image datasets IFS-TC and CASIA TIDE V2 are used for evaluation of the proposed method. The obtained results of the proposed method achieved accuracy rate 98.30% for Cb channel on IFS-TC image dataset and 98.60% of the Cb channel on CASIA TIDE V2 with 24-D feature vector. The proposed method exhibited superior results compared with other image splicing detection methods. © 2019 by the authors
Student achievement based on the use of scientific method in the natural science subject in elementary school
No full textThis research aims at investigating elementary school student achievement based on the use ofscientific method in teaching science from the test item types, as reflected by the item difficulty indexusing the classical test theory (CTT) and modern test theory (IRT). The first stage in developing the test was preparing the learning continuum of scientific method aspects by referring to the learning continuum of science process skill as developed by the previous existing research. In this research, the learning continuum was validated by expert judgment. As the tests were administered/carried out at the same time, four sets of tests were developed and administered to students of Grade 1 to 6 in Yogyakarta and Sleman Regency in the 2016-2017 school year. Samples were taken from three Technical Management Units (TMUs). Three TMUs were determined by observing the distribution of school locations from the center to the suburbs. The items were analyzed using CTT and IRT.The results of the research show that the student achievement reflected by item difficulty index based on CTT and IRT indicates the same level of category except for several sub-aspects. Those items from certain testsindicate higher difficulty level for Grade 4 to 6 students than for Grade 1 to 3 students. This case is not relevant to the expected learning outcomes. © 2019 Science Education Study Program FMIPA UNNES Semarang
Assessing ESL undergraduate performance in a group oral test: Rater orientations
No full textGroup oral testing has attracted increasing interests in performance-based assessment, mainly due to its ability to measure interactional competence. Increasing attention has consequently been paid to the performance of raters, whose orientations have an impact on the scores in view of their role as mediators between performances and scores. Studies have shown that despite training, raters' personal constructs can lead to different assessments. This study examines rater orientations before and after viewing student performance in an oral test, to discover whether raters subscribe to the view that interaction is individual-focused and is mainly a representation of cognitive or within-language user construct, or whether they believe in a social perspective of interaction. Fourteen participants were interviewed to ascertain their personal constructs for assessing group oral interaction, as well as their justifications for rating a videotaped group oral performance using these personal constructs. The findings show that while raters valued a number of qualities including linguistic abilities, their focus was on interaction. This suggests an inclination towards the social interactional perspective, as they seem well aware that successful interaction is co-constructed, and cannot be achieved through individual language ability alone. © 2018, IJAL
Conolodinines A–D, Aspidosperma–Aspidosperma Bisindole Alkaloids with Antiproliferative Activity from Tabernaemontana corymbosa
No full textExamination of the EtOH extract of the leaves of the Malayan Tabernaemontana corymbosa resulted in the isolation of four new (1-4) and two known bisindole alkaloids (5, 6) of the Aspidosperma-Aspidosperma type. The structures of these alkaloids were determined based on analysis of the spectroscopic data (NMR and HRESIMS). X-ray diffraction analyses of the related bisindole alkaloids conophylline (5) and conophyllinine (6) established the absolute configurations. Treatment of the bisindole alkaloid conophylline (5) with benzeneselenic anhydride gave, in addition to the known bisindole polyervinine (7) previously isolated from another Malayan Tabernaemontana, another bisindole product, 8, an isolable tautomer of 7. X-ray diffraction analyses yielded the absolute configurations of both bisindoles and in addition showed that polyervinine (7) exists primarily as the neutral dione structure. The bisindoles (1-8) and the related conophylline-type bisindoles (9-13) showed pronounced in vitro growth inhibitory activity against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, A549, HT-29, and HCT 116 cells, with IC50 values for the active compounds in the 0.01-5 μM range. © 2019 American Chemical Society and American Society of Pharmacognosy
Preparation and Characterization of Electrochemical Deposition Cobalt Triantimonide (CoSb3) Thick Film: Effects of Polyvinyl Alcohol (PVA) as an Additive
No full textA thick film of cobalt triantimonide (CoSb3) skutterudites was successfully synthesized via electrochemical deposition by using an electrolyte that contains antimony (Sb3+) and cobalt (Co2+) ions in a weak acid solution in the presence of polyvinyl alcohol (PVA) as an additive. The process was conducted under a potentiostatic condition of − 1000 mV versus Ag/AgCl at room temperature. Two hours (2 h) of electrochemical deposition produced a 13 μm assisted PVA CoSb3 thick film. In comparison, most studied electrochemical deposition of CoSb3 skutterudites thin films is in the thickness range of 700–800 nm. The morphological studies of the films appeared to have a cauliflower-like structure with a presence of fern-like dendrite for a non-PVA electrolyte due to the limitation of ion diffusion in the nucleation growth area. The absence of dendrite was observed in the assisted PVA films, which demonstrated an enhanced ion diffusion in the vicinity with a better stoichiometric ratio for Co:Sb of 1:3 thick film. © 2019, The Minerals, Metals & Materials Society
Automatic Speech Intelligibility Detection for Speakers with Speech Impairments: The Identification of Significant Speech Features
No full textSelection of relevant features is important for discriminating speech in detection based ASR system, thus contributing to the improved performance of the detector. In the context of speech impairments, speech errors can be discriminated from regular speech by adopting the appropriate discriminative speech features with high discriminative ability between the impaired and the control group. However, identification of suitable discriminative speech features for error detection in impaired speech was not well investigated in the literature. Characteristics of impaired speech are grossly different from regular speech, thus making the existing speech features to be less effective in recognizing the impaired speech. To overcome this gap, the speech features of impaired speech based on the prosody, pronunciation and voice quality are analyzed for identifying the significant speech features which are related to the intelligibility deficits. In this research, we investigate the relations of speech impairments due to cerebral palsy, and hearing impairment with the prosody, pronunciation, and voice quality. Later, we identify the relationship of the speech features with the speech intelligibility classification and the significant speech features in improving the discriminative ability of an automatic speech intelligibility detection system. The findings showed that prosody, pronunciation and voice quality features are statistically significant speech features for improving the detection ability of impaired speeches. Voice quality is identified as the best speech features with more discriminative power in detecting speech intelligibility of impaired speech. © 2019 Penerbit Universiti Kebangsaan Malaysia. All rights reserved
Diplomatic ties between Malaysia and the Holy See: A symbol of mutual respect, inter-religious coexistence and international cooperation
No full textThe workings within the Holy See has one of the oldest diplomatic institutions. Unlike other states with their national interests the diplomatic role of the Holy See within the international community is based on the moral authority of the Pope in favour of the wellbeing of people. Malaysia is the 179th state to have diplomatic relations with the Holy See. The relations are rather unique because no economy and consular divisions are involved. In fact, the core of the relations is based on the mutual interest of promoting justice, peace and tolerance. Although the diplomatic relations were established in 2011, this article demonstrates that there were already cordial engagements between the Popes and local leaders. This article explores the relations between Malaysia and the Holy See and analyses the reasons for Malaysia to establish relations with the Holy See and the bilateral activities. Copyright © IIUM Pres
Socioemotional wealth and performance in private family firms
No full textPurpose: Socioemotional wealth (SEW) has emerged as a defining concept that distinguishes family-owned business organizations from businesses that are not exclusively controlled by family coalitions. This empirical study expands the literature by presenting a more nuanced understanding of how individual dimensions of socioemotional wealth interacts with firm performance outcomes. Deploying the stakeholder theory, the purpose of this study is to propose a research model linking the five dimensions of SEW with firm performance to propose and test a set of hypotheses. Design/methodology/approach: To test the hypotheses, data were collected through a survey of 357 medium-to-large private family firms in Bangladesh that were involved in export-oriented production of ready-made garments. Based on structural equation modeling, the data were analyzed using SmartPLS. Findings: The results indicate that out of the five dimensions of SEW, three dimensions – family identification, emotional attachment and renewal of bonds through dynastic succession – have a positive and significant impact on firm performance. On the other hand, family control and influence have a significant but negative impact on firm performance. The only exception is in the case of binding social ties, which indicate a non-significant relationship. Research limitations/implications: By attempting to provide a clearer and predictable link between family-centric non-economic goals and firm-centric business goals, the study contributes to theory building and attempts to address the conflict in the literature in the study of family involvement in management and performance of the business enterprise. Practical implications: For industry practitioners and family business owners, it could provide guidance on which family-centric goals would maximize benefits to the firm and address the family-based utilities. Future strategic plans aimed at growth and sustainability of family firms can derive important clues from the findings of this study and design actionable goals that leverage those dimensions of socioemotional wealth that have a positive impact on firm performance. Social implications: Social implications of ensuring survival of family businesses are significant because of their role as one of the largest sources of employment generation in most societies. Policymakers and regulatory authorities would be able to frame customized initiatives to foster growth and sustainability of family enterprises that have such large impact on the economy. Originality/value: Theoretical contribution of the study comes from a more nuanced understanding of relationships between the individual dimension of SEW and firm performance, which will delineate a more consistent and predictable link between family-centric goals and firm-level outcomes. From the perspective of practical contribution, this may provide useful guidelines to industry practitioners and policymakers to frame initiatives that enable growth and sustainability of family firms that are typically the largest employment generators in most economies. © 2019, Emerald Publishing Limited
Design and Implementation of a Hybrid Single T-Type Double H-Bridge Multilevel Inverter (STDH-MLI) Topology
No full textMultilevel inverters are proficient in achieving a high-quality staircase output voltage waveform with a lower amount of harmonic content. In this paper, a new hybrid multilevel inverter topology based on the T-type and H-bridge module is presented. The proposed topology aims to achieve a higher number of levels utilizing a lower number of switches, direct current (dc) voltage sources, and voltage stresses across different switches. The basic unit of the proposed single T-type and double H-bridge multilevel inverter (STDH-MLI) produces 15 levels at the output using three dc voltage sources. The proposed topology can be extended by connecting a larger number of dc voltage sources in the T-type section. The nearest level control (NLC) switching technique is used to generate gate pulses for switches to achieve a high-quality output voltage waveform. In addition, a simplified way to achieve NLC is also described in the paper. A detailed comparison with other similar topologies is provided to set the benchmark of the proposed topology. Finally, experimental work is carried out to validate the performance of the proposed topology. © 2019 by the author