http://ajstd.org/index.php/ajstd/issue/feed ASEAN Journal on Science and Technology for Development 2022-08-31T00:00:00+07:00 Widodo ajstd.journal@gmail.com Open Journal Systems <h2>About the <em>ASEAN Journal on Science &amp; Technology for Development</em></h2> <p style="font-weight: 300; font-size: 1.01rem;">Jointly published by the ASEAN Committee on Science and Technology and the Ministry of Research, Technology, and Higher Education of the Republic of Indonesia, the <em>ASEAN Journal on Science &amp; Technology for Development</em> (print ISSN 0217-5460; online ISSN 2224-9028) is a peer-reviewed open access journal focusing on the publication of articles that make positive, tangible contributions to science and technology in the ASEAN region. Its main aim is to promote and Google Scholar, ID Scopus, ResearchGate, Orcid), accelerate the discovery and ultimate ASEAN-wide application of scientific and technological innovations, the consequence of which should be greater prosperity for the people of Southeast Asia.</p> <p style="font-weight: 300; font-size: 1.01rem;">AJSTD covers a wide range of technology-related subjects in the context of ASEAN, including biotechnology, non-conventional energy research, materials science and technology, marine sciences, meteorology and geophysics, food science and technology, microelectronics and information technology, space applications, science and technology policy, and infrastructure and resources development.</p> <h2>About The ASEAN Committee on Science and Technology</h2> <p style="font-weight: 300; font-size: 1.01rem;">The ASEAN Committee on Science and Technology was established to strengthen and enhance the capability of ASEAN in science and technology so that it can promote economic development and help achieve a high quality of life for its people. Its terms and reference are:</p> <ul class="asean-terms" style="font-weight: 300; font-size: 1.01rem;"> <li class="show">To generate and promote development of scientific and technological expertise and manpower in the ASEAN region;</li> <li class="show">To facilite and accelerate the transfer of scientific and technological development among ASEAN countries and from more advanced regions of the world to the ASEAN region;</li> <li class="show">To provide support and assistance in the development and application of research discoveries and technological practices of endogenous origin for the common good, and in the more effective use of natural resources available in the ASEAN region and in general; and</li> <li class="show">To provide scientific and technological support towards the implementation of existing and future ASEAN projects.</li> </ul> <p style="font-weight: 300; font-size: 1.01rem;">Further information about the activities of ASEAN COST can be <a class="border-hover" href="http://astnet.asean.org/index.php?option=com_content&amp;view=categories&amp;id=8&amp;Itemid=130" target="_blank" rel="noopener">found on its website</a>.</p> http://ajstd.org/index.php/ajstd/article/view/793 Hydrogeochemical Analysis of Unconfined Groundwater in the Surrounding Salt Farming Areas of Pademawu, Madura, Indonesia 2022-03-31T13:08:45+07:00 Wisnu Arya Gemilang wisnu.gemilang@kkp.go.id Ulung Jantama Wisha ulungjantama@gmail.com Mas Agus Mardyanto mardyanto@enviro.its.ac.id <p>The Pademawu coast has rapidly transformed into salt ponds, causing seawater intrusion and pollution. This study aims to examine the quality of groundwater in the surrounding settlement area of Pademawu and assess its eligibility for daily use. The psychochemical parameters of groundwater are measured <em>in situ</em>. Groundwater samples from several stations are analyzed in the laboratory and used to collect several chemical compounds, including Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>, HCO<sup>3-</sup>, Cl<sup>-</sup>, SO<sub>4</sub><sup>2-</sup>, Fe<sup>2+</sup>, Mn<sup>2+</sup>, F-, NO<sub>2</sub><sup>-</sup>, NO<sub>3</sub>, and CaCO<sub>3</sub>. The detected concentrations are then used to calculate TH, sodium adsorption ratio (SAR), %Na, PI, KR, and MH. Hydrochemical calculation and interpretation are also performed. The groundwater characteristics are determined according to TDS, conductivity, and water quality index (WQI). Results showed that the groundwater facies are predominated by Ca-HCO<sub>3</sub> (50%) in the northern and middle study areas and Na-Cl (37%) in the salt farming area. The groundwater is categorized as SAR (C<sub>2</sub>S<sub>1</sub>) in the north and SAR (C<sub>4</sub>S<sub>2</sub>) in the south. The primary groundwater consists of Na<sup>+</sup> and Cl<sup>-</sup> (dominant cation and anion) originating from salt farming. The TDS in the salt farming area ranges from 1000 mg/L to 3000 mg/L (slightly saline). The WQI ranges from 39.0 to 735.4, which encompasses excellent water, good water, very poor water, and unsuitable for consumption. Salt farming infiltration toward unconfined aquifers is the primary factor causing groundwater pollution. Mitigation efforts to minimize scattered infiltration must be applied in the Pademawu Subdistrict by modifying the system between salt farming and settlement areas.</p> 2022-08-31T00:00:00+07:00 Copyright (c) 2022 The Author(s) http://ajstd.org/index.php/ajstd/article/view/772 Design of High Gain and Improved Front-to-Back Ratio Multilayer Microstrip Patch Antenna using Modified Feed Line 2022-04-14T08:37:53+07:00 Partha Kumar Deb debpartha90@gmail.com Tamasi Moyra tamasi_moyra@yahoo.co.in Bidyut Kumar Bhattacharyya bkbhatta1@yahoo.com <p>A novel high gain miniaturized rectangular microstrip patch antenna is proposed with a high front-to-back ratio (FBR) using a modified feed line and two single-sided substrate layers to operate at 2.4 GHz frequency. The feed line is modified using a step impedance technique to achieve resonance at the operating frequency. The matched impedance of the feed line helps achieve enhanced bandwidth and antenna miniaturization. The substrate layers are introduced to achieve an enhanced gain and FBR of 6.329 dBi and 27.64 dB, respectively. The impedance bandwidths of 106.9 and 94.1 MHz are achieved for the two separate designs. These proposed designs have a total circuit area occupancy of 0.4 ?<sub>0</sub> × 0.304 ?<sub>0</sub>. The antenna has been designed and fabricated using FR4 substrate material. The measured results are in good agreement with the simulated results.</p> 2022-08-31T00:00:00+07:00 Copyright (c) 2022 The Author(s) http://ajstd.org/index.php/ajstd/article/view/780 Black Soldier Fly (Hermetia illucens) as a Potential Agent of Organic Waste Bioconversion 2022-06-30T10:02:20+07:00 Listya Purnamasari listyap.faperta@unej.ac.id Himmatul Khasanah himma@unej.ac.id <p>The use of black soldier fly (BSF) as a bioconversion agent has become an emerging breakthrough in waste processing. Organic wastes, such as household waste and livestock manure, can be used as a growth medium for BSF larvae and converted into favorable products. The average composting time of BSF larvae is around 12– 15 days, which is faster than that of microbes or earthworms (4–5 weeks). BSF shows potential as a feed and food ingredient because it has a high nutritional content, such as enzyme, chitin, medium-chain fatty acid, and antimicrobial peptides, and can be used as a functional food ingredient. From an economical perspective, the short composting period and the role of BSF as a feed and food alternatives can benefit producers and consumers. The safety aspects of BSF utilization, including microbial safety, chemical safety, and environmental safety, warrant clarification to ensure BSF safety. However, some challenges arise regarding the use of BSF larvae (BSFL) as a bioconversion agent, such as for heavy metal residues, pesticide residues, pathogens, and antimicrobial gene transmission and residues that require the best composting strategy for mitigation. The environmental safety of organic waste treated with BSFL has a good impact; therefore, this strategy can be used to reduce global warming. Research must focus on effectively and safely enhancing the cultivation and processing of BSF and its applications as a functional food. In conclusion, BSF is a profitable alternative for organic waste bioconversion in developed and developing countries.</p> 2022-08-31T00:00:00+07:00 Copyright (c) 2022 The Author(s) http://ajstd.org/index.php/ajstd/article/view/852 Defect and Distortion in Powder Bed Fusion of Metal Additive Manufacturing Parts 2022-07-19T08:55:07+07:00 Ajay Kumar Maurya maurya.me16@nitp.ac.in Amit Kumar maurya.me16@nitp.ac.in <p>One of the state-of-the-art technologies for metal fabrication is laser powder bed fusion, which includes the following printing techniques: selective laser melting, selective laser sintering, direct metal laser sintering, and electron beam melting. This work examines defect formation in laser powder bed fusion, predominately focusing on selective laser melting. It also explores recent research findings on defect formation and classification and analyzes various internal defects, such as porosity, lack of fusion, balling, and solidification cracking. The influence of process parameters on defect formation and the effect of defects on mechanical properties are analyzed. This review also discusses defect inspection technologies (melt pool, scan path, and slice monitoring), defect mitigation strategies (online detection, process parameters, and numerical simulation), and their applications in additive manufacturing, such as laser powder bed fusion. This review would aid manufacturers in determining the root cause of defect formation and developing inspection technologies and mitigation strategies.</p> 2022-08-31T00:00:00+07:00 Copyright (c) 2022 The Author(s) http://ajstd.org/index.php/ajstd/article/view/845 Using Convergent Parallel Mixed Methods and Datasets for Science, Technology, and Innovation Policy Dynamics Research in Indonesia 2022-06-28T09:29:29+07:00 Prakoso Bhairawa Putera prakoso19001@mail.unpad.ac.id Suryanto Suryanto suryanto@unpad.ac.id Sinta Ningrum sinta.ningrum@unpad.ac.id Ida Widianingsih ida.widianingsih@unpad.ac.id Yan Rianto yanr001@brin.go.id <p>The application of mixed methods has been widely implemented in several studies, particularly in the field of public policy; however, the implementation of convergent parallel mixed methods has been limited. Thus, such methods are appropriate to reveal the science, technology, and innovation (STI) policy dynamics in Indonesia during the 1945–2020 period, as policy dynamics research attempts to reveal the evolution of the changes regarding the policy itself. The following five concepts are analyzed through convergent parallel mixed methods: 1) regime/government change, 2) institutional change/transformation, 3) change in policy issuance, direction, and content, 4) actor role and existence, and 5) policy object input and output. This article discusses the method details, from the paradigm, research dataset, and technique selection for collecting and analyzing research data to the research implementation.</p> 2022-08-31T00:00:00+07:00 Copyright (c) 2022 The Author(s)