bluuebunny/crossref_metadata_2025 huggingface dataset:
Total phenolic and flavonoid test of Gleichenia linearis leaf extract as antioxidant using microwave assisted extraction
Authors: Pratiwi S R , Roanisca O , Nurhadini
Published: December 2023

Excessive exposure to free radicals can cause oxidative stress, thus requiring defense mechanisms to prevent damage, one of which is the use of antioxidants. Resam (Gleichenia linearis
) leaf extract is known to contain flavonoids, alkaloids, tannins, saponins, steroids, and triterpenoids. This research aims to determine the influence of solvents and extraction time variations on the yield, total phenolic content, total flavonoid content, and antioxidant activity of resam leaf extract. The testing comprises the determination of total phenolic content using the Folin-Ciocalteau method, total flavonoid content using the AlCl3 method, and antioxidant activity using the DPPH method. The highest yield, total phenolic content, total flavonoid content, and antioxidant activity in this research were obtained from ethanol as the solvent with a MAE time of 10 minutes, with respective values of 62.21%, 172.9 mg EAG/g, 110.60 mg QE/g, and 24.12 µg/mL. The correlation testing showed that total phenolic content contributes 95.5%, while total flavonoid content contributes 56.5% to the generated antioxidant activity (IC50). Phenolic compounds are the most dominant compounds in the resam leaf extract, which play a role as antioxidants.
Topography and land suitability analysis in the integrated waste management site building (IWMB) at the University of Lampung
Authors: Zulkia Dwi Rizka , Purwadi Ofik Taupik
Published: December 2023

Slope class maps are products resulting from the topographical analysis process. The results of this topographical analysis can also be used as a basis for land suitability analysis, supported by land cover maps and indicative maps of built and undeveloped areas. The Integrated Waste Management Site Building (IWMB) at the University of Lampung was used as an AoI (Area of Interest) or a study area for making land suitability maps. The AoI in the Unila campus area was 4.11 hectares. This study aims to explore the capabilities of drones as a complementary vehicle for field survey data to find out topographical data and to analyze spatial suitability plans. The method used in this research was an interpretation of aerial photographs and analysis using the ArcGIS application. From the slope class analysis results, the research location is included in the flat class category to be safe for all buildings (0-8%). For classification in spatial suitability analysis, the area is divided into 8 development plans to provide sustainable green open spaces in the campus area. Based on the research results, information was found that drone technology can assist visual interpretation in an area’s development plan.
Fishery potencies as environmental services of Pongok Islands, Bangka Belitung Province
Authors: Wahidin L O , Adibrata S , Pamungkas A , Priyambada A
Published: December 2023

One of the islands with huge potential for fishery in South Bangka Regency is the Pongok Islands. Most of the people living in the islands depend on marine and fishery resources. This research aimed to figure out fishery potencies located in the surrounding island of Pongok related to capture fishery, fish food processing, and aquaculture. Data were gathered on field observation and interviews conducting on August 2022. Results of the research three main fishery activities in this area are capture fishery, fish product processing, and aquaculture. The capture fishery is taken for pelagic and coral fish. Some economic fish are anchovy, sardine, squids, and mackerel kingfish. Harvesting each commodity is different due to species and season of wind blowing as well as fishing gear. Fish products of the island are marketed in Toboali, Pangkal Pinang, and Belitung, and even transported to Pontianak and Jakarta. Aquaculture activity is only conducted for raising groupers using floating nets. Moreover, environmental aspects of mariculture, two new fishery commodities like seaweeds and pearl oysters, have the potential to be introduced into the islands. Environmental services have still contributed directly and indirectly to the fishery activities on the islands now and then.
Analysis of Land Value Change in Genuk District
Authors: Firdaus H S , Qoyimah S , Zakiyatin I
Published: December 2023

Genuk District is a district in Semarang City which is designated as an industrial area. The development of industrial estates can lead to increased urbanization. According to data from Central Agency on Statistics in 2020, the population in Genuk District has always increased from year to year. The increasing population causes the need for land to also increase. Land prices can also rise considering the need for land and factors from industrial development. On the other hand, Genuk District is prone to tidal flooding. The worst tidal floods in Genuk District occurred in Gebangsari, Genuk and Banjardowo Sub-District in the 2000s. Based on the problem, this research aims to map land prices temporally in 2014, 2019 and 2022 and analyze the distribution pattern of land value changes in Genuk District with theLocal Moran’s Imethod. That method is used for analyze the pattern of land values in 2022 and the pattern of land price changes between 2019 and 2022. The method used in mapping land prices is based on a fair market land price approach and land valuation techniques using a mass valuation cost approach. The average land value zone in 2014 has a value of IDR 711,000 in 2019 has an average value of IDR 986,000 and in 2022 is IDR 1,599,000. According to the results of Local Moran’s I, the pattern land value change in 2019-2022 is different from the results of the land value pattern in 2022 for each category class. This shows that the high land value changes between 2019 to 2022 are not in the same location as the high land value in 2022.
Utilization of Mean Dynamic Topography for GNSS-Leveling Applications (Case Study: Jakarta Area)
Authors: Sarsito Dina Anggreni , Andreas Heri , Syahrullah Muhammad , Pradipta Dhota , Bramanto Brian
Published: December 2023

Conventionally, the determination of height that has physical meaning for a location or area can be determined geodetically by measuring the height difference relative to a reference point using the spirit-leveling method. This type of height, orthometric height, is essential to explain any physical phenomena, e.g., determining which direction fluid flows, which is used in many scientific and engineering applications. The coverage area is one limitation of conventional leveling, using waterpass precise leveling. The wider the coverage area, the more time and cost-consuming it will be. Another alternative to determine the height at a particular location is using the Global Navigation Satellite System – Leveling (GNSS-Leveling) method, which can be used to resolve the drawbacks of the previous method. GNSS-Leveling method is able to provide an efficient height determination solution if an accurate geoid undulation model and Mean Dynamic Topography (MDT) model are available over the area of interest. MDT is the height deviation between the geoid surface and the mean sea surface (MSS). Information related to geoid undulation and MDT is important to ensure any GNSS-Leveling measurement referring to the local Mean Sea Level (MSL) surface, which is widely needed in various applications. Applying the EGM2008 geoid model and altimetric-derived MDT solution to GNSS-Leveling measurements in the Jakarta area, the average orthometric height difference relative to the reference value is estimated to be about 5 cm. This shows that GNSS-Leveling is a promising solution when combined with geoid and MDT models.
Lahar Inundation Estimation of Mount Semeru Relating to the 4th December 2021 Volcano Eruption
Authors: Hendrawan A , Nabilah M , Setyadji B , Sadarviana V
Published: December 2023

The Semeru volcano – located at the boundary region of Lumajang and Malang districts of East Java province, Indonesia – which is categorized as one of the active volcanoes in Indonesia was enormously erupted the volcanic materials – the hot lahar and the volcanic ash - on 4th December 2021. The scale of the eruption event caused some disaster to several villages along the path of the lahar and volcanic ash in south to southeast direction from the Mount Semeru lahar dome. An inundation simulation of the lahar is done as a contribution to mitigating the disaster that may potentially occur in the future. The LAHARZ algorithm was used for these estimation calculations. The Digital Terrain Model (DTM) and Digital Surface Model (DSM) were used as the base data for estimating and simulating the lahar inundation scenario. The use of two types of elevation model data in the simulation was done for study the inundation characteristics in the presence of forest vegetation. Three scenarios of lahar volume were used for simulating the inundation over elevation models. Results of the estimation then be compared to the actual lahar inundation that was delineated from the high-resolution satellite images. Lahar flow simulations using DTM show that more flows were formed compared to using DSM. The DTM simulation results showed a flow that more closely resembled the existing flow map compared to the DSM simulation results.
Volume Calculation of Sidoarjo Mud Using TLS Data and Numerical Methods
Authors: Syah Amir Muhamad Hafidz , Yuwono
Published: December 2023

Sidoarjo Mud is one of the phenomena of mud volcanoes located in the northern part of Java Island. A mud volcano is a phenomenon where mud material is released from the earth due to pressure (eruption). The mud continuously flows and accumulates around the central embankments. This phenomenon has caused the embankments to break several times due to the uncontainable mud volume. Observing the volume of Sidoarjo Mud is expected to help mitigate this problem. The Sidoarjo Mud volume was calculated using point cloud data obtained from Terrestrial Laser Scanner (TLS). Numerical methods such as the Trapezoidal and Simpson rules were employed to determine the mud volume. These numerical methods involve approximating the volume of irregularly shaped earthwork surfaces using mathematical techniques. The numerical method approximates the area under a trapezoid or curve representing the cross-section of the earthwork. In this study, kriging interpolation was conducted with a grid size of five meters. The relative difference between the numerical methods was found to be within acceptable limits, not exceeding 2.78% based on the American Society for Testing and Materials (ASTM) 2002 and not exceeding 2% based on ASTM 1998 as an industry acceptance error. Considering the relative difference results and the institutional report, the Trapezoidal method with a 5-meter grid size was considered the accurate volume calculation method. Based on the processed data, the total volume of Sidoarjo Mud within the embankment was 32,793,917.171 m3 in February 2022, 32,889,012.793 m3 in April 2022, and 33,390,051.407 m3 in June 2022. The volume calculation results show a difference of 95,095.622 m3 between February-April and a difference of 501,038.613 m3 between April-June. The mud flow rate for the February-April period was calculated as 1,872.114 m3/day, while for the April-June period was determined as 9,278.492 m3/day.
Landscape Composition and Its Effect on the Urban Thermal Environment in Kendari City
Authors: Nurgiantoro  , Usman I , Bahdad  , Ma’ruf A , Harimudin J , Hadini L O , Aris A , Mando L O A S
Published: December 2023

The rapid urbanization activities in Kendari City over the last decade have changed its natural landscape, including demands for infrastructure development such as residential areas, which is currently one of the most massive activities. The purpose of this study was to analyse the effect of landscape composition on the urban thermal environment in the Kendari City area in relation to LST and UHI parameters based on UTFVI thresholds. Landsat 8 time series data for 2019 – 2023 is used to observe urban thermal environmental conditions in the study area. The results showed that during the last four years LST in Kendari City tends to increase every year with R
2 > 0.09. As a result of this increasing trend the UHI area in Kendari City also experienced an increase. More than 25% of the Kendari City area is indicated to experience the UHI phenomenon with SUHI ranging from 24 °C to the highest temperature and the concentration increases linearly with the density of the impervious surface area. However, this does not happen in areas with a landscape composition that is categorized as green space. As for the UTFVI results, more than 28% of the areas experiencing the UHI phenomenon are within the UTFVI threshold > 0.020 and more than 60% of the area in Kendari City is denoted as an area with relatively excellent conditions within the range ecological evaluation indices then the rest is in good and normal condition.
Permanent & Non-Permanent Water Identification Based on Image Fusion of Sentinel 1 & 2 Data (Case Study: Lamongan Regency)
Authors: Irbah Nafisatus Sania , Jaelani Lalu Muhamad
Published: December 2023

The Earth’s surface consists of land and water. Surface water is separated into two groups: permanent water and temporary water. Flooding is temporary water that is often experienced in many places in Indonesia, including Lamongan Regency. In this area, at the beginning of 2022, seasonal floods caused many residents’ houses, agricultural land, and access roads to be submerged in water. This is due to its topography, which is characterized by lowlands and water. Land cover monitoring in large areas can be identified and analyzed using remote sensing. In this case, remote sensing is used to obtain information about surface water for separating permanent water and temporary water for comprehensive treatment in the long term. This study uses two primary sources of data: Sentinel-1 and Sentinel-2 satellite images from five years of observation from January 2018 to December 2022. Sentinel-1 is used to exploit its Synthetic Aperture Radar (SAR) sensor, which is sensitive to dielectric properties; thus, the water objects can be identified easily. Meanwhile, the Sentinel-2 satellite provides up to 10 meters of spatial-resolution satellite data. Processing was carried out using Image Fusion with Fuzzy Logic Min to merge the advantages of different data sources. The result of processing obtained that the probability of permanent water distribution in Lamongan Regency from 2018 to 2022 has differences in the total area every year. The total area of permanent water from Image Fusion is 12.769 km2. Meanwhile, the total area for flood inundation is 57.023 km2. A comparison of the processing results with comparative data is carried out for the calculation of the accuracy test. Overall accuracy for permanent water is 91%, with a kappa coefficient of 0.82. Then an overall accuracy for flood inundation obtained 90% with a kappa coefficient is 0.79. The result of this study is a permanent water map and flood inundation map of the Lamongan Regency, which is expected to be a reference in flood disaster mitigation activities.
Geographic Element Extraction for Supporting Kota Lengkap Using Deep Learning
Authors: Kisworini Ita Dwi , Handayani Hepi Hapsari
Published: December 2023

An indicator of accelerating the ease of investment in land registration as legal certainty and protection of property assets. Pendaftaran Tanah Sistematis Lengkap (PTSL) is an effort to quickly and accurately develop data on all land parcels, both physical and legal. The use of deep learning to speed up mapping is a concrete example of how we are entering a new era of industrial revolution. The advantage of deep learning is to speed up the process of creating a Kota Lengkap map as a manifestation of a complete Pendaftaran Tanah Sistematis Lengkap (PTSL). The limitation in the number of human resources is a significant problem in measuring the road network to realise Kota Lengkap. This can be overcome by using automation to extract the road network. An orthophoto can more accurately show the location of all visible phenomena, thus enabling precise and accurate measurements of area, distance and direction. Deep learning methods can be applied to orthophotos and LIDAR to detect topographic features such as roads or rivers. Using the deep learning method and a split ratio of 80:20, it takes a total of 11 hours 45 minutes to automatically extract road features, while for river features it takes a total of 2 hours 38 minutes, resulting in an overall accuracy of 96.15%. The automated extraction of road and river networks from orthophotos cannot yet be applied directly to planar maps, as it requires post-processing to obtain gapless polygons.
3D Modelling of Sanggrahan Temple Using UAV Imagery and Terrestrial Photogrammetry Method
Authors: Bioresita Filsa , Hidayat Husnul , Kurniawan Juan Rivaldi , Purnomo Setyo , Grussenmeyer Pierre
Published: December 2023

As evidence of ancient Majapahit civilization existence, Sanggrahan Temple has been officially recognized as a cultural heritage building by Indonesian government in 2019. Sanggrahan temple is located in Boyolangu District, Tulungagung Regency, East Java. Conservation efforts in Sanggrahan temple have been done by BPK Wilayah XI Jawa Timur. Many parts of the temple have been damaged and are believed in different condition from its past original design. Therefore, a 3D documentation of Sanggrahan Temple needs to be carried out to provide sufficient data for future conservation efforts. The photogrammetry method which utilizes UAV (Unmanned Aerial Vehicles) and terrestrial imagery offers great efficiency in terms of fieldwork and cost. The technique applied close range photogrammetry for image-acquisition and Structure from Motion (SfM) processing. There are roughly 500 images captured for 3D modelling purposes. For georeferencing and geometric accuracy assessment, the Ground Control Point measurement was also carried out using GPS receiver and total station. The result show that the combination of aerial (UAV) and terrestrial images provide complete 3D model. The generated 3D model can provide architectural views of the temple from all sides which help architects and archaeologists to interpret architectural design and detail of the building. Accuracy assessment based on the coordinate measurement shows that the 3D model results meet the specified accuracy standard of 10 cm which is suitable for many architectural drawing applications.
Study The Effectiveness of Reservoir Utilization In The Fishpond Water Management System In Maintaining Salinity For Fishpond Cultivation
Authors: Riadi A , Triatmadja R , Yuwono N
Published: December 2023

The growing global population has led to an increased demand for food to meet humanity’s needs. However, the degradation of productive land presents a significant challenge regarding ensuring food availability. The utilization of wetlands has emerged as a feasible alternative. As the second-longest coastline in the world, Indonesia holds great potential for wetland development, for instance, fishpond. Nevertheless, the prevailing extensive traditional fishponds have low productivity and fail to maximize profits. Therefore, shifting towards more intensive cultivation methods is necessary to enhance productivity and increase profitability. This study aims to evaluate the effectiveness of reservoirs in maintaining salinity levels, aiming for technological improvement in semi-intensive fishponds. A water system model in the pond irrigation area is utilized to accomplish this. The model consists of two variations: Model 1, which includes rivers and channels, and Model 2, which combines rivers, channels, and reservoirs. The study results indicate that integrating reservoirs into the water system can significantly enhance salinity distribution. Model 2, which combines the reservoir component, demonstrates superior salinity dispersion. Furthermore, this enhanced dispersion persists over a longer period. These findings underscore the potential of reservoir utilization to improve the effectiveness of semi-intensive fishponds and their overall productivity.
Analysis of Abrasion Hazards on the Batupoaro Coast, Baubau City
Authors: Sriwardani R , Harimudin J , Nurgiantoro  , Sutikno
Published: December 2023

The coastal area of Batupoaro Sub-district is a strategic location but vulnerable to sea waves and abrasion. In early 2022, high waves hit the coast of Baubau City, including the Batupoaro coast. The waves have caused damage to infrastructure at several points of the coast and have even caused impacts on the people who live around the coast. This research is dedicated to examining abrasion hazard for disaster mitigation, with the aim of analyzing the condition of the coastal area and the level of abrasion hazard on the Batupuaro coast using qualitative descriptive analysis and abrasion hazard index analysis. The results showed that social conditions on the coast of Batupoaro are fishing activities, seaweed cultivation, tourism, public spaces, and transactional activities. While the physical condition is that there are several coastal protection buildings damaged by sea waves, then in several other locations abrasion has occurred, especially in segments that do not have coastal protection. Then in the results of the analysis of the level of abrasion hazard for each segment in the Batupoaro coastal area, all of them are categorized as high, this result is obtained from the assessment of abrasion hazard based on five parameters such as wave height, current speed, vegetation density, beach profile, and beach typology.
Worldwide Status of Geoportal and Geospatial Data Completeness at National Geoportals
Authors: Budi S. , Sutanta H
Published: December 2023

Geoportal is a specific web portal used to share geospatial datasets. It is part of a National Spatial Data Infrastructure (NSDI) which is used to disseminate geospatial data. In the NSDI framework, a geoportal is a platform where citizens can search, discover, and access geospatial datasets. Therefore, the availability of geoportal is an essential element in an NSDI. Further, the availability of geospatial datasets, particularly fundamental datasets, is indispensable. This paper aims to portray the worldwide status of geoportal and the completeness of fundamental datasets in those geoportals. We surveyed the availability of geoportal in the 193 countries in the world. We identify and list geoportal addresses worldwide. For every geoportal, we check the types of fundamental datasets available. Fourteen fundamental datasets have been identified and used as a benchmark. The availability of geoportal and fundamental datasets were then calculated and analysed. We found 105 countries in the world own geoportal. Of these geoportals, there were, on average, 63% fundamental datasets available. Only nine countries provide all fourteen fundamental datasets. Twenty-nine countries provide five or fewer fundamental datasets on their geoportal. We also classify geoportal and fundamental datasets availability based on four regions Asia-Pacific, Europe, Africa, and America. European countries have the highest percentage of countries with geoportal ownership as well as the highest available fundamental datasets. The finding complements a worldwide study on geoportal availability which has not been re-evaluated in recent years.
Potential Projection of Non-Production Waste and GIS-derived Biomass Waste Potential Mapping Outside PT. XYZ for Boiler Alternative Fuels
Authors: Firmansyah Mokhamad , Wahyuono Ruri Agung , Wicaksono Sigit Tri
Published: December 2023

Non-process waste such as wooden pallets, cardboard, and plastic in the manufacturing and/or processing industries can be used as a source of fuel that provides added value to the company. PT. XYZ is a Japanese manufacturing company that produces foodstuffs. During the production process, PT. XYZ produces non-process waste from internal sources in the form of wood, cardboard, and plastic. So far, this waste has not been used optimally. Therefore, in this study non-process waste will be projected using several time series models (AR, MA, ARMA, and ARIMA) as an illustration for the availability of raw materials to fulfil biomass fuel. In addition to waste in the factory, biomass waste is also mapped in the area around PT. XYZ for the fulfilment of biomass fuel using GIS (Geographic Information System). The time series analysis indicates that ARIMA model (0,1,1) without constants shows the smallest MAPE (14.7%) for wood waste, ARIMA model (1,1,0) without constants shows MAPE (27.39%) for cardboard waste, while plastic waste suits the ARIMA model (0,1,1) without constants yielding MAPE of 20.3%. Further, mapping of biomass waste potential around PT. XYZ, in Mojokerto, is subjected to the teak wood biomass waste (Tectona Grandis L.f) and eucalyptus. The biomass waste from teak wood waste and eucalyptus is potentially 783.1 tons/month and 0.3 tons/month, respectively. The projected results of biomass waste both inside and outside the factory can substitute 16.34% of coal fuel from the total fuel requirement in the boiler, i.e., 5143.7 tons/month.
Study on the process of purification of zinc sulfate solutions from impurities and their rheological properties
Authors: Absattorov Diyorbek , Makhmayorov Jasur , Abdullayev Bakhodir , Qodirov Sherzod , Davlatov Farrukh , Usmanov Ilkham , Samadiy Murodjon
Published: December 2023

The study was conducted to purify the zinc sulfate solution from impurities. A solution of zinc sulfate from a zinc-containing concentrate collected from the ore of the Khandiza deposit was taken for the study. Autoclave leaching of zinc concentrate with 30% sulfuric acid in an autoclave was done by introducing zinc dust after the stage of treatment of zinc concentrate with sulfuric acid. The possibility of reducing the copper content in the liquid phase from 0.26% to 0.01% at a ratio of Me:Zinc dust=1:(1.05-1.10) is presented here. Ammonization of a solution purified from copper makes it possible to reduce the copper content from 0.53% to 0.01% at a ratio of Fe:NH3=1:1.1. Empirical equations are derived for the effect of temperature, Zn:H2SO4 ratio, and process duration on the density and viscosity of pulps during the conversion of zinc concentrate with sulfuric acid.
Opportunities and challenges of recycling and reusing lithium-ion batteries for sustainable mobility
Authors: Harun I , Bahrudin F I , Daud N , Baba Zin N F S , Mat Yunus N F , Mahat M M , Shaffee S N A
Published: December 2023

The growth of lithium-ion battery (LIBs) applications in electric vehicles and consumer electronics are rapidly increasing, further supplemented by the global energy sector’s transition into more sustainable energy production and consumption. This not only boosts resources demand, but also generating huge amounts of spent batteries that must be properly managed. Recycling becomes a necessity, not only to support circular economy, but also to recover rare metals and reduce the hazardous pollution of LIBs components. There are many benefits for LIBs recycling, especially in environmental protection, energy transition, and economic benefits. Yet, a successful venture into LIBs recycling depends on a few factors: the recycling technology, the resources (spent LIBs), the location of the facilities for disposal and recycling, the local and regional regulatory framework, as well as the environmental impact. Therefore, it is necessary to identify and assess the systemic elements that exist within the recovery modes and phases of LIBs in a local context. This will enable a more informed decision to be made for further development of any LIBs recycling project.
Microalgae cultivation in flat panel photobioreactor as a method of carbon capture: A review
Authors: Syafiqa Abdul Nuri Nur Aqila , Mohamad Puad Noor Illi , Azmi Azlin Suhaida , Ahmad Farah , Syed Abdul Rahman Syarifah Nor Faizah
Published: December 2023

Biomass is one of the renewable energy technologies that plays a crucial role in fulfilling our energy needs while helping to mitigate carbon release. Microalgae biomass is a valuable product that can be utilized for a variety of applications which are generally high in proteins, carbohydrates, and lipids. In relation to that, photobioreactor (PBR) is known to be the appropriate system for microalgae to grow efficiently under controlled conditions. Nevertheless, handling this system can be challenging due to its complexity since it operates through different physical and chemical processes. This paper describes a systematic review of the recent literature published on flat panel photobioreactor (FPPBR) systems for microalgae cultivation that served as one of the critical technologies for the sustainable production of microalgae biomass and bio-based products. A total of 115 publications have been identified and analyzed from the literature search focusing on identifying different designs of FPPBR that have been developed and validated experimentally and numerically. Ultimately, this review is able to provide valuable insights into the current state of FPPBR implementation for microalgae cultivation that can aid in sorting out new strategies to support climate change attenuation and the commercialization of microalgae-based products.
Investigating the optical absorption and thermal conductivity of nano-enhanced lauric acid phase change material for energy storage application
Authors: Bhutto Yasir Ali , Pandey A. K. , Saidur R. , Laghari Imtiaz Ali , Buddhi D. , Tyagi V.V.
Published: December 2023

The issue of energy storage can be significantly reduced owing to phase change materials’ (PCMs) tremendous capacity for storing latent heat in a reliable and sustainable method. The limited thermal conductivity, however, prevents PCM from being widely used in a variety of uses. Highly conductive nanoparticles (NPs) are frequently integrated into PCMs to address this shortcoming. Due to their high thermal conductivity, such as Graphene (GR), carbon-based NPs are considered potential NPs to be implemented in PCMs. Herein, we report the Lauric acid (LA) PCM, and nano-enhanced LA with 0.3% and 0.7% additions of GR NPs. The composites were prepared by using two-step method. The samples were examined thermo-physically; thermal conductivity was obtained using a thermal property analyzer (TEMPOs), chemical composition was identified using Fourier transform infrared spectroscopy (FTIR), photo-transmittance by Ultra-Violet Visible spectra (UV-Vis) and thermal stability was assessed by employing thermal gravimetric analyzer (TGA). As per results, thermal conductivity of LA was enhanced by 13.5% and 18.4% by inclusion of 0.3 and 0.7 weight percentages of GR NPs. The 0.7 weight percentage addition of GR NPs to base PCM exhibited 60% transmittance reduction in comparison to base LA. Further all prepared samples were thermally stable with no weight degradation until 140°C. The FTIR confirmed the samples were chemically stable as no any new peak observed in composites. Therefore, based on results, GR enhanced LA PCM can be considered as future potential composite to be implemented in energy storage applications.
Utilization of Calliandra calothyrsus and Gliricidia sepium as co-firing fuel with consideration of ash-related issues
Authors: Putra H P , Kuswa F M , Prabowo  , Hariana
Published: December 2023

Biomass can be utilized as co-firing fuel in existing power plants. Woody biomass such as Calliandra calothyrsus and Gliricidia sepium, which can be planted in degraded land, have short cycle, good survivability, and high energy potency, are potential to be utilized. However, adding biomass to existing power plant fuel may cause ash deposition problems such as slagging, fouling, abrasion, corrosion, and agglomeration. This study investigates the ash-related problems of co-firing C. calothyrsus and G. sepium with different type of coal using theoretical indices. The results show that addition of C. calothyrsus and G. sepium up to 50 wt.% has insignificant effect to the risk of slagging, fouling, abrasion, and agglomeration of co-firing fuel. Since the chlorine content in these biomasses increases the corrosion risk to high, the addition of C. calothyrsus is recommended up to 10 wt.% while G.sepium up to 15 wt.% for co-firing fuel.
Resource recovery from palm kernel shell and its application for wastewater treatment: a circular economy approach
Authors: Tan Yan Ying , Zainal Abidin Mohd Izzudin Izzat , Buthiyappan Archina , Abdul Raman Abdul Aziz
Published: December 2023

In this study, cationic Methylene Blue (MB) dye removal was investigated through a batch adsorption process using a ternary adsorbent developed from palm oil biomass, graphene oxide, and iron oxide (M-PKSGO). Box-Behnken Design (BBD) was applied for modelling and analyzing the effects of independent operational parameters including pH of initial MB dye solution, M-PKSGO dosage and adsorption time on dye removal and adsorption capacity. The experimental results show an adsorption capacity of 82.7 mg/g was achieved using 1 g/L of M-PKSGO with 135 min at pH 11. Hence, the M-PKSGO composite is proven as an effective adsorbent for cationic dye removal from wastewater. The utilization of biomass from the palm oil industries promotes a circular economy via resource recovery activities. Overall, this work brings to light the opportunities created by green adsorbents in promoting a circular economy and stimulates further research and development in this highly pertinent field.
Investigation the influence of inclination angle for flat plate solar air collector through experiment and simulation
Authors: Wong S Y , Gobi K , Lim C H , Ong K S
Published: December 2023

The heat behaviour of a flat plate solar collector (FPSC) has been analyzed experimentally and numerically under natural convection air flow. The thermal energy transferred through the air by heat convection and heat radiation. The data collections for the solar collector includes various of the inclination angles (15°, 30°, 45°, and 60°). The conventional glazed solar collector has a very low efficiency. Hence, the collector is unglazed in this study. It also covered with the insulation on both sides and at the bottom plate to prevent heat loss. The analysis concluded that rising solar radiation causes temperature to rise. Besides that, it is found that the studies conducted simultaneously on the experimental and numerical models on the different inclination angles are still lacking. Hence, the numerical model was simulated through the utilization of Computational Fluid Dynamics (CFD) method. A comparison between the numerical model and experiment has revealed that the simulation results of FPSC are closer to the experiment result with less than 5% error. Thus, the numerical model that incorporates design parameters can be utilized for forecasting the way FPSC will operate properly. The results concluded that the FPSC with a 5 cm height of air gap has the highest heat output when inclined at 15 degrees.
Preliminary theoretical design of crossflow water turbine for rainwater rooftop harvesting system
Authors: Suhaime M A , Mat Tokit E , Sa’at F A Z M , Rosli M A M , Herawan S G , Oktarina R , Setyandito O
Published: December 2023

Harvesting energy is essential especially now that the demand of energy is high but the fuel supply is limited. This study theoretically designs the 5 m low head crossflow turbine in rainwater harvesting system. The characteristics of the site condition, the runner geometry, the blade geometry, and the turbine specification had been identified and the geometrical model of the design is shown. This paper reported the collection of theoretical formula for the design of low head crossflow turbine that can be used for rainwater harvesting system. The dimensional form of equations, as presented in Section 2, resulted to the two, four, and two parameters that represent the dimensions of the turbine, runner and the blade, respectively. As a conclusion, the designed turbine can be used for rainwater harvesting system with an efficiency that was calculated to be 88% with 22 kW expected power generated for 5 m head.
Preliminary study of the dual power source system for 11kV manufacturing substation’s battery charger
Authors: Faizil Anuar Putri Falyana Balqis , Ahmad Nurfadzilah , Pirdaus Nur Alfarina
Published: December 2023

In the future, renewable energy sources will be a more sustainable solution. Solar energy can be used by the factory to charge a substation’s battery charger. The plan is to use solar energy to charge a battery charger in a factory. Solar energy is more efficient than coal, petroleum, and natural gas. This paper demonstrates the design or reconstruction of an existing circuit drawing to achieve the goal of this project. The design incorporates a changeover switch to perform the power supply changeover for solar energy in order to compare the efficiency of the battery charger using solar power energy to the existing loads. The solar simulation will be built and performed by the MATLAB Simulink model for the simulation part. The PV array represents solar energy by stimulating the I-V and P-V for various irradiance (W/m2) and temperatures (oC). This project aims to improve the circuit design in the substation’s battery charger, develop a solar energy harvesting system, and create an efficient prototype of an energy storage automatic transfer switching system. As a result, this project helps to reduce the rate of global electricity consumption, which has an impact on the environment. Commercials’ pollution is significantly reduced by solar energy. We can demonstrate the global benefits and relevance of implementing this concept, particularly in our industry, by preparing this study. Solar energy is a dependable and cost-effective energy source. The sun is a renewable energy source. While fossil fuels will eventually run out, sunlight will not.
Feasibility study on electricity generation in Kg. Sabur Pulau Banggi Malaysia from wind energy using HOMER software
Authors: Kumar Y N S , Makmud M Z H , Hamid A S A , Rahman A B A , Miskon M T , Salleh S
Published: December 2023

The feasibility of electricity generation using wind turbine system in Kg. Sabur, Pulau Banggi, Sabah is studied by investigating the electrical load profile of Kg. Sabur and analyzing the techno-economic aspects. Pulau Banggi is an area that encountering with electricity shortage and the highlighted location from Pulau Banggi that facing this issue is Kg. Sabur. The diesel generator, main electricity supply insufficient to meet the load requirement in Kg. Sabur. Survey data is used to develop the electrical load profile in HOMER software. The meteorological data such as wind speed, solar GHI and temperature are inputted into HOMER as well as components sizing and costs details. Comparison is made between four electrical systems on the aspects of electricity production, economics, fuel consumption and gas emission to evaluate the efficiency of the system with wind turbine. The total electrical load of residential area in Kg. Sabur is 888 kWh/day. Type 1 electrical system that consists of wind turbine, solar PV, battery, generator and converter is the most cost-effective and highly reliable system to be implement in Kg. Sabur. Electrical generation from wind energy is the most feasible system to implement in Kg. Sabur, Pulau Banggi, Kudat.
Development of graphical user interface for boost converter employing visual studio
Authors: Krismadinata  , Aulia Firstia Bevi , Maulana Ricky , Yuhendri Muldi , Azri Maaspaliza , Kanimozhi Kannabiran
Published: December 2023

In power electronics, the boost converter is a typical circuit that raises the voltage from the input to the desired output voltage. For learning how a boost converter works, you need an easy-to-use GUI that lets you change the input voltage, output voltage, and load resistance. In this study, we look at how to use Visual Studio to make a boost converter’s simple user interface (GUI). Details are given about how the software was programmed and how the interface was made, as well as how the graphical user interface was made. This circuit has a total of four devices, two for current and two for voltage. Voltage sensors can measure both the input and output voltage, while current sensors can measure both the input and output current. The Arduino Uno microcontroller is used as a processor for getting data and as a link between sensor devices and personal computers. The results show that the GUI we made works well for analyzing the features of the boost converter circuit.
Thermodynamic and thermal degradation kinetics analysis of coconut shell biomass based phase change material
Authors: Kalidasan B , Pandey AK , Rahman Saidur , Buddhi D , Tyagi VV
Published: December 2023

Phase change materials (PCMs) stores and releases thermal energy in the form of latent heat during phase transition. Though PCMs are durable in nature, they suffer commercial application owing to low thermal conductivity. Inclusion of metal and carbon based nanoparticles are typically adopted to overcome the complication of poor conducting nature of organic PCMs. In this experimental research we develop a bio based nanoparticle using coconut shell in an environmental friendly manner to enhance the thermal conductivity of organic PCM polyethylene glycol 1000. Bio nanoparticle (BNP) improves the thermal conductivity of the developed nanocomposite PCM by 73.1% with 0.9 wt% of coconut shell BNP hence we evaluate the thermodynamic and thermal kinetics parameter of the nanocomposite PCM sample with 0.9 wt% biochar based nanoparticle. In addition the authors have analysed the thermal decomposition kinetics of the optimized PCM composite using Coats and Redfern method to exhibit the reaction mechanism, thermodynamic and kinetic parameter.
Optical performance and chemical stability evaluation of new era phase change material: Activated by hybrid nanoparticle
Authors: Pandey AK , Kalidasan B , Rajamony Reji Kumar , George Mathew
Published: December 2023

Inorganic salt hydrate phase change materials (PCMs) are ahead of organic PCMs in terms of energy storage ability and safety as they are non-flammable. However the major hindrance with inorganic PCM are degree of supercooling and low thermal conductivity though better than organic PCM. The common technique to enhance the thermal conductivity is via dispersion of metal and carbon nanoparticle. Though they enhance the thermal conductivity of the nanocomposite, with continuous operation the nanoparticle agglomerate and settles down owing to their density. Henceforth, in the current research work we conduct an experimental investigation to enhance the optical and thermal performance of commercialised inorganic salt hydrate PCM using metal-carbon hybrid nanoparticle. We disperse graphene silver nanoparticle at different weight ratio adopting a two-step method followed by probe sonication to ensure uniform dispersion. We achieve a highly stable nanocomposite with 584% increase in optical absorbance of electromagnetic waves and 86% decrease in transmittance. Thermal management of electronic gadgets has evolved to be a major consideration of research as overuse of gadgets lead to rapid temperature rise and is in need of passive cooling system. Henceforth the newly developed nanocomposite phase change materials (PCMs) not only acts as thermal batteries but can also be opted as energy materials for thermal regulation and heat mitigation.
Electrochemical fabrication and characterizations of Ag/AgCl pseudo-reference electrode: a preliminary study
Authors: Beh K P , Thong R Y , Saipul N S , Yam F K , Beh K K , Manaf A A , Oo C W , Hassan Z
Published: December 2023

In this work Ag/AgCl planar pseudo-reference electrodes (pREs) were fabricated and studied. The pRE was derived from typical copper-cladded flame retardant 4 (FR4) board, with layers of Ni, Au, and Ag electrochemically deposited sequentially. Lastly, the AgCl layer was obtained through electro-chlorination process. The morphology and Open Circuit Potential (OCP) of the samples were obtained from characterizations. It was revealed that the Au layer consisted of finer grains compare to that of Ag having larger granular structure. There was also morphological difference between as-prepared AgCl and post OCP run AgCl, where the later show signs of degradation. Based on the potential-transient curve of electro-chlorination, chlorination process took place on the surface of Ag, subsequently diffused into the bulk layer. Sample chlorinated for 1 min shows better stability in OCP test where the potential exhibit minimum changes. The duration of the sample being stable during electrochemical process was 10 minutes.
How many trees are required to offset the CO2 emissions from building operations? A case study of energy efficiency initiatives in Wisma R&D, Universiti Malaya building
Authors: Mohd Ali SB , Wan Md Adnan WN , Baharom AS , Hasanuzzaman Md , Rahim NA
Published: December 2023

Malaysia has pledged to GHG emissions by 45% by 2030 in light of the urgent need to reduce global emissions. One approach used by the government is to concentrate on energy sustainability programs, such as energy efficiency (EE). The success of this approach relies on the support from various parties. Persuading non-technical management and staff, however, might be particularly difficult. Hence, besides the technical-based impact, it is important to analyse the environmental and financial-based impact too. This paper portrayed the EE initiatives that could assist in reducing energy (kWh), cost (RM), and CO2 (tonne) simultaneously. The number of trees needed to neutralise or offset an emission might later be related to a reduction in CO2. A case study of Wisma R&D, UM was referred. The environmental-based impact of the lighting retrofitting projects at Wisma R&D was used in this study to illustrate the importance of EE approaches. Both parameters are obtained from the online Greentech carbon calculator. A 144,386 kWh annual savings resulted in RM 52,701 in cost savings, and a decrease of 100.2 tonnes of CO2 emissions was achieved. Ultimately, based on the decrease in CO2, 2569 fewer trees are needed to offset the emission.
Design and analysis of earth-air heat exchanger integrated into the building ventilation system
Authors: Lapisa Remon , Kurniawan Andre , Jasman  , Waskito  , Purwantono  , Arwizet  , Yuvenda Dori , Rahmadiawan Dieter , Ambiyar
Published: December 2023

This experimental study intent to design and to analyse the passive cooling effect of an Earth-Air Heat Exchanger (EAHE) integrated into the building ventilation system. For hot climate regions, ground thermal inertia can be used as a passive cooling strategy in the building ventilation where the air supply comes from outside with hot temperature. The proposed EAHE device consists of two main-components; a water tank and a PVC hose as a heat-exchanger between air and water in the tank. Fresh air from outside with a flow rate of 5.63 kg. min-1 is blown through a 2 ½-inch PVC hose, and cooled by the low water-soil temperature before being distributed into the room. To analyze the effectiveness of the passive cooling effect, measurements are performed for several parameters; inlet and outlet air temperature of ventilation ducts and indoor-outdoor air temperature using a multichannel thermocouple data logger for 48 hours of measurement time. The results present that the EAHE device can reduce the air temperature to a maximum of 10.6 °C. This proposed EAHE device presents good performance as a passive cooling technique for a building ventilation system, especially during the day.