Big Island Research Articles

First estimate of distribution, abundance, and risk of encounter with aquaculture vessels for the rare Chilean dolphin in the entire Northern Chilean Patagonia

Abstract Assessing distribution and abundance patterns for rare species is challenging yet imperative, considering the extant, potentially hazardous, anthropogenic activities. In particular, the poorly studied Chilean dolphin (Cephalorhynchus eutropia) exhibits an extremely patchy distribution and low densities, co‐occurring with the intensive aquaculture industry in Southern Chile, among other anthropogenic activities. The distribution and abundance patterns of Chilean dolphins were assessed in the entire Northern Chilean Patagonia. A hierarchical species distribution model was fitted to data from line transect surveys using distance sampling techniques and environmental variables derived from topographic features and oceanographic models. A second version of this model used a joint‐likelihood approach to incorporate presence–pseudoabsence data for improving parameter estimation. Spatial predictions arising from these models were used to evaluate the relative probability of a dolphin encountering vessels from the local, predominantly aquaculture fleet. The results show that using a joint‐likelihood approach drastically reduced uncertainty in the parameters controlling the effect of covariates and in the total abundance estimates. This model estimated an overall low abundance (median 2,225.8; 95% CI 1,340–3,867) for this species in the region, and indicates their preference for shallow, sheltered bays and inner channels, near river mouths, where low salinity is expected. The highest probabilities of dolphin–vessel interactions were found on the eastern coast of Chiloe Big Island, coinciding with the largest number of aquaculture concessions in the area. Considering that the overall population of the Chilean dolphin is expected to be in the low thousands, that suitable habitat for the species is highly restricted, and that the species is facing increasing anthropogenic impacts, with some areas undergoing or planning major expansions in development, the results provided here should be considered in management plans for extant marine protected areas, and in the evaluation of current International Union for Conservation of Nature (IUCN) and national conservation categories for the species.

Wave Farms Integration in a 100% renewable isolated small power system -frequency stability and grid compliance analysis.

In general terms, the variable penetration of RE in power systems has some inherent drawbacks, such as lack of manageability and resource variability [1]. Medium (in the range of minutes) and short term (in the range of seconds) variability has a negative impact on system reliability, causing a deterioration of system frequency quality in both interconnected and, moreover, isolated systems [1-2]. Specifically, the variability of the wave energy resource is medium- and short-term. Therefore, although wave energy could be very suitable to be integrated in islands due to its location, the variable nature of wave energy could negatively impact the stability of the power grid [3].
 The case study of the work focuses on the island of El Hierro (Canary Islands, Spain). It is an isolated electrical system with a very high penetration of renewable energy sources. The generation of the electrical system is composed of a wind farm, a pumped hydroelectric power plant and conventional generation by means of a diesel power plant.
 In a previous analysis [4], the integration of energy storage systems based on flywheels was analyzed. Based on this previous analysis, the manuscript studies the influence of the integration of the wave energy park in the electrical system of El Hierro.
 On the one hand, a wave farm will be proposed to evaluate the generated power and its associated oscillation [5]. The wave energy resource at different locations along the coast of El Hierro will be taken into account. On the other hand, an aggregated inertial dynamic mode of the electrical power system will be used to evaluate the impact of the generated power on the electrical frequency and the aging/degradation effects of the hydropumping elements. The Spanish Grid Code will be taken into account regarding frequency regulation mechanisms in isolated systems.
 The degradation of the hydraulic pumping systems due to additional frequency regulation stresses and electrical frequency deterioration will be calculated and evaluated in relation to the penetration of wave energy into the system, with and without the flywheel energy storage plant. This will allow quantification of certain technical limits to wave energy penetration in isolated systems and to draw conclusions with reference to the size of such a power system.
 [1] R. S. Kaneshiro et al. “Hawaii Island (Big Island) Wind Impacts” Proc. of Workshop on Active Power Control from Wind Power, Broomfield, CO, USA, 2013.
 [2] H. R. Iswadi et al. “Irish power system primary frequency response metrics during different system non synchronous penetration,” IEEE Eindhoven PowerTech 2015, doi: 10.1109/PTC.2015.7232425.
 [3] Isabel Villalba et al. “Wave farms grid code compliance in isolated small power systems,” IET Renewable Power Generation, 2019, doi: 10.1049/iet-rpg.2018.5351.
 [4] Hilel Garcia-Pereira et al. “Comparison and Influence of Flywheels Energy Storage System Control Schemes in the Frequency Regulation of Isolated Power Systems,” IEEE Access, 2022, doi: 10.1109/ACCESS.2022.3163708.
 [5] M. Blanco et al. “Study of the impact of wave energy generation in the frequency of an island electric grid,” Proc. of the 12th European Wave and Tidal Energy Conference (EWTEC). 2017.

Robust Behavior of Charge Density Wave Quantum Motif Star-of-David in 2D NbSe2 Nanocrystals.

Charge density wave (CDW) is a typical collective phenomenon, and the phase change is generally accompanied by electronic transition with potential device applications. For the continuous miniaturization of devices, it is important to investigate the size effect down to the nanoscale. In this work, single-layer (SL) 1T-NbSe2 islands provide an ideal research platform to investigate the size effect on CDW arrangement and electronic states. The CDW motifs (Star-of-David [SOD]) at the island border are along the edge, and those at the interior tend to arrange in a triangular lattice for islands as small as 5nm. Interestingly, in some small islands, the SOD clusters rearrange into a square-like lattice, and each SOD cluster remains robust as a quantum motif, both in the sense of geometry and electronic structures. Moreover, the electronic structure at the center of the small islands is downwards shifted compared to the big islands, explained by the spatial extension of the band bending originating from the edge of the islands. These findings reveal the robust behavior of CDW motifs down to the nanoscale and provide new insights into the size-limiting effect on 2D2D CDW ordering and electronic states down to a few nanometer extremes.

Occurrence and status of the European Pond Turtle, Emys orbicularis hellenica (Valenciennes, 1833), on Aegean and Ionian Islands (Greece, Turkey)

A study on the occurrence of Emys orbicularis in the Aegean, published in 2012, is here extended to the Ionian Islands. For the first time, a status analysis has also been carried out for the individual islands. Emys orbicularis is found on 11 Greek islands and one Turkish. Its presence on the big islands of Rhodes and Chios has not been ascertained so far, while for four previously mentioned islands there is no confirmation. On Corfu and Lesbos there are still viable larger Emys populations. Most other island occurrences are characterized by small populations. On Kefalonia, Zakynthos, Thassos and Samos, E. orbicularis is in danger of extinction because the wetland biotopes are threatened. In the meantime, many wetlands have been placed under protection. The enforcement of these nature conservation regulations needs to be monitored, and E. orbicularis can be a lead species for such monitoring.

Conceptual Design of a Floating Modular Energy Island for Energy Independency: A Case Study in Crete

This paper aims to investigate the development of a floating artificial sustainable energy island at a conceptual design level that would enhance the energy independence of islands focusing on a case study on the island of Crete. This paper provides a baseline assessment showing the immense potential of wind and solar energy in and around Crete integrating the third significant renewable energy source (RES) of ocean waves into the energy island. The selection of the best location for the floating offshore platforms that compose the energy island is addressed through exploiting the great potential of the above-mentioned RES, taking into consideration criteria with regard to several significant human activities. To this end, the concept of an innovative floating modular energy island (FMEI) that integrates different renewable energy resources is proposed; in addition, a case study that focuses on the energy independency of a big island illustrates the concept referring to the substitution of the local thermal power plants that are currently in operation in Crete with sustainable energy power. Although focused on the renewable energy resources around Crete, the work of this paper provides a basis for a systematic offshore renewable energy assessment as it proposes a new methodology that could be used anywhere around the globe.

Wildfire Hotspots Forecasting and Mapping for Environmental Monitoring Based on the Long Short-Term Memory Networks Deep Learning Algorithm

Global warming is raising the earth’s temperature, and resulting in increased forest fire events, especially in tropical regions with locations that are at high risk of wild and forest fires. Indonesia is a country in Southeast Asia that has experienced a severe number of wildfires, which have dangerous impacts on neighboring countries due to the emission of carbon and haze to the free air. The objective of this research is to map and plot the locations that consist of a significant number of fire hotspots and forecast the possible forest fire disasters in Indonesia based on the collected data of forest fires. The results of forecasting data are beneficial for the government and its policymakers to take preventive action and countermeasures regarding this wildfire issue. The Long Short-Term Memory (LSTM) algorithm, a deep learning method, was applied to analyze and then forecast the number of wildfire hotspots. The wildfire hotspot dataset from the year 2010 to 2022 is derived from the National Aeronautics and Space Administration’s (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS). The total number of collected observations is more than 700,000 wildfire data in Indonesia. The distribution of wildfire hotspots as shown in the results is concentrated mainly on two big islands, Kalimantan and Sumatra, Indonesia. The main issue is the peat type of land that is prone to spreading fire. Forecasting the number of hotspots for 2023 has achieved good results with an average error of 7%. Additionally, to prove that the proposed algorithm is working well, a simulation has been conducted using training data from 2018 to 2022 and testing data from 2021 to 2022. The forecasting result achieved a similar pattern of the number of fire hotspots compared to the available data in 2021 and 2022.

Physical and optical traits of tellurite glass: effect of bimetallic TiO2/Au nanoparticles

The dependence of TiO2/Au concentrations on the physical and optical properties of glass was investigated thoroughly. Variations in density, molar volume, molar refraction, refractive index, and polarizability with varying TiO2/Au contents were affected by the formation of non-bridging oxygen. The formation of big islands in the atomic force microscopy image signifies the growth of nanoparticles. The decrement in band gap manifests alteration in the glass network mainly the local field around the Er3+ ions. The rise in Urbach energy illustrates disorder in the glass. The beneficial features of the current glass composition may be useful for photonic devices.

Convergence of regional GDP per capita among the big islands in Indonesia

This research aims to analyze the regional GDP per capita convergence on the big five islands in Indonesia, which is Sumatera, Java, Borneo, Celebes, and Moluccas and Papua during period 2012-2021. Analyzed convergence included Sigma Convergence, Absolute Beta Convergence, and Conditional Beta Convergence. Data that is used in this research is Panel Data. Data analysis technique is Panel Data Analysis Method with Fixed Effect Model (FEM) approach. Results of the analysis show that the convergence the regional GDP per capita convergence on the big five islands in Indonesia is happened during period 2012-2021, meaning there is an indication that income dispersion between Sumatera, Java, Borneo, Celebes, and Moluccas and Papua is becoming smaller. Next, the results show that the beta absolute and conditional convergence is happened, which indicates that income growth per capita for the underdeveloped islands is higher than the advanced economic development islands, pushing for a convergent economic. Population growth and capital expenditure are variables that significantly affect in accelerating this convergence.

Multiple Affective Attributes for the Customization of Post-Pandemic Food Services

ABSTRACT Customization of multiple attributes is an innovative strategy to adapt to the uncertain situation in the post-pandemic food services. It is a nondeterministic polynomial-time NP-hard multi-criteria decision-making problem which requires Artificial Neural Network (ANN) and Particle Swarm Optimization (PSO). Attributes data were acquired using Kansei words through online in-depth interview and questionnaire. A total of 505 respondents were recruited from the five biggest islands in Indonesia. The data were modeled using an artificial neural network to predict the importance of the attributes. The predicted importance was optimized using Particle Swarm Optimization (PSO) based on the pandemic constraints of anxiety, familiarity, and trust. The PSO extracted 4, 12, and 3 attributes for dine-out, delivery, and take-out services, respectively. The findings of this study could help industries in minimizing research and development costs by utilizing the extracted affective attributes.

Smart City Policy: Strategy and Implementation to Realize Smart Urban Governance in Indonesia

This paper elaborates on policies, strategies, and implementation of Smart Cities in Indonesia. Due to regulatory, strategy, and implementation problems for Smart City, there are still differences in understanding and strategy in its implementation. Smart urban governance is part of a smart city, so one strategy to implement smart urban governance is a smart city policy in Indonesia. There is a fragmentation of inconsistent approaches, policies, implementations, and strategies in practice. This research will develop arguments, analyze published articles and regulations, and map them out. The research method used was a qualitative approach. The data sources used were articles from Scopus which found 213 articles using the keywords smart city policies and smart urban governance and regulations, which were then processed using VOSviewer and Nvivo 12 Plus software. This study indicated that to implement smart urban governance in Indonesia, strategies such as the first need to be supported by the central government to make a policy regarding smart cities, including smart urban governance, followed by smart city policies in the towns in Indonesia. Second, there are technological developments that support the implementation of smart cities. Third, there are institutional and human resource factors, but these are still obstacles to implementing smart cities in Indonesia. Meanwhile, the urban issues developed in Indonesia are mega-urban in the big island, urban management and financing, housing for lower-income, sustainable urban infrastructure, and resilient disaster mitigation and management.

Accounting for spatial habitat and management boundaries when estimating forest bird population distribution and density: inferences from a soap film smoother.

Birds are often obligate to specific habitats which can result in study areas with complex boundaries due to sudden changes in vegetation or other features. This can result in study areas with concave arcs or that include holes of unsuitable habitat such as lakes or agricultural fields. Spatial models used to produce species' distribution and density estimates need to respect such boundaries to make informed decisions for species conservation and management. The soap film smoother is one model for complex study regions which controls the boundary behaviour, ensuring realistic values at the edges of the region. We apply the soap film smoother to account for boundary effects and compare it with thin plate regression spline (TPRS) smooth and design-based conventional distance sampling methods to produce abundance estimates from point-transect distance sampling collected data on Hawai'i 'Ākepa Loxops coccineus in the Hakalau Forest Unit of the Big Island National Wildlife Refuge Complex, Hawai'i Island, USA. The soap film smoother predicted zero or near zero densities in the northern part of the domain and two hotspots (in the southern and central parts of the domain). Along the boundary the soap film model predicted relatively high densities where 'Ākepa occur in the adjacent forest and near zero elsewhere. The design-based and soap film abundance estimates were nearly identical. The width of the soap film confidence interval was 16.5% and 0.8% wider than the width of the TPRS smooth and design-based confidence intervals, respectively. The peaks in predicted densities along the boundary indicates leakage by the TPRS smooth. We provide a discussion of the statistical methods, biological findings and management implications of applying soap film smoothers to estimate forest bird population status.

Multimedia Interaktif Berbasis Articulate Storyline 3 Sebagai Alternatif Media Pembelajaran Materi Karakteristik Geografis Indonesia di Sekolah Dasar

The study was conducted based on observations at SDN Sukorame 2 Kediri, which showed that as many as 69.09% of students in Grade V on Indonesian geographical characteristics obtained scores below KKM (Minimum Criteria of Mastery Learning). This problem occurred because of the incompleteness of the material presented in learning resources and no learning media that could clearly describe the geographical characteristics of big islands in Indonesia. In addition, the information obtained that as many as 96.36% of students prefer digital-based learning resources equipped with writing, images, sound, and animation. However, SDN Sukorame 2 Kediri currently still lacked of digital-based learning resources. Based on problem analysis and needs analysis, researchers will develop interactive multimedia by utilizing Articulate Storyline 3 software. This research and development aim to produce innovation in learning activities to be more effective in the form of interactive multimedia that helps students understand the material and increase motivation in learning. This research uses the R&D method with the ADDIE model. The results of this study showed that the validity of material experts was 90% and media experts were 82%, so the average validation results were 86%. The practical results of the questionnaire of expert responses of limited-scale practitioners are 91% and broad-scale practitioner experts are 95%, so an average practical result of 93% is obtained. The results of effectiveness on a limited scale of 84 and extensive trials of 82 so that it is known that student learning outcomes after using interactive multimedia are higher than before the use of multimedia. Based on the data from the validity, practicality and effectiveness test results, it can be concluded that interactive multimedia by utilizing Articulate Storyline 3 is valid, practical and effective use.

Mauna Loa awakens

On 27 November 2022, Hawaii’s Mauna Loa volcano on the Big Island began erupting for the first time in 38 years. A day later, a flight over the eruption captured this photo. It clearly shows a line of fissures, at an elevation of 3 km, from which lava flowed across the volcano’s northeast rift zone. The eruption continued for about two weeks, with lava traveling some 20 km from the summit. The US Geological Survey observed an increase in the number of earthquakes beneath the volcano’s cauldron-shaped summit and to the northwest roughly two months before the eruption began. The island’s nearby Kīlauea volcano has been erupting since September 2021.PPT|High resolutionThe two volcanoes appear to be connected underground by a deep, widespread network of pathways, according to a recently published paper by researchers from Caltech. Although previous studies have hypothesized that such a network may exist, the large data set the Caltech team analyzed showed enough seismic activity to map out a detailed plumbing system that connects Mauna Loa to Kīlauea, 34 km away. Future monitoring of volcanic activity may benefit from considering both volcanoes as part of a larger, interconnected system. (J. D. Wilding et al., Science 379, 462, 2023, doi:10.1126/science.ade5755; image courtesy of the US Geological Survey.) Section:ChooseTop of page <<© 2023 American Institute of Physics.

Assessing the Impact of Extensive Severe Cyclonic Storm Fani on the Coastal Communities of Bangladesh: A Case Study

This research article presents a numerical simulation of the extensive severe cyclonic storm Fani and its impact along the coast of Bangladesh, which made landfall in the coastal region of Odisha, India, on May 3, 2019. A semi-implicit finite difference method in Cartesian coordinates was employed in this study to solve vertically integrated shallow water equations. The approach allowed for effective forecasting of the storm Fani's impact on the region of choice. Our considered physical domain is discretized with high-resolution gird to cover all the big and small offshore islands. The model predicted water levels for a total of sixteen coastal stations of the Bay of Bengal along the coast of Bangladesh (from 2 May to 03 May 2019, at 3-h interval). Simulated water levels are found closely co-related to the reported data. The simulation results demonstrate that the semi-implicit finite difference method is an effective tool for simulating the storm surge and flooding caused by any severe cyclonic storm. The study also shows that the storm surge and flooding caused by Fani were significant, with a maximum surge height of over 5 meters in some areas. The simulated results provide insights into the spatial and temporal evolution of the storm surge and flooding, which can be useful for designing and implementing appropriate disaster management strategies in the affected regions. Overall, this research article contributes to the scientific understanding of the behavior of severe cyclonic storms and the associated storm surge and flooding, and provides a valuable tool for policymakers and stakeholders to develop and implement effective disaster management strategies in cyclone vulnerable coastal regions.

Titus Coan: "Apostle to the Sandwich Islands." by Phil Corr (review)

Reviewed by: Titus Coan: "Apostle to the Sandwich Islands." by Phil Corr Clifford Putney Titus Coan: "Apostle to the Sandwich Islands." By Phil Corr. (Eugene, Oregon: Wipf & Stock. 2021. Pp. 513. $60.00. ISBN: 978-1-6667-1393-0). In the annals of missionary history, few places were evangelized as thoroughly as Hawaii (the Sandwich Islands), where missionaries from the American Board of Commissioners for Foreign Missions (Congregational/Presbyterian) converted the bulk of the populace to Christianity in the 1800s. Generally intolerant of native Hawaiian customs and beliefs, ABCFM missionaries on the islands were definitely not broad-minded by the standards of today. They were at the forefront of progressive nineteenth-century movements such as abolitionism, however, and they were exceptionally well educated for their day (the women as well as the men). They also included intellectually curious individuals such as the Reverend Titus Coan (1801–1882), whom Phil Corr writes about in his absorbing new biography, Titus Coan: "Apostle to the Sandwich Islands." That Coan is the worthy subject of a biography cannot be denied. A Presbyterian missionary in Hilo on Hawaii (the big island) for forty-eight years (1835–1882), he was a powerful preacher, and he was a prolific writer, with a gift for describing people and places. He was also an ardent revivalist, and he did more than anyone else to instigate the Great Awakening in Hawaii (1836–1840), a [End Page 433] period during which tens of thousands of Hawaiians converted to Christianity. On a Sunday in 1838, at the height of the Awakening, Coan used a bucket and paintbrush to baptize 1,705 adults, whom he subsequently made members of his church in Hilo. The church had over 7,000 members in 1841, and Coan could boast of it being the largest church in the world at that time. In addition to being a successful evangelist, Coan was a skillful (albeit amateur) scientist, and he made important discoveries in the field of vulcanology. As a resident of Hawaii (one of the most geologically active islands in the world), Coan experienced earthquakes, tsunamis, and volcanic eruptions, and he provided detailed descriptions of them for missionary publications and leading scientific journals. He also made innumerable trips to Mauna Loa and Kilauea (the island's two active volcanos), and he risked death on many of those trips. Most people avoid erupting volcanoes, but Coan (who possessed a strong physique and a fearless nature) liked to climb them, even when plumes of red-hot lava were splashing down around him. For his biography of Coan, Phil Corr spent years doing research, relying on published works (especially Coan's autobiography) and unpublished materials, such as letters. From these materials, Corr provides readers with a richly comprehensive portrait of Coan ("the bishop of Kilauea"), encompassing the missionary's childhood on a farm in Connecticut, his conversion during America's Second Great Awakening, his acquaintance with the famous revivalist Charles Finney, his experimental mission in the wilds of Patagonia (1833–1834), his clashes with conservative members of the ABCFM (who opposed Coan's style of revivalism), his two marriages (the latter to a woman thirty-three years his junior), his successful outreach to white sailors, his participation in the American peace movement, his two-year (1870–1871) tour of America (where he was greeted by crowds that sometimes numbered in the thousands), and his long presidency (1863–1882) of the Hawaiian Evangelical Association, the successor body to the ABCFM in Hawaii. Throughout his biography of Coan, Corr expresses admiration for the man and his work. Corr is an evangelical pastor (just as Coan was), and he rarely provides secular explanations for religious phenomena, preferring instead to take the religious phenomena at face value. Doubtlessly this will frustrate secular readers of his book, but even they might well come away from the volume with a liking for Coan, who was not a toxic missionary of the sort found in novels such as The Poisonwood Bible. Rather than being harshly judgmental and arrogant, Coan was a deeply caring individual, and he won the enduring love of people around him. Clifford Putney Bentley University [End Page 434] Clifford Putney Bentley University Copyright...

Field Evaluation of In2Care Mosquito Traps to Control Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Hawai'i Island.

Aedes aegypti Linnaeus and Aedes albopictus Skuse are vectors of dengue virus and responsible for multiple autochthonous dengue outbreaks in Big Island, Hawai'i. Control of Ae. aegypti and Ae. albopictus has been achieved in In2Care trap trials, which motivated us to investigate this potential control approach in the Big Island. Our In2Care trial was performed in the coastal settlement of Miloli'i in the southwest of Big Island where both Ae. aegypti and Ae. albopictus are found. This trial starting in the second week of July and ending in the last week of October 2019 fell within the traditional wet season in Miloli'i. No significant reduction in egg or adult counts in our treatment areas following 12 wk of two In2Care trap placements per participating household were observed. In fact, an increase in numbers of adults during the trial reached levels that required the local mosquito abatement program to stop the In2Care trap trial and institute a thorough source reduction and treatment campaign. The source reduction campaign revealed a large variety and quantity of water sources competed with the oviposition cups we had placed, which likely lowered the chances of our oviposition cups being visited by pyriproxyfen-contaminated Aedes adults exiting the In2Care traps.

Complete mitogenome sequence of Aedes (Hulecoeteomyia) japonicus japonicus from Hawai’i Island

We report the first complete mitogenome (Mt) sequence of Aedes japonicus japonicus (Diptera: Culicidae). The sequence was extracted from one adult from the Big Island of Hawai’i Island. The length of the Ae. japonicus japonicus Mt was 16,528bp with 78.1% AT content. Its sequence is most similar to the Mt sequence of Aedes koreicus with 90.81% sequence identity. This is the first full Mt sequence available for this species and provides important genetic resource for studying population genetics and dynamics of this important invasive mosquito species.

Assessment of Raw Water Infrastructure Performance for the Performance Index Modeling

This research aimed at the performance assessment of raw water infrastructure. The performance of raw water infrastructure in this case is as the service function of the infrastructure for supplying the raw water. Generally, the benchmark for determining the infrastructure performance is seen from the ability of raw water infrastructure in distributing the raw water discharge according to the demand for the raw water acceptor service. This research is conducted in the Nusa Tenggara Barat (NTB) Province, one of the island provinces consisting of two big islands and several small islands surrounding them. The two big islands are Lombok and Sumbawa, with their uniqueness in the water use pattern, water availability, rainfall, and the economic matters of water user society. The methodology consists of the assessment of the monetary aspect, service aspect, operational aspect, and human resources aspect. The assessment result will be used as the validation standard in building the performance index modeling. However, the assessment of existing raw water infrastructure performance in NTB based on the PP 122, 2015. The result shows that the monetary aspect is increasing in several PDAM; the service aspect is decreasing; the operational aspect is increasing at the beginning, but by the time, it is decreasing; however, the human resources aspect shows an increasing condition. Keywords : assessment, infrastructure, raw water, monetary aspect, service aspect, operational aspect, human resource aspect. https://doi.org/10.55463/issn.1674-2974.50.3.11

Context and mitigation of lost circulation during geothermal drilling in diverse geologic settings

Lost circulation is one of the most common and expensive problems facing geothermal energy development, representing up to 30% of drilling costs. We examined drilling records from four geothermal fields—McGinness Hills in central Nevada, Don A. Campbell and Steamboat Hills in western Nevada, and Puna Geothermal Venture on the Big Island of Hawai'i— to identify geologies most prone to lost circulation, as well as common mitigation strategies. Depths of lost circulation events varied, but their frequency often increased in the production interval. Lost circulation commonly occurred near fault intersections, and heavily faulted fields like McGinness Hills and Don A. Campbell showed secondary mineralization within approximately 100 m (328 ft) or less of where circulation was lost. Lost circulation mitigation strategies included using locally available materials (e.g., cotton seed hulls) as well as more expensive proprietary lost circulation materials, cement plugs above the reservoir, and drilling blind with aerated, polymer-based mud in the production zone. Addressing lost circulation using a well thought out decision-making approach and materials above the reservoir will save time and cost, and provide needed well integrity. Mitigation often requires a series of steps, typically applied from perceived least expensive to most, and are dependent on the severity and location in the well where circulation was lost and availability of materials. Placing cement plugs can cure lost circulation events, however these plugs are often expensive, time-consuming, and may not be successful.

Investigating The Determinants of Muslim Intention to Accelerate Zakat Payment During The Covid19 Pandemic

The crisis caused by the COVID-19 pandemic is more severe than other crises that have occurred before such as the crisis in 2008. This is because of the speed and scale it has created. The purpose of this study was to determine the effects of the COVID-19 pandemic crisis on changes in the behavior of Muslims in Indonesia, namely accelerating the payment of zakat during the Covid-19 pandemic. The data used in this study is primary data, where data were collected through questionnaires to respondents who were selected purposively throughout the big islands of Indonesia and collected as many as 256 respondents. By using the Structural Equation Modeling (SEM) Partial Least Square approach, it is found that several variables have an influence on the behavior of Muslims to accelerate paying zakat, including the Attitude variable and the Perceived Behavioral Control variable. However, it was found that the Subjective Norm variable was not proven to significantly influence the behavior of Indonesian Muslims to accelerate paying zakat during the COVID-19 pandemic crisis. The limitations of this study are that the sample that dominates is only from the island of Java and the age proportion of the respondents is dominated by millennials and generation z.