bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fully-printed metamaterial-type flexible wings with controllable flight characteristics
Authors: Zhilyaev Igor , Anerao Nitesh , Kottapalli Ajay Giri Prakash , Yilmaz Mahmut Cihat , Murat Mustafa , Ranjbar Mostafa , Krushynska Anastasiia 
Published: December 2021

Abstract
Insect wings are an outstanding example of how a proper interplay of rigid and flexible materials enables an intricate flapping flight accompanied by sound. The understanding of the aerodynamics and acoustics of insect wings has enabled the development of man-made flying robotic vehicles and explained basic mechanisms of sound generation by natural flyers. This work proposes the concept of artificial wings with a periodic pattern, inspired by metamaterials, and explores how the pattern geometry can be used to control the aerodynamic and acoustic characteristics of a wing. For this, we analyzed bio-inspired wings with anisotropic honeycomb patterns flapping at a low frequency and developed a multi-parameter optimization procedure to tune the pattern design in order to increase lift and simultaneously to manipulate the produced sound. Our analysis is based on the finite-element solution to a transient three-dimensional fluid–structure interactions problem. The two-way coupling is described by incompressible Navier–Stokes equations for viscous air and structural equations of motion for a wing undergoing large deformations. We 3D-printed three wing samples and validated their robustness and dynamics experimentally. Importantly, we showed that the proposed wings can sustain long-term resonance excitation that opens a possibility to implement resonance-type flights inherent to certain natural flyers. Our results confirm the feasibility of metamaterial patterns to control the flapping flight dynamics and can open new perspectives for applications of 3D-printed patterned wings, e.g. in the design of drones with target sound.
Estimating unprecedented extremes in UK summer daily rainfall
Authors: Kent Chris , Dunstone Nick , Tucker Simon , Scaife Adam A , Brown Simon , Kendon Elizabeth J , Smith Doug , McLean Lynsay , Greenwood Shirley 
Published: December 2021

Abstract
The UNSEEN (unprecedented simulated extremes using ensemble) method involves using a large ensemble of climate model simulations to increase the sample size of rare events. Here we extend UNSEEN to focus on intense summertime daily rainfall, estimating plausible rainfall extremes in the current climate. To address modelling limitations simulations from two climate models were used; an initialised 25 km global model that uses parameterised convection, and a dynamically downscaled 2.2 km model that uses explicit convection. In terms of the statistical characteristics that govern very rare return periods, the models are not significantly different from the observations across much of the UK. Our analysis provides more precise estimates of 1000 year return levels for extreme daily rainfall, reducing sampling uncertainty by 70%–90% compared to using observations alone. This framework enables observed daily storm profiles to be adjusted to more statistically robust estimates of extreme rainfall. For a damaging storm in July 2007 which led to surface water flooding, we estimate physically plausible increases in the total daily rainfall of 50%–100%. For much of the UK the annual chance of record-breaking daily summertime rainfall is estimated to be around 1% per year in the present-day climate. Analysis of the dynamical states in our UNSEEN events indicates that heavy daily rainfall is associated with a southward displaced and meandering North Atlantic jet stream, increasing the advection of warm moist air from across Southern Europe and the Mediterranean, and intensifying extratropical storms. This work represents an advancement in the use of climate modelling for estimating present-day climate hazards and outlines a framework for applying UNSEEN at higher spatial and temporal resolutions.
Modification of Septic Tank for Sedimentation Optimization in the Public Toilet (Case Study at Wisdom Park UGM)
Authors: Syafira K , Ahmad J S M , Saraswati S P 
Published: December 2021

AbstractSeptic tank with sedimentation and anaerobic processes in the same tank is commonly used as a domestic wastewater treatment technology in individual households and communal systems. Although simple to construct, such a system has some problems, such as effluent not meeting the quality requirement and blocking by trash and suspended solid before the second treatment chamber. This research aims to develop a new septic tank design that is simpler to construct and improve performance. The new design uses HDPE material, which is easier to build and standardized compared to the conventional concrete structure. The performance of the new design was compared to the conventional septic tank. The start-up process was monitored for flowrate, COD, TSS, NH3N, PO4-P parameters and evaluated against effluent standards. The study was conducted at public toilet facilities at Wisdom Park UGM and Sunday Morning Market. Results from the study show that the new design effectively improves effluent quality and overcomes the trash problem.
Microplastic pollution in the sediment of Jakarta Bay, Indonesia
Authors: Azizi A , Setyowati W N , Fairus S , Puspito D A , Irawan D S 
Published: December 2021

Abstract
During the COVID-19 pandemic, the increased use of plastic for personal protective equipment (PPE), single-use plastic bags, and food packaging raised significant environmental concerns. This study aimed to investigate the shape, abundance, and type of microplastics in the sediment of Jakarta Bay, specifically Tanjung Priok, Ancol Beach, and Sunda Kelapa Port. Sediment was collected using an Ekman sediment grab sampler and was extracted using the density separation method. The microplastics were counted and categorized according to the shape under a microscope. The differences in microplastic abundance in three different stations were determined using a one-way ANOVA. The polymer of microplastics was identified using Fourier Transform Infra-Red (FTIR). The results show that the abundance of the microplastics from coastal sediment was highest in the Sunda Kelapa Port (45066.67 ± 5205.13 particle/kg dry weight), which is significantly different (p<0.05) from Tanjung Priok (40533.33 ± 2444.04 particle/kg dry weight) and Ancol Beach (34666.67 ± 2444.04 particle/kg dry weight). Fragments dominated the shape of microplastic in Tanjung Priok, Ancol Beach, and Sunda Kelapa Post, comprising 36%, 40%, 38%, respectively, followed by fiber, film, and pellet. The FT-IR tests indicated that polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyamide are the most prevalent microplastic polymers.
Diffusion of chloride from seawater into the concrete analysis: a literature review on implemented approaches
Authors: Ariningsih Y S , Nuralinah D , Saputra A W W 
Published: December 2021

Abstract
Infrastructures near the sea, such as ports, offshore platforms, bridges, and coastal buildings, are affected by seawater due to the coastal region. Chloride, contained in seawater, causes a decrease in the strength and durability of the concrete. Some researchers have published a paper on analyzing the penetration of chloride ions into concrete under different coastal environments and predicted chloride diffusion in concrete with computational modeling. This paper aims to review the existing literature related to various laboratory work tests and analytical methods in evaluating the diffusion of chloride from seawater into concrete. A set of forty papers were collected and reviewed that were published from 2011 until 2020 for studying. The review showed that chloride diffusion was a complex process and affected by many factors such as material properties, curing time, immersion/exposure time, and environmental conditions. Various experimental methods in the Laboratory were conducted using concrete specimens made from various materials in the exposed and submerged conditions. Researches in the field were carried out on existing structures with a certain building age using non-destructive testing. Meanwhile, the analytical methods applied simple equations and numerical simulation computational software.
Sustainable ground improvement method using encapsulated polypropylene (PP) column reinforcement
Authors: Hasan M , Zaini M S I , Hong N A W , Wahab A , Masri K A , Jaya R P , Hyodo M , Winter M J , Sholichin M , Haribowo R 
Published: December 2021

Abstract
This study investigates the effectiveness of encapsulated polypropylene (PP) column in enhancing the undrained shear strength of kaolin (soft clay). The usage of PP in treating problematic soil is a more sustainable and cost-effective alternative compared to other materials. The installation of granular column can be done by using vibro-replacement method. Several geotechnical tests to determine the properties of materials were conducted. The shear strength of treated kaolin sample was examined by using Unconfined Compression Test (UCT). There are seven (7) batches of soil sample in total which included a control sample, three (3) batches of 14 mm and three (3) batches of 20 mm diameter PP column. Different diameters of PP column were examined with 60 mm, 80 mm and 100 mm height, respectively with soil sample of 50 mm in diameter and 100 mm in height. The shear strength improvement of kaolin is 33.82%, 46.51%, and 49.88% when implanted with a PP column with a 7.84 area replacement ratio and 0.6, 0.8 and 1.0 penetration ratio. The soft soil treated using 16.00 area replacement ratio with 0.6, 0.8 and 1.0 penetration ratio has a shear strength increment of 25.22%, 33.39% and 37.59% respectively. In short, the shear strength improvement of the kaolin clay depends on the parameter of the PP column used to reinforce the sample.
Evaluation of water supply alternatives for mineral water teaching factory
Authors: Sarosa M , Hapsari R I , Moentamaria D , Adhisuwignjo S , Putri R I , Buwono H P , Rohadi E , Wibowo S 
Published: December 2021

Abstract
The teaching factory (TEFA) in State Polytechnic of Malang (Polinema) attempts to address the replication of the real industrial process inside the traditional educational setting. In Polinema, the TEFA deals with the bottled mineral drinking water, and its supply chain starts from the water purifying until the marketing. A key aspect of achieving an economically and technically feasible production is the selection of wellspring as the source of raw material. The potential water sources are located at Wringinsongo, Ampeldento, Prigen, and Ngijo in Malang area. A decision support system is required to select the suitable source by integrating weighted tangible and intangible criteria, namely water quality, distance, and willingness to pay. Multicriteria decision-making by analytical hierarchy process is applied to assign criteria weight and select the source. The results demonstrate that Ngijo wellspring is recommended, followed by Wringinsongo, Ampeldento, and Prigen according to the performance value. The system could serve as a tool for the selection, instead of intuitive judgment with a better compromise for improving the TEFA productivity.
Seasonal Spatio-temporal Land Cover Dynamics in the Upper Brantas Watershed
Authors: Beselly S M , Lufira R D , Andawayanti U 
Published: December 2021

Abstract
Quantitative assessment for sustainable watershed management is essential. Hydrological parameters such as stream discharge, surface runoff, infiltration, groundwater recharge, and water quality are susceptible to the changes of the components in the river basin ecosystem. Numerous studies have shown that the Land Use Land Cover (LULC) changes such as deforestation, extensive agriculture, urbanization, and mining are recognized as the main factors to changes in LULC, which are related to the changes of the hydrological components of the river basin of all scale. This paper particularly shows the spatiotemporal variability of LULC in the Upper Brantas Basin and the effects on the river discharge variation. We showed that the changes in LULC, particularly cultivated and managed vegetation and urban/built-up area, contributed significantly to the river discharge. Particularly in the Upper Brantas Basin, it was indicated that almost half of the increased river discharge was explained by the increase of urban/built-up and the decrease in cultivated and managed vegetation area.
Investigation Of Hydraulic Flow Characteristics On Drop Structures
Authors: Dermawan V , Dermawan D R , Ismoyo M J , Wicaksono P H 
Published: December 2021

Abstract
Drop structures are required if the slope of the ground level is steeper than the maximum allowable gradient channel. Drop structures become bigger as height increases. Its hydraulic capability may be reduced due to variations of jets falling on the stilling basin floor due to discharge changing. Drop structures should not be used if the change in energy level exceeds 1.50 m. The free-falling overflow on drop structures will hit the stilling basin and move downstream. As a result of overflows and turbulence in the pool below the nappe, some energy is dissipated at the front. The rest of the energy will be reduced downstream. The objectives of this study are to investigate the hydraulics flow behavior in straight and sloping drop structures and to investigate hydraulics flow behavior in a single and serial vertical drop (stepped drop). The hydraulic model results of single and stepped drop structures are compared to obtain flow behavior and energy dissipation information. The comparisons are specific to the flow parameters, including flow depth at the drop structures toe, flow depth after the jump, and hydraulic jump length.
Pattern and direction of groundwater flow and distribution of physical-chemical properties of groundwater in Randublatung basin
Authors: Tantama E E , Kumara M A , Putra D P E , Marliyani G I 
Published: December 2021

Abstract
The people in the Randublatung basin (Grobogan, Blora, and Bojonegoro Regencies) using groundwater for daily needs and agriculture activity. As the initial step of basin-based groundwater management, it is necessary to understand the groundwater potential in this area: pattern and direction of groundwater flow and groundwater physical-chemical properties (pH, temperature, total dissolved solids, and electrical conductivity). This research aims to analyze the pattern and directions of groundwater flow, the physical-chemical properties, and the correlation between the two. This research method is field measurement of 45 different spots of dug wells in the Randublatung basin. Our results indicate that the pattern and direction of groundwater flow in the Randublatung basin are heading to Bengawan Solo River and then following the river’s flow. The groundwater physical-chemical properties measured: pH value is 6.8 on average, the temperature is 28.9 °C on average, TDS concentration is 409 mg/L average, and electrical conductivity rate is 843 μS/cm average. There is no significant correlation between groundwater flow with pH value and groundwater temperature. However, groundwater TDS concentration and electrical conductivity rate in the Randublatung basin increase as groundwater flows to the Bengawan Solo River, which is affected by the minerals of aquifer rocks (alluvial deposits).
Modification of basic hydrology formulation based on an approach of the rational method at field measurement
Authors: Kencanawati M , Anwar N , Maulana M A 
Published: December 2021

Abstract
The rational method was a simple technique for estimating the design discharge of a small watershed and can be used in a probabilistic approach. The main parameter in the rational method formula was the C coefficient. The rational method was the primary method for determining the peak discharge from surface runoff flow. At the end of the dry season and the beginning of the rainy season, it placed an automatic water level recorder and automatic rain gauges for the initial water level. This field research aimed to correct a simple hydrological formulation with field measurements and build a numerical rainfall modelling based on rainfall simulation, infiltration, land use, and flow parameters according to the relationship model of precipitation. The hypothesis in this study, the basic formulation of hydrology, is simple: it requires experience to fit the theoretical hydrological formula so simply (simplicity). The theory needs to be simplified because it is an experience of field necessary to explain.
Evaluation of surface water for agricultural irrigation in Lobalain District, Rote Ndao Regency, East Nusa Tenggara Province, Indonesia
Authors: Riady R R , Wilopo W , Warmada I W 
Published: December 2021

Abstract
The average rice productivity of the Rote Ndao Regency is still below the national rice productivity. The cropping pattern’s lack of management and limited water sources can only be planted once a year. This study aims to determine the availability and quality of surface water used for irrigation with the existing rice-corn-fallow cropping pattern. The research was carried out by measuring discharge in the field, surveying the types and cropping patterns, irrigation area research, surface water quality analysis, and hydrological analysis. The results showed that the need for irrigation water for agriculture in the study area with the current cropping pattern was 0.84 lt/second/ha. Therefore, the existing irrigation area of ±3,762.00 Ha requires a water discharge of ±3.159 m3/second. The availability of surface water in the Lobalain District is low, with a discharge of ±1.598 m3/second. Surface water quality shows the percentage of sodium (Na%) dominated by excellent to permissible class, and the sodium adsorption ratio (SAR) excellent. The existing resource of surface water could not support agricultural irrigation. Therefore, it is necessary to find an alternative water source such as groundwater.
Determination Of Groundwater Recharge Area In Raimanuk And Surroundings, Timor Island
Authors: Manta W F , Hendrayana H , Amijaya D H 
Published: December 2021

Abstract
The Raimanuk area in Timor, East Nusa Tenggara, is located in the Aroki Groundwater Basin. The decreasing quality and potential groundwater availability in the Aroki Groundwater Basin is feared due to its widespread use for household needs and agriculture. The lack of the groundwater recharge area map will pose an obstacle in policymaking regarding the management and preparation of spatial conservation areas in the Raimanuk Region. This study aims to determine the zone and classification of groundwater recharge areas in the Raimanuk area based on spatial data analysis. The groundwater recharge area can be determined using slope, river flow patterns, spring emergence, and groundwater table depth. The classification of the recharge area uses a scoring approach with an overlapping analysis of the parameter assessments, which are hydraulic conductivity, precipitation, soil cover, slope, and depth of unconfined groundwater. The result of the study is the groundwater recharge area map of Raimanuk. The groundwater recharge area is located in the Mandeu Hill area, which is the main recharge area. The groundwater discharge area is located in the Aroki plain area that can be the main recharge area.
Economic Feasibility Analysis Development of Intake and Raw Water Pipelines in Kota Bangun Sub-District, Indonesia
Authors: Marsudi S , Lufira R D , Sari S , Riadi D 
Published: December 2021

Abstract
Increasing the population in Kota Bangun Sub-District, Kutai Kartanegara Regency, in line with the consequence that growing needs for drinking water and raw water for local communities become a top priority. Public complaints about the increasing difficulty of obtaining clean water seem to be an obstacle that the Regional Government has yet to resolve fully. The production capacity of PDAM Kota Bangun is currently only 30 liters/sec, which is far from sufficient for the needs of all people in the Kota Bangun Sub-District. Economic feasibility calculation analysis utilized the NPV, IRR, and BCR methods and sensitivity analysis to obtain the economic feasibility for the value of developing intake and raw water networks. The results indicate, with a reasonable life condition of 30 years, the construction of water networks in Kota Bangun is still economically feasible. Reasonable with the minimum requirement of BCR = 1, with sensitivity analysis on two scenarios, considerations of 30% and 20% leakage, and 30.55% and 25% administrative costs. The results of the research show that IRR = 17.70%. If the analysis conditions are that investment costs increase by 10% with Fixed Benefits, the payback period is 6.8 years.
An Alternative Algorithm for Simulating Flash Flood
Authors: Khaldirian M F , Rahardjo A P , Luknanto D , Sondi R D R 
Published: December 2021

Abstract
Most of the approaches in numerical modeling techniques are based on the Eulerian coordinate system. This approach faces difficulty in simulating flash flood front propagation. This paper shows an alternative method that implements a numerical modeling technique based on the Lagrangian coordinate system to simulate the water of debris flow. As for the interaction with the riverbed, the simulation uses an Eulerian coordinate system. The method uses the conservative and momentum equations of water and sediment mixture in the Lagrangian form. Source terms represent deposition and erosion. The riverbed in the Eulerian coordinate system interacts with the flow of the mixture. At every step, the algorithm evaluates the relative position of moving nodes of the flow part to the fixed nodes of the riverbed. Computation of advancing velocity and depth uses the riverbed elevation, slope data, and the bed elevation change computation uses the erosion or deposition data of the flow on the moving nodes. Spatial discretization is implementing the Galerkin method. Furthermore, temporal discretization is implementing the forward difference scheme. Test runs show that the algorithm can simulate downward, upward, and reflected backward 1-D flow cases. Two-D model tests and comparisons with SIMLAR software show that the algorithm works in simulating debris flow.
Performance of Flushing Efficiency of Sediment Evacuation from Wlingi and Lodoyo Reservoirs
Authors: Legono D , Hidayat F , Sisinggih D , Wahyuni S , Suharyanto A 
Published: December 2021

Abstract
The sediment evacuation from the reservoir should be carried out when it disturbs the dam development’s functional design. There are issues regarding the objection to releasing sediment from the reservoir, especially related to potential environmental degradation of the river downstream. The sediment source entering the reservoirs is considerably variable, depending upon the catchment characteristics and the hydrological triggers. When limiting the erosion yield and controlling the sediment in the catchment, evacuating sediment from the reservoir could be the only alternative to avoid environmental degradation. Several issues showed that sediment evacuation from reservoirs is a cost-effective solution. Therefore, assessing the efficiency of sediment evacuation from a reservoir through flushing has become of high interest. This paper presents the analysis of the flushing efficiency performance of the flushing operation of Wlingi and Lodoyo Reservoir that was carried out on 10-17 March 2019. The flushing efficiencies are found to be 0.005 and 0.003 for Wlingi and Lodoyo Reservoirs, respectively. These figures are lower than that of Mrica Reservoir and other world reservoirs at higher than 0.1. Further analysis suggests the critical timing of the sediment evacuation schedule considering the inflow condition.