bluuebunny/crossref_metadata_2025_split huggingface dataset:
Students’ Errors in solving the PISA mathematics problem using Newman’s error categories
Authors: Ahyan S , Turmudi  , Prabawanto S 
Published: November 2019

AbstractThe purpose of the study is to analyze the students’ errors of a junior high school student in solving the Program for International Student Assessment (PISA) mathematics problem. Then, it will be analyzed that what kinds of students’ errors regarding Newman’s error categories, which were connected to the PISA’s stage of mathematization. The Newman’s error categories are comprehending a task, transforming the task into a mathematical problem, processing mathematical procedures, and interpreting or encoding the solution regarding of the real solutions. The participants were two students of junior high schools. According to the finding of this study, all of the students are making error in transformation and process skills. While the second student is also making comprehension error, no student is doing a mistake in encoding.
The analysis of mortar concrete with the variety of sands in jepara (keling sand, bangsri sand) using strong pressure method
Authors: Saputro Yayan Adi , Mudiyono Rachmat , Antonius  
Published: November 2019

Abstract
Along with the increasing of infrastructure development in Indonesia especially in jepara, so the necessary of material also increase, for example: sand. Nowadays, muntilan is the sand that often be used in making infrastructure in the government because it is considered that it has the good quality, whereas in the other hand the river sand is also abundant, but the government perverted mintilan sand as the development material. River sand is usually used by the middle to lower county because the house because the price is cheaper than muntilan sand. After doing this research we hope that: can know the quality of the river sand if it is used in infeastructure, knowing the river sand in jepara that have the good quality, such as: keling sand, bangsri sand, The stages of this research are: preparation, sand inspection (mud content and organic faces, filter analysis, moister content and weight, and specific gravity), making spacimens based on SKSNI 03-6825-2002 ASTM C 305, making compressive strength test. The test result show that at 3,7,14,21,28 days old show that keling sand (93,2 kg/cm2), bangsri sand (135,2 kg/cm2). The use of river sand as the construction material by the government and community will have consequence on the balance kf muntilan sand and river sand. The specific treatment on the river sand will that quality that is almost same as muntilan sand.
The formulation Robusta coffee bark Jember Indonesia for charcoal Briquettes as alternative energy : The comparison organic starch adhesive and anorganic adhesive
Authors: Moelyaningrum Anita Dewi , Molassy Honest Dody , Setyowati Intan Kartika 
Published: November 2019

Abstract
The Robusta coffee plantation were founded from Silo Jember district Indonesia. One of the solid waste coffee plantation is coffee bark. The objective of this study is to find the formulation of Robusta coffee bark Jember for charcoal briquette as alternative energy. The formulation of charcoal robusta coffee bark were comparisson within organic starch adhesive and anorganic adhesive. The formulation were analyzed in physical and chemical quality base on SNI Number. 01-6235-2000. the solid waste coffee plantation were collected from smallholders coffee plantation on Silo Jember. The first step were drying the solid waste coffee bark in the sun almost 2 days till dried. Then, the dried coffee bark were using pod waste pyrolysis in reactor with a temperature of 400 C until became charcoal. Organic starch adhesive were making by mixing the the 6 gram starch and 60 milliliter water (ratio 1:10), and then mixing down with 60 gram charcoa (formula 1). Formula 2 were mixing the 60 gram charcoal, organic starch adhesive and added 3 gram anorganic adhesive. The briquettes were formed into tube with diameter 6 cm and the thickness 4 cm. The result showed that using organic starch adhesive were more fragile, harder to light the fire first but dried faster than using anorganic adhesive. The chemical analysis on the formula 1 (briquette with organic starch adhesive) and formula 2 (briquette with anorganic adhesive) showed that moisture were 9,87%; 7,7 %, volatil matter were 5,87%; 4,2 %, the Ash content were 8,01 %; 5,03 %, the caloric value were 4870 cal/gr; 7233 cal/gr and the fixed carbon were 65%; 81%. The formula 2 showed the better quality than formula 1.
Formalin and Borax Qualitative Test Use Natural Indicator
Authors: Rahman Nanang 
Published: November 2019

Abstract
The purpose of this study is to identify natural indicators that can be used to test the qualitative presence of formalin and borax. The results of this qualitative test can be used for student learning in schools, especially for harmful additive substances in food. Qualitative test using a drop test. Formalin test using extract flower of ribose ruellia, hibiscus rosa-sinensis L and Impatiens L balsamina, while for borax test using ruellia simplex, plumeria rubra, portulaca grandiflora and curcuma longa. Based on the results of the research that has been done, the extract can be used to determine the presence of borax and formalin with a drop test.
Designing the Mitigation Model of Urban Sprawl Potential Impact in Suburban Denpasar, Bali
Authors: Christiawan Putu Indra 
Published: November 2019

Abstract
This study is aimed to list the impacts of urban sprawl in the suburban area in Denpasar City. The implications that force growth in suburban areas is responsible for undesirable pattern or process of urban growth. The consequences or the impacts of urban sprawl, whether negative or positive, are also necessary to be understood and evaluated towards achieving sustainable development. Urban sprawl means more growth than the usual and what makes it different from urban growth is this excessive nature. Cities tended to grow and planned extension reached while there is an appropriate proportion between urban growth and urban population. However, when the increase is more than usual, its pressure on the boundaries, suburban area will face new significant problems. Significant problems that occur in the suburbs of Denpasar include environmental, social, economic and mobility issues. The impact analysis of urban sprawl on these four dimensions forms the basis for determining comprehensive urban sprawl mitigation models in suburban areas.
Estimating meltwater retention and associated nitrate redistribution during snowmelt in an Arctic tundra landscape*
Authors: Westergaard-Nielsen Andreas , Balstrøm Thomas , Treier Urs A , Normand Signe , Elberling Bo 
Published: November 2019

Abstract
Nitrogen availability in Arctic ecosystems is a key driver for biological activity, including plant, growth and thereby directly linked to the greening of the Arctic. Here, we model the redistribution of meltwater following spring snowmelt as well as the accumulation of meltwater and dissolved nitrate at landscape scale. By combining snow mapping with unmanned aerial systems, snow chemistry, and hydrological modelling, we argue that the majority of nitrate in the snowpack is flushed out of the landscape due to the limited storage capacity of meltwater in the early growing season frozen soil. We illustrate how landscape micro-topography is a crucial parameter to quantify storage capacity of meltwater at landscape scale and thereby the associated pool of soluble compounds such as nitrate. This pool will be available for plants and may be important for plant diversity and growth rates in the wettest part of the landscape. This study illustrates that the evenly distributed nitrate input during the Arctic winter may be redistributed during the initial snowmelt and lead to marked differences in biologically available nitrate at the onset of the growing season, but also that the majority of deposited nitrate in snow is lost from the terrestrial to the aquatic environment during snowmelt.
A spatial pattern analysis of forest loss in the Madre de Dios region, Peru
Authors: Nicolau Andrea Puzzi , Herndon Kelsey , Flores-Anderson Africa , Griffin Robert 
Published: November 2019

Abstract
Over the past decades, the Peruvian Amazon has experienced a rapid change in forest cover due to the expansion of agriculture and extractive activities. This study uses spectral mixture analysis (SMA) in a cloud-computing platform to map forest loss within and outside indigenous territories, protected areas, mining concessions, and reforestation concessions within the Madre de Dios Region in Peru. The study area is focused on key areas of forest loss in the western part of the Tambopata National Reserve and surrounding the Malinowski River. Landsat 8 Operational Land Imager and Landsat 7 Enhanced Thematic Mapper Plus surface reflectance data spanning 2013–2018 were analyzed using cloud-based SMA to identify patterns of forest loss for each year. High-resolution Planet Dove (3m) and RapidEye (5m) imagery were used to validate the forest loss map and to identify the potential drivers of loss. Results show large areas of forest loss, especially within buffer zones of protected areas. Forest loss also appears in the Kotsimba Native Community within a 1 km buffer of the Malinowski River. In addition to gold mining, agriculture and pasture fields also appear to be major drivers of forest loss for our study period. This study also suggests that gold mining activity is potentially not restricted to the legal mining concession areas, with 49% of forest loss occurring outside the mining concessions. Overall accuracy obtained for the forest loss analysis was 96%. These results illustrate the applicability of a cloud-based platform not only for land use land cover change detection but also for accessing and processing large datasets; the importance of monitoring not only forest loss progression in the Madre de Dios, which has been increasing over the years, especially within buffer zones, but also its drivers; and reiterates the use of SMA as a reliable change detection classification approach.
Climate change impacts the spread potential of wheat stem rust, a significant crop disease
Authors: Prank Marje , Kenaley Shawn C , Bergstrom Gary C , Acevedo Maricelis , Mahowald Natalie M 
Published: November 2019

Abstract
Long range atmospheric transport is an important pathway for the spread of plant pathogens, such as rust fungi which can devastate cereal crop health and food security worldwide. In recent years, serious concern has been caused by the evolution of new virulent races of Puccinia graminis f. sp. tritici, a pathogen causing wheat stem rust that can result in close to 100% yield losses on susceptible wheat cultivars in favourable weather conditions. We applied an Earth system model to compare the suitability of the current climate and a business-as-usual climate scenario (RCP 8.5) for 2100 for wheat stem rust. Although there are large uncertainties in modelling changes in disease spread, we focus in this paper on the changes which are likely to be robust to model assumptions. We show that the warmer climate with lower relative humidity and enhanced turbulence will lead to ∼40% increase in the urediniospore emitting potential of an infected field as global average. The main predicted changes in the atmospheric long-range transport include reduced connections between Europe, Africa and South Asia, and increased frequency of spores crossing the mid-latitude oceans. Due to reduction in subfreezing conditions, the overwintering areas of the fungus will expand. On the other hand, projected drier conditions will reduce substantially the probability of an infection starting from deposited spores, except in irrigated fields.
Volcanological context of the Bouillante high temperature geothermal system, Guadeloupe, Lesser Antilles
Authors: Gadalia A , Legendre Y , Bouchot V 
Published: November 2019

Abstract
The hydrothermal manifestations of Bouillante area (Guadeloupe, Lesser Antilles) motivated a geothermal survey in the sixties. Nevertheless, the heat source of the Bouillante hydrothermal system is still debated: (i) local magma body, (ii) magmatic source beneath the centre of the island or (iii) result from the deep circulation.
Several arguments support the first hypothesis and the definition of a specific volcanic series, the « Bouillante chain », according to the following characteristics:
➢ location: small monogenic volcanoes are scattered along the Caribbean coastline, on- and off-shore;
➢ structural control: volcanic centres have developed at the junction of two regional tectonic systems, the NNW-SSE trending Montserrat - Les Saintes fault and the sub-E-W trending Marie-Galante’s grabens system;
➢ dynamics: their products often result from a magma - water interaction between, either in an external or internal hydromagmatism;
➢ petrology: specific magmatic trend reached an extreme (rhyolitic) level by crystal fractionation.
The links between the Bouillante chain and contemporary / neighbouring other Guadeloupe volcanic formations (Les Mamelles domes, Axial chain, Caraïbes mountains, Grande Découverte volcano) are discussed but partly remain to be specified.
Geothermal heat pump systems in cold regions: efficiency improvement by use of ambient air
Authors: Vasilyev G P , Gornov V F , Kolesova M V , Dmitriev A N 
Published: November 2019

Abstract
We examine the problem of efficiency in both air-source and geothermal heat pumps in regions with low ambient air temperature, and the advantage of using a combination of both systems in one equipment. Both geothermal and air heat pumps have their advantages and disadvantages. Geothermal heat pumps are more expensive to install and, in colder climates, experience a progressive decrease in efficiency with constant use during the winter season because of chilling of the ground adjacent to geothermal heat exchangers during heat extraction. Air-source heat pumps are less expensive to install and experience a decrease in efficiency as ambient temperature is getting lower. A numerical model simulation was conducted using the program “INSOLAR.GSHP.12” for a 200 sq.m. house in Moscow. The model tested the efficiency of combined use of a ground heat pump at ambient temperatures below -10°C, and air heat pump for ambient temperatures above -10°C. The results were compared to simulation of using only a geothermal heat pump. The results show a 13.3% reduction in energy consumption using the combined ground and air heat pumps over the energy requirement of using only the geothermal heat pump.
Main outcomes for Mexico at the half of the GEMex Project
Authors: Gutiérrez-Negrín L C A , López-Hernández A , Garduño-Monroy V H , Ramírez-Montes M A 
Published: November 2019

Abstract
The GEMex project is a binational endeavour developed by a Mexican and a European consortium coordinated by a common executive board. Each consortium is financed by their own resources, which are approximately 10 million euros for each part. The project is focused on two geothermal areas, Los Humeros and Acoculco, and was started two years ago. In January 2019 it reached its half point for the Mexican partners, and from the Mexican viewpoint the main results up to then can be summarized as follows. There is a new volcano-tectonic framework and characterization that has been rising from the geoscientific work developed, integrated and modelled by the project, which in the case of the Los Humeros geothermal field is profiling the most promising areas where the superhot geothermal fluids could be found. In the case of Acoculco, the integration model has provided the current stress field that can be used to develop an EGS project in the area, which still needs to be completed with the interpretation of the remaining seismic data, and that is planned to be tested at the final stages of the project with a stimulation test. The expected outcomes can be used by the CFE (Comisión Federal de Electricidad), which is the public utility that has the proper permits to explore and develop both geothermal areas.
Tolmachevsky active magmatic center (South Kamchatka) and its heat-power capacity as estimated by deep geophysical surveys
Authors: Nurmukhamedov A G , Sidorov M D 
Published: November 2019

Abstract
The structure of the Earth’s crust and upper mantle has been estimated by using geologic-geophysical cross-sections developed along two orthogonal geophysical profiles in the area of the Tolmachevsky active magmatic center. Comprehensive geophysical data have revealed the existence of an intrusive massif of predominantly intermediate-medium-felsic composition whose formation is accounted for by the presence of powerful heat flows and local melting sites. A swarm of small earthquakes reported in 1987-1988 was triggered by the advance of magma in the zone of the assumed eruptive fissure. Meteoric waters interact with the high-temperature media through the infiltration zone, which results in intense hydrothermal activity including the formation of steam-hydrothermal occurrences. The area of the proposed intrusive body is a promising zone for a high-temperature geothermal reservoir.
Geothermal system characteristics on Northern Ternate region, Indonesia based on interpretation of magnetic anomalies
Authors: Ningrum Rohima Wahyu , Aryuni Vrita Tri , Pambudi Nugroho Agung 
Published: November 2019

Abstract
Geothermal resources can be indicated by surface manifestations such as hot springs, hot mud puddles, and geysers. In the Northern Ternate region, in the villages of Tobololo and Sulamadaha, the manisfestation of hot springs is present. Therefore the purpose of this research is to study the geothermal characteristic in the Northern Ternate region, Indonesia, based on interpretation of magnetic anomalies in the hot surface temperature of hot springs. The method employed a fluxgate magnetometer to measure a sample of random temperature. Furthermore it examined for their chemical content to determine their resource type.
The results show that the magnetic anomalies value in the Northern Ternate region is of -3678.63 nT up to 2679.57 nT. The contour map is then developed by indicating three levels of magnetic anomalies; low, medium, and high. This is an indication that the area is of geothermal manifestation and it is classified as a hypothetical resource that could become an unexpected reserve. The temperature is measured at 50 cm depth and it shows of 27-38.50 °C. The result of the temperature anomaly in the Tobololo area is due to the flow of hot springs along the coastline. Meanwhile the Sulamadaha area has a smaller hot spring discharge, which is due to hydrothermal activity below the surface. Based on the the geochemistry assessments, both areas have alkali chloride water type.
The performance of ventilation in internal buildings affected by differences of building orientation
Authors: Aini Q , Nadia N 
Published: November 2019

Abstract
Natural ventilation is a passive cooling strategy with maximize of airflow into the building. Profil of hills and building orientation are some factor that influences the air quality, and it can control the wind speed. By the author’s previous research that building with configured in a grid pattern on the contoured land has enhanced the airflow quality than the grid pattern applied on the flat land. That condition affected building adaptation, such as good position of the opening in the building can optimize the utilization of airflow as the refreshment. This study purposed to evaluates performance of building ventilation of grid patterns on the hillside. This study using Jacky Chan Settlements that was located in Neuhen, Aceh Besar, Aceh Province, Indonesia. Computational Fluids Dynamics (CFD) Fluent used to analyze how far the performance of ventilation in the internal building. This study found that the pattern of airflow and the airflow quality in the room influenced by orientation. All orientation in the settlements created good cross ventilation with differences in wind speed. Contribute of this study is can be a reference for designing better settlements in a contoured land.
Prototype development of smart brake controller (SBC) for light-duty vehicles (LDVs) with manual
Authors: Munahar S , Setiyo M , Purnomo B C , Waluyo B , Himawan W 
Published: November 2019

Abstract
This paper presents the development of a smart brake controller (SBC) that applied to passenger cars to reduce accidents while stopped on a hill road. Crash accidents often occur due to the lack of driver skill or negligence in holding the brake pedal. The smart brake controller works by electro-mechanically to lock the brake system even though the brake pedal is released. The results showed that SBC could work well on a variety of vehicle loads and variations in road slope.
Mathematical modeling of drying behavior of coconut grate in a modified screw mixed dryer
Authors: Santosa I , Sulistiawati E , Aktawan A 
Published: November 2019

Abstract
The research aimed to examine the drying behavior of coconut grate in an oil bath pilot-scale modified screw mixed dryer using scientific mathematical models. Various drying temperatures of 80, 85, 90, 95 and 100 °C were used to investigate it using a recognized mathematical model of drying. Exploratory information of moisture ratio, temperature and relative humidity attained from various dryer conditions were fitted to the different experimental drying models. The drying model performances were contrasted based on their correlation coefficient (R2) between the observed moisture ratios. The result of the research showed that Wang and Singh’s model demonstrated the best fit model among the modified screw mixed dryer.
Biomass conversion of tamarind waste to syngas through gasification process on downdraft gasifier
Authors: Aktawan A , Maryudi  , Salamah S 
Published: November 2019

Abstract
National energy demand has been fulfilled by non-renewable energy sources, such as natural gas, petroleum, coal and so on. However, non-renewable energy reserves deplete increasingly which can cause an energy crisis. Conversion of biomass into energy becomes one of the solutions to overcome it. Indonesia has an enormous biomass potential, especially from tamarind. Tamarinds produce waste tamarind shells. These wastes can be treated with gasification technology to produce syngas. The gasification model used in this research is downdraft gasifier equipped with a cyclone to separate gas with solid or liquid gasification process. The more dry waste of Javanese tamarind, the more syngas produced during the gasification process. And the more dry waste of Javanese tamarind, then the longer the expenditure time of syngas. In syngas analysis known at 5 ml syngas contain 3,046% of CH4, 14,337% CO and 9,031% H2.