bluuebunny/crossref_metadata_2025_split huggingface dataset:
Citrate Addition Increased Phosphorus Bioavailability and Enhanced Gasoline Bioremediation
Authors: Chen Tingting , Philips Courtney , Hamilton Jordan , Chartbrand Blaine , Grosskleg Jay , Bradshaw Kris , Carlson Trevor , Timlick Karen , Peak Derek , Siciliano Steven D. 
Published: August 2017

Phosphorus (P) bioavailability often limits gasoline biodegradation in calcareous cold‐region soils. One possible method to increase P bioavailability in such soils is the addition of citrate. Citrate addition at the field scale may increase hydrocarbon degradation by: (i) enhancing inorganic and organic P dissolution and desorption, (ii) increasing hydrocarbon bioavailability, and/or (iii) stimulating microbial activity. Alternatively, citrate addition may inhibit activity due to competitive effects on carbon metabolism. Using a field‐scale in situ biostimulation study, we evaluated if citrate could stimulate gasoline degradation and what the dominant mechanism of this stimulation will be. Two large bore injectors were constructed at a site contaminated with gasoline, and a biostimulation solution of 11 mM MgSO4, 1 mM H3PO4, and 0.08 mM HNO3 at pH 6.5 in municipal potable water was injected at ∼5000 L d−1 for about 4 mo. Following this, 10 mM citric acid was incorporated into the existing biostimulation solution and the site continued to be stimulated for 8 mo. After citrate addition, the bioavailable P fraction in groundwater and soil increased. Iron(II) groundwater concentrations increased and corresponded to decreases in benzene, toluene, ethylbenzene, xylenes (BTEX) in groundwater, as well as a decrease in F1‐BTEX in the soil saturated zone. Overall, citrate addition increased P bioavailability and may stimulate anaerobic microbial activity, resulting in accelerated anaerobic gasoline bioremediation in cold‐region calcareous soils.Core Ideas
Citrate addition increased P amendment efficiency for hydrocarbon bioremediation.
Citrate boosted organic P dissolution to increase soil P bioavailability.
Citrate enhanced gasoline dissipation, possibly by stimulating iron‐reducing degraders.
Laboratory Column Evaluation of High Explosives Attenuation in Grenade Range Soils
Authors: Won Jongho , Borden Robert C. 
Published: August 2017

High explosives (HEs) deposited on military ranges can leach through the soil and contaminate groundwater. We examined the transport and fate of HEs in laboratory columns containing soils from two hand grenade bays (Bays C and T) and the impact of organic amendments on biodegradation. Soil characteristics were similar; however, Bay C had somewhat higher clay and organic C. Experimental treatments included addition of crude glycerin and lignosulfonate, and parallel control columns. Experimental results showed extensive 2,4,6‐trinitrotoluene (TNT) degradation with minimal leaching, consistent with prior batch microcosm results. Amendment addition enhanced TNT degradation in both Bays C and T compared with controls. Although hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (Royal Demolition Explosive, or RDX) did not biodegrade in prior aerobic batch microcosms, 64 to 77% of RDX biodegraded in untreated soil columns with O2 present in the mobile soil gas. The RDX biodegradation was likely associated with short‐term anoxic conditions or anoxic micro‐niches. In nearly saturated Bay C columns, RDX removal increased to >92%. Amendment addition to unsaturated Bay T columns increased RDX removal to >86%. In one column, the soil remained anoxic (O2 < 5% by volume) for about a year after amendment addition, significantly reducing RDX leaching. Nitroso degradation products were produced equivalent to 9 to 39% of the RDX degraded, with most retained in the soil (9–37%) and 0 to 3% in the effluent. These results demonstrate that RDX biodegradation can occur in soils with measurable O2, and that amendment addition can reduce RDX leaching by stimulating anaerobic biodegradation.Core Ideas
TNT extensively degraded in soil under both aerobic and anoxic conditions.
RDX degradation was enhanced under anoxic soil conditions.
There was significant RDX degradation in soil columns that were sometimes aerobic.
Organic substrate addition generated anoxic conditions enhancing RDX degradation.
Modeling Zinc and Copper Movement in an Oxisol under Long‐Term Pig Slurry Amendments
Authors: Mallmann Fábio Joel Kochem , Santos Danilo Rheinheimer dos , Bender Marcos Antonio , Gubiani Elci , da Veiga Milton , Minella Jean Paolo Gomes , van Oort Folkert , Šimůnek Jirka 
Published: August 2017

Core Ideas
Eleven years of Zn and Cu movement in an Oxisol amended with pig slurry (PS) was modeled.
Root growth and water uptake effects were successfully added in HYDRUS simulations.
Concentration profiles of Zn were described better than those of Cu.
DOC‐facilitated Cu transport needs to be considered when modeling Cu transport in soils.
Zn concentrations will not be a problem during the next 50 yr in PS‐amended soils.
Increases in Zn and Cu concentrations in soils amended with pig slurry (PS) can be described using numerical models. Our main objective was to validate that the HYDRUS‐1D model is able to numerically describe profile concentrations and long‐term vertical transport of Zn and Cu in a clay soil (Oxisol) cultivated under annual cropping in a no‐till system and contaminated by successive doses of PS amendments. We first used a modeling approach that had previously been validated for an Alfisol. Then, we additionally also evaluated the effects of root growth and root water uptake on the transport of trace metals (TMs). Finally, we carried out 50‐yr‐long prospective simulations for different doses of PS amendments. Consideration of root growth and root water uptake processes in HYDRUS‐1D simulations improved the description of measured field Zn concentrations. Although the correspondence between simulated and measured Cu concentrations was not as good as for Zn, we performed prospective simulations for both elements. Future scenarios that considered large PS doses showed large increases in concentrations of both TMs in the soil surface layer. The feasibility of using PS amendments on agricultural Oxisols will be limited by Cu because the soil Cu threshold concentration is exceeded in approximately 29 yr. Moreover, the total loads of both TMs allowed on agricultural soils are reached very fast when large rates are used, especially for Cu (19 yr), indicating that the long‐term disposal of PS on agricultural soils should be done at low doses. These conclusions are probably conservative because our model did not consider potential leaching of TMs from the surface soil into deeper soil layers by dissolved organic C facilitated transport.
Mechanics and Energetics of Soil Penetration by Earthworms and Plant Roots: Higher Rates Cost More
Authors: Ruiz Siul , Schymanski Stanislaus J. , Or Dani 
Published: August 2017

Core Ideas
We quantified mechanical differences between earthworms and roots using penetration rates.
Mechanical modeling was justified by direct imaging of both plant roots and earthworms.
We validated model predictions with rate‐controlled miniature cone penetrometer experiments.
Earthworm burrows are dominantly formed through mechanical processes, not ingestion.
We outline mechanical and energetic limitations for a range of water contents.
We quantified the mechanics and energetics of soil penetration by burrowing earthworms and growing plant roots considering different penetration rates and soil mechanical properties. The mechanical model considers cavity expansion by cone‐like penetration into a viscoelastic soil material in which penetration rates affect the resulting forces and hence the mechanical energy required. To test the predicted penetration rate effects on forces and energetics, we conducted rate‐controlled cone penetration experiments across rates ranging from 1 to 200 μm s−1 to determine the mechanical resistance forces for cone geometries similar to plant roots and earthworms. These measurements also enabled inverse estimation of soil rheological parameters that were in good agreement with literature values for similar soils and water contents. The results suggest that higher soil penetration rates typical for earthworm activity (about 200 μm s−1) may significantly increase resistance forces and energy expenditure by up to threefold relative to slower penetration rates of plant roots (0.2 μm s−1) for similar soil properties and geometries. Another important mechanical difference between earthworms and roots is the radial pressures that earthworms' hydro‐skeleton exerts (<230 kPa), whereas plant roots may exert radial pressures exceeding 1 MPa. These inherent differences in burrowing rates and expansion pressures may significantly extend the range of conditions suitable for root growth in drier and compacted soil compared to earthworm activity. Results suggest that the mechanical energy costs of soil bioturbation under agricultural intensification and drier climate could greatly increase the energetic costs of these ecologically important soil structure‐forming bioprocesses.
Data-driven multi-time-step ahead daily rainfall forecasting using singular spectrum analysis-based data pre-processing
Authors: Unnikrishnan Poornima , Jothiprakash V. 
Published: August 2017

AbstractAccurate forecasting of rainfall, especially daily time-step rainfall, remains a challenging task for hydrologists' invariance with the existence of several deterministic, stochastic and data-driven models. Several researchers have fine-tuned the hydrological models by using pre-processed input data but improvement rate in prediction of daily time-step rainfall data is not up to the expected level. There are still chances to improve the accuracy of rainfall predictions with an efficient data pre-processing algorithm. Singular spectrum analysis (SSA) is one such technique found to be a very successful data pre-processing algorithm. In the past, the artificial neural network (ANN) model emerged as one of the most successful data-driven techniques in hydrology because of its ability to capture non-linearity and a wide variety of algorithms. This study aims at assessing the advantage of using SSA as a pre-processing algorithm in ANN models. It also compares the performance of a simple ANN model with SSA-ANN model in forecasting single time-step as well as multi-time-step (3-day and 7-day) ahead daily rainfall time series pertaining to Koyna watershed, India. The model performance measures show that data pre-processing using SSA has enhanced the performance of ANN models both in single as well as multi-time-step ahead daily rainfall prediction.
Keefektifan Pendekatan Realistik Ditinjau dari Prestasi Belajar, Kemampuan Pemecahan Masalah, dan Kepercayaan Diri Matematika
Authors: Sopia Hanna Filen , Wutsqa Dhoriva Urwatul 
Published: August 2017

Penelitian ini bertujuan untuk mendeskripsikan: keefektifan pembelajaran matematika dengan pendekatan realistik; dan pembelajaran yang lebih efektif antara pendekatan realistik dengan pembelajaran konvensional ditinjau dari prestasi belajar, kemampuan pemecahan masalah, dan kepercayaan diri matematika siswa. Penelitian ini merupakan penelitian eksperimen semu dengan desain kelompok kontrol pretes-postes beracak. Penelitian ini menggunakan satu kelompok eksperimen dan satu kelompok kontrol. Populasi penelitian ini adalah seluruh siswa kelas VIII SMP Negeri 3 Pandeglang. Sampel penelitian sebanyak dua kelas yang dipilih secara acak. Data hasil penelitian dianalisis dengan MANOVA, dan untuk mengetahui keefektifan pendekatan realistik menggunakan uji one sample t-test. Hasil penelitian ini menunjukkan bahwa: pendekatan realistik efektif terhadap pembelajaran matematika ditinjau dari prestasi belajar dan kepercayaan diri matematika siswa namun tidak efektif ditinjau dari kemampuan pemecahan masalah; pendekatan realistik lebih efektif dari pembelajaran konvensional ditinjau dari prestai belajar, kemampuan pemecahan masalah, dan kepercayaan diri matematika siswa.Kata kunci: pendekatan realistik, prestasi belajar, kemampuan pemecahan masalah, kepercayaan diri. The Effectiveness of Realistic Approach Based on Learning Achievement, Problem Solving Ability, and Mathematical Self Confidence AbstractThis study aims to describe: the effectiveness of teaching mathematics using realistic approach; and the more effective teaching between realistic approach and conventional teaching based on studens’ learning achievement, problem solving ability, and mathematical self-confidence. This research was a quasi experimental study employing a random pretest-posttest control group design. It involved one experimental group and one control group. The research population comprised nine classes of Year VIII student of SMP Negeri 3 Pandeglang. The sample consisted of two classes that were randomly established. The data were analysed by means of MANOVA, and to test the effectiveness of realistic approach using one sample t-test. The result of the study show that: realistic approach is effective in learning mathematics based on learning achievement and mathematical self confidence of student but not effective based on problem solving ability; realistic approach more effective than conventional learning based on learning achievement, problem solving ability and mathematical self confidence of student.Keywords: realistic approach, learning achievement, problem solving ability, self-confidence.
Perbandingan keefektifan pendekatan problem solving dan problem posing dalam pembelajaran matematika pada siswa SMP
Authors: Falach Harinda Nurril 
Published: August 2017

Penelitian ini bertujuan untuk mendeskripsikan: 1) keefektifan pendekatan problem solving terhadap kemampuan pemahaman dan penalaran matematis; 2) keefektifan pendekatan problem posing terhadap kemampuan pemahaman dan penalaran matematis; 3) perbandingan keefektifan antara pendekatan pembelajaran problem solving dan problem posing terhadap kemampuan pemahaman dan penalaran matematis siswa SMP pada pembelajaran bangun ruang sisi datar. Penelitian ini merupakan penelitian eksperimen semu (quasi experiment). Data dianalisis menggunakan one sample t test, uji MANOVA rumus T2 Hotteling, dan uji t kriteria Bonferroni. Hasil penelitian menunjukkan bahwa: 1) pendekatan problem solving efektif terhadap kemampuan pemahaman dan penalaran matematis; 2) pendekatan problem posing efektif terhadap kemampuan pemahaman dan penalaran matematis; 3) pendekatan problem solving lebih efektif dibandingkan problem solving terhadap kemampuan pemahaman matematis tetapi pendekatan problem solving tidak lebih efektif dibandingkatn problem posingterhadap kemampuan penalaran matematis siswa SMP pada pembelajaran bangun ruang sisi datar.Kata kunci: pendekatan problem solving, pendekatan problem posing, kemampuan pemahaman matematis, dan kemampuan penalaran matematis. The effectiveness comparison of problem solving and problem posing approaches in mathematics learning towards junior high school students AbstractThe aim of this study is to describe: 1) the effectiveness of problem solving approach on mathematical understanding and reasoning ability; 2) the effectiveness of problem posing approach on mathematical understanding and reasoning ability; 3) the comparison effectiveness of polyhedral learning using problem solving approach and problem posing approach on mathematical understanding and reasoning ability of State Junior High School. This study was a quasi experiment. The data were analyzed using one-sample t test, MANOVA test with T2 Hotteling's formula, and t-test with Bonferroni criterion. The results of the study show that: 1) the problem solving approach has an effect on mathematical understanding and reasoning ability; 2) the problem posing approach has an effect on mathematical understanding and reasoning ability; and 3) the problem solving approach is more effective than the problem posing approach on mathematical understanding ability, but the problem solving approach is not more effective in polyhedral learning than the problem posing approach on mathematical reasoning ability of State Junior High.Keywords: problem solving approach, problem posing approach, mathematical understanding ability, and mathematical reasoning ability
Pengembangan tes kemampuan pemecahan masalah dan penalaran matematika siswa SMP kelas VIII
Authors: Sinaga Nurul Afni 
Published: August 2017

Penelitian ini bertujuan untuk menghasilkan perangkat tes kemampuan pemecahan masalah dan penalaran matematika siswa SMP kelas VIII di Yogyakarta yang valid dan memiliki karakteristik yang baik. Penelitian ini merupakan penelitian pengembangan yang mengembangkan tes kemampuan pemecahan masalah dan penalaran SMP kelas VIII. Uji coba lapangan dilakukan di tiga sekolah SMP Negeri di Yogyakarta yaitu SMP Negeri I Yogyakarta, SMP Negeri 6 Yogyakarta dan SMP Negeri 14 Yogyakarta. Analisis data dilakukan dengan mengkonversi total skor aktual yang diperoleh menjadi data kualitatif skala lima untuk memperoleh kevalidan dan telaah butir soal secara kuantitatif melalui teori tes klasik (Clasiccal Test Theory) dan teori respons butir (Item Respone Theory) menggunakan model rasch dengan program QUEST. Hasil validasi isi menunjukkan bahwa perangkat yang dikembangkan memiliki kategori valid. Karakteristik dari tes yang dikembangkan juga memiliki karakteristik yang baik ditinjau dari tingkat kesulitan tes berada pada kategori sedang dan memiliki daya beda cukup memuaskan. Secara keseuruhan, hasil penelitian menunjukkan bahwa perangkat tes yang dikembangkan adalah layak untuk digunakan.Kata Kunci: pengembangan tes, pemecahan masalah, penalaran Development of problem solving ability and mathematical reasoning test of junior high school students class VIII AbstractThis research’s aim is to produce device for problem solving ability and mathematical reasoning test of JHS student class VIII in Yogyakarta which valid and has a good characteristic. This research is a development research which develops problem solving ability and reasoning test of JHS class VIII. Field trial was performed in three JHS in Yogyakarta namely JHS State I Yogyakarta, JHS State 6 Yogyakarta and JHS State 14 Yogyakarta. Data analysis was performed by converting the total collected actual score into five scales qualitative data to derive validity and study on question items quantitatively through classical test theory and item respone theory was using Rasch model with QUEST program. Content Validaty result suggested that this developed device has a valid category. Characteristic of the developed test was also has a good characteristic, reviewed from the test difficulty level it was in medium category and has a quite satisfying different power. Overall, the research result suggested that the developed test device was feasible to use.Keywords: test development, problem solving, reasoning
Latent root regression dalam mengatasi multikolinearitas
Authors: Untari Desy Pramesti , Susanti Mathilda 
Published: August 2017

Salah satu metode yang dapat digunakan untuk mengatasi masalah multikolinearitas pada model regresi adalah latent root regression. Latent root regression merupakan perluasan dari principal component regression. Tujuan penelitian ini adalah untuk melakukan analisis latent root regression dalam mengatasi multikolinearitas yang diterapkan pada faktor-faktor yang mempengaruhi IHSG di Bursa Efek Indonesia. Variabel-variabel yang digunakan pada penelitian ini adalah IHSG, jumlah uang beredar, kurs rupiah terhadap dolar AS, harga emas dunia dan Indeks Dow Jones. Hasil penelitian yang diperoleh adalah faktor jumlah uang beredar, kurs rupiah terhadap dolar AS, harga emas dunia dan Indeks Dow Jones berpengaruh terhadap IHSG, namun terjadi multikolinearitas diantara faktor-faktor tersebut sehingga diselesaikan dengan latent root regression. Kemudian analisis latent root regression tersebut dibandingkan dengan analisis principal component regression pada faktor-faktor yang mempengaruhi IHSG di Bursa Efek Indonesia yang hasilnya adalah latent root regression lebih baik daripada principal component regression karena lebih tinggi dan asumsi regresi lebih banyak dipenuhi pada latent root regression.Kata Kunci: latent root regression, multikolinearitas, IHSG. Latent Root Regression to Solve Multicolinearity AbstractOne of methods can be used to overcome the problem of multicollinearuty in a regression model is latent root regression. Latent root regression is an extension of principal component regression. The purpose of this research is to perfom a latent root regression analysis in solving multicollinearity on the factors that affect JSX Composite in Indonesia Stock Exchange. The variables used in this research are JSX Composite, money supply, rupiah exchange rate against the US dollar, gold price and DJI. The research result obtained are the factors of money supply, rupiah exchange rate against the US dollar, gold price and DJI affect JSX Composite, but multicollinearity occur among these factors thus solved by latent root regression. Then the latent root regression analysis is compared with principal component regression on the factors that affect JSX Composite in Indonesia Stock Exchange that the result is better than latent root regression of principal component regression because is higher and regression assumptions more fulfilled in latent root regression.Keywords: latent root regression, multicollinearity, JSX composite
Analisis penguasaan kompetensi pedagogik dan profesional mahasiswa calon guru matematika dalam mata kuliah micro-teaching
Authors: Linda Linda 
Published: August 2017

Penelitian ini bertujuan untuk mendeskripsikan penguasaan kompetensi pedagogik dan profesional mahasiswa calon guru matematika dalam mata kuliah micro-teaching di Universitas Sultan Ageng Tirtayasa Provinsi Banten. Penelitian ini merupakan penelitian deskriptif. Subjek sebanyak 16 mahasiswa yang dipilih secara acak dari 72 mahasiswa jurusan pendidikan matematika, Universitas Sultan Ageng Tirtayasa Provinsi Banten tahun ajaran 2014/2015. Objek penelitian adalah kompetensi pedagogik dan profesional mahasiswa calon guru matematika dalam mata kuliah micro-teaching di Universitas Sultan Ageng Tirtayasa Provinsi Banten. Data hasil penelitian dianalisis dengan melihat kriteria penguasaan kompetensi pedagogik dan profesional. Hasil penelitian menunjukkan bahwa penguasaan kompetensi pedagogik mahasiswa calon guru matematika dalam mata kuliah micro-teaching di Universitas Sultan Ageng Tirtayasa Provinsi Banten, berada pada kriteria baik. Penguasaan kompetensi profesional mahasiswa calon guru matematika Universitas Sultan Ageng Tirtayasa Provinsi Banten, berada pada kriteria kurang.Kata Kunci: kompetensi pedagogik, kompetensi profesional, micro-teaching An Analysis of Pedagogical and Professional Competence Mastery of Student Teachers of Mathematics in Micro-Teaching Course AbstractThe study aims to describe the mastery of the pedagogical competence and the professional competence of student teachers of mathematics in micro-teaching courses at the University of Sultan Ageng Tirtayasa in Banten Province. The study was descriptive research. The subjects were 16 students who were randomly selected from 72 students of the Department of Mathematics Education, University of Sultan Ageng Tirtayasa Banten, in the academic year of 2014/2015. The object of this research was the pedagogical competence and professional competence of student teachers. The data were analyzed by observing the criteria for pedagogical competence mastery and mastery of professional competence criteria. The results of study show that the pedagogical competence mastery of the student teachers in the subjects of micro-teaching at the University of Sultan Ageng Tirtayasa in Banten Province is in the good criterion. The mastery of the professional competence of the student teachers in the same subjects is not in a less criterion.Keywords: pedagogical competence, professional competence, micro-teaching