259 research outputs found
Pengaruh Kurs, Inflasi, Libor dan PDB terhadap Foreign Direct Invesment (Fdi) di Indonesia
This study aims to determine the effect of the influence of Exchange Rates, Inflation, Libor, and GDP to the Foreign Direct Invesment (FDI) In Indonesia. The data used in this study is a time series data from 1998 to 2013 were sourced from Invesment Coordinating Board (Badan Koordinasi Penanaman Modal), Bank Indonesia, and Central Bureau of Statistics (Badan Pusat Statisitik). This study used quantitative research methods, and analyzed using multiple linear regression analysis using SPSS 20 application for Windows computers. In this study, the independent variable is Exchange Rates (X1), Inflation (X2), Libor (X3), and GDP (X4), while the dependent is realitation Foreign Direct Invesment (Y).This study tested the hypothesis of regression coefficient (coefficient of determination, a significant test concurrent / F test, and the significant individual test / t test). The result showed that the variable Exchange Rates, Inflation, libor and GDP at once / simultaneously have a significant influence on the realitation Foreign Direct Invesment (FDI). The individual test / partial showed that Gross Domestic Product variable acquired that contributes greater than the variable rate of Exchange Rates, Inflation,and Libor ont the realitation Foreign Direct Invesment (FDI).Keywords:Exchange Rate, Inflation, London Inter Bank Offering Rate (LIBOR), Gross Domestic Product (GDP), and Foreign Direct Invesment (FDI)
Modeling symbiotic biological nitrogen fixation in grain legumes globally with LPJ-GUESS (v4.0, r10285)
Biological nitrogen fixation (BNF) from grain legumes is of significant importance in global agricultural ecosystems. Crops with BNF capability are expected to support the need to increase food production while reducing nitrogen (N) fertilizer input for agricultural sustainability, but quantification of N fixing rates and BNF crop yields remains inadequate on a global scale. Here we incorporate two legume crops (soybean and faba bean) with BNF into a dynamic vegetation model LPJ-GUESS (Lund–Potsdam–Jena General Ecosystem Simulator). The performance of this new implementation is evaluated against observations from a range of water and N management trials. LPJ-GUESS generally captures the observed response to these management practices for legume biomass production, soil N uptake, and N fixation, despite some deviations from observations in some cases. Globally, simulated BNF is dominated by soil moisture and temperature, as well as N fertilizer addition. Annual inputs through BNF are modeled to be 11.6±2.2 Tg N for soybean and 5.6±1.0 Tg N for all pulses, with a total fixation of 17.2±2.9 Tg N yr for all grain legumes during the period 1981–2016 on a global scale. Our estimates show good agreement with some previous statistical estimates but are relatively high compared to some estimates for pulses. This study highlights the importance of accounting for legume N fixation process when modeling C–N interactions in agricultural ecosystems, particularly when it comes to accounting for the combined effects of climate and land-use change on the global terrestrial N cycle
Fe-doped TiO2/Kaolinite as an Antibacterial Photocatalyst under Visible Light Irradiation
In this work, undoped and Fe-doped TiO2 immobilized on kaolinite surface was successfully synthesized by sol-gel method with various Fe concentrations (0.05, 0.125, and 0.25 wt%). The effects of Fe doping into TiO2 lattice were thoroughly investigated by a diffuse reflectance UV-visible (DRS) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The optical band gap of undoped and Fe-doped TiO2/kaolinite is red shifted with respect to the incorporation of Fe3+ into the structure of TiO2 resulted band gap. The FTIR spectra shows a shift of peak at the wave number at 586 cm−1 and 774 cm−1 which is attribute of the Fe−O vibration as an indication of the formation of Fe-TiO2 bonds. Incorporation of Fe3+ cation into the TiO2 lattice replacing the Ti4+ ions, which induced a perturbation in anatase crystal structure, causes the change in the distance spacing of the crystal lattices dhkl(101) of 8.9632 to 7.9413. The enhanced photocatalytic performance was observed for Fe-doped TiO2/kaolinite compared with TiO2/kaolinite with respect to Escherichia coli growth inhibition in solution media under visible light irradiation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
In Vitro Antioxidant Activity of Bark Extracts of Rhizophora mucronata
The present study was conducted to evaluate the antioxidant activity of medicinal plant Rhizophora mucronata (R. mucronata). Shade dried stem bark of R. mucronata was powdered and extracted with 95% ethanol and water by cold extraction method. The total phenolic and flavonoid contents of water and ethanol extract of air dried stem bark was estimated by using spectrometric method. Antioxidant activity of R. mucronata was determined by using different methods namely DPPH radical scavenging assay, ferric reducing assay, nitric oxide radical scavenging assay, superoxide radical scavenging assay and ABTS radical scavenging assay, and its IC50 values were found to be 110.85, 193.47, 109.06, 88.69 and 12.56 ìg/ml for aqueous extract and 59.63, 242.71, 103.21, 84.95 and 4.21 ìg/ml respectively. The extracts exhibited marked dose dependent in vitro antioxidant activity. Secondary metabolite isolation and characterization and in vivo evaluation of aqueous and ethanolic extracts were under progress
Assessing the impacts of agricultural managements on soil carbon stocks, nitrogen loss, and crop production – a modelling study in eastern Africa
Improved agricultural management plays a vital role in protecting soils from degradation in eastern Africa. Changing practices such as reducing tillage, fertilizer use, or cover crops are expected to enhance soil organic carbon (SOC) storage, with climate change mitigation co-benefits, while increasing crop production. However, the quantification of cropland management effects on agricultural ecosystems remains inadequate in this region. Here, we explored seven management practices and their potential effects on soil carbon (C) pools, nitrogen (N) losses, and crop yields under different climate scenarios, using the dynamic vegetation model LPJ-GUESS. The model performance is evaluated against observations from two long-term maize field trials in western Kenya and reported estimates from published sources. LPJ-GUESS generally produces soil C stocks and maize productivity comparable with measurements and mostly captures the SOC decline under some management practices that is observed in the field experiments. We found that for large parts of Kenya and Ethiopia, an integrated conservation agriculture practice (no-tillage, residue and manure application, and cover crops) increases SOC levels in the long term (+11 % on average), accompanied by increased crop yields (+22 %) in comparison to the conventional management. Planting nitrogen-fixing cover crops in our simulations is also identified as a promising individual practice in eastern Africa to increase soil C storage (+4 %) and crop production (+18 %), with low environmental cost of N losses (+24 %). These management impacts are also sustained in simulations of three future climate pathways. This study highlights the possibilities of conservation agriculture when targeting long-term environmental sustainability and food security in crop ecosystems, particularly for those with poor soil conditions in tropical climates
PENINGKATAN KEMAMPUAN BERPIKIR KRITIS DENGAN MENGGUNAKAN PENDEKATAN OPEN ENDED PADA MATA PELAJARAN MATEMATIKA DIKELAS IV SD
The problem in this study is the learning process and the critical thinking skills of students in mathematics learning in Class IV SD Negeri 176/II Renah Sungai Ipuh is still low, this is evidenced by the results of preliminary observations made by researchers from 33 students only 9.09% those who score in criteria are quite critical. The reason is that the teacher only uses a conventional approach in the classroom, which causes the learning process and students' critical thinking skills to be low.
The purpose of this study was to describe the application of an open ended approach to the learning process of students and students' critical thinking abilities. The method used in this study is classroom action research (CAR). This study consisted of 2 cycles, each cycle carried out through 4 stages, namely planning, action, observation and reflection and consisted of 2 meetings.
The results of the study can be explained as follows: (1) the application of the open ended approach in the learning process is seen from the obervation sheet that the first cycle is only from the aspect of the teacher 66,25% and the aspect of the students 64,7% while in the second cycle there is an increase from the teacher aspect 83,75% and the aspect of the students 85,97% who have achieved an indicator of success. (2) the application of the open ended approach in learning in the first cycle is still not maximal. This can be seen from the results of the tests in the first cycle, only 27,27% of the students who received the criteria were quite critical and 72,72% of the students had not yet achieved the indicators of success. students' critical thinking skills improve very well in cycle II. From 9.09% (initial observation), it becomes 27,27% (cycle I) and 57,57% (cycle II).Masalah dalam penelitian ini ialah proses belajar dan kemampuan berpikir kritis peserta didik pada pembelajaran matematika di Kelas IV SD Negeri 176/II Renah Sungai Ipuh masih rendah, hal ini dibuktikan dengan hasil observasi awal yang dilakukan oleh peneliti dari 33 peserta didik hanya 9,09% yang memperoleh nilai dalam kriteria cukup kritis. Penyebabnya adalah guru hanya menggunakan pendekatan yang konvensional di kelas, yang menyebabkan proses pembelajaran dan kemampuan berpikir kritis peserta didik rendah.
Tujuan penelitian ini ialah untuk mendeskripsikan penerapan pendekatan open ended pada proses belajar peserta didik dan kemampuan berpikir kritis peserta didik. metode yang digunakan dalam penelitian ini adalah penelitian tindakan kelas (PTK). Penelitian ini terdiri dari 2 siklus, setiap siklus dilkasanakan melalui 4 tahap, yaitu perencanaan, tindakan, observasi dan refleksi dan terdiri dari 2 kali pertemuan.
Hasil penelitian dapat dijelaskan sebagai berikut: (1) penerapan pendekatan open ended dalam proses pembelajaran dilihat dari lembar observasi yaitu siklus I hanya dari aspek guru 66,25% dan aspek peserta didik 64,7% sedangkan pada siklus II terjadi peningkatan dari aspek guru 83,75% dan aspek peserta didik 85,97% yang telah mencapai indikator keberhasilan. (2) penerapan pendekatan open ended dalam pembelajaran pada siklus I masih belum maksimal. Hal ini dapat dilihat dari hasil tes pada siklus I, hanya 27,27% peserta didik yang memperoleh nilai dalam kriteria kritis dan 72,72% peserta didik yang belum mencapai indikator keberhasilan. kemampuan berpikir kritis peserta didik meningkat sangat baik pada siklus II. Dari 9,09% (observasi awal), menjadi 27,27% (siklus I) dan 57,57% (siklus II)
Estimating the Global Influence of Cover Crops on Ecosystem Service Indicators in Croplands With the LPJ‐GUESS Model
Cover crops (CCs) can improve soil nutrient retention and crop production while providing climate change mitigation co-benefits. However, quantifying these ecosystem services across global agricultural lands remains inadequate. Here, we assess how the use of herbaceous CCs with and without biological nitrogen (N) fixation affects agricultural soil carbon stocks, N leaching, and crop yields, using the dynamic global vegetation model LPJ-GUESS. The model performance is evaluated with observations from worldwide field trials and modeled output further compared against previously published large-scale estimates. LPJ-GUESS broadly captures the enhanced soil carbon, reduced N leaching, and yield changes that are observed in the field. Globally, we found that combining N-fixing CCs with no-tillage technique could potentially increase soil carbon levels by 7% (+0.32 Pg C yr in global croplands) while reducing N leaching loss by 41% (−7.3 Tg N yr) compared with fallow controls after 36 years of simulation since 2015. This integrated practice is accompanied by a 2% of increase in total crop production (+37 million tonnes yr including wheat, maize, rice, and soybean) in the last decade of the simulation. The identified effects of CCs on crop productivity vary widely among main crop types and N fertilizer applications, with small yield changes found in soybean systems and highly fertilized agricultural soils. Our results demonstrate the possibility of conservation agriculture when targeting long-term environmental sustainability without compromising crop production in global croplands
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