Mechanism of Carbon Absorption by Iron During Sintering of Iron—Graphite

The structure of a continuous-grid chiral cubic phase made of achiral constituent molecules is a hot topic in the field of thermotropic liquid crystals. Several structural models have been proposed so far. Resonant X-ray scattering (RXS), which gives information on the molecular orientation in the unit cell, could be applied to select the most appropriate model. We modeled the RXS response for the recently proposed chiral cubic phase structure with an all-hexagon chiral continuous grid. A tensor form factor of a unit cell is constructed, which enables calculation of intensities of peaks for all Miller indices. We find that all the symmetry allowed peaks are resonantly enhanced, and their intensity is much stronger than the intensity of the symmetry forbidden (resonant) peaks. In particular, we predict that a strong resonant enhancement of the symmetry allowed peaks (011) and (002), not observed in a nonresonant scattering, could be observed by RXS at the carbon absorption edge. By RXS at the sulfur absorption edge, one might observe a resonant peak (113) and resonantly enhanced peak (233), and resonant enhancement of all the peaks that are observed in a nonresonant scattering, which probably hide the rest of the predicted resonant peaks.

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Effective Controlled Method Adding Carbon into Molten Steel to Produce 55Q Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.785-786.12 ◽

2013 ◽

Vol 785-786 ◽

pp. 12-15 ◽

Cited By ~ 1

Author(s):

Tie Jun Zhang

Keyword(s):

Carbon Content ◽

Molten Steel ◽

Rail Steel ◽

Light Rail ◽

Carbon Powder ◽

Cored Wire ◽

Injection Process ◽

Carbon Absorption ◽

The Mean ◽

Low Solubility

It is very important to produce 55Q steel with the exact carbon content. Low and inconsistent carbon elemental recovery problems are often encountered when adding pig iron, or carbon powder into the baths of light rail steel. This is the case because carbon presents some of the following characteristics: lower density much more than the molten steel, low solubility in the liquid steel, high affinity due to oxygen. These circumstances lead to difficulties or risks, such as: poor or erratic recovery of alloying carbon element, violent and dangerous splashing, adverse environmental impact. To counter these problems existed in conventional method, carbon cored wire was prepared and wire injection process introduced in this work, and the effects of parameters such as feeding rate, etc on carbon recovery are investigated. The results show when using the carbon wire injection method, stable carbon addition is obtained, that is, the mean recovery of the carbon absorption is 90%, and what's more, the carbon content is under control accurately and environment improved.

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The Optimal Felling Rate in the Palm Oil Plantation System

MATEMATIKA ◽

10.11113/matematika.v35.n1.1037 ◽

2019 ◽

Vol 35 (1) ◽

pp. 95-104

Author(s):

Mohd Ismail Abd Aziz ◽

Noryanti Nasir ◽

Akbar Banitalebi

Keyword(s):

Optimal Control ◽

Palm Oil ◽

Oil Palm ◽

Oil Production ◽

Real Data ◽

Palm Trees ◽

Environmental Friendly ◽

Proposed Model ◽

Carbon Absorption ◽

Plantation System

Successful palm oil plantation should have high returns profit, clean and environmental friendly. Since oil palm trees have a long life and it takes years to be fully grown, controlling the felling rate of the palm oil trees is a fundamental challenge. It needs to be addressed in order to maximize oil production. However, a good arrangement of the felling palm oil trees may still affect the amount of carbon absorption. The objective of this study is to develop an optimal felling model of the palm oil plantation system taking into account both oil production and carbon absorption. The model facilitates in providing the optimal control of felling rate that results in maximizing both oil production and carbon absorption. With this aim, the model is formulated considering palm oil biomass, carbon absorption rate, oil production rate and the average prices of carbon and oil palm. A set of real data is used to estimate the parameters of the model and numerical simulation is conducted to highlight the application of the proposed model. The resulting parameter estimation is solved that leads to an optimal control of felling rate problem.

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Fullerite C60 optical constants in the C 1s NEXAFS region

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012168 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012168

Author(s):

D V Sivkov ◽

S V Nekipelov ◽

O V Petrova ◽

D V Bogachuk ◽

R N Skandakov ◽

...

Keyword(s):

Cross Sections ◽

Optical Constants ◽

Absorption Cross ◽

X Ray ◽

Carbon Absorption ◽

Cross Section Spectrum ◽

Integral Relations ◽

Atomic Form Factor ◽

Using Data ◽

X Ray Absorption

Abstract Using data on the absorption cross sections the refraction coefficient spectral dependence n(E) and the spectra of the remaining optical coefficients (reflection coefficient, phase shift, and atomic form factor) in the fullerite C60 C 1s near edge X-ray absorption fine structure (NEXAFS) region (280–350 eV) were determined. For the n(E) calculations the Kramers-Kronig integral relations (KKRs) were used. The KKR computations were performed using data on atomic carbon absorption cross sections in the 10–30000 eV range and on solid and gaseous C60 – in the 0–120 eV. Absorption cross section spectrum in the fullerite C60 C 1s NEXAFS region were measured.

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Decolorization of Waste Water from Reed Three-Stage Count-Current Ethanol-Water Batch Cooking

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.1793 ◽

2013 ◽

Vol 295-298 ◽

pp. 1793-1797

Author(s):

Lan Qiang Tian ◽

Na Li ◽

Qing Wei Ping ◽

Jian Zhang ◽

Hai Qing Shi

Keyword(s):

Waste Water ◽

Activated Carbon ◽

Ph Value ◽

Combination Method ◽

Column Height ◽

Waste Liquor ◽

Carbon Absorption ◽

Counter Current ◽

Calcium Superphosphate

The waste liquor from the first cooking stage of reed three-stage counter-current batch cooking with ethanol-water process was decolorized by preliming, sulfitation and activated carbon absorption combination method. The preliming temperature, calcium superphosphate dosage, pH Value, Na2SO3dosage in preliming and sulfitation, column height and velocity in activated carbon absorption have effect on decolorization. The results indicated that the 50 mL un decolorized waste liquor have the best decolorizing effect when the preliming temperature was 80°C, calcium superphosphate dosage was 1 g, pH value was 7, Na2SO3dosage was 0.04 mol, column height was 12 cm and velocity was 2mL/min, the decolorized rate of waste liquor could be up to 98.1%.

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Analisis Perubahan Penutupan Lahan dan Potensi Karbon di Taman Hutan Raya Pocut Meurah Intan, Aceh Indonesia

Jurnal Ilmu Lingkungan ◽

10.14710/jil.19.2.450-458 ◽

2021 ◽

Vol 19 (2) ◽

pp. 450-458

Author(s):

Rahmat Fadhli ◽

Sugianto Sugianto ◽

Syakur Syakur

Keyword(s):

Land Cover ◽

Carbon Potential ◽

Land Use Land Cover ◽

Plantation Forest ◽

Dry Land ◽

Forest Park ◽

Carbon Absorption ◽

Open Land ◽

Cover Class ◽

Object Area

Perubahan penutupan lahan merupakan sektor penyumbang emisi gas rumah kaca terbesar, termasuk di dalamnya adalah pemanfaatan lahan. Analisis tutupan lahan menjadi bagian penting dalam menentukan jumlah potensi karbon yang tersedia. Penelitian bertujuan untuk menganalisis perubahan tutupan lahan dari tahun 2003 hingga 2018 dan menghitung potensi karbon di Taman Hutan Raya Pocut Meurah Intan dengan luas objek penelitian 6.215 ha. Penelitian dilaksanakan selama 5 (lima) bulan. Penelitian ini menggunakan metode stock difference, yaitu metode perhitungan luas tutupan lahan dan stok karbon pada dua titik waktu. Hasil penelitian menunjukkan bahwa perubahan luas tertinggi tahun 2018 seluas 263 ha dan terendah tahun 2009 seluas 108 ha. Lahan terbuka meningkat seluas 100 ha, pemukiman 81 ha, semak belukar 65 ha, pertanian lahan kering campur semak 32 ha. Sementara hutan lahan kering sekunder menurun 79 ha, hutan tanaman 76 ha, savanna 21 ha dan pertanian lahan kering 103 ha. Selama kurun waktu 15 tahun berdasarkan kelas penutupan lahan, cadangan karbon tertinggi pada tahun 2003 sebesar 656.053 ton, terendah tahun 2012 sebesar 620.992 ton. Laju serapan karbon tertinggi pada periode tahun 2015-2018 sebesar 94.615 ton CO2 dan terendah pada periode tahun 2009-2012 sebesar 1.981 ton CO2. Laju emisi tertinggi pada periode tahun 2003-2006 sebesar 79.559 ton CO2 dan terendah periode tahun 2006-2009 sebesar 9.069 ton CO2. Peningkatan serapan karbon diakibatkan oleh meningkatnya luas tutupan lahan pada hutan lahan kering sekunder dan adanya pemanfaatan lahan untuk pertanian lahan kering campur semak.ABSTRACTChanges in land cover are the largest contributor to greenhouse gas emissions, including land use. Land cover analysis is an important part in determining the potential amount of carbon available. The study aims to analyze changes in land cover from 2003 to 2018 and calculating the carbon potential in the Pocut Meurah Intan Forest Park with a research object area of 6,215 ha. The research was conducted for 5 (five) months. This research uses the stock difference method, namely the method of calculating land cover area dan stok karbon pada dua titik waktu. The results showed that the highest area change in 2018 was 263 ha and the lowest was in 2009 at 108 ha. Open land increased by 100 ha, settlement 81 ha, scrub 65 ha, dry land agriculture mixed with shrubs 32 ha. Meanwhile, secondary dry land forest decreased by 79 ha, plantation forest 76 ha, savanna 21 ha and dry land agriculture 103 ha. Over a 15 year period based on land cover class, the highest carbon stock in 2003 was 656,053 tons, the lowest was in 2012 at 620,992 tons. The highest carbon absorption rate in the 2015-2018 period was 94,615 tons of CO2 and the lowest was in the 2009-2012 period of 1,981 tons of CO2. The highest emission rate in the 2003-2006 period was 79,559 tonnes of CO2 and the lowest for the 2006-2009 period was 9,069 tonnes of CO2. The increase in carbon sequestration is caused by the increase in land cover in secondary dryland forest and the use of land for mixed dry land agriculture.

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Carbon sequestration and growth of Anthocephalus cadamba plantation in North Kalimantan, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d180414 ◽

2017 ◽

Vol 18 (4) ◽

pp. 1385-1393

Author(s):

AGUS SARJONO ◽

ABUBAKAR M. LAHJIE ◽

B.D.A.S. SIMARANGKIR ◽

R. KRISTININGRUM ◽

YOSEP RUSLIM

Keyword(s):

Carbon Sequestration ◽

Biomass Production ◽

Primary Source ◽

Maximum Point ◽

Forest Plantation ◽

Annual Increment ◽

Carbon Absorption ◽

Environmental Amelioration ◽

Mean Annual Increment ◽

Anthocephalus Cadamba

Sarjono A, Lahjie AM, Simarangkir BDAS, Kristiningrum R, Ruslim Y. 2017. Carbon sequestration and growth of Anthocephalus cadamba plantation in North Kalimantan, Indonesia. Biodiversitas 18: 1385-1393. Forest plantation of Jabon (Anthocephalus cadamba) plays many important roles for the primary source of timber production and also the carbon absorption for environmental amelioration. The growth of A. cadamba trees was measured using the formulas of MAI (Mean Annual Increment) and PAI (Periodic Annual Increment) as the basis of the increment measurement, while the analysis of biomass and carbon with simple linear regression (y = a + bx) was used, with the coefficient of R2 = 0.90. The annual increment of A. cadamba trees reached its maximum point or the intersection between MAI and PAI at the age of 8 years, showing the maximum production of A. cadamba trees. Forest plantation of A. cadamba produced biomass and carbon sequestration of 81.90 ton ha-1 and 39.31 ton ha-1, respectively at the age of 8 years. However, the amount of biomass and carbon in another plot of A. cadamba trees was 96.85 ton ha-1 and 46.49 ton ha-1, respectively. While the values of the third plot were 116.84 ton ha-1 and 56.08 ton ha-1, respectively. The correlation between the diameter and biomass production and the correlation between the age of stands and carbon production were very strong with R2 value was higher than 0.90. This indicated that Jabon (Anthocephalus cadamba) plantation had important roles in carbon sequestration and biomass production.

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Size-resolved measurements of brown carbon and estimates of their contribution to ambient fine particle light absorption based on water and methanol extracts

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-18233-2013 ◽

2013 ◽

Vol 13 (7) ◽

pp. 18233-18276 ◽

Cited By ~ 3

Author(s):

J. Liu ◽

M. Bergin ◽

H. Guo ◽

L. King ◽

N. Kotra ◽

...

Keyword(s):

Organic Carbon ◽

Light Absorption ◽

Fine Particle ◽

Elemental Carbon ◽

Fine Particles ◽

Water Soluble ◽

Rural Site ◽

Brown Carbon ◽

Methanol Extracts ◽

Carbon Absorption

Abstract. Light absorbing organic carbon, often termed brown carbon, has the potential to significantly contribute to the visible light absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon are poorly understood. With this in mind field measurements were made at both urban (Atlanta), and rural (Yorkville) sites in Georgia. Measurements in Atlanta were made at both a central site and a road side site adjacent to a main highway near the city center. Fine particle brown carbon optical absorption is estimated based on Mie calculations using direct size resolved measurements of chromophores in filter extracts. Size-resolved atmospheric aerosol samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC), organic and elemental carbon (OC and EC), and solution light absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Fine particle absorption was also measured with a Multi-Angle Absorption Photometer (MAAP) and seven-wavelength Aethalometer. Scattering-corrected aethalometer and MAAP absorption were in good agreement at 670 nm and Mie-estimated absorption based on size-resolved EC data were within 30% of these optical instruments. When applied to solution measurements, at all sites, Mie-predicted brown carbon absorption at 350 nm contributed a significant fraction (20 to 40%) relative to total light absorption, with highest contributions at the rural site where organic to elemental carbon ratios were highest. Brown carbon absorption, however, was highest by the roadside site due to vehicle emissions. The multi-wavelength aethalometer did not detect brown carbon, having an absorption Ångstrom exponent near one. Although the results are within the estimated Aethalometer uncertainties, the direct measurement of brown carbon in solution definitively shows that it is present and this Mie analysis suggests it is optically important in the near UV range in both a rural and urban environment during summer when biomass burning emissions are low.

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APLIKASI KARBON AKTIF DARI CANGKANG KELAPA SAWIT DENGAN AKTIVATOR H3PO4 UNTUK PENYERAPAN LOGAM BERAT Cd DAN Pb

Jurnal Teknik Kimia USU ◽

10.32734/jtk.v3i1.1493 ◽

2014 ◽

Vol 3 (1) ◽

pp. 5-10 ◽

Cited By ~ 1

Author(s):

Erika Mulyana Gultom ◽

M. Turmuzi Lubis

Keyword(s):

Heavy Metals ◽

Activated Carbon ◽

Research Methodology ◽

Contact Time ◽

Optimum Conditions ◽

Atomic Adsorption ◽

Carbon Absorption ◽

Carbon Mass

This research aims to determine the optimum conditions ofactivated carbon made of palm shells activated with H3PO4as an absorber of heavy metals such as Cd and Pb. The research methodology includes the preparation of activated carbon, absorption, and testing. Absorption stage is done by varying the concentration of heavy metals are 5 ppm, 10 ppm, 15 ppm, 20 ppm and activated carbon mass per run, which is0.5 grams. Another variable are the contact time with intervals of 5 minutes and the pH arranged heavy metals 2-9. Testing activated carbon absorption to heavy metals using atomic adsorption spectrofotometric (AAS). The results showed that the most optimum absorption is concentration of 10 ppm, 40 minutes and pH absorption3-4. Absorption of heavy metals Cd and Pb obtained 84,61 % and 80,13 %.

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A Decrease in Carbon Absorption Potential Due to Timber Harvesting in Natural Forest

Jurnal Sylva Lestari ◽

10.23960/jsl.v9i3.516 ◽

2021 ◽

Vol 9 (3) ◽

pp. 389-399

Author(s):

Yuniawati ◽

Rossi Margareth Tampubolon

Keyword(s):

Carbon Sequestration ◽

Carbon Storage ◽

Timber Harvesting ◽

Natural Forests ◽

Intergovernmental Panel ◽

Distribution Maps ◽

Carbon Sequestration Potential ◽

Tree Distribution ◽

Sequestration Potential ◽

Carbon Absorption

Timber harvesting is an activity in producing wood to supply the lumber industry. However, timber harvesting brought consequences such as decreasing carbon sequestration potential of natural forests. This study aimed to determine the reduction in the potential for carbon sequestration due to timber harvesting in natural forests. Data were collected using non-destructive methods through stand inventory before felling for all tree species, cruising results report, and tree distribution maps. Biomass was calculated using the existing allometric, and carbon stocks were calculated using the Intergovernmental Panel on Climate Change method. The results showed that there were 238 trees (65.29 m3) of stands in the study area (6 ha) based on stand inventory before felling. Potential biomass and carbon storage before trees felling were 16.12 ton ha-1 and 7.58 ton ha-1, respectively. Potential biomass and carbon storage after tree felling were 5.15 ton ha-1 and 2.42 ton ha-1, respectively. Carbon absorption before and after tree felling is 28.37 ton CO2eq ha-1 and 4.44 ton CO2eq ha-1, respectively. Carbon emissions during tree felling was 18.93 ton CO2eq ha-1 (81.00%). The application of environmentally friendly wood harvesting shall be carried out appropriately to minimize a decrease in carbon absorption from timber harvesting. Keywords: biomass, carbon emission, timber harvesting

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