Journal articles: 'NSDF Soils'

1

Iarmosh, I., and Yu Olkhovyk. "Conceptual Model to Determine Maximum Activity of Radioactive Waste in Near-Surface Disposal Facilities." Nuclear and Radiation Safety, no. 3(71) (August 15, 2016): 61–64. http://dx.doi.org/10.32918/nrs.2016.3(71).11.

Full text

Abstract:

For development of the management strategy for radioactive waste to be placed in near-surface disposal facilities (NSDF), it is necessary to justify long-term safety of such facilities. Use of mathematical modelling methods for long-term forecasts of radwaste radiation impacts and assessment of radiation risks from radionuclides migration can help to resolve this issue. The purpose of the research was to develop the conceptual model for determining the maximum activity of radwaste to be safely disposed in the NSDF and to test it in the case of Lot 3 Vector NSDF (Chornobyl exclusion zone). This paper describes an approach to the development of such a model. The conceptual model of 90Sr migration from Lot 3 through aeration zone and aquifer soils was developed. The results of modelling are shown. The proposals on further steps for the model improvement were developed.

APA, Harvard, Vancouver, ISO, and other styles

2

Gupta, V. V. S. R., M. M. Roper, and D. K. Roget. "Potential for non-symbiotic N2-fixation in different agroecological zones of southern Australia." Soil Research 44, no. 4 (2006): 343. http://dx.doi.org/10.1071/sr05122.

Full text

Abstract:

Nitrogen fixation by symbiotic and non-symbiotic bacteria can be a significant source of nitrogen in cropping systems. However, contributions from non-symbiotic nitrogen fixation (NSNF) are dependent on available carbon in the soil and environmental conditions (soil moisture and temperature). In Australia, measurements of NSNF have been made in the field by quantifying nitrogenase activity. These studies have included determinations of the moisture and temperature requirements for NSNF and for crop residue decomposition that supplies carbon to NSNF bacteria. Other studies have determined the N input by NSNF using N budget calculations. These data together with information about carbon supply and environmental conditions were used to estimate potential NSNF in the cropping zones of southern Australia. Using the ArcviewGIS Spatial Analyst (v3.1), maps of Australia showing estimates of NSNF in different cropping zones as determined by rainfall and temperature or carbon availability were generated. In Western Australia (represented by Wongan Hills) and South Australia (represented by Avon), where summers are dry, estimates of NSNF were generally low (10–15 kg N/ha from January to June) due to limitations of soil moisture. In New South Wales, particularly in the north where summer rainfall patterns develop (represented by Gunnedah), the warm, moist conditions produced higher estimates of NSNF (totaling 32–38 kg N/ha from January to June). In this region, the majority of estimated NSNF occurred in January and February leading to the depletion of carbon supplies and reduced NSNF in autumn (March–June). Information about potential supplies of N from NSNF across the cropping zones should be useful for researchers to select and study areas that are most likely to benefit from NSNF. It should also help agronomists and extension officers explain changes in N status within paddocks or within specific farming systems and to provide more accurate advice on N fertiliser requirements, particularly in low-input farming systems.

APA, Harvard, Vancouver, ISO, and other styles

3

Al-Murshedi, Alaa D., Mahdi O. Karkush, and Hussein H. Karim. "Collapsibility and Shear Strength of Gypseous Soil Improved by Nano Silica Fume (NSF)." Key Engineering Materials 857 (August 2020): 292–301. http://dx.doi.org/10.4028/www.scientific.net/kem.857.292.

Full text

Abstract:

The problematic soils have complex and irregular behavior such as gypseous soils, which concentrated mainly in the dry and semi-dry regions in the world. In Iraq, the gypseous soils cover about 30 to 35% of its total area in the west desert and extended to the southern parts of Iraq. The gypseous soils experience sudden collapse upon wetting. The present paper focuses on studying the effects of nano silica fume (NSF) on the collapsibility and shear strength of gypseous soil before and after soaking. Also, this study, the influence of NSF on the chemical and physical characteristics of gypseous soil have been investigated. A gypseous soil sample obtained from Al-Najaf Sea has gypsum content of 42%. The gypseous soil samples are mixed with three percentages of nano silica fume (1, 2, and 4) % calculated as ratio of the dry mass of soil to measure their influence on the geotechnical characteristics of soil samples. The collapse potential of gypseous soil is reduced with increasing the content of nano silica fume. Also, increasing the content of NSF and curing time resulted in increasing the shear strength of soil samples.

APA, Harvard, Vancouver, ISO, and other styles

4

Abadie, Marc, Zaid Romani, Michel Burlot, Jérôme Nicolle, Pierre Peigné, Lionel Druette, Bernard Collignan, and Francis Allard. "Development of a Natural Soil Depressurization System Sizing Tool." Journal of Physics: Conference Series 2069, no. 1 (November 1, 2021): 012185. http://dx.doi.org/10.1088/1742-6596/2069/1/012185.

Full text

Abstract:

Abstract This paper presents a summary of the main developments and results achieved in the frame-work of the French research project called EVAL-SDS. This project aims to analyse the performance of Natural, i.e. without use of fan for extraction, Soil Depressurization Systems (NSDS) to protect the built indoor environment from soil gaseous pollutant (Radon, Volatile Organic Compounds…). In this paper, the aeraulic performance of NSDS is studied i.e. its capacity to extract air from the ground to protect building’s occupants. To this end, we first performed measurements of airflow rates extracted by a NSDS integrated in a test-house during one year. Those data include various weather conditions (stack effect, wind) for several key parameters (wind extractor type, slab air permeability and basement pressure). Then, a dedicated calculation tool has been developed and validated against the experimental results. This numerical model has been used to evaluate the NSDS performance in France for different building heights and ventilation systems. The results show that NSDS succeed in creating a negative pressure under the building slab most of the time and that the extracted airflow rates can be enhanced by better design of wind extractor, association with mechanical insufflating ventilation system and thermal transfer from the building during the heating season.

APA, Harvard, Vancouver, ISO, and other styles

5

Wijdan Ahmed Ali, Bahrouz M.M AL-Jaaf, and SajidS.Saleam AL-SaeedI. "Detection of Unculturable Fungi in Soil Regions of Aziz Awa in Sulaimani province." Tikrit Journal of Pure Science 23, no. 9 (January 30, 2023): 32–38. http://dx.doi.org/10.25130/tjps.v23i9.810.

Full text

Abstract:

Unculturable and non-sporulting fungi represent a great challenge instudying biotrophic, endotrophic and mycorrhizal fungal groups. In thisstudy collection of soil sample from region Aziz Awa in sulaimaniprovince and using culture-dependent and culture in-dependenttechniques for cultivation of unculturable fungi for the purpose ofexpanding studies on fungal biodiversity in soil. Sabouraud DextroseAgar with supplement as pyridoxine by replicating master plate fromhigher dilution of soil three tinny colonies (less than 1mm in diameter)had grown on medium after incubation for 5-7 weeks at 280C but had notshown growth when replicated on traditional mycological media (PDA,Czapack Dox Agar and Sabouraud Dextrose Agar) were selected,purified, studied culturally and microscopically and identified bymolecular methods. Four specific primer sets (NSIF/ITS4r, NSIF/ LRIF,EF4F/ITS4r and EF60F/ITS4r) were used to amplify partial sequences offungal r RNA gene included ITS sequences. The partial sequences ofthree clones were aligned through the BLASTN phylogenetic analysis inNCBI were available at GenBank database and revealed higher scoresand identities with Fusarium sp, Penicillium sp and Uncultured soilfungus clone. These results led us to consider the clones as viable butnon culturable (VBNC) soil fungi like the common phenomenon in somebacterial species.

APA, Harvard, Vancouver, ISO, and other styles

6

Khan, V. A., C. Stevens, J. Y. Lu, D. I. Collins, M. A. Wilson, J. E. Brown, M. K. Kabwe, and O. Adeyeye. "RESPONSE OF OKRA TRANSPLANTS GROWS ON SOIL SOLARIZING PLOTS DURING THE ACTIVE PERIOD OF SOIL SOLARIZATION." HortScience 29, no. 7 (July 1994): 733e—733. http://dx.doi.org/10.21273/hortsci.29.7.733e.

Full text

Abstract:

A study was conducted in 1991 to determine the effect high soil temperatures would have on `Clemson Spineless' okra plants transplanted into field plots during 60 days of active soil solarization (solar heating of the soil using clear plastic during the summer period). Solarized plots were planted to a winter cover crop which served as an organic amendment, which was rototilled into the top 15 cm of the soil before solarizing. Okra transplants were planted on the outer edges of the plots one month after the solarization process commenced and drip irrigated. Three weeks (wk) after transplanting, a complete fertilizer at the rate of 200 parts per million was applied to the plots giving the following treatment combinations: solarized non-fertilized control (SNF), non-solarized non-fertilized control (NSNF), solar fertilized (SF). and non-solarized fertilized (NSF). Results showed that the increased soil temperature did not have any deleterious effect on the okra plants grown in SNF or SF plots. However, plants grown in SF plots suffered severe fertilizer bums which affected plant density and yield. This indicated a rapid breakdown of soil organic matter provided sufficient nutrients to sustain a late-season crop of okra. Plant height, marketable yield vegetative branching and income generated were greater in SNF compared to SF, NSF and NSNF plots, respectively.

APA, Harvard, Vancouver, ISO, and other styles

7

Demsie, Tarekegn Shumetie, Markos Tsegaye Beyene, Abuye Boja Lemma, and Esayas Alemayehu. "NSF (Nylon Synthetic Fiber) Effectiveness in Stabilizing Weak Subgrade Soil: An Experimental Investigation." Advances in Civil Engineering 2023 (May 30, 2023): 1–13. http://dx.doi.org/10.1155/2023/3085842.

Full text

Abstract:

Improvement in subgrade soil has always been an area of concern for highway and geotechnical engineers. Weak subgrade soil results in a greater thickness of the pavement layer, which increases the cost of pavement construction. It further leads to large deformations, which in turn cause continuous deterioration of the paved surface. To solve this problem, various engineering solutions and soil improvement mechanisms were previously proposed. This study was designed to investigate the stabilization of weak subgrade soil with nylon synthetic fiber (NSF) in a compromising combination. Previously, some investigations used a lower fiber content with a higher fiber length, whereas others used a lower fiber length with a higher fiber content. However, this investigation was uniquely designed to stabilize weak subgrade soil with the consideration of appropriate fiber length (10 mm and 20 mm) and content (0.5%, 1%, 1.5%, and 2.5%). The engineering properties of the soil, the effect of NSF on weak subgrade soil, various fiber content and aspect ratios, and the optimum content and critical fiber aspect ratio were investigated in a laboratory. The effect of fibers on compaction, CBR values, and CBR swell values has also been studied. Laboratory results on the modified compaction tests showed that maximum dry density (MDD) was increased with the increment of fiber content, whereas optimum moisture content (OMC) remained constant. The soaked CBR and CBR swell values of natural soil were 1.80% and 8.95%, respectively. Due to reinforcement, the percentage increase in soaked CBR value at the optimum NSF content is 265.3, 310.0, 282.8, and 342.2 for aspect ratios of 33.33, 66.67, 25, and 50, respectively, with reference to natural soil. Also, the percentage decrease in swelling is 34.7, 52.75, 43.55, and 36.9, respectively. Moreover, the CBR value increases with the increase in aspect ratio by keeping the diameter constant and decreases with the increase in aspect ratio by keeping the length constant. It was also observed that increasing the length and diameter of NSF further increased the CBR value of reinforced soil. This increment was substantial at a fiber content of 1.5% for an aspect ratio of 50 (length = 20 mm, diameter = 0.4 mm). There was also a decrease in the CBR swelling value with an increase in fiber content. Finally, this investigation concluded that the use of NSF is a solution to weak soils with regard to moisture and performance problems.

APA, Harvard, Vancouver, ISO, and other styles

8

Shaikh, Janarul, Sudheer Kumar Yamsani, Sanjeet Sahoo, Sreedeep Sekharan, and Ravi Ranjan Rakesh. "Hydraulic performance assessment of a multi-layered landfill cover system under constant water ponding." Acta Horticulturae et Regiotecturae 25, no. 2 (November 1, 2022): 129–40. http://dx.doi.org/10.2478/ahr-2022-0017.

Full text

Abstract:

Abstract The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into the wastes accommodated in near surface waste disposal facility (NSDF). It is important to assess the hydraulic performance of MLCS before deploying it in the field. For this purpose, an instrumented three-layered soil column representing MLCS was subjected to 1.5 m constant ponding head for 400 days. The variation of volumetric water content and soil water potential was monitored as a function of depth and time. The objective of the study is to understand the long-term hydraulic performance and rate of saturation of different layers of MLCS. Under constant water ponding, the time to saturation for 0.3 m in surface layer, 0.6 m in drainage layer and 1.0 m in hydraulic barrier layer was observed as 24, 223 and 262 days, respectively. The numerical analysis of the MLCS predicted comparable time duration of 25, 234 and 272 days, respectively. It was noted that the numerical simulation performed by using measured wetting hydraulic parameters matched well with the experimental observation. The importance of soil specific calibration of water content sensors to improve the accuracy of observations was demonstrated. Percentage error in the estimation of layer specific soil water storage, clearly indicates that the volumetric water content measurements using profile probe was marginally better than 5TM measurements.

APA, Harvard, Vancouver, ISO, and other styles

9

Sun, Ting Cong, Jack D. Jarrell, and Robert L. Schafer. "Computer instrumentation for the NSDL soil bin penetrometer car." Computers and Electronics in Agriculture 1, no. 3 (December 1986): 281–88. http://dx.doi.org/10.1016/0168-1699(86)90015-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Cemiloglu, Ahmed, Licai Zhu, Biyun Chen, Li Lu, and Yaser A. Nanehkaran. "Enhancing Urban Surface Runoff Conveying System Dimensions through Optimization Using the Non-Dominated Sorting Differential Evolution (NSDE) Metaheuristic Algorithm." Water 15, no. 16 (August 14, 2023): 2927. http://dx.doi.org/10.3390/w15162927.

Full text

Abstract:

Rapid urban development and increase in construction have significantly altered the surface coverage of cities, resulting in a rise in impervious surfaces such as roofs, streets, and pavements. These changes act as barriers against rainwater infiltration into the soil, leading to a substantial increase in surface runoff. Managing surface runoff has become a critical task in civil engineering and urban planning, as it can mitigate damage and provide opportunities for utilizing excess water. However, traditional flood control and guidance systems tend to be extensive and expensive, prompting researchers to explore cost-effective alternatives that consider all design parameters and variables. In this research, we propose an innovative approach that combines the NSDE (non-dominated sorting differential evolution) metaheuristic algorithm as an optimizer with the SWMM (storm water management model) as a simulator. The objective is to design efficient surface runoff collection networks by thoroughly investigating their hydraulic behaviors. This study focuses on the Chitgar watershed in Tehran, Iran, utilizing the SWMM model and NSDE multi-objective metaheuristic algorithm to determine the optimal dimensions of the channel and its intersecting structures. The aim is to minimize costs and reduce water leakage from the network. A comparison is made between the optimized design results and the existing network plan (without any design modifications). The analysis reveals substantial reductions in water leakage for all three design scenarios: a 7.66% reduction when considering only bridges, a 7.35% reduction with only the canal, and an impressive 95.26% reduction when both the canal and bridges are incorporated. These findings demonstrate the superiority of the optimized designs in terms of cost-effectiveness and the efficient management of surface runoff.

APA, Harvard, Vancouver, ISO, and other styles

11

Youd, T. L., I. M. Idriss, Ronald D. Andrus, Ignacio Arango, Gonzalo Castro, John T. Christian, Richardo Dobry, et al. "Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils." Journal of Geotechnical and Geoenvironmental Engineering 127, no. 10 (October 2001): 817–33. http://dx.doi.org/10.1061/(asce)1090-0241(2001)127:10(817).

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Youd, T. L., and I. M. Idriss. "Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils." Journal of Geotechnical and Geoenvironmental Engineering 127, no. 4 (April 2001): 297–313. http://dx.doi.org/10.1061/(asce)1090-0241(2001)127:4(297).

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Keresztesi, Ágnes, Réka Boga, Zsolt Bodor, Katalin Bodor, Szende Tonk, György Deák, and Ion-Andrei Nita. "The Analysis of the Chemical Composition of Precipitation During the Driest Year from the Last Decade." Present Environment and Sustainable Development 13, no. 1 (June 1, 2019): 19–32. http://dx.doi.org/10.2478/pesd-2019-0002.

Full text

Abstract:

Abstract In order to investigate the precipitation chemistry, studies were carried out from January 2013 to December 2013 in Odorheiu Secuiesc and Miercurea Ciuc, Eastern Carpathians, Romania. During a period of eleven years (2006 – 2016), 2013 was the driest year. The rainwater samples were analyzed for pH, major anions and cations. HCO3− concentrations were calculated based on the empirical relationship between pH and HCO3−. NH4+, Ca2+, SO42− were the dominant ions in precipitation at both sites. The pH values varied from 6.75 to 7.46 Miercurea Ciuc, and from 6.69 to 7.67 in Odorheiu Secuiesc. The neutralization was mainly brought by Ca2+ and NH4+. Estimated ratios of sea-salt fraction (SSF), non-sea-salt fraction (NSSF), and results from Spearman’s rank correlation and Principal Component Analysis (PCA), showed that the acidic ions (SO42−, NO3−) were derived from anthropogenic activities, NH4+ from soil fertilization, while Ca2+, Mg2+, K+ originated from terrestrial source. These influence the precipitations ionic content, especially during droughts. Spatial variations and the rim effect of the Eastern Carpathians on precipitation chemistry is also shown.

APA, Harvard, Vancouver, ISO, and other styles

14

Solodei, Ivan, Eduard Petrenko, and Herman Zatyliuk. "Study of parameters of nonlinear slope deformation under the action of power and natural factors." Strength of Materials and Theory of Structures, no. 107 (October 29, 2021): 35–44. http://dx.doi.org/10.32347/2410-2547.2021.107.35-44.

Full text

Abstract:

Construction planning in complex engineering and geological conditions, which include landslide-prone areas, requires a detailed analysis of the existing state of the slope and the forecast of its behavior depending on changes in natural and technogenic factors. This possibility can be provided only by modeling deformation processes using numerical calculation methods. On the example of construction of a three-storey cottage on a landslide-prone slope, the analysis of the operating conditions of existing anti-landslide structures was carried out and their role in ensuring the slope stability was determined. The preliminary calculation of the slope stability was performed by the method of round cylindrical sliding surfaces for soils of natural humidity and in water-saturated state. The method of round cylindrical surfaces is a simplified method of calculating the slopes stability, which in the conditions of heterogeneous layered slope leads to the overestimation of its stability. Therefore, to determine the actual NSDT of the slope, the calculation profile was developed, on which several formulations of the above problem were performed. The calculation was performed on the basis of the developed methodology presented in the works of the article authors. The stress-strain state (SSS) of the slope is considered using the finite element method (FEM) and its torque circuit. The base is presented in the form of a modified model of fortified soils with the criterion of the limit state of Mises-Schleicher-Botkin. In numerical implementation, the slope on the basis of engineering surveys was presented as a finite-element discrete model with an elemental grid, a fragment of which is a separate engineering-geological element. The considered in the article example of the method of calculation of the system «supporting structure-nonlinear base-house» gives the opportunity to give a reliable assessment of the territory state and offer a number of rational measures for its engineering protection, which ensures reliable operation of buildings and structures.

APA, Harvard, Vancouver, ISO, and other styles

15

Xia, Li Nong, Hai Tao Hu, Yun Dong Miao, and Chang Bin Liao. "3D Finite Element Analysis of Negative Skin Friction (NSF) Behaviors in Pile Groups with Cap." Applied Mechanics and Materials 405-408 (September 2013): 390–95. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.390.

Full text

Abstract:

The pile-soil interactions are constrained by the pile cap in pile groups with cap, while mutually independent in pile groups without cap. The mechanism of changing of NSF in pile groups with cap are analyzed briefly. The NSF behaviors of pile groups with cap under the condition of groundwater level lowering are analyzed by three-dimensional finite element method. The analysis shows that the NSF of pile groups with cap is generally similar to that of a single pile: as the working loads on cap increasing, the neutral point moves up, additional settlement increases and the downdrag decreases, though there are differences between piles in different positions. The constraints of settlement of piles in various positions by the cap are significant when the working load is not large, so that the neutral point of piles are almost coincident. As the working load increasing, the deformation of the cap increases and the neutral point of piles become more various, lowest for the corner pile, second for the perimeter pile and highest for the interior pile. The NSF of each pile in pile groups with cap mobilizes differently along the depth. It is mobilized most fully for the corner pile, second for the perimeter pile and least for the interior pile.

APA, Harvard, Vancouver, ISO, and other styles

16

Pyke, Robert. "Discussion of “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils” by T. L. Youd, I. M. Idriss, Ronald D. Andrus, Ignacio Arango, Gonzalo Castro, John T. Christian, Richardo Dobry, W. D. Liam Finn, Leslie F. Harder Jr., Mary Ellen Hynes, Kenji Ishihara, Joseph P. Koester, Sam S. C. Liao, William F. Marcuson III, Geoffrey R. Martin, James K. Mitchell, Yoshiharu Moriwaki, Maurice S. Power, Peter K. Robertson, Raymond B. Seed, and Kenneth H. Stokoe II." Journal of Geotechnical and Geoenvironmental Engineering 129, no. 3 (March 2003): 283–84. http://dx.doi.org/10.1061/(asce)1090-0241(2003)129:3(283).

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Youd, T. L., I. M. Idriss, Ronald D. Andrus, Ignacio Arango, Gonzalo Castro, John T. Christian, Ricardo Dobry, et al. "Closure to “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils” by T. L. Youd, I. M. Idriss, Ronald D. Andrus, Ignacio Arango, Gonzalo Castro, John T. Christian, Richardo Dobry, W. D. Liam Finn, Leslie F. Harder Jr., Mary Ellen Hynes, Kenji Ishihara, Joseph P. Koester, Sam S. C. Liao, William F. Marcuson III, Geoffrey R. Martin, James K. Mitchell, Yoshiharu Moriwaki, Maurice S. Power, Peter K. Robertson, Raymond B. Seed, and Kenneth H. Stokoe II." Journal of Geotechnical and Geoenvironmental Engineering 129, no. 3 (March 2003): 284–86. http://dx.doi.org/10.1061/(asce)1090-0241(2003)129:3(284).

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Jiang, Junjie, Junguo Hu, Xiaojun Xu, Yongfu Li, and Jie Sheng. "Effect of near-surface winds on the measurement of forest soil CO2 fluxes using closed air chambers." Frontiers in Ecology and Evolution 11 (July 28, 2023). http://dx.doi.org/10.3389/fevo.2023.1163704.

Full text

Abstract:

Forest soil CO2 flux measurements are important for studying global climate change. Current monitoring methods are based on closed gas chambers, which block the wind pumping effect of near-surface winds in the measurements, resulting in biased values. Therefore, in this study, the effects of near-surface winds on chamber-monitored fluxes were investigated. The CO2 flux was quantified using a designed flux reference system with different CO2 concentrations, and the monitoring performance of the closed chamber was studied. Wavelet coherence was used to analyze the response relationship between near-surface winds and soil gas, and was combined with a flux calculation model to explore the relevant factors influencing gas chamber measurement-produced bias. The data indicate that at near-surface wind speeds greater than 0.8 m·s−1, gas transport enhancement was significant and further increased the deviation of the gas chamber-monitored CO2 fluxes. The monitoring error of the flow chamber (NSF) increased from 7% to 30% in soils with low carbon content, but did not vary significantly (3–7%) in soils with high CO2 concentrations. The flux measurement bias of the non-flow chamber (NSNF) was positively correlated with the soil carbon content, with the measurement error expanding by 16–24% with increasing soil CO2 concentrations. The measurement errors of the exponential and linear models in a windless environment were 9.8% (Exp) and 18.7% (Lin), respectively. The estimation errors of both models were positively correlated with both the time of a single monitoring event and the wind-induced coefficient Dw. Therefore, flux calculation models should be improved by considering environments with wind disturbances to reduce the effect of wind on measured values, which will help improve the accuracy of ecosystem carbon budgets.

APA, Harvard, Vancouver, ISO, and other styles

19

"Signals in the Soil (NSF)." Federal Grants & Contracts 46, no. 5 (January 29, 2022): 2. http://dx.doi.org/10.1002/fgc.32185.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

"Signals in the Soil (NSF)." Federal Grants & Contracts 43, no. 9 (April 2, 2019): 2. http://dx.doi.org/10.1002/fgc.30352.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Barak, M. S., Rajesh Kumar, Rajneesh Kumar, and Vipin Gupta. "The effect of memory and stiffness on energy ratios at the interface of distinct media." Multidiscipline Modeling in Materials and Structures, March 15, 2023. http://dx.doi.org/10.1108/mmms-10-2022-0209.

Full text

Abstract:

PurposeThis paper aims to study the energy ratios of plane waves on an imperfect interface of elastic half-space (EHS) and orthotropic piezothermoelastic half-space (OPHS).Design/methodology/approachThe dual-phase lag (DPL) theory with memory-dependent derivatives is employed to study the variation of energy ratios at the imperfect interface.FindingsA plane longitudinal wave (P) or transversal wave (SV) propagates through EHS and strikes at the interface. As a result, two waves are reflected, and four waves are transmitted, as shown in Figure 2. The amplitude ratios are determined by imperfect boundaries having normal stiffness and transverse stiffness. The variation of energy ratios is computed numerically for a particular model of graphite (EHS)/cadmium selenide (OPHS) and depicted graphically against the angle of incidence to consider the effect of stiffness parameters, memory and kernel functions.Research limitations/implicationsThe energy distribution of incident P or SV waves among various reflected and transmitted waves, as well as the interaction of waves for imperfect interface (IIF), normal stiffness interface (NSIF), transverse stiffness interface (TSIF), and welded contact interface (WCIF), are important factors to consider when studying seismic wave behavior.Practical implicationsThe present model may be used in various disciplines, such as high-energy particle physics, earthquake engineering, nuclear fusion, aeronautics, soil dynamics and other areas where memory-dependent derivative and phase delays are significant.Originality/valueIn a variety of technical and geophysical scenarios, wave propagation in an elastic/piezothermoelastic medium with varying magnetic fields, initial stress, temperature, porosity, etc., gives important information regarding the presence of new and modified waves.

APA, Harvard, Vancouver, ISO, and other styles

22

He, Qi-Peng, Shuai Zhao, Jiu-Xiang Wang, Cheng-Xi Li, Yu-Si Yan, Long Wang, Lu-Sheng Liao, and Jia-Xun Feng. "Transcription Factor NsdD Regulates the Expression of Genes Involved in Plant Biomass-Degrading Enzymes, Conidiation, and Pigment Biosynthesis inPenicillium oxalicum." Applied and Environmental Microbiology 84, no. 18 (July 6, 2018). http://dx.doi.org/10.1128/aem.01039-18.

Full text

Abstract:

ABSTRACTSoil fungi produce a wide range of chemical compounds and enzymes with potential for applications in medicine and biotechnology. Cellular processes in soil fungi are highly dependent on the regulation under environmentally induced stress, but most of the underlying mechanisms remain unclear. Previous work identified a key GATA-type transcription factor,Penicillium oxalicumNsdD (PoxNsdD; also called POX08415), that regulates the expression of cellulase and xylanase genes inP. oxalicum. PoxNsdD shares 57 to 64% identity with the key activator NsdD, involved in asexual development inAspergillus. In the present study, the regulatory roles of PoxNsdD inP. oxalicumwere further explored. Comparative transcriptomic profiling revealed that PoxNsdD regulates major genes involved in starch, cellulose, and hemicellulose degradation, as well as conidiation and pigment biosynthesis. Subsequent experiments confirmed that a ΔPoxNsdDstrain lost 43.9 to 78.8% of starch-digesting enzyme activity when grown on soluble corn starch, and it produced 54.9 to 146.0% more conidia than the ΔPoxKu70parental strain. During cultivation, ΔPoxNsdDcultures changed color, from pale orange to brick red, while the ΔPoxKu70cultures remained bluish white. Real-time quantitative reverse transcription-PCR showed thatPoxNsdDdynamically regulated the expression of a glucoamylase gene (POX01356/Amy15A), an α-amylase gene (POX09352/Amy13A), and a regulatory gene (POX03890/amyR), as well as a polyketide synthase gene (POX01430/alb1/wA) for yellow pigment biosynthesis and a conidiation-regulated gene (POX06534/brlA). Moreover,in vitrobinding experiments showed that PoxNsdD bound the promoter regions of the above-described genes. This work provides novel insights into the regulatory mechanisms of fungal cellular processes and may assist in genetic engineering ofP.oxalicumfor potential industrial and medical applications.IMPORTANCEMost filamentous fungi produce a vast number of extracellular enzymes that are used commercially for biorefineries of plant biomass to produce biofuels and value-added chemicals, which might promote the transition to a more environmentally friendly economy. The expression of these extracellular enzyme genes is tightly controlled at the transcriptional level, which limits their yields. Hitherto our understanding of the regulation of expression of plant biomass-degrading enzyme genes in filamentous fungi has been rather limited. In the present study, regulatory roles of a key regulator, PoxNsdD, were further explored in the soil fungusPenicillium oxalicum, contributing to the understanding of gene regulation in filamentous fungi and revealing the biotechnological potential ofP.oxalicumvia genetic engineering.

APA, Harvard, Vancouver, ISO, and other styles

23

Dewata, Indang. "WATER QUALITY ASSESSMENT OF RIVERS IN PADANG USING WATER POLLUTION INDEX AND NSF-WQI METHOD." International Journal of GEOMATE 17, no. 64 (December 1, 2019). http://dx.doi.org/10.21660/2019.64.16793.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Huebert, Barry. "Measurements of organic and elemental carbon in Asian outflow during ACE-Asia from the NSF/NCAR C-130." Journal of Geophysical Research 109, no. D19 (2004). http://dx.doi.org/10.1029/2004jd004700.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Moore, K. G. "A comparison of similar aerosol measurements made on the NASA P3-B, DC-8, and NSF C-130 aircraft during TRACE-P and ACE-Asia." Journal of Geophysical Research 109, no. D15 (2004). http://dx.doi.org/10.1029/2003jd003543.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'NSDF Soils'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles