Lime application effects on soil aggregate properties: Use of the mean weight diameter and synchrotron-based X-ray μCT techniques

The role of tillage practices on soil aggregate properties has been mainly addressed at the pedon scale (i.e., soilscape scale) by treating landscape elements as disconnected. However, there is observed heterogeneity in aggregate properties along flowpaths, suggesting that landscape scale hydraulic processes are also important. This study examines this supposition using field, laboratory and modeling analysis to assess aggregate size and stability along flowpaths under different management conditions: (1) tillage-induced abrasion effects on aggregate size were evaluated with the dry mean weight diameter (DMWD); (2) raindrop impact effects were evaluated with small macroaggregate stability (SMAGGSTAB) using rainfall simulators; and (3) these aggregate proxies were studied in the context of connectivity through the excess bed shear stress (δ), quantified using a physically-based landscape model. DMWD and SMAGGSTAB decreased along the flowpaths for all managements, and a negative correspondence between the proxies and δ was observed. δ captured roughness effects on connectivity along the flowpaths: highest connectivity was noted for parallel-ridge-till flowpaths, where δ ranged from 0–8.2 Pa, and lowest connectivity for contour-ridge-till flowpaths, where δ ranged from 0–1.1 Pa. High tillage intensity likely led to an increase in aggregate susceptibility to hydraulic forcing, reflected in the higher gradients of aggregate size and stability trendlines with respect to δ. Finally, a linear relationship between DMWD and SMAGGSTAB was established.

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Inoculation of bacteria for the amelioration of sandy soil under drought

10.5194/egusphere-egu2020-15917 ◽

2020 ◽

Author(s):

Violeta Carmen Angulo Fernández ◽

Mariet Hefting ◽

George Kowalchuk

Keyword(s):

Soil Compaction ◽

Biofilm Formation ◽

Soil Structure ◽

Soil Microorganisms ◽

Soil Aggregate ◽

Soil Aggregation ◽

Bacterial Strains ◽

Mean Weight Diameter ◽

Microbial Strains ◽

The Mean

Soil degradation represents a pressing worldwide problem that is being accelerated by processes of erosion, depletion of soil organic matter, soil compaction, acidification, salinization, and drought. Soil microorganisms can influence soil aggregation via a range of mechanisms such as the production of exopolysaccharides and other extracellular matrix polymers such those involved in biofilm formation. In this study, we south to use bacteria harboring specific traits to enhance soil aggregation. To this end, 120 bacterial strains were isolated from an experiment field under drought conditions and tested for their ability to grow under drought, salinity tolerance, rapid growth, biofilm, and exopolysacharides production. Based upon this trait assessment, 24 strains were further tested at two moisture levels for their ability to impact soil structure after 8 weeks of incubation at 25&#186;C. The mean weight diameter (MWD) of water-stable aggregates and carbohydrates were determined for treated soils. Three strains were shown to impact soil aggregate properties at the higher moisture content: one affiliated with Bacillus niacini, one affiliated with Paenarthrobacter nitroguajacolicus and one of unclear classification. The first of these strains also affected soil structure at the lower moisture level. This B. niacini strain also increased the carbohydrate content of the soil, as did two other strains, related to B. wiedmannii and B. aryabhattai, respectively. However, no positive correlation was observed between the MWD and the production of carbohydrates in soil. Our results suggest that soil inoculation with specific microbial strains can improve soil structure.

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Soil Aggregate-Associated Carbon Fraction Dynamics during the Process of Tea (Camellia sinensis L.) Planting in Southern Guangxi, China

Forests ◽

10.3390/f12111530 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1530

Author(s):

Chao Zhang ◽

Xinxin He ◽

Shaoming Ye ◽

Shengqiang Wang

Keyword(s):

Soil Aggregates ◽

Aggregate Size ◽

Soil Aggregate ◽

Vital Role ◽

Soil Layers ◽

Mean Weight Diameter ◽

Recalcitrant Carbon ◽

Tea Plantations ◽

The Mean ◽

The Stability

Revealing the variation in soil aggregate-associated organic carbon (Corg) in tea plantations of various planting ages is crucial to shed more light on the accumulation and decomposition of soil Corg in the tea-planting period. This study measured the concentrations of soil Corg, active carbon (Cact), and recalcitrant carbon (Crec) in different-sized aggregates obtained from tea plantations of various planting ages (8, 17, 25, and 43 years old) at the soil depths of 0–20 and 20–40 cm in southern Guangxi, China. According to the wet-sieving approach, soil aggregates were classified as macro- (>0.25 mm) and micro- (<0.25 mm) aggregates, and the former were further divided into coarse (>2 mm), medium (2–1 mm), and fine (1–0.25 mm) fractions. Based on the mean weight diameter (MWD), the stability of soil aggregates was the highest in the 17-year-old tea plantations, and it was closely related to the concentration of soil Cact (0–20 cm: R2 = 0.9744, p < 0.05; 20–40 cm: R2 = 0.8951, p < 0.05), but not Corg (0–20 cm: R2 = 0.1532, p > 0.05; 20–40 cm: R2 = 0.4538, p > 0.05), during the tea-planting process. In the 0–20 and 20–40 cm soil layers, the coarse and medium macro-aggregates had higher concentrations of Corg, Cact, and Crec, regardless of the tea-planting age; meanwhile, the soil Cact/Crec ratio, indicating the Corg availability, increased as aggregate size increased, implying that the soil Corg was younger and more labile in coarse macro-aggregates relative to finer aggregates. Moreover, the tea-planting age significantly affected the Corg, Cact, and Crec reserves in both soil layers. To be specific, continuous tea planting facilitated the accumulation of soil Corg and Crec, but their reserves’ increase rates decreased over time; meanwhile, the soil Cact reserve increased during the early (from 8 to 17 years) tea-planting stage and later decreased. Therefore, during the middle (from 17 to 25 years) and late (from 25 to 43 years) tea-planting stages, maintaining the soil as an Cact pool plays a vital role in facilitating the formation and stabilization of soil aggregates in southern Guangxi, China.

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Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075968 ◽

1983 ◽

Vol 41 ◽

pp. 446-447

Author(s):

William F. Tivol ◽

Murray Vernon King ◽

D. F. Parsons

Keyword(s):

Electron Diffraction ◽

Heavy Atom ◽

Isomorphous Substitution ◽

X Ray Diffraction ◽

Salt Solutions ◽

X Ray ◽

Isomorphous Replacement ◽

Structure Factors ◽

Diffraction Structure ◽

The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

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Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173959 ◽

1990 ◽

Vol 48 (4) ◽

pp. 164-165

Author(s):

Noriyuki Kuwano ◽

Masaru Itakura ◽

Kensuke Oki

Keyword(s):

Electron Microscopy ◽

Mean Value ◽

Heavy Elements ◽

Arc Furnace ◽

X Ray ◽

Long Period ◽

Ultra High Purity ◽

Heat Treated ◽

Atomic Scattering ◽

The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

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Localization of calcium and zinc in the sperm storage tubules of chicken, quail and turkey using X-ray microanalysis

Reproduction ◽

10.1530/reprod/118.2.331 ◽

2000 ◽

pp. 331-336 ◽

Cited By ~ 9

Author(s):

L Holm ◽

H Ekwall ◽

GJ Wishart ◽

Y Ridderstrale

Keyword(s):

Calcium Concentration ◽

Sperm Storage ◽

X Ray ◽

Elemental Concentrations ◽

Low Concentrations ◽

Intracellular Content ◽

Wet Weight ◽

The Mean ◽

Sperm Storage Tubules ◽

Scanning Electron

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.

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Use of the electro-separation method for improvement of the utility value of winter rapeseeds

International Agrophysics ◽

10.2478/intag-2013-0012 ◽

2013 ◽

Vol 27 (4) ◽

pp. 419-424 ◽

Cited By ~ 9

Author(s):

S.J. Kovalyshyn ◽

O.P. Shvets ◽

S. Grundas ◽

J. Tys

Keyword(s):

Corona Discharge ◽

Mechanical Damage ◽

Edible Oil ◽

Separation Method ◽

Utility Value ◽

X Ray ◽

Winter Rapeseed ◽

The Mean ◽

Discharge Field ◽

Prototype Apparatus

Abstract The paper presents the results of a study of the use of electro-separation methods for improvement of the utility value of 5 winter rapeseed cultivars. The process of electro-separation of rapeseed was conducted on a prototype apparatus built at the Laboratory of Application of Electro-technologies in Agriculture, Lviv National Agriculture University. The process facilitated separation of damaged, low quality seeds from the sowing material. The initial mean level of mechanically damaged seeds in the winter rapeseed cultivars studied varied within the range of 15.8-20.1%. Verification of the amount of seeds with mechanical damage was performed on X-ray images of seeds acquired by means of a digital X-ray apparatus. In the course of analysis of the X-ray images, it was noted that the mean level of mechanical damage to the seeds after the electro-separation was in the range of 2.1-3.8%. The application of the method of separation of rapeseeds in the corona discharge field yielded a significant reduction of the level of seeds with mechanical damage. The application of the method in practice may effectively contribute to improvement of the utility value of sowing material or seed material for production of edible oil.

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Preparation of high-entropy carbides by different sintering techniques

Journal of Materials Science ◽

10.1007/s10853-021-06004-y ◽

2021 ◽

Vol 56 (19) ◽

pp. 11237-11247 ◽

Cited By ~ 1

Author(s):

Johannes Pötschke ◽

Manisha Dahal ◽

Mathias Herrmann ◽

Anne Vornberger ◽

Björn Matthey ◽

...

Keyword(s):

Grain Size ◽

Single Phase ◽

X Ray Diffraction ◽

Vacuum Sintering ◽

X Ray ◽

High Entropy ◽

Mean Grain Size ◽

The Mean ◽

Gas Pressure Sintering ◽

Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

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AB0267 BODY COMPOSITION IN PATIENTS WITH RHEUMATOID ARTHRITIS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.2318 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 1432.2-1432

Author(s):

N. Toroptsova ◽

O. Dobrovolskaya ◽

N. Demin ◽

L. Shornikova

Keyword(s):

Rheumatoid Arthritis ◽

Body Composition ◽

Muscle Mass ◽

Dual Energy ◽

X Ray ◽

T Score ◽

Osteosarcopenic Obesity ◽

The Mean ◽

Total Fat ◽

Appendicular Muscle Mass

Background:Rheumatoid arthritis (RA) is a complex inflammatory disease that modifies body composition. Using the dual-energy x-ray absorptiometry (DXA) in RA patients could be a method for body composition changes detection.Objectives:To study the body composition using DXA in patients with RA.Methods:The study involved 79 women with RA, median age 60 [55; 65] years. The bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry using «Discovery A» (Hologic, USA). Assessment of body composition was carried out, using the program «Whole body». Sarcopenia (SP) was diagnosed as a decrease in appendicular mass index (AMI) <6.0 kg/m2. Osteoporosis (OP) was diagnosed as a decrease in T-score <-2.5 SD. Osteosarcopenia was determined when T-score was <-1.0 SD, AMI was <6.0 kg/m2, osteosarcopenic obesity - T-score was <-1.0 SD, AMI was <6.0 kg/m2and total fat was >35%.Results:The mean duration of RA was 9 [3; 11] years. The mean body mass index (BMI) was 27.6±4.8 kg/m2. Disease activity score in 28 joints-erythrocyte sedimentation rate was 4.5±1.3 points for the group. 39 (49.3%) patients used oral glucocorticoids continuously. Appendicular muscle mass and AMI were on average 17.8±3.0 kg and 6.8±1.0 kg/m2, respectively. AMI <6 kg/m2was detected in 20 (25.3%) patients. 56 (70.9%) women with RA had total fat > 35%, while only 22 (27.8%) of women with RA had obesity according to BMI (BMI >30 kg/m2). Isolated OP was found in 13 (16.5%), osteosarcopenia in 7 (8.9%) and osteosarcopenic obesity in 13 (16.5%) patients RA. No cases with isolated sarcopenia or sarcopenic obesity were detected. Only 3 (3.8%) patients did not have appendicular muscle mass, AMI and BMD decrease and overfat or obesity.Conclusion:About 97% women with RA had abnormal body composition phenotype: 16,5% - OP, 8.9% -osteosarcopenia, 16,5% - osteosarcopenic obesity and 54,4% - overfat.Disclosure of Interests:None declared

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Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

Mineralogical Magazine ◽

10.1180/minmag.2009.073.6.1027 ◽

2009 ◽

Vol 73 (6) ◽

pp. 1027-1032 ◽

Cited By ~ 11

Author(s):

F. Nestola ◽

A. Guastoni ◽

L. Bindi ◽

L. Secco

Keyword(s):

Polarized Light ◽

New Mineral ◽

X Ray Diffraction ◽

X Ray ◽

Elemental Concentrations ◽

Reflected Light ◽

Mohs Hardness ◽

The Mean ◽

The University ◽

Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

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