scholarly journals Effects of Rock Fragments on the Soil Physicochemical Properties and Vegetation on the Northeastern Tibetan Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Ying Zheng ◽  
Ning Chen ◽  
Cankun Zhang ◽  
Xiaoxue Dong ◽  
Changming Zhao
Keyword(s):  
Surface Area ◽  
Soil Water Storage ◽  
Rock Fragment ◽  
Available Phosphorus ◽  
Number Density ◽  
Undisturbed Soil ◽  
Area Density ◽  
Rock Fragments ◽  
Significant Difference ◽  
Volumetric Content

Stony soils are very widely distributed and contain abundant rock fragments (>2 mm), which impose major effects on soil properties and plant growth. However, the role of rock fragments is still often neglected, which can lead to an inadequate understanding of the interaction between plants and soil. Undisturbed soil columns were collected from three alpine grasslands on the Qilian Mountain, and the X-ray computed tomography method was applied to investigate the characteristics of rock fragments. The results showed there was significant difference in number density, volumetric content and surface area density of rock fragment among the three grasslands, and followed the order of alpine meadow > alpine steppe > alpine desert steppe. In addition, the soil organic carbon, total nitrogen, total phosphorus, available phosphorus, N-NH4+, and N-NO3− contents in fine earth all increased with increasing number density, volumetric content and surface area density but to different degrees. Furthermore, positive correlations were observed between the rock shape factor and belowground biomass (R2 = 0.531, p < 0.05), between the rock volumetric content and aboveground biomass (R2 = 0.527, p < 0.05), and between number density and Simpson’s index (R2 = 0.875, p < 0.05). Our findings suggest that within a certain range, the increase in rock fragment content is conducive to soil nutrient accumulation and soil water storage and circulation and changes plant features, which contributes to the growth of plants. In addition, rock fragments should be given more consideration when investigating the relationships between soil and vegetation and their response to climate change in future studies.

scholarly journals The interaction between wheat roots and soil pores in structured field soil

2020 ◽  
Author(s):  
Hu Zhou ◽  
William R Whalley ◽  
Malcolm J Hawkesford ◽  
Rhys W Ashton ◽  
Brian Atkinson ◽  
...  
Keyword(s):  
Management Practices ◽  
Quantitative Relationship ◽  
Soil Core ◽  
Root Number ◽  
Number Density ◽  
Wheat Roots ◽  
Wheat Varieties ◽  
Undisturbed Soil ◽  
Significant Difference ◽  
Soil Macropore

Abstract Wheat (Triticum aestivum L.) root growth in the subsoil is usually constrained by soil strength, although roots can use macropores to elongate to deeper layers. The quantitative relationship between the elongation of wheat roots and the soil pore system, however, is still to be determined. We studied the depth distribution of roots of six wheat varieties and explored their relationship with soil macroporosity from samples with the field structure preserved. Undisturbed soil cores (to a depth of 100 cm) were collected from the field and then non-destructively imaged using X-ray computed tomography (at a spatial resolution of 90 µm) to quantify soil macropore structure and root number density (the number of roots cm–2 within a horizontal cross-section of a soil core). Soil macroporosity changed significantly with depth but not between the different wheat lines. There was no significant difference in root number density between wheat varieties. In the subsoil, wheat roots used macropores, especially biopores (i.e. former root or earthworm channels) to grow into deeper layers. Soil macroporosity explained 59% of the variance in root number density. Our data suggested that the development of the wheat root system in the field was more affected by the soil macropore system than by genotype. On this basis, management practices which enhance the porosity of the subsoil may therefore be an effective strategy to improve deep rooting of wheat.

Impact of plot length on the effectiveness of different soil-surface covers in reducing runoff and soil loss by water

2008 ◽  
Vol 32 (6) ◽  
pp. 654-677 ◽  
Author(s):  
T. Smets ◽  
J. Poesen ◽  
E. Bochet
Keyword(s):  
Soil Loss ◽  
Soil Surface ◽  
Water Erosion ◽  
Rock Fragment ◽  
Organic Mulch ◽  
Rock Fragments ◽  
Significant Difference ◽  
Runoff And Soil Loss ◽  
The Impact ◽  
Field Plots

Covering the soil surface by rock fragments, organic mulches or vegetation is often done to reduce runoff and soil loss by water erosion compared to a bare soil treatment. The runoff or erosion-reducing effectiveness of these soil surface covers has been investigated for a range of plot lengths under different environmental conditions. Recent research indicates that the effectiveness of soil surface covers in reducing runoff and soil loss by water erosion may be affected by the size of the laboratory or field plots (ie, spatial scale). Therefore, the main objective of this review is to explore to what extent the impact of plot length on the effectiveness of different surface covers (ie, rock fragments, organic mulch and vegetation) in reducing runoff and soil loss by water erosion emerges from a worldwide data set. Furthermore, it is investigated whether there is a significant difference in runoff or erosion-reducing effectiveness between rock fragments, organic mulches and vegetation. Data from 65 experimental studies, investigating the impact of surface cover by rock fragments, organic mulch or vegetation on runoff or soil loss, are collected and analysed in this review. The results indicate that for plot lengths <11 m there is a large variation in the runoff and erosion-reducing effectiveness of a soil cover, depending on various factors and on the larger number of studies conducted on these plots compared to longer field plots. However, with an increasing plot length (up to 50 m) this variation is reduced and surface covers by rock fragments, organic mulches and vegetation become on average more effective in reducing runoff or soil loss by water erosion. A vegetation cover is significantly more effective in reducing runoff rate compared to a rock fragment cover. No other significant differences in runoff or in erosion-reducing effectiveness between the studied soil surface covers are observed. Finally, two equations are proposed describing the possible effect of plot length and cover by rock fragments, organic mulches and vegetation on relative runoff and soil loss by water erosion. These findings have important consequences for the design of runoff and erosion plots, for modelling runoff and soil erosion rates and for scaling up plot data.

scholarly journals Land Uses, Altitude and Texture Effects on Soil Parameters. A Comparative Study in Two Districts of Nagaland, Northeast India

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 171
Author(s):  
Gaurav Mishra ◽  
Rosa Francaviglia
Keyword(s):  
Soil Properties ◽  
Soil Texture ◽  
Soil Parameters ◽  
Available Phosphorus ◽  
Land Uses ◽  
Management Options ◽  
Available N ◽  
P Content ◽  
Significant Difference ◽  
Soc Stocks

Northeast (NE) India is a typical tropical ecosystem with a luxuriant forest vegetation cover, but nowadays forests are under stress due to exploitation and land use changes, which are known to affect soil health and productivity. However, due to a scarcity of data, the influence of land uses and altitude on soil properties of this peculiar ecosystem is poorly quantified. This study presents the changes in soil properties in two districts of Nagaland (Mon and Zunheboto) in relation to land uses (forest, plantation, jhum and fallow jhum), altitude (<500 m, 500–1000 m, >1000 m) and soil texture (coarse, medium, fine). For this, a random soil sampling was performed in both the districts. Results indicated that soil organic carbon (SOC) stocks and available potassium (K) were significantly influenced by land uses in the Mon district, while in Zunheboto a significant difference was observed in available phosphorus (P) content. SOC stocks showed an increasing trend with elevation in both districts. The influence of altitude on P was significant and the maximum concentration was at lower elevations (<500 m). In Mon, soil texture significantly affected SOC stocks and the available N and P content. The variability in soil properties due to land uses, altitudinal gradients and textural classes can be better managed with the help of management options, which are still needed for this ecosystem.

Evidence for pyroclastic emplacement of the Crowsnest Formation, Alberta

1996 ◽  
Vol 33 (5) ◽  
pp. 715-728 ◽  
Author(s):  
R.N. Adair ◽  
R.A. Burwash
Keyword(s):  
Elevated Temperatures ◽  
Pyroclastic Flows ◽  
Coarse Grained ◽  
Rock Fragment ◽  
Fine Grained ◽  
Rock Fragments ◽  
Explosive Phase ◽  
Graded Structures ◽  
Textural Evidence ◽  
Charred Wood

The middle Cretaceous Crowsnest Formation west of Coleman, Alberta, is composed of bedded alkaline volcanic deposits containing heterolithic volcanic rock fragments and crystal clasts. Comparison with modern examples of subaerial pyroclastic rocks suggests that pyroclastic flows, surges, fallout of material from vertical eruption columns, and minor mud flows emplaced the deposits. Textural evidence in the form of plastically deformed volcanic fragments, chilled deposit margins, baked rock fragment margins, recrystallization, and the presence of charred wood and charred wood molds indicate emplacement at elevated temperature. Massive deposits containing a fine-grained basal zone are interpreted as the product of pyroclastic flows, whereas deposits characterized by a block-rich base overlain by a thin layer of block-depleted stratified material are interpreted as the product of density-stratified surges. Deposits exhibiting pronounced stratification were emplaced by ash-cloud surges. Thickly bedded breccias exhibiting rheomorphic textures were emplaced as vent-proximal pyroclastic flows. Deposits characterized by parallel beds and graded structures are interpreted as fallout tephra deposits, and deposition by lahars is indicated by coarse-grained beds that lack evidence for emplacement at elevated temperatures. The eruptions of the Crowsnest Formation were cyclical. An initial explosive phase generated deposits by pyroclastic flows, surges, fallout, and lahars. As an eruption progressed, it evolved into a poorly gas-charged effusive stage that emplaced coarsely porphyritic domes, plugs, spines, and vent-proximal lava flows. Subsequent eruptions destroyed the effusive vent facies deposits and produced abundant heterolithic clasts typical of the formation.

589 Methadone in Procedural Care for Burn Injuries of 20–30% Total Burn Surface Area: A Retrospective Chart Review

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S146-S146
Author(s):  
Loryn Taylor ◽  
Kimberly Maynell ◽  
Thanh Tran ◽  
David J Smith
Keyword(s):  
Physical Therapy ◽  
Postoperative Pain ◽  
Pain Intensity ◽  
Surface Area ◽  
Chart Review ◽  
Retrospective Chart Review ◽  
Opioid Consumption ◽  
Burn Injuries ◽  
Methadone Group ◽  
Significant Difference

Abstract Introduction Prolonged opioid usage remains a concern in pain management in procedural care. Recent evidence also suggests that a considerable number of patients who were prescribed opioids struggle with transitioning to non-opioid pain medications. As a continuous effort to reduce opioid consumption following burn surgical procedures, our institution recently evaluated methadone administration for burn procedural care in patients with 20–30% total burn surface area (TBSA) requiring excision and grafting. Methods After IRB approval, we performed a retrospective chart review of patients who underwent excision and grafting procedure for 20–30% TBSA burn injuries between January 1, 2019 and June 30, 2020. The following data was evaluated: postoperative opioid consumption, postoperative pain intensity (rated as “No Pain” [NRS=0], “Minor Pain” [NRS 1 to 3], “Moderate Pain” [NRS 4 to 6], “Severe Pain” [NRS 7 to 10]), time to physical therapy and time to hospital discharge. Data was analyzed using chi square/Fisher exact test for categorical variables and t-test/Wilcoxon rank sum test for continuous variables. Results Our preliminary data included 12 patients who met inclusion criteria, of which two patients received methadone administration. Our patient sample consisted of average age of 43 years, 75% male, and 24% TBSA (92% were flame burns). Patients in both methadone and non-methadone groups had no significant differences in medical histories and TBSA (23% TBSA in methadone, 25% TBSA in non-methadone). There was no significant difference in reported preoperative pain intensity between the two groups, rating moderate to severe. Postoperative pain intensity remained the same, rating moderate to severe and controlled with fentanyl, oxycodone, morphine and non-opioid analgesics. While there was no difference in postoperative fentanyl, opioid and non-opioid analgesic consumptions between the two groups, morphine consumption was significantly lower in the methadone group compared to non-methadone group (2±2 mg vs 51±54 mg, respectively, p=0.02). There was no significant difference between average time from surgery to first physical therapy session and time to hospital discharge (about 21 days after surgery) between the two groups. Conclusions This evaluation shows a potential trend in reduction of inpatient postoperative opioid consumption with the conjunctive administration of methadone, although a bigger sample size is needed for further assessment.

Transport of Particle-Laden Fluids Through Fixed-Valve Micropumps

1999 ◽  
Author(s):  
Ling-Sheng Jang ◽  
Christopher J. Morris ◽  
Nigel R. Sharma ◽  
Ron L. Bardell ◽  
Fred K. Forster
Keyword(s):  
Surface Charge ◽  
Surface Area ◽  
Flow Rate ◽  
Pure Water ◽  
Maximum Flow ◽  
Total Surface Area ◽  
Maximum Flow Rate ◽  
Number Density ◽  
Polystyrene Microspheres ◽  
Negative Surface

Abstract Micropumps designed for the flow-rate range of 100–1000μl/min have been developed by a number of research groups. However, little data is available regarding the ability of various designs to directly transport liquids containing particles such as cells, microspheres utilized for bead chemistry, or contaminants. In this study the ability of pumps with no-moving-parts valves (NMPV) to transport particles was investigated. The results showed that a NMPV micropump was able to directly pump suspensions of polystyrene microspheres from 3.1 to 20.3μm in diameter. The pump functioned without clogging at microsphere number densities as high as 9000 particles/μl of suspension, which corresponded to over 90,000 particles per second passing through the pump at a flow rate of 600μl/min. Performance with polystyrene microspheres was the same as pure water up to the point of cavitation. Microspheres manufactured with negative surface charge cavitated less readily that other microspheres studied that were manufactured without surface charge. However, cavitation did not appear to be a function of microsphere size, total surface area or number density. Thus pumping polystyrene microspheres was found to be more affected by surface effects than by size, surface area or number density within the range of parameters considered. In the case of charged microspheres, the maximum flow rate was reduced by 30% compared to pure water whereas for uncharged microspheres the maximum flow rate was reduced by approximately 80%.

A 2010 Mapping of the Constructed Surface Area Density for S.E. Asia - Preliminary Results

2010 ◽  
Vol 30 (0) ◽  
pp. 181 ◽  
Author(s):  
Paul C. Sutton ◽  
Christopher D. Elvidge ◽  
Benjamin T. Tuttle ◽  
Daniel Ziskin ◽  
Kimberly Baugh ◽  
...  
Keyword(s):  
Surface Area ◽  
Area Density ◽  
Preliminary Results

scholarly journals Organosilane-functionalization of nanostructured indium tin oxide films

2016 ◽  
Vol 6 (6) ◽  
pp. 20160056 ◽  
Author(s):  
R. Pruna ◽  
F. Palacio ◽  
M. Martínez ◽  
O. Blázquez ◽  
S. Hernández ◽  
...  
Keyword(s):  
Surface Area ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Annealing Treatment ◽  
Electrochemical Analysis ◽  
Cyclic Voltammograms ◽  
X Ray ◽  
Chip Technology ◽  
Significant Difference

Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab-on-a-chip configurations, providing benefits such as reduced size and weight to facilitate on-chip integration, and leading to low-cost mass production of microanalysis systems.

scholarly journals Study of thyroid volume by ultrasonography in clinically euthyroid patients

1970 ◽  
Vol 32 (2) ◽  
pp. 36-43 ◽  
Author(s):  
P Kayastha ◽  
S Paudel ◽  
DM Shrestha ◽  
RJ Ghimire ◽  
S Pradhan
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Reference Values ◽  
Body Surface ◽  
Pearson Correlation ◽  
Thyroid Volume ◽  
Specific Reference ◽  
Reference Ranges ◽  
Hilly Region ◽  
Significant Difference

Introduction: The purpose of this study was to establish reference ranges of total thyroid volume among clinically euthyroid Nepalese population using Ultrasonography and correlate this volume with age, sex, individual’s built and geographic location. Methods: This was a prospective cross sectional study involving 485 clinically euthyroid individuals. B - mode Ultrasonography was used to measure the total thyroid volume by combining the volume of both the lobes obtained by using formula for prolate ellipsoid. Age specific reference values for thyroid volume were obtained and Pearson correlation test was used to see the relationship with various factors. Results: Among 485 individuals between 1 to 83 years of age, 221(45.57%) were males and 264(54.43%) were females. Maximum [354 individuals (72.99%)] were from hilly region and minimum [16 individual (3.30%)] were from Himalayan region. Mean thyroid volume was 6.629 ± 2.5025 ml. In general, thyroid volume was found to be more in older individuals than in young age group. There was no significant difference of thyroid volume between males and females. Thyroid volume best correlated with body surface area (r=0.444, p<0.0001). The volume had a positive correlation with weight (r=0.443, p<0.0001), body mass index (r=0.371, p<0.0001) and height (r=0.320, p<0.0001) of the individual. Conclusions: This study estimated the reference range of total thyroid volume for Nepalese population. These ranges are significantly lower than the WHO/ICCIDD thyroid volume references and reference values obtained in various other countries. Total thyroid volume best correlated with Body surface area. Keywords: Body surface area; clinically euthyroid; total thyroid volume; ultrasonography DOI: http://dx.doi.org/10.3126/joim.v32i2.4944 Journal of Institute of Medicine, August, 2010; 32: 36-43

Relation between anatomic respiratory dead space and body size and lung volume

1963 ◽  
Vol 18 (3) ◽  
pp. 519-522 ◽  
Author(s):  
M. C. Hart ◽  
M. M. Orzalesi ◽  
C. D. Cook
Keyword(s):  
Surface Area ◽  
Functional Residual Capacity ◽  
Dead Space ◽  
Technical Assistance ◽  
Newborn Infants ◽  
Early Period ◽  
Somatic Growth ◽  
Normal Subjects ◽  
Significant Difference ◽  
Residual Capacity

The respiratory anatomic dead space has been measured by the single breath nitrogen washout method of Fowler in 73 normal subjects ranging from 4 to 42 years of age. The volume of the anatomic dead space correlated closely with height (Vd (ml) = 7.585 x Ht (cm)2.363 x 10-4·ɣ = .917), but also with body weight, surface area, and functional residual capacity. When compared on the basis of any of these parameters there was no significant difference between the anatomic dead space values for males and females. Comparisons with available data for newborn infants suggest that the value of the anatomic dead space has a relatively constant relation to height from birth to adulthood. Dead space appears to increase more rapidly than weight, surface area, and functional residual capacity during, at least, the early period of somatic growth. Note: (With the Technical Assistance of J. H. Shaw) Submitted on October 25, 1962

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