scholarly journals Hydration Mechanism and Hardening Property of α-Hemihydrate Phosphogypsum

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 733
Author(s):  
Xianbo Li ◽  
Qin Zhang
Keyword(s):  
Ct Scanning ◽  
Hydration Process ◽  
Stable Region ◽  
Unstable Region ◽  
Crystal Water ◽  
Ion Concentrations ◽  
Hydration Mechanism ◽  
Pass Through ◽  
Crystallization Stage

The hydration and hardening of α-hemihydrate phosphogypsum (HH) prepared in the absence and presence of L-Aspartic acid (L-Asp) were investigated by thermodynamic analysis, measurements of ion concentrations and crystal water content, and morphology observation. In addition, computed tomography (CT) scanning was proposed to analyze the hole characteristic of hardened gypsum in situ. The results show that HH will pass through the unstable region and the stable region of dihydrate gypsum (DH) in turn during the hydration. The hydration of HH follows the dissolution–crystallization principle; the hydration process can be divided into the dissolution stage, dissolution–crystallization stage and equilibrium stage. Compared with the HH prepared without crystal modifier, the hydration process of HH prepared with L-Asp is obviously prolonged, and the morphology of DH changes from needle-like to diamond-shape crystals with an aspect ratio of 1:1. Meanwhile, the defect-specific surface and porosity of hardened gypsum significantly decreases, achieving a more compact, hardened paste with higher compressive strength.

scholarly journals Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Daisy (Jihyung) Ko ◽  
Tess Kelly ◽  
Lacey Thompson ◽  
Jasmene K. Uppal ◽  
Nasim Rostampour ◽  
...  
Keyword(s):  
Onset Time ◽  
Ct Scanning ◽  
Micro Ct ◽  
Third Molars ◽  
Developmental Duration ◽  
Dental Lamina ◽  
Permanent Molars ◽  
Dental Epithelium ◽  
Space Conditions

For humans and other mammals to eat effectively, teeth must develop properly inside the jaw. Deciphering craniodental integration is central to explaining the timely formation of permanent molars, including third molars which are often impacted in humans, and to clarifying how teeth and jaws fit, function and evolve together. A factor long-posited to influence molar onset time is the jaw space available for each molar organ to form within. Here, we tested whether each successive molar initiates only after a minimum threshold of space is created via jaw growth. We used synchrotron-based micro-CT scanning to assess developing molars in situ within jaws of C57BL/6J mice aged E10 to P32, encompassing molar onset to emergence. We compared total jaw, retromolar and molar lengths, and molar onset times, between upper and lower jaws. Initiation time and developmental duration were comparable between molar upper and lower counterparts despite shorter, slower-growing retromolar space in the upper jaw, and despite size differences between upper and lower molars. Timing of molar formation appears unmoved by jaw length including space. Conditions within the dental lamina likely influence molar onset much more than surrounding jaw tissues. We theorize that molar initiation is contingent on sufficient surface area for the physical reorganization of dental epithelium and its invagination of underlying mesenchyme.

Chemical characteristics and in situ ruminal parameters of barley for cattle: Comparison of the malting cultivar AC Metcalfe and five feed cultivars

2008 ◽  
Vol 88 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Kenton J Hart ◽  
Brian G Rossnagel ◽  
Peiqiang Yu
Keyword(s):  
Nutritive Value ◽  
Degradation Kinetics ◽  
Starch Degradation ◽  
Barley Cultivars ◽  
Degradation Rates ◽  
Key Words Barley ◽  
In Situ Degradation ◽  
The Mean ◽  
Pass Through

The objective of this study was to compare the most widely grown barley cultivar in Canada, AC Metcalfe, a malting type barley, with five feed cultivars. Barley cultivars were grown at one location during 3 consecutive years and barley samples were milled to pass through a 1-mm screen and analysed to determine nutritive value. Additional samples were passed through a roller mill with a gap set at 1.12 mm and incubated ruminally for 0, 2, 4, 8, 12, 24, and 48 h in 3 dry Holstein cows fitted with rumen cannulae. The rate and extent of rumen digestion were estimated. AC Metcalfe had a higher (P < 0.001) concentration of NDF, and lower (P < 0.05) concentrations of non structural carbohydrates, starch, ADF, total digestible nutrients, and fermentable cell wall carbohydrates compared with the mean of the feed cultivars. The malting cultivar had a higher (P < 0.001) soluble DM fraction, lower (P < 0.05) CP and starch degradation rates, and a lower (P < 0.001) ruminally degradable starch concentration compared with the mean of the five feed cultivars. The results demonstrate that there are only small differences in terms of chemical composition and in situ degradation kinetics between the malting cultivar AC Metcalfe and the five feed cultivars of barley reported here. Key words: Barley, energy, protein, ruminants

scholarly journals How the Local People Face the Rapid Change of the Tropical Freshwater Wetland Environment

2020 ◽  
Vol 20 ◽  
pp. 01001
Author(s):  
Krisdianto Slamat ◽  
Pahmi Anshary ◽  
Anang Kadarsyah ◽  
Ika Oksi Susilawati
Keyword(s):  
Grey Literature ◽  
Rapid Change ◽  
Local People ◽  
Freshwater Wetland ◽  
Data Sets ◽  
Face To Face ◽  
Development Data ◽  
Pass Through ◽  
Big Rivers

Barito River crosses from the northeast of Central Kalimantan province, but almost two-third of 1000 km length lies in South Kalimantan. While water comes from Schwaner Mountain in the upper, this river receives water from Meratus pass through five big rivers, such as Tabalong, Batang Alai, Pagat, Amandit, and Riam Kiwa. Before the water flowed into Barito River, it retains for sometimes in the low land swampy area, forming huge lowland muddy into shallow lakes, simply named wetlands. How do people commit to sustainability living in extreme tropical wetlands for generations? The ecological investigation was conducted for 2016 – 2019, in-situ observation on the daily life-behavior of local people of 200 local people living Barito Kuala, Tapin, Hulu Sungai Selatan, Hulu Sungai Tengah, Hulu Sungai Utara residences, their technologies, their progress in sustainability development. Data was collected by interviewing directly to the local, face to face, meeting with family, observing and confirming nature with them, as well as studying scientific articles and grey literature from official reports. Statistical calculation helps to compare several data sets, as well as serial of photographs, which documented to support the evidence visually. In conclusion, the locals face the rapid change environments which influence their life, income, health, and their properties and prosperity. Mostly, they complain that life is much more difficult now than several decades ago.

Rat renal peritubular transport and metabolism of plasma [35S]glutathione

1985 ◽  
Vol 249 (2) ◽  
pp. F198-F204 ◽  
Author(s):  
B. B. Rankin ◽  
W. Wells ◽  
N. P. Curthoys
Keyword(s):  
Single Injection ◽  
Arterial Infusion ◽  
Venous Circulation ◽  
Peritubular Capillaries ◽  
Residual Level ◽  
Plasma Glutathione ◽  
Pass Through ◽  
Subsequent Addition ◽  
Venous Plasma

More than 80% of the plasma glutathione is extracted during a single pass through the kidney. The peritubular component of this extraction was characterized by in situ arterial infusion of [35S]glutathione and [3H]inulin. The peak of 35S-labeled material recovered in the renal venous effluent was delayed approximately 10 S compared with the peak of [3H]inulin. As a result, the initial fractions exhibited a decreased 35S/3H ratio, indicating that 35S-labeled material is transported out of the postglomerular peritubular capillaries. Later fractions exhibited a normalized 35S/3H ratio greater than 1, consistent with the subsequent addition of a 35S-labeled metabolite to the venous circulation. An identical profile was observed when perfusion experiments were repeated using gamma-[35S]glutamyl-S-methylcysteine and [3H]inulin. Renal venous plasma samples obtained from a rat perfused with [35S]glutathione were reduced with sodium borohydride, reacted with monobromobimane, and analyzed by high-pressure liquid chromatography. More than 70% of the recovered 35S-labeled material was identified as cysteine and 20% was recovered as unmetabolized glutathione. Pretreatment of rats with a single injection of AT-125 resulted in 96% inactivation of renal gamma-glutamyltranspeptidase. Under these conditions, the percent of glutathione converted to cysteine (35%) was significantly less than the observed level of renal extraction (61%). Two injections of AT-125 caused a complete inhibition of cysteine formation. However, the residual level of renal extraction (41%) was still significantly greater than the filtration fraction (26%). The peritubular transport of glutathione is stimulated by prior depletion of renal glutathione with buthionine-L-sulfoximine and is competitively inhibited by simultaneous infusion of gamma-glutamylcysteine.(ABSTRACT TRUNCATED AT 250 WORDS)

Research on the Hydration Mechanism of Portland Cement with Magnesium Slag

2014 ◽  
Vol 576 ◽  
pp. 57-62 ◽  
Author(s):  
Jun Ping Deng ◽  
Xiao Liang Wang ◽  
Yi Ping Guo
Keyword(s):  
Portland Cement ◽  
Industrial Waste ◽  
Activity Index ◽  
Early Period ◽  
Performance Testing ◽  
Hydration Process ◽  
Hydration Products ◽  
Hydration Mechanism ◽  
Products Analysis ◽  
Strength Improvement

Magnesium slag is a kind of industrial waste during the silicothermic process for magnesium reduction which has potential hydration activity. By adding 20% to 50% of magnesium slag into Portland cement, the influence principle of the additive amount of magnesium slag on the pozzolanic activity is investigated through performance testing and hydration products analysis. During the early period of hydration process, the strength of pozzolanic effectiveness ratio weakens with the increasing additive amount of magnesium slag, while during the later period of hydration process with the additive amount of magnesium slag less than 40%, the strength of pozzolanic effectiveness ratio increases with increasing additive amount of magnesium slag. The activity index of magnesium slag increases with the increase of period and additive amount, and the strength brought by hydration of magnesium slag is a key source of the strength improvement of Portland cement with magnesium slag.

The effect of micronization of full-fat canola seed on digestion in the rumen and total tract of dairy cows

1997 ◽  
Vol 77 (3) ◽  
pp. 431-440 ◽  
Author(s):  
Y. Wang ◽  
T. A. McAllister ◽  
D. R. Zobell ◽  
M. D. Pickard ◽  
L. M. Rode ◽  
...  
Keyword(s):  
Digestive Tract ◽  
Gas Production ◽  
Canola Seed ◽  
In Vitro Gas Production ◽  
Internal Structures ◽  
Pass Through ◽  
Ruminal Protein Degradability ◽  
Protein Degradability

The effect of micronization of full-fat canola seed on dry matter disappearance (DMD) and total nitrogen disappearance (TND) in the rumen and intestine were investigated. Full-fat canola seed was left untreated (C) or micronized for 1.5 min (M), and left whole (CW, MW) or ground to pass through a 1.25-mm sieve (CG, MG). In vitro gas production from CW and MW were determined at 0, 1, 2, 3, 8, 12, 20, 24, 32, 48, 52, 68 and 72 h. For subsequent studies, CW was hand-cracked (CH) for comparison against MW. In situ DMD and TND from CH, MW, CG and MG were determined after 0, 2, 4, 8, 16, 24, 48 and 96 h of ruminal incubation. The mobile nylon bag technique was used to estimate intestinal digestion (DM and N disappearance) of samples incubated in the rumen for 16 h and in acid-pepsin for 1 h. Scanning electron microscopy revealed the pattern and extent of seed coat rupture from hand-cracking and from micronization to be similar, but micronization-mediated changes to the internal structures were evident in ground samples. Micronization increased (P < 0.05) in vitro gas production from whole canola seed (CW vs. MW), but relative to CH, DMD and TND from MW were lower (P < 0.001) in situ and in the whole digestive tract (P < 0.001). Estimated intestinal DMD and TND did not differ (P > 0.05) between CH and MW. Ruminal DMD and TND from ground seed were reduced (P < 0.05) by micronization (CG vs. MG) in the rumen, but intestinal DMD and TND were increased (P < 0.05 and P < 0.01, respectively), thus in the whole digestive tract, these values did not differ (P > 0.05) between treatments. Micronization reduced potential ruminal protein degradability (P < 0.05) and effective ruminal protein degradability (P < 0.01) of full-fat canola, and in combination with grinding, increased the proportion of protein digestion in the intestine. Key words: Micronization, full-fat canola seed, digestibility, rumen, dairy cow, in situ

scholarly journals Observations of sunlit N<sub>2</sub><sup>+</sup> aurora at high altitudes during the RENU2 flight

2020 ◽  
Author(s):  
Pål Gunnar Ellingsen ◽  
Dag Lorentzen ◽  
David Kenward ◽  
Jams H. Hecht ◽  
J. Scott Evans ◽  
...  
Keyword(s):  
Major Part ◽  
Photon Flux ◽  
High Altitudes ◽  
Polar Cusp ◽  
Rocket Experiment ◽  
Pass Through ◽  
Using Data

Abstract. We present measurements of sunlit aurora during the launch of the Rocket Experiment for Neutral Upwelling 2 (RENU2) on the 13th of December 2015 at 07:34 UT. The in situ auroral conditions coincide with those of sunlit aurora, and were characterised by the 391.4 nm and 427.8 nm N2+ emissions. A correlation between several auroral wavelengths, as measured by a meridian scanning photometer was used to detect sunlit aurora and indirectly neutral upwelling. These results, based on ground data, agree well with the RENU2 measurements recorded during its pass through the sunlit polar cusp. Using data from RENU2 and the solar photon flux, it was found that sunlit aurora was a major part (≈ 40 %) of the observed 427.8 nm emission.

scholarly journals Nitrate Fluctuations in Antarctic Snow and Firn: Potential Sources and Mechanisms of Formation

1982 ◽  
Vol 3 ◽  
pp. 243-248 ◽  
Author(s):  
Bruce C. Parker ◽  
Edward J. Zeller ◽  
Anthony J. Gow
Keyword(s):  
Solar Activity ◽  
Upper Atmosphere ◽  
South Pole ◽  
Ion Concentrations ◽  
Potential Sources ◽  
Long Term Changes ◽  
Antarctic Snow ◽  
Mechanisms Of Formation

We summarize here data on in situ nitrate ion concentrations in snow pits and firn cores over the last ∼3 250 a. Nitrate fluctuations show seasonal, 11 and 22 a periodicities, and long-term changes both at South Pole station and Vostok. High nitrate levels conform to winter darkness and solar activity peaks. Long-term lows and highs conform to solar activity minima and maxima. The data available support the hypothesis that nitrate is fixed in the upper atmosphere by some solar-mediated phenomenon causing a periodicity in East Antarctica snow. Background levels and non-periodic spikes in nitrate come from other sources.

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