Improved Phosphate Ore Leaching with Physical Mutagenized Acidithiobacillus Ferrooxidans Based on Modified Logistic Model

2012 ◽  
Vol 214 ◽  
pp. 520-524 ◽  
Author(s):  
En Wen Wang ◽  
Shao Min Lei ◽  
Wen Qi Gong
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Treatment Time ◽  
Ph Value ◽  
Hot Spring ◽  
Temperature Treatment ◽  
Low Grade ◽  
Initial Growth ◽  
Illumination Time ◽  
Phosphate Ore ◽  
Low Temperature Treatment

Strains of Acidithiobacillus ferrooxidans (At.f) were separated and purified from water sample collected from a hot spring and bioleaching a low grade phosphate ore. The results indicated that bioleaching phosphorus rate increasing sharply was starting at the ending of pH value decreasing, and ascend velocity had slowed down after linear regression of pH was at its second peak. In the environment of ultraviolet mutagenesis, the initial growth of At.f (r) was decreased by illumination time increased, but the maximum rate of bioleaching phosphate ore (ηm) was increased. In the condition of ultrasonic vibration, r was increased by vibration time added, and ηm was almost increased, except 20 min, owing to the modificatory coefficient was large enough. In circumstances of low temperature treatment, r was decreased by treatment time raised; ηm was more increase than the sample of un-treatment (CK).

Endometrial Thermal Balloon Ablation Using a High Temperature, Pulsed System: A Mathematical Model

2003 ◽  
Vol 125 (6) ◽  
pp. 841-851 ◽  
Author(s):  
Daniel M. Reinders ◽  
Susan A. Baldwin ◽  
Joel L. Bert
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Treatment Time ◽  
Uterine Cavity ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Low Temperature Treatment ◽  
Balloon Ablation ◽  
Pulsed Treatment ◽  
Thermal Balloon

A new endometrial thermal balloon ablation treatment for menorrhagia is modeled mathematically to predict its efficacy and safety. A device preheats a fluid to 173°C within a reservoir external to the uterus, and then pulses this fluid without further heating between the reservoir and the balloon for 2.1 min of treatment time. The model predicted this treatment to result in consistent immediate tissue death (coagulation) depths of 3.4±0.1 mm for uterine cavities of 7 to 26 mL, and that eventual necrosis (tissue death that would occur 1–5 days post burn) may occur to depths of 6.5±0.2 mm. Whereas, burn depths varied with uterine cavity volume when a low temperature treatment (constant 75°C for 15 min) was modeled (2.3–2.9 mm and 6.8–8.2 mm, for immediate tissue death and eventual necrosis respectively). Similarly, the high temperature, pulsed treatment was less sensitive to blood perfusion rate than the low temperature treatment. Predicted eventual necrosis depth was 1.5 mm less for the high temperature, pulsed treatment than that predicted for a low temperature treatment (constant 87°C for 7 min) for the same immediate tissue death depth (3.5 mm), indicating that the new high temperature treatment may result in less damage to non targeted tissues.

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

scholarly journals A 25-year retrospective, single center analysis of 343 WHO grade II/III glioma patients: implications for grading and temozolomide therapy

2021 ◽  
Author(s):  
Eike Steidl ◽  
Katharina Filipski ◽  
Pia S. Zeiner ◽  
Marlies Wagner ◽  
Emmanouil Fokas ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Molecular Markers ◽  
Treatment Time ◽  
Real Life ◽  
Patient Characteristics ◽  
Low Grade ◽  
Who Grade ◽  
Idh1 R132h ◽  
Treatment Data ◽  
Grade Ii

Abstract Purpose Classification and treatment of WHO grade II/III gliomas have dramatically changed. Implementing molecular markers into the WHO classification raised discussions about the significance of grading and clinical trials showed overall survival (OS) benefits for combined radiochemotherapy. As molecularly stratified treatment data outside clinical trials are scarce, we conducted this retrospective study. Methods We identified 343 patients (1995–2015) with newly diagnosed WHO grade II/III gliomas and analyzed molecular markers, patient characteristics, symptoms, histology, treatment, time to treatment failure (TTF) and OS. Results IDH-status was available for all patients (259 mutant, 84 IDH1-R132H-non-mutant). Molecular subclassification was possible in 173 tumors, resulting in diagnosis of 80 astrocytomas and 93 oligodendrogliomas. WHO grading remained significant for OS in astrocytomas/IDH1-R132H-non-mutant gliomas (p < 0.01) but not for oligodendroglioma (p = 0.27). Chemotherapy (and temozolomide in particular) showed inferior OS compared to radiotherapy in astrocytomas (median 6.1/12.1 years; p = 0.03) and oligodendrogliomas (median 13.2/not reached (n.r.) years; p = 0.03). While radiochemotherapy improved TTF in oligodendroglioma (median radiochemotherapy n.r./chemotherapy 3.8/radiotherapy 7.3 years; p < 0.001/ = 0.06; OS data immature) the effect, mainly in combination with temozolomide, was weaker in astrocytomas (median radiochemotherapy 6.7/chemotherapy 2.3/radiotherapy 2.0 years; p < 0.001/ = 0.11) and did not translate to improved OS (median 8.4 years). Conclusion This is one of the largest retrospective, real-life datasets reporting treatment and outcome in low-grade gliomas incorporating molecular markers. Current histologic grading features remain prognostic in astrocytomas while being insignificant in oligodendroglioma with interfering treatment effects. Chemotherapy (temozolomide) was less effective than radiotherapy in both astrocytomas and oligodendrogliomas while radiochemotherapy showed the highest TTF in oligodendrogliomas.

Preparing Process and Properties of Collagen Modified Cotton Fiber

2011 ◽  
Vol 236-238 ◽  
pp. 1415-1419 ◽  
Author(s):  
Yun Hui Xu ◽  
Zhao Fang Du
Keyword(s):  
Cotton Fiber ◽  
Treatment Time ◽  
Ph Value ◽  
Periodate Oxidation ◽  
Aqueous Acetic Acid ◽  
Collagen Concentration ◽  
Acid Media ◽  
Xps Characterization ◽  
Aldehyde Groups

In order to develop cotton fabric underwear with the health care function, the cotton fiber was modified with the collagen (CMCF) using periodate oxidation method. The aldehyde groups on the glucose chains of the oxidized cotton cellulose were reacted with the amino groups of collagen to obtain the CMCF, and the oxidized cellulose was crosslinked with collagen in aqueous acetic acid media. The effects of collagen concentration, treatment time, reaction temperature, pH value of solution and periodate concentration on the amount of collagen crosslinked on cotton fiber were respectively discussed, and the optimal reaction technology was obtained. XPS characterization of the modified cotton fiber showed a characteristic peak about 400.0–405.0 eV corresponding to collagen, which indicated that the collagen was combined on the surface of cotton fiber. The mechanical properties of the collagen modified cotton fiber were improved. The resulting CMCF is a new natural ecological fiber and has the extensive application as a carrier for the controlled release of drugs.

Separation of Heavy Metal Ions from the Solution Obtained by Leaching Low-Grade Pyrolusite with Pyrite and H2SO4

2013 ◽  
Vol 773 ◽  
pp. 283-288
Author(s):  
Xing Zou ◽  
Xiang Quan Chen ◽  
Hai Chao Xie ◽  
Xiao Dan Qiu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Separation Efficiency ◽  
Ph Value ◽  
Sulfate Solution ◽  
Ion Concentration ◽  
Manganese Sulfate ◽  
Low Grade ◽  
High Concentration

The manganese sulfate solution leached from low-grade pyrolusite with pyrite and H2SO4 contains heavy metal ions of high concentration, influencing the quality of the final products of manganese compounds and causing manganese ions not to be electrolyzed. The present study was focused on the separation of Co, Ni and Zn ions from the leached solution with BaS. By controlling the pH value at 5.0-6.5, temperature at 50-60°C, reaction time at 15 min and mixing velocity at 78 rpm, the heavy metal ions could be separated effectively. Under the above optimized conditions, the ion concentration of Co, Ni, and Zn in the solution was reduced to 0.06 mg.L-1, 0.27mg.L-1 and 0.01mg.L-1, and the separation efficiency was 99.72%, 99.18% and 99.9% respectively. The obtained pure solution meets the demands of manganese electrowinning.

Studies on Freshwater Osmoregulation in the Ammocoete larva of Lampetra Planeri (Bloch)

1968 ◽  
Vol 48 (3) ◽  
pp. 597-609
Author(s):  
R. MORRIS ◽  
J. M. BULL
Keyword(s):  
Low Temperature ◽  
Extracellular Space ◽  
Ringer Solution ◽  
Temperature Treatment ◽  
Sodium Influx ◽  
Sodium Chloride Solutions ◽  
Low Temperature Treatment ◽  
Lampetra Planeri ◽  
Equilibrium Concentrations ◽  
Sodium Loss

1. An investigation has been made of the factors which cause sodium loss from ammocoetes when they are immersed in de-ionized water at 1° and 10° C. 2. Sodium influx ceases when animals are first immersed in de-ionized water, but can recommence when the animal loses sufficient sodium to the environment. The concentration of sodium required for influx to take place decreases with succeeding periods of immersion in de-ionized water at 10° C. and reaches minimum equilibrium concentrations as low as 0.005 mM-Na/l. 3. Low temperature inhibits sodium influx and thus promotes net loss of sodium to de-ionized water. 4. Low temperature also decreases the initial loss of sodium to de-ionized water and probably lowers the permeability of the external surfaces of the animal to ions. This effect is small compared with the inhibition of ion uptake so that the combined result is to increase the net loss of sodium from the animal. 5. Since animals lose calcium to de-ionized water and show a decreased rate of sodium loss when calcium salts are added, it is believed that the high rates of sodium loss in de-ionized water are attributable to the effect of calcium on permeability. 6. Lack of calcium may also explain why animals which have been depleted of sodium by low-temperature treatment take up sodium much faster at higher temperatures from dilute Ringer solutions than from pure sodium chloride solutions. 7. When animals lose ions to de-ionized water at low temperature, sodium and chloride are lost from the extracellular space, whilst the muscle cells lose potassium. These ions are recovered into the extracellular space when animals are allowed to take up ions at 10° C. from diluted Ringer solution later.

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