Role of nickel and chrome in the active-passive transition in low-strength steels in media with high pH values

1989 ◽  
Vol 25 (1) ◽  
pp. 35-39
Author(s):  
A. V. Vasilik ◽  
S. I. Girnyi ◽  
R. K. Melekhov
Keyword(s):  
High Ph ◽  
Ph Values ◽  
Passive Transition ◽  
Low Strength

The orientation of sickle hemoglobin fibers within fascicles

1988 ◽  
Vol 46 ◽  
pp. 400-401
Author(s):  
Christopher A. Miller ◽  
Bridget Carragher ◽  
William A. McDade ◽  
Robert Josephs
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Relative Orientation ◽  
Unit Cell ◽  
Red Cell ◽  
High Ph ◽  
Sickle Hemoglobin ◽  
Polar Crystal ◽  
Helical Configuration

Highly ordered bundles of deoxyhemoglobin S (HbS) fibers, termed fascicles, are intermediates in the high pH crystallization pathway of HbS. These fibers consist of 7 Wishner-Love double strands in a helical configuration. Since each double strand has a polarity, the odd number of double strands in the fiber imparts a net polarity to the structure. HbS crystals have a unit cell containing two double strands, one of each polarity, resulting in a net polarity of zero. Therefore a rearrangement of the double strands must occur to form a non-polar crystal from the polar fibers. To determine the role of fascicles as an intermediate in the crystallization pathway it is important to understand the relative orientation of fibers within fascicles. Furthermore, an understanding of fascicle structure may have implications for the design of potential sickling inhibitors, since it is bundles of fibers which cause the red cell distortion responsible for the vaso-occlusive complications characteristic of sickle cell anemia.

Impact of climate and bulking materials on characteristics of compost from ecological toilets

2012 ◽  
Vol 2 (2) ◽  
pp. 79-86 ◽  
Author(s):  
James W. McKinley ◽  
Rebecca E. Parzen ◽  
Álvaro Mercado Guzmán
Keyword(s):  
Low Carbon ◽  
Pathogen Inactivation ◽  
High Ph ◽  
Moisture Contents ◽  
Urine Diversion ◽  
Ph Values ◽  
Dominant Process ◽  
Nitrogen Ratio ◽  
Storage Times ◽  
Carbon Concentrations

Urine-diversion dehydration toilets (UDDT) are common throughout the developing world, and the toilet product is widely used as compost. There is no comprehensive research to date that characterizes the compost to determine its quality, extent of pathogen inactivation, and the effects of climate and bulking materials on the compost. Compost was collected from 45 UDDT in Bolivia and analyzed for physical, chemical, and biological parameters. Eighty percent and 56% of samples did not meet acceptable compost guidelines for moisture content and pH, respectively, indicating desiccation was the dominant process in UDDT. Bulking materials significantly impacted compost characteristics in terms of pH, carbon, carbon-to-nitrogen ratio, and carbon stability (P < 0.05). Composts with ash exhibited, on average, low carbon concentrations (4.9%) and high pH values (9.7), which can be harmful to plants and composting microorganisms. Composts with sawdust exhibited, on average, high carbon concentrations (40.0%) and carbon-to-nitrogen ratios (31.0). Climate had no significant impact on chemical characteristics, however composts from humid regions had significantly higher moisture contents (34.4%) than those from arid climates (24.8%) (P < 0.05). Viable Ascaris lumbricoides ova were identified in 31% of samples, including samples with high pH, low moisture contents, and long storage times.

The role of calcium in high pH excursions for reactivated GAC

Carbon ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 511-518 ◽  
Author(s):  
David W. Mazyck ◽  
Fred S. Cannon ◽  
Morgana T. Bach ◽  
Ljubisa R. Radovic
Keyword(s):  
High Ph

scholarly journals The role of pH on the survival of rumen protozoa in steers

2010 ◽  
Vol 39 (10) ◽  
pp. 2262-2267 ◽  
Author(s):  
Raul Franzolin ◽  
Burk A. Dehority
Keyword(s):  
Experimental Period ◽  
Adaptation Period ◽  
Individual Animal ◽  
Effect Of Ph ◽  
Ph Values ◽  
Rumen Protozoa ◽  
Rumen Ph ◽  
Sampling Times ◽  
Ciliate Protozoa

In order to study the effect of pH on defaunation in the rumen, four rumen fistulated steers were fed a basal roughage diet for a 4-week adaptation period followed by 17 weeks of feeding with three diets and two feeding levels of high concentrate diet. Rumen outflow fluid rate was evaluated in both ration levels. Rumen protozoa population was monitored weekly and when animals became defaunated, protozoa were reinoculated with rumen contents from one of the faunated steers. At every two weeks, during all the experimental period, rumen pH was measured in all animals at 0, 4, 8 and 12 h after feeding. It was observed an individual animal influence on the establishment and maintenance of the rumen ciliate protozoa population. In all sampling times, mean rumen pH values were higher in faunated steers than in the defaunated ones. No differences were observed in rumen outflow fluid rates between the two ration levels. Extended periods of low rumen pH are probably more detrimental to the survival of ciliate protozoa in the rumen than other factors.

scholarly journals Self-assembly of alkyl chains of fatty acids in papermaking systems: A review of related pitch issues, hydrophobic sizing, and pH effects

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 4591-4635
Author(s):  
Martin A. Hubbe ◽  
Douglas S. McLean ◽  
Karen R. Stack ◽  
Xiaomin Lu ◽  
Anders Strand ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Self Assembly ◽  
Review Article ◽  
Ph Effects ◽  
Monolayer Films ◽  
Alkyl Chains ◽  
Ph Values ◽  
Self Association ◽  
Long Chain

This review article considers the role of fatty acids and the mutual association of their long-chain (e.g. C18) alkyl and alkenyl groups in some important aspects of papermaking. In particular, published findings suggest that interactions involving fatty acids present as condensed monolayer films can play a controlling role in pitch deposition problems. Self-association among the tails of fatty acids and their soaps also helps to explain some puzzling aspects of hydrophobic sizing of paper. When fatty acids and their soaps are present as monolayers in papermaking systems, the pH values associated with their dissociation, i.e. their pKa values, tend to be strongly shifted. Mutual association also appears to favor non-equilibrium multilayer structures that are tacky and insoluble, possibly serving as a nucleus for deposition of wood extractives, such, as resins and triglyceride fats, in pulp and paper systems.

Resistance of Spirulina platensis to Ammonia at High pH Values

1991 ◽  
Vol 32 (7) ◽  
pp. 953-958 ◽  
Author(s):  
Shimshon Belkin ◽  
Sammy Boussiba
Keyword(s):  
Spirulina Platensis ◽  
High Ph ◽  
Ph Values

The Role of CaCO3 Dissolution As a Source of HCO3- For the Buffering of Hypercapnic Acidosis in Aquatic and Terrestrial Decapod Crustaceans

1981 ◽  
Vol 94 (1) ◽  
pp. 269-274 ◽  
Author(s):  
R. P. HENRY ◽  
G. A. KORMANIK ◽  
N. J. SMATRESK ◽  
J. N. CAMERON
Keyword(s):  
Hypercapnic Acidosis ◽  
Decapod Crustaceans ◽  
Blood Calcium ◽  
Partial Restoration ◽  
Ph Values ◽  
Blood Ph ◽  
Gecarcinus Lateralis

Blood calcium concentrations are elevated during a hypercapnic acidosis in the terrestrial crab Gecarcinus lateralis, but not in the aquatic Callincetes sapidus. The increase occurs concomitantly with a rise in blood HCO3- and partial restoration of resting blood pH values. It is believed that in G. lateralis that a source of CaCO3, possibly the shell, is being dissolved for buffering purposes.

scholarly journals Photo-Fenton Degradation of Pentachlorophenol: Competition between Additives and Photolysis

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1157 ◽  
Author(s):  
Erika Pia Vergura ◽  
Sara Garcia-Ballestreros ◽  
Rosa Francisca Vercher ◽  
Lucas Santos-Juanes ◽  
Alessandra Bianco Prevot ◽  
...  
Keyword(s):  
Crucial Role ◽  
Process Efficiency ◽  
Solar Irradiation ◽  
Fenton Process ◽  
Solar Simulator ◽  
Urban Waste ◽  
Ph Values ◽  
Degradation Rates ◽  
Positive Effect

In the present work, the photo-Fenton degradation of pentachlorophenol (PCP, 1 mg/L) has been studied under simulated and natural solar irradiation; moreover, the effect on the process efficiency of urban waste-derived soluble bio-based substances (SBO), structurally comparable to humic acids, has been investigated. Experiments showed a crucial role of PCP photolysis, present in the solar pilot plant and hindered by the Pyrex® filter present in the solar simulator. Indeed, the SBO screen negatively affects PCP degradation when working under natural solar light, where the photolysis of PCP is relevant. In contrast, in the absence of PCP photolysis, a significant improvement of the photo-Fenton process was observed when added to SBO. Furthermore, SBO were able to extend the application of the photo-Fenton process at circumneutral pH values, due to their ability to complex iron, avoiding its precipitation as oxides or hydroxides. This positive effect has been observed at higher concentration of Fe(II) (4 mg/L), whereas at 1 mg/L, the degradation rates of PCP were comparable in the presence and absence of SBO.

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