scholarly journals THE ADSORPTION OF GELATIN BY COLLODION MEMBRANES

1932 ◽  
Vol 15 (5) ◽  
pp. 551-559 ◽  
Author(s):  
Albert H. Palmer
Keyword(s):  
Experimental Study ◽  
Isoelectric Point ◽  
Maximum Amount ◽  
Low Permeability ◽  
High Permeability ◽  
Ph Values ◽  
A Value ◽  
Effects Of Ph ◽  
High Concentrations ◽  
Very High

An experimental study has been made of the adsorption of gelatin from solution at 37°C. by collodion membranes. In the case of membranes of high permeability, very high concentrations of gelatin were required to produce maximum adsorption, and the maximum amounts adsorbed were independent of the pH values of the solutions over the range 3.8 to 4.8. With membranes of low permeability, maximum adsorption was reached at lower gelatin concentrations, and the maximum amounts adsorbed varied with the pH, being lower on either side of the isoelectric point, over the range 3.8 to 6.6. The addition of salt in such experiments raised the maximum amount adsorbed to a value equal to that obtained with solutions at the isoelectric point in the absence of salt. These experiments can be explained by, and seem to lend support to, the theory proposed by Loeb and further developed by Kunitz concerning the effects of pH and salt on the size of gelatin particles in solution.

scholarly journals Effect of Shatt Al-Arab Salinity on the Groundwater of Al-Fao and Al-Siba in Southern Iraq

2021 ◽  
Vol 54 (1E) ◽  
pp. 114-122
Author(s):  
Shahad Abdul-Hameed ◽  
Amal Jabbar Hatem
Keyword(s):  
Electrical Conductivity ◽  
High Salinity ◽  
Saline Water ◽  
Arabian Gulf ◽  
Karun River ◽  
Ph Values ◽  
High Concentrations ◽  
Extent Of Damage ◽  
Southern Iraq ◽  
Very High

This study was conducted to estimate the extent of damage to the population in Basra, southern Iraq, specifically the areas adjacent to the Shatt al-Arab and the Arabian Gulf, which are the Al-Fao district and the Al-Siba region. They are affected by the progression of saline water resulting from the lack of water imports and the Karun River interruption, which led to high concentrations of salts in the Shatt Al-Arabs. Consequently, its effect on lands and all life types in these areas requires correcting a map of the study area to drop the groundwater sites as well as calculate the total dissolved salts, electrical conductivity and pH. This study concluded that the groundwater contains very high percentages of total dissolved solids (2880–10415 mg/l) and electrical conductivity (4450–14190 µs/cm). As it has very high salinity, so it is not suitable for drinking, irrigation, or industry. The values of the pH values (7.1-7.5) indicate that it is a light alkaline.

The activation of β-galactosidase (E.coli) by Mg2+at lower pH values

1996 ◽  
Vol 74 (2) ◽  
pp. 295-298 ◽  
Author(s):  
Mercedes Martinez-Bilbao ◽  
Reuben E. Huber
Keyword(s):  
Glutamic Acid ◽  
Key Words ◽  
Free Enzyme ◽  
Site Analysis ◽  
E Coli ◽  
Ph Values ◽  
Low Levels ◽  
High Concentrations ◽  
High Level ◽  
Very High

The activation of β-galactosidase (E. coli) by Mg2+at pH values below 7.6 was studied. If the Mg2+concentration was high enough, the kcatvalues at pH values down to 5.0 remained at the same high level as at pH 7 and 7.6 (600–620 s−1with o-nitrophenyl-β-D-galactopyranoside as the substrate). Very high concentrations of Mg2+(greater than 100 mM at pH 5) were, however, needed to saturate the Mg2+site at lower pH values. The Kmvalues at low levels of Mg2+were high at every pH but they decreased and approached the same low value at every pH (about 0.13 mM) as the [Mg2+] was increased. These data indicate that it is difficult to bind Mg2+at lower pH values, but the kcatand Kmvalues of the enzyme, and therefore the rates of galactosylation (k2), degalactosylation (k3), and binding (Ks), do not change substantially as a function of pH provided that a Mg2+is bound to the enzyme. The data also showed that Mg2+and protons compete for the same site. Analysis by plotting log [Mg2+]midvs. pH showed that the binding of Mg2+to the free enzyme involves two groups with pKavalues in the vicinity of 7 and one group with a pKavalue near 5.5. (The values referred to as [Mg2+]midare the Mg2+concentrations that resulted in kcatvalues midway between basal and maximum.) The "apparent" pKavalues of the groups when a Mg2+was bound (at saturating [Mg2+]) all appeared to be below 5.0.Key words: β-galactosidase, magnesium, pH, activation, glutamic acid, histidine, binding.

scholarly journals PROTEIN FILMS ON COLLODION MEMBRANES

1925 ◽  
Vol 8 (2) ◽  
pp. 61-74 ◽  
Author(s):  
David I. Hitchcock
Keyword(s):  
Linear Function ◽  
Protein Concentration ◽  
Plane Surface ◽  
Maximum Amount ◽  
Protein Films ◽  
High Permeability ◽  
Egg Albumin ◽  
Relative Cross Section ◽  
Effects Of Ph ◽  
Adsorption Of Gases

1. Collodion membranes of high permeability were found to adsorb weighable amounts of gelatin and egg albumin from solution at 37°C. 2. The effect of protein concentration could be expressed fairly well by a hyperbolic equation proposed by Langmuir for the adsorption of gases by a plane surface, while the usual parabolic adsorption equation of Freundlich did not fit the results. 3. In comparing this effect with solutions of varying pH, it was found there was a decided maximum of adsorption in solutions of isoelectric protein. The effects of acids and salts on the amount of gelatin adsorbed were like those observed by Loeb on the viscosity of gelatin solutions, but opposite in direction. The effects of pH on the amount of adsorbed gelatin and on the fluidity of the gelatin solutions were nearly parallel. 4. Membranes made impermeable by long drying took up very little or no gelatin from solution. 5. In the case of membranes of varying permeability the maximum amount of adherent gelatin increased with the permeability and thickness of the membranes, and appeared to be, within limits, a linear function of the relative pore surface of the membranes as calculated from Poiseuille's law. 6. The film of gelatin greatly decreased the permeability of the membranes, as measured by the flow of water through them. The relative cross-section of the pore openings, as calculated from the permeability measurements, was a linear function of the amount of adherent gelatin. These results led to the conclusion that the gelatin formed a film inside the pores.

The Retention of Amino Acids in the Haemolymph During Diuresis in Rhodnius

1980 ◽  
Vol 87 (1) ◽  
pp. 315-330
Author(s):  
S.H.P. MADDRELL ◽  
B.O.C. GARDINER
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fluid Secretion ◽  
Malpighian Tubules ◽  
High Rate ◽  
Excretory System ◽  
Low Permeability ◽  
High Concentrations ◽  
Active Reabsorption ◽  
Very High

The haemolymph of Rhodnius is rich in amino acids. During the rapid diuresis after a blood meal, no more than trace amounts of amino acids are lost in the urine. There is no significant reabsorption of amino acids in the excretory system. That they escape elimination can instead be attributed to a combination of the low permeability of the Malpighian tubules to amino acids, the very high rate of fluid secretion by the tubules, and the dilution of the haemolymph by an expansion in its volume after feeding. Amino acid losses are low in spite of the fact that the tubules actively accumulate high concentrations of amino acids in their cells and passive losses from these stores augment to some extent the flux of amino acids into the lumen. At times other than during diuresis, fluid secretion by the Malpighian tubules is slow. Calculations show that haemolymph solutes can then passively reach the higher concentrations in the lumen that are required for the operation of the excretory system (which relies on unselective passive entry and active reabsorption of useful substances). An advantage of the extraordinarily high rate of fluid secretion during diuresis is that fluid excretion can be rapidly completed. There is then little time for significant amounts of haemolymph solute to be lost passively.

PO4 recovery using mixtures of biochar and carbonate materials

2021 ◽  
Author(s):  
Carlotta Carlini ◽  
Antonio Primante ◽  
Nicolas Greggio ◽  
Enrico Balugani ◽  
Andrea Contin ◽  
...  
Keyword(s):  
Food Industry ◽  
Ph Value ◽  
Ph Values ◽  
A Value ◽  
Component Material ◽  
Carbonate Materials ◽  
Different Sources ◽  
Very High ◽  
Mild Acid ◽  
Exact Amount

<p>The recovery of PO<sub>4</sub> from wastewaters by using biochar proves not to be completely satisfactory. The surface of the biochar is typically negatively charged, which prevents the adsorption of PO<sub>4</sub>. For this reason, mixtures of biochar and natural carbonate materials have been tested as a novel sorbent material for PO<sub>4 </sub>recovery from both synthetic-and waste- water. The goal of the research is to obtain a PO<sub>4 </sub>based complex starting from natural second-generation materials such as food industry byproducts, plants and other residues to prepare fertilisers compliant to the component material category CMC 6 defined in the Regulation <strong>(</strong>EU) 2019/1009/EU It has to be noted that natural carbonate materials are not pure CaCO<sub>3</sub>, but present small impurities that contribute to modify their properties. Therefore, the use of carbonate materials obtained from different sources can lead to different performances when it comes to PO<sub>4</sub> removal from wastewaters.</p><p>In this work we present results of PO<sub>4</sub> removal obtained from a mixture of biomass and different carbonate materials. The mixture has been treated through a specific thermal protocol to obtain two different calcium-oxide rich charcoals here named composites C1 and C2. Initially, each composite was added to synthetic waters with different PO<sub>4 </sub>concentration, with a composite:water ratio of 1:1000. The initial concentrations of PO<sub>4 </sub>were 10, 100 and 1000 mg/l. After treatment with the composite, regardless of whether C1 or C2 was used, the PO<sub>4 </sub>concentration in the waters with initial concentration of 10 and 100 mg/L was nearly zero, with pH values at equilibrium around 11.9. The treatment of the water with initial PO<sub>4 </sub>concentration of 1000 mg/l shows a reduction of 20% and 40% with C1 and C2, respectively, with final pH values around 7.8.</p><p>After addition of the composites to the water, the solutions present very high pH values except for the water with the highest concentration. Although this is an optimal situation for the removal of PO<sub>4</sub>, it leads to two problems. First, the filtered water is not suitable for direct disposition in sewers, since the pH is higher than the limit established by the wastewater legislation (9.5). Second, a pH value larger than 9 determines the precipitation of PO<sub>4 </sub>regardless of the presence of the composite, which suggests that the PO<sub>4</sub> is not adsorbed by the composites, thus not leading to the desired complex</p><p>In order to quantify the exact amount of PO<sub>4</sub> adsorbed by the composite, the experiments have been repeated under controlled pH, keeping it around a value of 7 by the use of a mild acid. In this condition, after 1h treatment, 50% of phosphate was removed and bound to the composite</p><p>The work intends to present the results at laboratory scale and next steps at higher TRL.</p>

scholarly journals THE INFLUENCE OF pH UPON THE CONCENTRATION POTENTIALS ACROSS THE SKIN OF THE FROG

1928 ◽  
Vol 11 (6) ◽  
pp. 823-841 ◽  
Author(s):  
William R. Amberson ◽  
Henry Klein
Keyword(s):  
Isoelectric Point ◽  
Concentration Gradient ◽  
Opposite Sign ◽  
Electrical Charge ◽  
Dilute Solution ◽  
Ph Values ◽  
Charged Surfaces ◽  
A Value ◽  
Alkaline Side ◽  
Influence Of Ph

The production of concentration P.D.'s across the skin of the frog is very intimately related to the pH of the applied solutions. On the alkaline side of an isoelectric point the dilute solution is electropositive; on the acid side this solution becomes electronegative. When the pH is suddenly lowered from a value more alkaline than this isoelectric point to one considerably more acid the change in polarity may occur within a few seconds. The effect is reversible. When a series of unbuffered solutions at different pH values are applied reversal curves may be obtained. When the concentration gradient is .1 N-.001 N KCl the reversal points lie between pH 4.1 and 4.8. When studied in acetate buffers this electromotive reversal is found to be closely correlated with the electrical charge upon the membrane, as determined by electroendosmosis through it. Reversal occurs between pH 4.9 and 5.2. It is concluded that the electromotive behavior of this material is controlled by some ampholyte, or group of ampholytes, within the membrane. This ampholyte is probably a protein. On both sides of their isoelectric point these membranes, in common with protein membranes, behave as if they retarded or prevented the movement through them of ions of the same electrical sign as they themselves bear, while permitting the movement of ions of the opposite sign. It is suggested that this correlation arises because of electrostatic effects between the charged surfaces and ions in the solution.

MUMETAL

Alloy Digest ◽  
1991 ◽  
Vol 40 (12) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Magnetic Alloy ◽  
High Permeability ◽  
Soft Magnetic ◽  
Soft Magnetic Alloy ◽  
Very High ◽  
Specialty Metals

Abstract MUMETAL is a very high permeability soft magnetic alloy. (See also Alloy Digest Ni-25, April 1956.) This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on heat treating. Filing Code: Ni-398. Producer or source: Spang Specialty Metals.

BLENDALLOY 25-7904

Alloy Digest ◽  
1972 ◽  
Vol 21 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Coercive Force ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Heat Treating ◽  
Magnetic Shielding ◽  
High Permeability ◽  
Magnetic Cores ◽  
Very High

Abstract BLENDALLOY 25-7904 is an 80% nickel-15% iron-5% molybdenum alloy having very high permeability and low coercive force for magnetic cores in such applications as transformer laminations, sensitive magnetic amplifiers and magnetic shielding. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-181. Producer or source: Spang Industries Inc..

PENGELUARAN KOLOSTRUM DENGAN PEMBERIAN PERAWATAN PAYUDARA DAN ENDORPHIN MASSAGE PADA IBU POST SEKSIO SESAREA

2019 ◽  
Vol 2 (1) ◽  
pp. 34-40
Author(s):  
Diah Evawanna Anuhgera ◽  
Eka Fitria Panjaitan ◽  
Desika Wali Pardede ◽  
Desika Wali Pardede ◽  
Nikmah Jalilah Ritonga ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cesarean Section ◽  
Alternative Therapy ◽  
Control Group ◽  
Control Group Design ◽  
Group Design ◽  
A Value ◽  
Quasi Experimental ◽  
Breast Care ◽  
June July

Spending colostrum in post-cesarean section mothers is difficult in the first week postpartum. Efforts to overcome colostrum disruption can use non-pharmacological methods, namely breast care and endorphin massage. This study aims to determine the expenditure of colostrum by giving breast care and endorphin massage to post-cesarean mothers. This research is a quasi-experimental study with a nonequivalent design posttest control group design. This research was carried out in the midwifery room of the second floor of Grand Medistra Lubuk Pakam Hospital during the June-July 2019 period. There were 48 participants selected using purposive sampling, with 18 assigned in breast care, endorphin massage and combination of breast care and endorphin massage. The time of spending colostrum expenditure is assessed every day while the amount of colostrum expenditure is assessed after intervening. Analysis of the data used is one-way Annova. The results showed that the combination of breast care and endorphin massage was the most effective action in the time of spending colostrum and the amount of colostrum with a value of p = 0,000. The combination of breast care and endorphin massage could be applied as an alternative therapy post-cesarean mothers    

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