Iron losses

Core loss is the magnetizing or hysteresis loss and represents the iron loss of the machine. 

To reduce the no-load iron losses caused by such harmonics the machine core may be formed of thinner low-loss laminates (see also Section 1.6,2(A-iv)). When the machine has already been manufactured and there is a need to suppress these harmonics, filter circuits may be employed along the lines discussed in Section 23.9. 

Due to smaller output and torque, the slip would rise and add to the rotor s losses (mainly iron losses) (see Figure 12.3). The voltage unbalance can be calculated as follows ... 

By the harmonic flux and frequencies Increased iron losses in the inductive machines, operating on such a system, due to saturation effects (equations (1.12) and (1.13). 

For such ratings, enclosure of non-magnelic material alone is recommended due to high iron losses in a magnetic material. 

Since there is no true excretion of iron from the body, iron-deficiency anemia occurs mostly because of inadequate absorption of iron or excess blood loss. Inadequate absorption may occur in patients who have congenital or acquired intestinal diseases, such as inflammatory bowel disease, celiac disease, or bowel resection. Achlorhydria and diets poor in iron also may contribute to poor absorption of iron. In contrast, iron deficiency also may occur in patients who exhibit a higher rate of iron loss from the body. This is manifested in... 

By applying the chemistry indicated by Equations 28.3 and 28.4, an environmental engineer can calculate the acid requirement to pickle 1 ton of steel, assuming an average iron loss of 0.35% that is typical for pickling strip steel ... 

Accordingly, between 3.6 and 4.2 gallons of 32% hydrochloric acid are needed to pickle 1 ton of steel (assuming that the iron loss is 0.35%). 

Figure 8.1 Body iron stores and daily iron exchange. The figure shows a schematic representation of the routes of iron movement in normal adult male subjects. The plasma iron pool is about 4 mg (transferrin-bound iron and non-transferrin-bound iron), although the daily turnover is over 30 mg. The iron in parenchymal tissues is largely haem (in muscle) and ferritin/haemosiderin (in hepatic parenchymal cells). Dotted arrows represent iron loss through loss of epithelial cells in the gut or through blood loss. Numbers are in mg/day. Transferrin-Tf haemosiderin - hs MPS - mononuclear phagocytic system, including macrophages in spleen and Kupffer cells in liver.

The capacity of the human body to excrete iron is severely limited as compared with most other mammals (Finch et al.f 1978). Iron loss in human beings (per kg body weight) is only one-tenth that of other mammals (Dubach et ah, 1955 Green et ah, 1968 Finch et ah, 1978) and human dietary intake only one-fiftieth to one-hundredth that of other mammals. It follows, as was originally suggested by McCance and... 

The importance of the hydrogenase enzyme was also demonstrated in experiments in which mixed cultures of SRB recently isolated from the production water of two pipeline systems in Alberta were circulated through two Robbins Devices (McCoy et al. 1981) at a flow rate of 4Lmin Both loops showed detectable SRB attached to corrosion coupons. One population of the SRB had a high level of hydrogenase activity, which correlated well with the subsequent high corrosion of the metal coupons the other population of SRB had low levels of hydrogenase and low levels of iron loss detected (Bryant et al. 1991). 

Catalyst recycling. Figure 29 shows the performanee achieved for the B02 degradation in three eonseeutive runs. In order to recover and reuse the C2-Ms catalyst, the catalyst was allowed to settle on the bottom of the reactor overnight after each oxidation cycle that lasted 340 min. Afterwards, the treated effluent was earefully deeanted to minimize the loss of eatalyst. After the first eyele, the dye solution beeame eolorless and the measurement of the absorbanee at 456 nm reported a eolor removal of 99%. For subsequent cycles, it was observed that both the eolor removal and COD abatement decreased reveahng that the catalytic activity was diminishing. The B02 discoloration decreased from 99 to 69%, whereas COD removal deereased from 98% to 39% in 3 eyeles that corresponds to 17 h of operation. Iron loss from the eatalyst per eyele corresponds to 4.3% (0.388 mg 1" ). 

In their paper in 1987, Hibbs et al. (1987a) proposed that the characteristic pattern of metabolic dysfunction inflicted by CAMs is due to iron loss from aconitase and other iron-sulfur-containing enzymes resulting from nitrite or oxygenated nitrogen intermediates in the pathway of nitrite and nitrate synthesis. Much data have since been published to support this proposal, although as described below the chemical details of this process are still not clear. 

Wharton, M., Granger, D. L., and Durack, D. T. (1988). Mitochondrial iron loss from leukemia cells injured by macrophages. A possible mechanism for electron transport chain defects. J. Immunol. 141, 1311-1317. 

Different iron salts provide different amounts of elemental iron, as shown in Table 33-3. In an iron-deficient individual, about 50-100 mg of iron can be incorporated into hemoglobin daily, and about 25% of oral iron given as ferrous salt can be absorbed. Therefore, 200-400 mg of elemental iron should be given daily to correct iron deficiency most rapidly. Patients unable to tolerate such large doses of iron can be given lower daily doses of iron, which results in slower but still complete correction of iron deficiency. Treatment with oral iron should be continued for 3-6 months after correction of the cause of the iron loss. This corrects the anemia and replenishes iron stores. 

The iron losses arise in the armature stampings and consist of eddy current losses and magnetic losses. To reduce eddy currents, the poles are manufactured from laminated material. Magnetic losses are determined by the choice of material. 

Hb is low - generally due to reduced iron intake or possibly excessive iron loss... 

Iron-deficiency anaemia is common in premenopausal females and is associated with iron loss in pregnancy, childbirth and menstruation and in nutritional iron deficiency. Anaemia reduces the oxygen-carrying capacity ofblood. 

Mild to moderate iron-deficiency anaemia is treated by iron supplementation with ferrous sulphate or ferrous gluconate. Vitamin C can aid iron absorption. A diagnosis of iron deficiency may indicate other potential sources of iron loss, such as gastrointestinal bleeding from ulcers or colon cancer. 

Fig. 7. Cartoon depicting the functional and epistatic relationship between copper and iron uptake and trafficking in yeast. The handling of iron hy eukaryotic cells is ultimately dependent on a copper ferroxidase. In yeast, either copper deficiency or loss of function in any of the copper-handling proteins indicated in the cartoon causes an iron deficiency that is correctable readily by extranutritional copper but not by iron. Loss of function in FetSp or Ftrlp, however, is correctable by neither metal ion.

S. cerevisiae and S. carlsbergensis, and their presence in C. utilis have suggested a possible connection between the two phenomena. Light et al. 131) demonstrated that in C. utilis iron-limited growth conditions result in a decrease of mitochondrial cytochromes and nonheme iron, loss... 

Reactions involving mackinawite and an oxidized sulfur species have been repeatedly shown to lead to pyrite formation (e.g., Bemer, 1969 Rickard, 1969, 1975). In addition, Wilkin and Bames (1996) and Penning et al. (2000) have shown that pyrite formation is exceptionally rapid when the mackinawite is pre-oxidized (e.g., exposed briefly to air) prior to the experiment. Based partly on X-ray photoelectron and Auger spectroscopy results of pyrrhotite oxidation (Mycroft et al., 1995), Wilkin and Bames (1996) hypothesized that this oxidative exposure initiates an iron-loss pathway similar to Equation (13). In sulfidic solutions, Fe(II) oxyhydroxides, shown as a product in this reaction, would not accumulate, but instead would undergo reductive dissolution by a reaction similar to Equation (14) ... 

The loss of one-fourth of the iron from mackinawite with simultaneous oxidation of one-half of the initial iron leads to formation of greigite (Wilkin and Barnes, 1996 Equation (15)). Iron loss (as opposed to sulfur gain— Equation (11)) is energetically favored, because mackinawite and greigite share the same close-packed sulfur sublattice ... 

Iron balance is determined by the difference between iron absorption and iron loss. Humans lack a mechanism to excrete excess iron and physiological control of iron balance is achieved by regulation of absorption. There is a reciprocal relationship between stores and absorption so that, as stores decline absorption increases and vice versa. 

Although there was no evidence for blood loss, the anemia was caused by iron deficiency. We concluded that this may have been attributable to a lack of availability of iron from the bread, greater iron loss attributable to excessive sweating in hot climate, and adverse effect of geophagia on iron absorption. In every case, the anemia completely corrected by administration of oral iron. 

Figure 7 shows the composition of the slag phase, which shows qualitatively good agreement with measured values. The FeO content rises towards the end of the process, resulting in iron losses. 

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