Production of hematite concentrate from hematite-magnetite ore

The main useful minerals in composition of hematite-magnetite ore are magnetite and hematite. Magnetite is extracted by wet magnetic separation in weak magnetic field with production of magnetite concentrate and nonmagnetic product. The nonmagnetic product is a feed of the processing circuit for hematite. It is difficult to produce concentrate with iron content of 58-60 mass % if hematite grains are smaller than 0.05 mm. For hematite concentrate production from finely disseminated hematite-magnetite ore, the magnetic-gravitation and magnetic- flotation circuits are designed. This article discusses the magnetic-gravitational separation circuit for hematite grains smaller than 0.05 mm. The first stage of this circuit is fine screening intended to remove large particles. The second stage is high-gradient magnetic separation. The high-gradient separator performance depends on the mineral composition of initial ore and on the rate of mineral dissociation. In finely disseminated hematite-magnetite ore, the associate minerals are mainly represented by quart and amphiboles. Magnetic properties of hematite and amphiboles are similar. For this reason, the high-gradient magnetic separation product contained hematite, amphiboles and quartz-magnetic accretions. The iron content of the magnetic product was 28.9 %. Thus, additional treatment is required, and separation by gravity is applicable in this case. The gravitational separation was carried out on centrifugal concentrator, jigging machine, spiral separator and sluice, and on concentration table. The best results are obtained on the concentration table. The iron content of the final concentrate was 62.3 %.

Segregated Expression of ENaC Subunits in Taste Cells

Salt taste is one of the 5 basic taste qualities. Depending on the concentration, table salt is perceived either as appetitive or aversive, suggesting the contribution of several mechanisms to salt taste, distinguishable by their sensitivity to the epithelial sodium channel (ENaC) blocker amiloride. A taste-specific knockout of the α-subunit of the ENaC revealed the relevance of this polypeptide for low-salt transduction, whereas the response to other taste qualities remained normal. The fully functional ENaC is composed of α-, β-, and γ-subunits. In taste tissue, however, the precise constitution of the channel and the cell population responsible for detecting table salt remain uncertain. In order to examine the cells and subunits building the ENaC, we generated mice carrying modified alleles allowing the synthesis of green and red fluorescent proteins in cells expressing the α- and β-subunit, respectively. Fluorescence signals were detected in all types of taste papillae and in taste buds of the soft palate and naso-incisor duct. However, the lingual expression patterns of the reporters differed depending on tongue topography. Additionally, immunohistochemistry for the γ-subunit of the ENaC revealed a lack of overlap between all potential subunits. The data suggest that amiloride-sensitive recognition of table salt is unlikely to depend on the classical ENaCs formed by α-, β-, and γ-subunits and ask for a careful investigation of the channel composition.

Modeling the movement of broadcast on the concentration table

The article attempts to analyze the work of the concentration table, on which the distribution of the material under investigation takes place. The efficiency of separation or otherwise enrichment depends on the drive that puts the concentration table plate into an asymmetrical reciprocating movement. The most frequently used solutions are concentration tables, on which the distribution of enriched material takes place in an aqueous medium commonly called wet enrichment. The AGH University of Science and Technology conducted simulation tests of material enrichment on a concentration table using the differences in friction coefficient commonly referred to as dry enrichment, i.e. without an additional medium. The article presents the effects of simulations that have been carried out for reference materials characterized by different friction coefficients and densities. The summary presents the analysis of obtained effects of computer simulations of material movement with different coefficients of friction. The simulations were carried out for variables: the frequency of vibrations of the concentration table and the angle of inclination of the table of the concentration table. It has been shown that it is possible to enrich the material by changing the above-mentioned operating parameters of the device.

Methods of enlarging material to the concentration table

Concentration tables are one of the oldest oscillatory enrichments with over 100 years of tradition. On this type of distribution tables are made according to material mass in many recurring cycles induced by appropriate drives. So-called wet tables are the devices most often used for coal enrichment in Polish mines because this process generates very high costs, high water consumption and pollution of the environment, as well as the need for, among others, water and mud management is increasingly being replaced mainly in areas poor in water by the modern model of the air concentration table – FGX produced in China. The process of enrichment on this type of table itself runs in a manner comparable to the method of wet enrichment with the difference that the FGX is distributed on a perforated plate, in this case we deal with air pollution. Department of Machinery Engineering and Transport's attempts to use the differences in coefficients of friction in over-resonance screens have shown that it is possible effective separation of grains with different coefficients of friction. The article presents a theoretical analysis and presents the results of performed dry enrichment trials using different coefficients of friction. The summary presents the advantages of using the enrichment method using the differences in friction coefficients and test results.

Abstract WP190: Excessive Daytime Sleepiness and Depression in Stroke Survivors

Introduction: Excessive daytime sleepiness (EDS) and post-stroke depression (PSD) are risk factors for stroke morbidity and mortality. EDS is commonly seen after stroke, but is not routinely assessed after stroke. EDS may be related to sleep disordered breathing (SDB) including obstructive and central sleep apneas, but can also occur in the absence of SDB. The relationship between EDS and PSD is not well understood. Hypothesis: We sought to assess the association between EDS and PSD. We hypothesized that patients with EDS are more likely to demonstrate symptoms of moderate to severe depression compared to patients without EDS. Methods: We identified ischemic stroke patients from the outpatient clinic registry (06/2014 - 10/2015). We screened for depressive symptoms using the Patient Health Questionnaire-9 (PHQ-9; range 0-27, higher worse), and for EDS using the Epworth Sleepiness Scale (ESS; range 0-24, higher worse). Univariate and multivariate analyses were used to evaluate association between EDS and PHQ-9 (moderate to severe depression = PHQ-9 > 9). Regression analysis was also used to evaluate association between EDS and symptoms included in the PHQ-9. Results: Among 200 ischemic stroke patients, 166 completed ESS and PHQ-9 within 90 days of stroke occurrence. Mean age was 61.5 and 54.8% were male. EDS (ESS>9) and moderate to severe depression were each present in 28.9% of patients. Patients with EDS had 3.5 times odds of moderate to severe depression compared to patients without EDS (table 1). Moreover, EDS was associated with higher odds of anhedonia, impaired mood, sleep disturbance, low energy, poor appetite, and impaired concentration (table 1). Conclusion: The presence of EDS is associated with moderate to severe depression in stroke survivors. This is not related solely to SDB symptoms. Patients with fatigue and EDS should be screened for depression. Future studies are also needed to explore the role that SDB plays in this relationship.

163 EFFECTS OF SERUM AND L-CARNITINE ON DEVELOPMENT AND CRYOTOLERANCE OF BOVINE EMBRYOS PRODUCED IN VITRO

Cryotolerance of bovine embryos produced in vitro (PIV) can be improved by l-carnitine. The objective of the present study was to determine whether the optimal concentration of l-carnitine is dependent on serum. Bovine embryos were produced in vitro with abattoir-derived oocytes. After fertilization (Day 0), oocytes (n = 2768) were randomly assigned in a 2 × 4 factorial design to culture in SOF-BE1 medium supplemented with or without 5% fetal bovine serum and l-carnitine at concentrations of 0.0, 0.75, 1.5, and 3.03 mM at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90% N2. The proportion of oocytes that cleaved was assessed on Day 3, and the proportion of oocytes that developed to the blastocyst and advanced blastocyst (expanded, hatching, and hatched) stages was determined on Day 7. Blastocysts and expanded blastocysts (n = 466) were harvested on Day 7 and subjected to controlled-rate freezing following equilibration in 1.5 M ethylene glycol. After thaw, embryos were cultured for 72 h in SOF-BE1 supplemented with 10% (v/v) fetal bovine serum and 50 mM dithiothreitol at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90% N2. Post-thaw re-expansion and hatching rates were determined at 24, 48, and 72 h. The experiment was replicated 9 times, and data were analysed by logistic regression. There was no interaction between serum and l-carnitine, at any of the concentrations tested, on embryo development or cryotolerance. Cleavage rates were not affected by serum or l-carnitine. Addition of serum during culture increased (P < 0.05) development to the blastocyst (19.7 ± 1.1% v. 25.3 ± 1.4%) and advanced blastocyst (9.1 ± 0.8% v. 12.4 ± 1.2%) stages. While l-carnitine did not affect blastocyst development, advanced blastocyst development was reduced (P < 0.05) for l-carnitine at 3.03 mM (0 mM: 10.9 ± 1.2%, 0.75 mM: 12.2 ± 1.4%, 1.5 mM: 13.5 ± 1.5%, 3.03 mM: 7.0 ± 1.0%). Serum reduced (P < 0.01) re-expansion (78.1 ± 3.4% v. 65.5 ± 3.1%, 81.0 ± 3.0% v. 68.4 ± 2.7%, 78.4 ± 3.4% v. 65.8 ± 3.1%, for 24, 48, and 72 h, respectively) and hatching (52.0 ± 4.0% v. 39.8 ± 3.6%, 61.2 ± 4.1% v. 45.4 ± 3.8%, 61.2 ± 4.1% v. 45.4 ± 3.8%, for 24, 48, and 72 h, respectively) rates at all time points. In contrast, treatment of embryos with l-carnitine during culture increased (P < 0.05) post-thaw re-expansion rates at 24 and 48 h, regardless of concentration (Table 1). In conclusion, post-thaw viability of bovine embryos PIV can be improved by the addition of l-carnitine during culture. Moreover, the beneficial effects of l-carnitine on cryosurvival are not dependent on serum supplementation. Table 1.Effect of addition of l-carnitine during culture on post-thaw re-expansion and hatching rates

The effect of dietary protein concentration on the performance of triplet rearing ewes and their lambs

In ewes rearing triplets high milk yields in early lactation are vitally important. The trial was conducted to investigate the influence of dietary protein intake on ewe milk yield and the performance of their triplet reared lambs.The trial involved 24 Cambridge (C) and 12 Suffolk x Cambridge (SxC) ewes rearing triplets. Ewes and their lambs were housed and penned in individual family groups until 35 days post partum. During the 7-35 day period ewes were fed ad libitum one of two coarsely milled complete diets differing in protein concentration (Table 1) together with a daily allocation of 510 g hay (oven dry).

Systematical and Physiological Notes On the Brine Shrimp, Artemia

Animals from California (Marina) and from Italy (Cagliari, Sardinia) were reared in the laboratory from eggs, and fed on a unicellular alga Dunaliella viridis Teod., which abounds in most natural brines in which Artemia occurs. In the course of the main experiments (described in Chapter III-V) several observations and small experiments on other subjects from the biology of the animal were made, and the results of these are laid down in Chapter II. In 1910 DADAY brought all animals living in salt water from the genus Artemia, which had hitherto been described, under one species: Artemia salina (L.). From a study of the data now available in literature and from hybridising experiments, which are here described, the conclusion is drawn that there are at least two distinct species in the genus. The animals from America then have to beare the name Artemia gracilis Verrill, but as further experiments may show further differentiation within this species the solution can only be considered as preliminary. Artemia lives constantly in a medium which has a higher osmotic pressure than the blood. Consequently the osmoregulatory activity will necessarily reduce the concentration of the blood. The refractive index of the blood was determined as a function of the concentration of the brine (Table I, fig. 6). The changes in the osmotic pressure of the blood were determined as a function of the concentration of the brine (fig. 7). Both these series of determinations showed an increase of the concentration of the blood with that of the brine, but to a much smaller extent. The amounts of water excreted by the animals when transferred to brines of higher concentration were measured. The change in size of the animals was measured directly when they had been transferred to brines of different concentration (Table II, fig. 8). When comparing the results of these different methods it appeared that the amounts of water excreted from the body were less than the amounts necessary to increase the concentration of the brine to the measured level (and vice versa). This leads to the conclusion that water can be stored in the animal. The intestine may act as such a storage chamber. This follows from the following observations. The rate of defecation is reduced after the animal is transferred to a different concentration. The diameter of the intestine can be shown to change considerably. Crystals have been shown to occur in the intestine sometimes, which also indicates an activity in the water regulation. Finally the histology showed a marked activity of the wall of the intestine after transfer of the animals to other concentrations. When aquatic animals are transferred to media of different concentration, a marked change in the rate of respiration can often be shown. This may, according to different theories, be either due to the change in the water content of the tissues, or to a change in the intensity of the osmoregulatory activity. Oxygen consumption was measured in brines of ½, 1 and 2 molar NaCl and it was shown that it was greater in the higher concentrations. This shows that the osmoregulation influences the rate of respiration to a higher degree than the water content of the tissues, as the first increases in higher concentrations while the last becomes less.