Search results for: potassium silicate

Authors: Dinoo Kirthinanda, Sujani Wijeratne

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Pseudohyperkalaemia is a common benign in vitro phenomenon caused by the release of potassium ions (K+) from cells during specimen processing. Analysis of haemolysed blood samples for predominantly intracellular electrolytes may lead to re-investigation and potentially harmful interventions. We report a case of a 52-year male with myeloproliferative disease manifested as Polycythaemia Rubra Vera, Hypertension and hypertensive nephropathy with stage 3 chronic kidney disease admitted to Neuro-intensive care unit (NICU) with an intra-cerebral haemorrhage secondary to hypertensive bleed. His initial blood investigations showed hyperkalemia with serum K+ 6.2 mmol/L yet the bedside arterial blood gas analysis yielded K+ of 4.6 mmol/L. The patient was however given hyperkalemia regime twice based on venous electrolyte analysis. The discrepancy between the bedside electrolyte analysis using arterial blood and venous blood prompted further evaluation. The 12 lead Electrocardiogram showed U waves and sinus bradycardia corresponding to the serum K+ of 2.8 mmol/L on arterial blood gas analysis. Immediate K+ replacement ensured the patient did not develop life-threatening cardiac complications. Pseudohyperkalaemia may pose diagnostic challenges in the absence of detectable haemolysis and should be suspected in susceptible patients with normal Electrocardiogram and Glomerular Filtration Rate to avoid potentially life-threatening interventions. When in doubt, rapid analysis of arterial blood gas may be useful for accurate quantification of potassium.

Keywords: patient safety, pseudohyperkalaemia, haemolysis, myeloproliferative disorder

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Authors: Sharvare Palwai, Padmaja Guggilla

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Smart materials, also called as responsive materials, undergo reversible physical or chemical changes in their properties as a consequence of small environmental variations. They can respond to a single or multiple stimuli such as stress, temperature, moist, electric or magnetic fields, light, or chemical compounds. Hence smart materials are the basis of many applications, including biosensors and transducers, particularly electroactive polymers. As the polymers exhibit good flexibility, high transparency, easy processing, and low cost, they would be promising for the sensor material. Polyvinylidene Fluoride (PVDF), being a ferroelectric polymer, exhibits piezoelectric and pyro electric properties. Pyroelectric materials convert heat directly into electricity, while piezoelectric materials convert mechanical energy into electricity. These characteristics of PVDF make it useful in biosensor devices and batteries. However, the influence of nanoparticle fillers such as Lithium Tantalate (LiTaO₃/LT), Potassium Niobate (KNbO₃/PN), and Zinc Titanate (ZnTiO₃/ZT) in polymer films will be studied comprehensively. Developing advanced and cost-effective biosensors is pivotal to foresee the fullest potential of polymer based wireless sensor networks, which will further enable new types of self-powered applications. Finally, nanocomposites films with best set of properties; the sensory elements will be designed and tested for their performance as electric generators under laboratory conditions. By characterizing the materials for their optical properties and investigate the effects of doping on the bandgap energies, the science in the next-generation biosensor technologies can be advanced.

Keywords: polyvinylidene fluoride, PVDF, lithium tantalate, potassium niobate, zinc titanate

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Authors: Murad Ali, Shoji Arai, Mohamed Khedr, Mukhtar Nasher, Shawki Nasr

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The Wadi Bayhan area of southeastern Yemen is about 60 km NW of Al-Bayda city in the Al-Bayda uplift terrane at the southeast margin of the Arabian-Nubian Shield. Intrusion of alkali gabbro into carbonate rocks apparently produced an 8m to 10 m thick reaction zone at the contact. This had been identified as nepheline pyroxenite. We have observed this to be mineralogically zoned with calc-silicate assemblages (e.g. pyroxene, calcite, spinel, garnet and melilite). The presence of melilite implies a skarn. The sinuous embayed pyroxenite-skarn contact, the presence of skarn minerals in pyroxenite, and textural evidence for growth of calc-silicate skarn by replacement of both carbonate rocks and solid pyroxenite indicate that reaction involved assimilation of carbonate wall rock by magma and loss of Al and Si to the skarn. Textural relationships between minerals provide evidence for a metasomatic development of the skarn at the expense of the pyroxenite. This process, related to the circulation of fluids equilibrated with carbonates, is responsible for those pyroxenite-spinel (± calcite) skarns. The uneven modal distribution of euhedral pyroxenite and enveloping nepheline in pyroxenite, the restricted occurrence of alkali gabbro as dikes in pyroxenite and skarn and the leucocratic matrix of pyroxenite suggest that pyroxenite represents an accumulation of titanaugite cemented by an alkali-rich residual magma and that alkali gabbro represents a part of the residual contaminated magma that was squeezed out of the pyroxene crystal mush. Carbonate assimilation is modeled by reaction of calcite and magmatic plagioclase, which results in resorption of plagioclase, growth of pyroxene enriched in Ca, Fe, Ti, and Al, and solution of nepheline in residual contaminated magma. The composition of nepheline pyroxenite evolved by addition of Ca from dissolved carbonate rocks, loss of Al and Si to skarn, and local segregation of solid pyroxene and alkali gabbro magma. The predominance of pyroxenite among contaminated rocks and their restriction to a large zone along the intrusive contact provide little evidence for the genesis of a significant volume of alkaline magmatic surroundings by carbonate assimilation.

Keywords: Yemen, Wadi Bayhan, skarn, pyroxenite, carbonatite, metasomatic

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Authors: Wasan Ismail Khalil, Hisham Khalid Ahmed, Zainab Ali

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Structural Lightweight Aggregate Concrete (SLWAC) has been developed in recent years because it reduces the dead load, cost, thermal conductivity and coefficient of thermal expansion of the structure. So SLWAC has the advantage of being a relatively green building material. Lightweight Aggregate (LWA) is either occurs as natural material such as pumice, scoria, etc. or as artificial material produced from different raw materials such as expanded shale, clay, slate, etc. The use of SLWAC in Iraq is limited due to the lack in natural LWA. The existence of Iraqi clay deposit with different types and characteristics leads to the idea of producing artificial expanded clay aggregate. The main aim in this work is to present of the properties of artificial LWA produced in the laboratory. Available local bentonite clay which occurs in the Western region of Iraq was used as raw material to produce the LWA. Sodium silicate as liquid industrial waste material from glass plant was mixed with bentonite clay in mix proportion 1:1 by weight. The manufacturing method of the lightweight aggregate including, preparation and mixing of clay and sodium silicate, burning of the mixture in the furnace at the temperature between 750-800˚C for two hours, and finally gradually cooling process. The produced LWA was then crushed to small pieces then screened on standard sieve series and prepared with grading which conforms to the specifications of LWA. The maximum aggregate size used in this investigation is 10 mm. The chemical composition and the physical properties of the produced LWA are investigated. The results indicate that the specific gravity of the produced LWA is 1.5 with the density of 543kg/m3 and water absorption of 20.7% which is in conformity with the international standard of LWA. Many trail mixes were carried out in order to produce LWAC containing the artificial LWA produced in this research. The selected mix proportion is 1:1.5:2 (cement: sand: aggregate) by weight with water to cement ratio of 0.45. The experimental results show that LWAC has oven dry density of 1720 kg/m3, water absorption of 8.5%, the thermal conductivity of 0.723 W/m.K and compressive strength of 23 N/mm2. The SLWAC produced in this research can be used in the construction of different thermal insulated buildings and masonry units. It can be concluded that the SLWA produced in this study contributes to sustainable development by, using industrial waste materials, conserving energy, enhancing the thermal and structural efficiency of concrete.

Keywords: expanded clay, lightweight aggregate, structural lightweight aggregate concrete, sustainable

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Authors: Parvin Mirmiran, Zahra Bahadoran, Sahar Mirzae, Fereidoun Azizi

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Background and aim: Lifestyle factors, especially dietary intakes play an important role in metabolism of lipids and lipoproteins. In this study, we assessed the association between dietary factors and 3-year changes of serum triglycerides (TG), HDL-C and the atherogenic index of plasma among Iranian adults. This longitudinal study was conducted on 1938 subjects, aged 19-70 years, who participated in the Tehran Lipid and Glucose Study. Demographics, anthropometrics and biochemical measurements including serum TG were assessed at baseline (2006-2008) and after a 3-year follow-up (2009-2011). Dietary data were collected by using a 168-food item, validated semi-quantitative food frequency questionnaire at baseline. The risk of hypertriglyceridemia in the quartiles of dietary factors was evaluated using logistic regression models with adjustment for age, gender, body mass index, smoking, physical activity and energy intakes. Results: Mean age of the participants at baseline was 41.0±13.0 y. Mean TG and HDL-C at baseline was 143±86 and 42.2±10.0 mg/dl, respectively. Three-year change of serum TG were inversely related energy intake from phytochemical rich foods, whole grains, and legumes (P<0.05). Higher intakes compared to lower ones of dietary fiber and phytochemical-rich foods had similar impact on decreased risk of hyper-triglyceridemia (OR=0.58, 95% CI=0.34-1.00). Higher- compared to lower-dietary sodium to potassium ratios (Na/K ratio) increased the risk of hypertriglyceridemia by 63% (OR=0.1.63, 95% CI= 0.34-1.00). Conclusion: Findings showed that higher intakes of fiber and phytochemical rich foods especially whole grain and legumes could have protective effects against lipid disorders; in contrast higher sodium to potassium ratio had undesirable effect on triglycerides.

Keywords: lipid disorders, hypertriglyceridemia, diet, food science

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Authors: N. N. Lingaraju, A. Sathish, K. N. Geetha, C. A. Srinivasamurthy, S. Bhaskar

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Studies on spent wash utilization as a nutrient source through 'Effect of distillery spentwash application on soil properties and yield of maize (Zea may L.) and finger millet (Eleusine coracana (L.) G)' was carried out in Malavalli Taluk, Mandya District, Karnataka State, India. The study was conducted in fourteen different locations of Malavalli (12) and Maddur taluk (2) involving maize and finger millet as a test crop. The spentwash was characterized for various parameters like pH, EC, total NPK, Na, Ca, Mg, SO₄, Fe, Zn, Cu, Mn and Cl content. It was observed from the results that the pH was slightly alkaline (7.45), EC was excess (23.3 dS m⁻¹), total NPK was 0.12, 0.02, and 1.31 percent respectively, Na, Ca, Mg and SO₄ concentration was 664, 1305, 745 and 618 (mg L⁻¹) respectively, total solid content was quite high (6.7%), Fe, Zn, Cu, Mn, values were 23.5, 5.70, 3.64, 4.0 mg L⁻¹, respectively. The crops were grown by adopting different crop management practices after application of spentwash at 100 m³ ha⁻¹ to the identified farmer fields. Soil samples were drawn at three stages i.e., before sowing of crop, during crop growth stage and after harvest of the crop at 2 depths (0-30 and 30-60 cm) and analyzed for pH, EC, available K and Na parameters by adopting standard procedures. The soil analysis showed slightly acidic reaction (5.93), normal EC (0.43 dS m⁻¹), medium available potassium (267 kg ha⁻¹) before application of spentwash. Application of spentwash has enhanced pH level of soil towards neutral (6.97), EC 0.25 dS m⁻¹, available K2O to 376 kg ha⁻¹ and sodium content of 0.73 C mol (P+) kg⁻¹ during the crop growth stage. After harvest of the crops soil analysis data indicated a decrease in pH to 6.28, EC of 0.22 dS m⁻¹, available K₂O to 316 kg ha⁻¹ and Na 0.52 C mol (P⁺) kg⁻¹ compared with crop growth stage. The study showed that, there will be enhancement of potassium levels if the spentwash is applied once to dryland. The yields of both the crops were quantified and found to be in the range of 35.65 to 65.55 q ha⁻¹ and increased yield to the extent of 13.36-22.36 percent as compared to control field (11.36-22.33 q ha⁻¹) in maize crop. Also, finger millet yield was increased with the spentwash application to the extent of 14.21-20.49 percent (9.5-17.73 q ha⁻¹) higher over farmers practice (8.15-14.15 q ha⁻¹).

Keywords: distillery spentwash, finger millet, maize, waste water

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Authors: A. Gürses, T. B. Barın, Ç. Doğar

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Bitumen has been widely used as the binder of aggregate in road pavement due to its good viscoelastic properties, as a viscous organic mixture with various chemical compositions. Bitumen is a liquid at high temperature and it becomes brittle at low temperatures, and this temperature-sensitivity can cause the rutting and cracking of the pavement and limit its application. Therefore, the properties of existing asphalt materials need to be enhanced. The pavement with polymer modified bitumen exhibits greater resistance to rutting and thermal cracking, decreased fatigue damage, as well as stripping and temperature susceptibility; however, they are expensive and their applications have disadvantages. Bituminous mixtures are composed of very irregular aggregates bound together with hydrocarbon-based asphalt, with a low volume fraction of voids dispersed within the matrix. Montmorillonite (MMT) is a layered silicate with low cost and abundance, which consists of layers of tetrahedral silicate and octahedral hydroxide sheets. Recently, the layered silicates have been widely used for the modification of polymers, as well as in many different fields. However, there are not too much studies related with the preparation of the modified asphalt with MMT, currently. In this study, organo-clay-modified bitumen, and calcareous aggregate and organo-clay blends were prepared by hot blending method with OMMT, which has been synthesized using a cationic surfactant (Cetyltrymethylammonium bromide, CTAB) and long chain hydrocarbon, and MMT. When the exchangeable cations in the interlayer region of pristine MMT were exchanged with hydrocarbon attached surfactant ions, the MMT becomes organophilic and more compatible with bitumen. The effects of the super hydrophobic OMMT onto the micro structural and mechanic properties (Marshall Stability and volumetric parameters) of the prepared blends were investigated. Stability and volumetric parameters of the blends prepared were measured using Marshall Test. Also, in order to investigate the morphological and micro structural properties of the organo-clay-modified bitumen and calcareous aggregate and organo-clay blends, their SEM and HRTEM images were taken. It was observed that the stability and volumetric parameters of the prepared mixtures improved significantly compared to the conventional hot mixes and even the stone matrix mixture. A micro structural analysis based on SEM images indicates that the organo-clay platelets dispersed in the bitumen have a dominant role in the increase of effectiveness of bitumen - aggregate interactions.

Keywords: hot mix asphalt, stone matrix asphalt, organo clay, Marshall test, calcareous aggregate, modified bitumen

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Authors: Wei Qu, Cassandra Agius, Nikki Varvazovsky, Angela Meade

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The goals of the case study are to address the importance of early diagnosis of osmotic demyelination syndrome (ODS) and to analyse the types, duration, and intensities of the rehabilitation program to promote neurological and functional recovery. It can be associated with biphasic course of disease and severe neurological and neuropsychiatric symptoms. Although a few treatment modalities, such as plasmapheresis, immunoglobulin therapy, steroid, and thyrotrophin-releasing hormone, have been suggested, there is no effective treatment for ODS. The overall prognosis of established ODS is generally poor. A high proportion of patients have a severe permanent disability, which has led to social, economic, and emotional burdens to carers and societies. In this case, a 69-year-old retired pensioner with chronic alcoholism was admitted to the hospital with a reduced level of consciousness and tonic-clonic seizure. He had severe hyponatraemia (serum sodium 118 mmol/L) and hypokalemia (serum potassium 2.8 mmol/L). He was treated with anticonvulsants, 150ml 3% hypertonic saline over one hour, and 40 mmol potassium chloride over one hour, and his sodium was increased by 11 mmol/L in the first 24 hours. However, he had worsened neurological symptoms with quadriplegia, dysphagia, anarthria, and confusion, and the radiological features suggested the diagnosis of ODS. He had minimal neurological recovery during the first four weeks of hospital admission. He was treated with seven weeks of a multi-disciplinary intensive rehabilitation program. On discharge, he had made a significant cognitive and functional recovery and could mobilize independently without a walking aid. In conclusion, ODS can still occur despite correcting sodium following the current clinical guidelines. Patients with severe neurological deficits in the context of osmotic demyelination syndrome would benefit from intensive rehabilitation to facilitate their functional improvement and to promote their quality of life.

Keywords: osmotic demyelination syndrome, hyponatremia, central pontine and extrapontine myelinolysis, rehabilitation

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Authors: Z. Abdollahnejad, P. Torgal, J. Barroso Aguiar

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Publications on the field of alkali-activated binders, state that this new material is likely to have high potential to become an alternative to Portland cement. Classical alkali-activated cements could be made more eco-efficient if the use of sodium silicate is avoided. Besides, most alkali-activated cements suffer from severe efflorescence originated by the fact that alkaline and/or soluble silicates that are added during processing cannot be totally consumed. This paper presents experimental results on hybrid alkaline cements. Compressive strength results and efflorescence’s observations show that the new mixes already analyzed are promising. SEM results show that no traditional porous ITZ was detected in these binders.

Keywords: hybrid alkaline cements, compressive strength, efflorescence, SEM, ITZ

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Authors: Dovilė Bačėninaitė, Karina Džermeikaitė, Justinas Kirvela, Ramūnas Antanaitis

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Bacteria are often present in the mouth of cattle. Some of them can cause abscesses. Starting with severe swelling of the mouth, muscle spasm, or locked jaw, it can lead to inability to open its mouth, move the neck, cause pain while eating. While the calf is unable to eat properly, it becomes more susceptible to infectious diseases, lower weight gain can be observed. Abscesses can be considered as a continuum of oral disease, whereby early stages of the lumpy jaw could proceed from gingivitis to periodontal disease. In the event of tissue damage, bacteria can enter the bloodstream, even cause sepsis. The most common lesions occur when animals eat sharp grass, coarse fodder, sharp, piercing foreign bodies (this is especially common for calves when they are trying to eat inedible objects). A crossbred Holstein calf presented with a history of proliferative outgrowth in the mandibular region. On clinical examination, needle aspiration, mandibular swelling revealed sticky, white curd-like fluid containing. Pus bacteriology revealed gram-negative cocci. They were sensitive to amoxicillin, cephalexin, enrofloxacin, ceftiofur. Blood morphology was in physiological ranges. The calf was treated surgically. The growth was excised, the puss drained and the wound was flushed with potassium permanganate solution (0,01%). A week after clinical surgery examination was performed. The swelling was decreased. Superficial bacterial infections are often associated with poor hygiene, which should be improved before treatment is commenced. Clipping away dirty hair and gently washing affected areas of skin daily with solutions such as povidone-iodine, potassium permanganate is effective. Appropriate antibiotic therapy, based on sensitivity testing, may be used where there is evidence of systemic illness.

Keywords: calf, abscess, lumpy jaw, pus, Streptococcus, Staphylococcus, Actinobacillus, infection

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Authors: Ananya Govindarajan

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Tetrahymena thermophila is a single-cell, eukaryotic organism that belongs to the Protozoa Kingdom. Tetrahymena thermophila is often used in signal transduction pathway studies because of its ability to model sensory input and the effects of environmental conditions such as chemicals and temperature. The recently discovered G37 chemorepellent receptor showed increased responsiveness to all chemorepellents. Investigating the mutant G37 Tetrahymena gene in various test solutions, including ferric chloride, ferrous sulfate, hydrogen peroxide, tetrazolium blue, potassium chloride, and dithiothreitol were performed to determine the role of oxidants and reducing agents with the mutant and wild-type cells (CU427) to assess the role of the receptor. Behavioral assays and recordings processed by ImageJ indicated that ferric chloride, hydrogen peroxide, and tetrazolium blue yielded little to no chemorepellent responses from G37 cells (<20% ARs). CU427 cells were over-responsive based on the mean percent of cells (>50% ARs). Reducing agents elicited chemorepellent responses from both G37 and CU427, in addition to potassium chloride. Cell responses were classified as over-responsive (>50% ARs). Dithiothreitol yielded unexpected results as G37 (37.0% ARs) and CU427 (38.1% ARs) had relatively similar responses and were only responsive and not over-responsive to the reducing agent test chemical solution. Ultimately, this indicates that the G37 receptor is more interactive with molecules that are reducing agents or non-oxidant compounds; G37 may be unable to sense and respond to oxidants effectively, further elucidating the pathways of the G37 strain and nature of this receptor. Results also indicate that the CSF most likely contained an oxidant, like ferric chloride. This research can be further applied to neuronal influences and how specific compounds may affect human neurons individually and their excitability as the responses model action potentials and membrane potential.

Keywords: tetrahymena thermophila, signal transduction, chemosensory, oxidant, reducing agent

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Authors: Philip A. Moore Jr., Jerry Martin, Hong Li

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Research has shown that over half of the nitrogen (N) excreted from broiler chickens is emitted to the atmosphere before the manure is removed from the barns, resulting in air and water pollution, as well as the loss of a valuable fertilizer resource. The objective of this study was to determine the fertilizer efficiency of N captured from the exhaust air from poultry houses using acid scrubbers. This research was conducted using 24 plots located on a Captina silt loam soil. There were six treatments: (1) unfertilized control, (2) aluminum sulfate (alum) scrubber solution, (3) potassium bisulfate scrubber solution, (4) sodium bisulfate scrubber solution, (5) sulfuric acid scrubber solution and (6) ammonium nitrate fertilizer dissolved in water. There were four replications per treatment in a randomized block design. The scrubber solutions were obtained from acid scrubbers attached to exhaust fans on commercial broiler houses. All N sources were applied at an application rate equivalent to 112 kg N ha⁻¹. Forage yields were measured five times throughout the growing season. Five months after the fertilizer sources were applied, a rainfall simulation study was conducted to determine the potential effects on phosphorus (P) runoff. Forage yields were significantly higher in plots fertilized with scrubber solutions from potassium bisulfate and sodium bisulfate than plots fertilized with scrubber solutions made from alum or sulfuric acid or ammonium nitrate, which were higher than the controls (7.61, 7.46, 6.87, 6.72, 6.45, and 5.12 Mg ha ⁻¹, respectively). Forage N uptake followed similar trends as yields. Phosphorus runoff and water soluble P was significantly lower in plots fertilized with the scrubber solutions made from aluminum sulfate. This study demonstrates that N captured using ammonia scrubbers is as good or possibly better than commercial ammonium nitrate fertilizer.

Keywords: air quality, ammonia emissions, nitrogen fertilizer, poultry

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Authors: J. Martin, A. Nominé, T. Czerwiec, G. Henrion, T. Belmonte

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The plasma electrolytic oxidation (PEO) is a particular electrochemical process to produce protective oxide ceramic coatings on light-weight metals (Al, Mg, Ti). When applied to aluminum alloys, the resulting PEO coating exhibit improved wear and corrosion resistance because thick, hard, compact and adherent crystalline alumina layers can be achieved. Several investigations have been carried out to improve the efficiency of the PEO process and one particular way consists in tuning the suitable electrical regime. Despite the considerable interest in this process, there is still no clear understanding of the underlying discharge mechanisms that make possible metal oxidation up to hundreds of µm through the ceramic layer. A key parameter that governs the PEO process is the numerous short-lived micro-discharges (micro-plasma in liquid) that occur continuously over the processed surface when the high applied voltage exceeds the critical dielectric breakdown value of the growing ceramic layer. By using a bipolar pulsed current to supply the electrodes, we previously observed that micro-discharges are delayed with respect to the rising edge of the anodic current. Nevertheless, explanation of the origin of such phenomena is still not clear and needs more systematic investigations. The aim of the present communication is to identify the relationship that exists between this delay and the mechanisms responsible of the oxide growth. For this purpose, the delay of micro-discharges ignition is investigated as the function of various electrical parameters such as the current density (J), the current pulse frequency (F) and the anodic to cathodic charge quantity ratio (R = Qp/Qn) delivered to the electrodes. The PEO process was conducted on Al2214 aluminum alloy substrates in a solution containing potassium hydroxide [KOH] and sodium silicate diluted in deionized water. The light emitted from micro-discharges was detected by a photomultiplier and the micro-discharge parameters (number, size, life-time) were measured during the process by means of ultra-fast video imaging (125 kfr./s). SEM observations and roughness measurements were performed to characterize the morphology of the elaborated oxide coatings while XRD was carried out to evaluate the amount of corundum -Al203 phase. Results show that whatever the applied current waveform, the delay of micro-discharge appearance increases as the process goes on. Moreover, the delay is shorter when the current density J (A/dm2), the current pulse frequency F (Hz) and the ratio of charge quantity R are high. It also appears that shorter delays are associated to stronger micro-discharges (localized, long and large micro-discharges) which have a detrimental effect on the elaborated oxide layers (thin and porous). On the basis of the results, a model for the growth of the PEO oxide layers will be presented and discussed. Experimental results support that a mechanism of electrical charge accumulation at the oxide surface / electrolyte interface takes place until the dielectric breakdown occurs and thus until micro-discharges appear.

Keywords: aluminium, micro-discharges, oxidation mechanisms, plasma electrolytic oxidation

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Authors: Lee A. Browne, K. Rumbold

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The first fluorinating enzyme, 5'-fluoro-5'-deoxyadenosine synthase (fluorinase) was isolated from the soil bacterium Streptomyces cattleya. Such an enzyme, with the ability to catalyze a C-F bond, presents great potential as a biocatalyst. Naturally fluorinated compounds are extremely rare in nature. As a result, the number of fluorinases identified remains relatively few. The field of fluorination is almost completely synthetic. However, with the increasing demand for fluorinated organic compounds of commercial value in the agrochemical, pharmaceutical and materials industries, it has become necessary to utilize biologically based methods such as biocatalysts. A key step in this crucial process is the large-scale production of the fluorinase enzyme in considerable quantities for industrial applications. Thus, this study aimed to optimize expression of the fluorinase enzyme in both prokaryotic and eukaryotic expression systems in order to obtain high protein yields. The fluorinase gene was cloned into the pET 41b(+) and pPinkα-HC vectors and used to transform the expression hosts, E.coli BL21(DE3) and Pichia pastoris (PichiaPink™ strains) respectively. Expression trials were conducted to select optimal conditions for expression in both expression systems. Fluorinase catalyses a reaction between S-adenosyl-L-Methionine (SAM) and fluoride ion to produce 5'-fluorodeoxyadenosine (5'FDA) and L-Methionine. The activity of the enzyme was determined using HPLC by measuring the product of the reaction 5'FDA. A gradient mobile phase of 95:5 v/v 50mM potassium phosphate buffer to a final mobile phase containing 80:20 v/v 50mM potassium phosphate buffer and acetonitrile were used. This resulted in the complete separation of SAM and 5’-FDA which eluted at 1.3 minutes and 3.4 minutes respectively. This proved that the fluorinase enzyme was active. Optimising expression of the fluorinase enzyme was successful in both E.coli and PichiaPink™ where high expression levels in both expression systems were achieved. Protein production will be scaled up in PichiaPink™ using fermentation to achieve large-scale protein production. High level expression of protein is essential in biocatalysis for the availability of enzymes for industrial applications.

Keywords: biocatalyst, expression, fluorinase, PichiaPink™

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Authors: A. T. Zhakiyenova, E. E. Zhatkanbaev, Zh. K. Zhatkanbaeva

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Nickel plays an important role in mechanical engineering and creation of military equipment; practically all steel are alloyed by nickel and other metals for receiving more durable, heat-resistant, corrosion-resistant steel and cast iron. There are many ways of processing of nickel in the world. Generally, it is igneous metallurgy methods. In this article, the review of majority existing ways of technologies of processing silicate nickel - cobalt ores is considered. Leaching of ores of a field Bugetkol is investigated by solution of sulfuric acid. We defined a specific consumption of sulfuric acid in relation to the mass of ore and to the mass of metal.

Keywords: cobalt, degree of extraction, hydrometallurgy, igneous metallurgy, leaching, matte, nickel

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Authors: Maria L. G. Lourenço, Keylla H. N. P. Pereira, Viviane Y. Hibaru, Fabiana F. Souza, Joao C. P. Ferreira, Simone B. Chiacchio, Luiz H. A. Machado

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Anasarca is generalized congenital edema that is often lethal. The condition is transmitted hereditarily and is autosomal dominant, with a racial predisposition in French Bulldogs and English Bulldogs. This study aims at reporting a case of anasarca treatment in neonates. The fetuses of a one year and six months old, primiparous English Bulldog mother were diagnosed with anasarca during an ultrasound examination performed at the 55th day of pregnancy and, therefore, an elective cesarean section was scheduled to prevent fetal dystocia. At birth, all puppies presented anasarca, and one of the six was stillborn. The newborns presented cyanosis, dyspnea, bradycardia, absent reflexes, low vitality scores (3/10), and hypothermia ( < 32ºC). The weight of the puppies at the time of birth varied between 347 and 373 grams, about 100 grams above the average weight estimated for the breed. Immediate neonatal care was applied with oxygen therapy via a mask, aminophylline (0.2 ml/100 g/PV/sublingual), and slow heating. After 10 minutes, there was a significant improvement in the neonatal parameters. The anasarca was treated with the drug furosemide, administered subcutaneously, at a dose of 0.2 mg per 100 grams of weight, every three hours. The stimulation for urination of newborns was performed every 30 minutes, and weight loss was monitored every 30 minutes. Five grams of potassium chloride were administered orally for every 30 grams of weight loss to counterbalance the loss of potassium caused by the diuretic medication. After 15 hours, the neonates reached the ideal weight for the breed, around 209 to 230 grams. In total, four neonates received five doses of furosemide, while one received six doses. The puppies are currently ten months old, healthy and neutered. Anasarca should not be ignored and is considered potentially lethal and an indication for euthanasia in all cases. Early intervention is of utmost importance for the survival of these patients.

Keywords: Walrus syndrome, congenital edema, water puppy syndrome, puppies

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Authors: Etukudo, M. Mbosowo, Nyananyo, L. Bio, Negbenebor, A. Charles

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An aqueous extract of palm bunch ash from Elaeis guineensis Jacq., equilibrated with water was used to assess the growth and minerals composition of Amaranthus hybridus L. in agricultural soil of Abak, Akwa Ibom State, nigeria. Various concentrations, 0 (control), 10, 20, 30, 40, and 50% of palm bunch extract per 4kg of sandy-loam soil were used for the study. Chemical characteristics of the extract, Growth parameters (Plant height, root length, fresh weight, dry weight and moisture content), leaf minerals composition (Nitrogen, phosphorus, potassium, calcium and magnesium) of the crop and soil chemical composition before and after harvest (pH, organic matter, nitrogen, phosphorus, potassium, calcium and magnesium) were examined. The results showed that palm bunch ash extract significantly (P < 0.05) increased the soil pH at all levels of treatments compared to the control. Similarly, the soil and leaf minerals component (N, P, K. Ca, and Mg) of the crop increased with increase in the concentration of palm bunch extract, except at 40 and 50% for leaf minerals composition, Soil organic matter, nitrogen and phosphorus J(before and after harvest). In addition, The plant height, Root length, fresh weight, dry weight and moisture content of the crop increased significantly (P < 0.05) with increase in the concentration of the extract, Except at 30, 40 and 50% where these growth parameters decreased in relation to the control treatment. Therefore, this study suggests that palm bunch ash extract could be utilized at lower concentration as a nutrient supplement for both Amaranthus hubridus L. and soil medium, most especially in the tropical soils of the Niger Delta region of Nigeria.

Keywords: Amaranthus hybridus L., growth, leaf minerals composition, palm bunch ash extract

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Authors: Gusa Hall, Barrie Keeler, Achal Khanna

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Introduction: NICE guidelines have highlighted the consequences of IV fluid mismanagement. The main aim of this study was to audit fluid prescribing post laparotomies to identify if fluids were prescribed in accordance to NICE guidelines. Methodology: Retrospective database search of eight specific laparotomy procedures (colectomy right and left, Hartmann’s procedure, small bowel resection, perforated ulcer, abdominal perineal resection, anterior resection, pan proctocolectomy, subtotal colectomy) highlighted 29 laparotomies between April 2019 and May 2019. Two of 29 patients had secondary procedures during the same admission, n=27 (patients). Database case notes were reviewed for date of procedure, length of admission, fluid prescribed and amount, nasal gastric tube output, daily bloods results for electrolytes sodium and potassium and operational losses. Results: n=27 based on 27 identified patients between April 2019 – May 2019, 93% (25/27) received IV fluids, only 19% (5/27) received the correct IV fluids in accordance to NICE guidelines, 93% (25/27) who received IV fluids had the correct electrolytes levels (sodium & potassium), 100% (27/27) patients received blood tests (U&E’s) for correct electrolytes levels. 0% (0/27) no documentation on operational losses. IV fluids matched nasogastric tube output in 100% (3/3) of the number of patients that had a nasogastric tube in situ. Conclusion: A PubMed database literature review on barriers to safer IV prescribing highlighted educational interventions focused on prescriber knowledge rather than how to execute the prescribing task. This audit suggests IV fluids post laparotomies are not being prescribed consistently in accordance to NICE guidelines. Surgical management plans should be clearer on IV fluids and electrolytes requirements for the following 24 hours after the plan has been initiated. In addition, further teaching and training around IV prescribing is needed together with frequent surgical audits on IV fluid prescribing post-surgery to evaluate improvements.

Keywords: audit, IV Fluid prescribing, laparotomy, NICE guidelines

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Authors: Zipeng Zhang, Yat C. Wong, Arul Arulrajah

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Since automobiles became widely popular around the early 20th century, end-of-life tyres have been one of the major types of waste humans encounter. Every minute, there are considerable quantities of tyres being disposed of around the world. Most end-of-life tyres are simply landfilled or simply stockpiled, other than recycling. To address the potential issues caused by tyre waste, incorporating it into construction materials can be a possibility. This research investigated the viability of manufacturing bricks using mill waste and tyre crumb by alkali-activation at a relatively low temperature. The mill waste was extracted from a brick factory located in Melbourne, Australia, and the tyre crumbs were supplied by a local recycling company. As the main precursor, the mill waste was activated by the alkaline solution, which was comprised of sodium hydroxide (8m) and sodium silicate (liquid). The introduction ratio of alkaline solution (relative to the solid weight) and the weight ratio between sodium hydroxide and sodium silicate was fixed at 20 wt.% and 1:1, respectively. The tyre crumb was introduced to substitute part of the mill waste at four ratios by weight, namely 0, 5, 10 and 15%. The mixture of mill waste and tyre crumbs were firstly dry-mixed for 2 min to ensure the homogeneity, followed by a 2.5-min wet mixing after adding the solution. The ready mixture subsequently was press-moulded into blocks with the size of 109 mm in length, 112.5 mm in width and 76 mm in height. The blocks were cured at 50°C with 95% relative humidity for 2 days, followed by a 110°C oven-curing for 1 day. All the samples were then placed under the ambient environment until the age of 7 and 28 days for testing. A series of tests were conducted to evaluate the linear shrinkage, compressive strength and water absorption of the samples. In addition, the microstructure of the samples was examined via the scanning electron microscope (SEM) test. The results showed the highest compressive strength was 17.6 MPa, found in the 28-day-old group using 5 wt.% tyre crumbs. Such strength has been able to satisfy the requirement of ASTM C67. However, the increasing addition of tyre crumb weakened the compressive strength of samples. Apart from the strength, the linear shrinkage and water absorption of all the groups can meet the requirements of the standard. It is worth noting that the use of tyre crumbs tended to decrease the shrinkage and even caused expansion when the tyre content was over 15 wt.%. The research also found that there was a significant reduction in compressive strength for the samples after water absorption tests. In conclusion, the tyre crumbs have the potential to be used as a filler material in brick manufacturing, but more research needs to be done to tackle the durability problem in the future.

Keywords: bricks, mill waste, tyre crumbs, waste recycling

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Authors: Huihui Zhang, Zhongzhi Zhang

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Coagulation/flocculation is regarded a simple and effective wastewater treatment technology. Chlorine-containing coagulants may release chloride ions into the wastewater, causing corrosion. A green chlorine-free coagulant of polyaluminum ferric silicate (PSAF) was prepared by the copolymerization method to treat oily refractory wastewaters. Results showed that the highest removal efficiency of turbidity and chemical oxygen demand (COD) achieved 97.4% and 93.0% at a dosage of 700 mg/L, respectively. After PSAF coagulation, the chloride ion concentration was also almost the same as that in the raw wastewater. Thus, the chlorine-free coagulant is highly efficient and does not introduce additional chloride ions into the wastewater, avoiding corrosion.

Keywords: coagulation, chloride-free coagulant, oily refractory wastewater, coagulation performance

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Authors: Qian Li, Zhaoping Zhong

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Sewage sludge, a typical solid waste, has inevitably been produced in enormous quantities in China. Still worse, the amount of sewage sludge produced has been increasing due to rapid economic development and urbanization. Compared to the conventional method to treat sewage sludge, pyrolysis has been considered an economic and ecological technology because it can significantly reduce the sludge volume, completely kill pathogens, and produce valuable solid, gas, and liquid products. However, the large-scale utilization of sludge biochar has been limited due to the considerable risk posed by heavy metals in the sludge. Heavy metals enriched in pyrolytic biochar could be divided into exchangeable, reducible, oxidizable, and residual forms. The residual form of heavy metals is the most stable and cannot be used by organisms. Kaolin and zeolite are environmentally friendly inorganic minerals with a high surface area and heat resistance characteristics. So, they exhibit the enormous potential to immobilize heavy metals. In order to reduce the risk of leaching heavy metals in the pyrolysis biochar, this study pyrolyzed sewage sludge mixed with kaolin/zeolite in a small rotary kiln. The influences of additives and pyrolysis temperature on the leaching concentration and morphological transformation of heavy metals in pyrolysis biochar were investigated. The potential mechanism of stabilizing heavy metals in the co-pyrolysis of sludge blended with kaolin/zeolite was explained by scanning electron microscopy, X-ray diffraction, and specific surface area and porosity analysis. The European Community Bureau of Reference sequential extraction procedure has been applied to analyze the forms of heavy metals in sludge and pyrolysis biochar. All the concentrations of heavy metals were examined by flame atomic absorption spectrophotometry. Compared with the proportions of heavy metals associated with the F4 fraction in pyrolytic carbon prepared without additional agents, those in carbon obtained by co-pyrolysis of sludge and kaolin/zeolite increased. Increasing the additive dosage could improve the proportions of the stable fraction of various heavy metals in biochar. Kaolin exhibited a better effect on stabilizing heavy metals than zeolite. Aluminosilicate additives with excellent adsorption performance could capture more released heavy metals during sludge pyrolysis. Then heavy metal ions would react with the oxygen ions of additives to form silicate and aluminate, causing the conversion of heavy metals from unstable fractions (sulfate, chloride, etc.) to stable fractions (silicate, aluminate, etc.). This study reveals that the efficiency of stabilizing heavy metals depends on the formation of stable mineral compounds containing heavy metals in pyrolysis biochar.

Keywords: co-pyrolysis, heavy metals, immobilization mechanism, sewage sludge

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Authors: Natsumi Murakami, Jae-Ho Kim, Susumu Yonezawa

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The calcium fluorosilicate (CaSiF₆) was prepared from calcium silicate (CaSiO₃) with fluorine gas at 25 ~ 200 ℃ and 760 Torr for 1~24 h. Especially, the pure CaSiF₆ could be prepared at 25 ℃ for 24 h with F₂ gas from the results of X-ray diffraction. Increasing temperature to higher than 100 ℃, the prepared CaSiF₆ was decomposed into CaF₂ and SiF₄. The release of SiF₄ gas was confirmed by the results of gas-phase infrared spectroscopy. In this study, we tried to modify the surface of polycarbonate (PC) resin using the SiF₄ gas released from CaSiF₆ particles. By using the prepared CaSiF₆, the surface roughness of fluorinated PC samples was approximately four times larger than that (1.4 nm) of the untreated sample. The results of X-ray photoelectron spectroscopy indicated the formation of fluorinated bonds (e.g., -CFx) on the surface of PC after surface fluorination. Consequently, the CaSiF₆ particles can be useful for a new fluorinating agent.

Keywords: calcium fluorosilicate, fluorinating agent, polycarbonate, surface fluorination

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Authors: Ounassa Adjroud

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Potassium dichromate (K2Cr2O7) is one of the most toxic elements to which man can be exposed at work or in the environment. The purpose of the current work is to compare the effect of K2Cr2O7 using variations in the dose, route of administration and duration of exposure in male and female Wistar albino rats with a special focus on biochemical parameters. K2Cr2O7 was subcutaneously administered alone (10, 50 and 100 mg/kg body weight) to female Wistar albino rats. Male rats received in their drinking water K2Cr2O7 30 mg/L/day) for 20 consecutive days. The Biochemical parameters were evaluated on days 3, 6 and 21 after subcutaneous (sc.) treatment in female rats and on days 10 and 20 after oral administration in male rats. The subcutaneous (s.c.) administration of 25 mg/kg of K2Cr2O7 to Wistar albino rats induced a slight change in plasma glucose levels during the experiment period. On the contrary, a significant decrease in plasma glucose levels was observed with 50 mg/kg mainly on days 3 (-26%) and 21 (-48%) after treatment compared to controls females rats. On the other hand, the higher dose provoked a significant increase in plasma glucose concentrations on days 6 (+31%) and 21 (+60%). similarly, the lower dose of chromium had no effect on the plasma urea levels. Conversely, a significant increase (122%) in this parameter was obtained during the first three days after treatment. In addition, a significant decrease in plasma glucose levels was observed with 50 mg/kg mainly on days 3 (-26%) and 21 (-48%) after treatment. On the other hand, the higher dose provoked a significant increase in plasma glucose concentrations on days 6 (+31%) and 21 (+60%). similarly, the lower dose of chromium had no effect on the plasma urea levels. Conversely, a significant increase in this parameter (122%) was obtained during the first three days after treatment. In addition, administration of 100 mg/kg of K2Cr2O7 by s.c markedly augmented the levels of plasma urea on days 3 (62%) and 6 (121%). Administration of 30 mg/L/day of K2Cr2O7 in the drinking water induced a significant augmentation in both of plasma glucose (27%) and urea (126%) during the first ten days of treatment. These results suggested that K2Cr2O7 administered subcutaneously or in the drinking water may induce harmful effects on biochemical parameters.

Keywords: glucose, potassium dichromate, Wistar albino rat, urea

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Authors: H. Gonen, M. Dogan

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Meerschaum, which is found in the earth’s crust, is a white and clay like hydrous magnesium silicate. It has a wide area of use from production of carious ornaments to chemical industry. It has a white and irregular crystalline structure. It is wet and moist when extracted, which is a good form for processing. At drying phase, it gradually loses its moisture and becomes lighter and harder. In through-dry state, meerschaum is durable and floats on the water. After processing of meerschaum, A ratio between %15 to %40 of the amount becomes waste. This waste is usually kept in a dry-atmosphere which is isolated from environmental effects so that to be used right away when needed. In this study, use of meerschaum waste as aggregate in lightweight concrete is studied. Stress-strain diagrams for concrete with meerschaum aggregate are obtained. Then, stress-strain diagrams of lightweight concrete and concrete with regular aggregate are compared. It is concluded that meerschaum waste can be used in production of lightweight concrete.

Keywords: lightweight concrete, meerschaum, aggregate, sepiolite, stress-strain diagram

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Authors: Liang-Yi Lin, Hsunling Bai

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In this work, transition metal (metal= Co, Fe, Ni, Cu, and Mn) modified cerium oxide catalysts supported on mesoporous aluminosilicate particles (Ce/Al-MSPs) were prepared using waste silicate as the precursors through aerosol-assisted flow process, and their catalytic performances were investigated for acetone incineration. Tests on the bimetallic Ce/Al-MSPs and Mn/Al-MSPs and trimetallic Mn-Ce, Fe-Ce, Co-Ce, Ni-Ce, and Cu-Ce/Al-MSPs in the temperature range of 100-300 oC demonstrated that Ce was the main active metal while Mn acted as a suitable promoter in acetone incineration reactions. Among tested catalysts, Mn-Ce/Al-MSPs with a Mn/Ce molar ratio of 2/1 exhibited the highest acetone catalytic activity. Moreover, the synergetic effect was observed for trimetallic Mn-Ce/Al-MSPs on the acetone removal as compared to the bimetallic Ce/Al-MSPs or Mn/Al-MSPs catalysts.

Keywords: acetone, catalytic oxidation, cerium oxide, mesoporous silica

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Authors: Allam Srinivasa Rao, Ch. Annapurna Devi, G. Vijaya Prakash

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A new-fangled series of white light emitting 1 mol% of Dy3+ ions doped Single-Alklai and Mixed-Alkai fluoro tungstunate tellurite glasses have been prepared using melt quenching technique and their spectroscopic behaviour was investigated by studying XRD, optical absorption, photoluminescence and lifetime measurements. The bonding parameter studies reveal the ionic nature of the Dy-O bond in the present glasses. From the absorption spectra, the Judd–Ofelt (J-O) intensity parameters have been determined which are used to explore the nature of bonding and symmetry orientation of the Dy–ligand field environment. The evaluated J-O parameters (Ω_4>Ω_2>Ω_6) for all the glasses are following the same trend. The photoluminescence spectra of all the glasses exhibit two intensified peaks in blue and Yellow regions corresponding to the transitions 4F9/2→6H15/2 (483 nm) and 4F9/2→6H13/2 (575 nm) respectively. From the photoluminescence spectra, it is observed that the luminescence intensity is maximum for Dy3+ ion doped potassium combination of fluoro tungstunate tellurite glass (TeWK: 1Dy). The J-O intensity parameters have been used to determine the various radiative properties for the different emission transitions from the 4F9/2 fluorescent level. The highest emission cross-section and branching ratio values observed for the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions suggest the possible laser action in the visible region from these glasses. By using the experimental lifetimes (τ_exp) measured from the decay spectral features and radiative lifetimes (τ_R), the quantum efficiencies (η) for all the glasses have been evaluated. Among all the glasses, the potassium combined fluoro tungstunate tellurite (TeWK:1Dy) glass has the highest quantum efficiency (94.6%). The CIE colour chromaticity coordinates (x, y), (u, v), colour correlated temperature (CCT) and Y/B ratio were also estimated from the photoluminescence spectra for different compositions of glasses. The (x, y) and (u, v) chromaticity colour coordinates fall within the white light region and the white light can be tuned by varying the composition of the glass. From all these studies, we are suggesting that the 1 mol% of Dy3+ ions doped TeWK glass is more suitable for lasing and White-LED applications.

Keywords: dysprosium, Judd-Ofelt parameters, photo luminescence, tellurite glasses

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Authors: S. K. Gali

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Spentwash, An effluent of distillery is an environmental pollutant because of its high load of pollutants (pH: 2-4; BOD>40,000 mg/l, COD>100,000mg/l and TDS >70,000mg/l). But However, after subjecting it to primary treatment (bio-methanation), Its pollutant load gets drastically reduced (pH: 7.5-8.5, BOD<10,000 mg/l) and could be disposed off safely as a source of organic matter and plant nutrients for crop production. With the consent of State Pollution Control Board, the distilleries in Karnataka are taking up ‘one time controlled land application’ of bio-methanated spentwash in farmers’ fields. A monitoring study was undertaken in Belgaum district of Karnataka State with an objective of studying the effect of land application of bio-methanated spent wash of a distillery on soil properties and crop growth. The treated spentwash was applied uniformly to the fallow dry lands in different farmers’ fields during summer, 2012 at recommended rate (based on nitrogen requirement of crops). The application was made at least a fortnight before sowing/planting operations. The analysis of soils collected before land application of spentwash and after harvest of crops revealed that there was no adverse effect of applied spentwash on soil characteristics. A slight build up in soluble salts was observed but, however all the soils recorded EC of less than 2.0 dSm-1. An increase in soil organic carbon (SOC) and available nitrogen (N) by about 10 to 30 % was observed in the spentwash applied soils. The presence of good amount of biodegradable organics in the treated spentwash (BOD of 6550 mg/l) contributed for increase in SOC and N. A substantial build up in available potassium (K) status (50 to 200%) was observed due to spentwash application. This was attributed to the high K content in spentwash (6950 mg/l). The growth of crops in the spentwash applied fields was higher and farmers could get nearly 10 to 20 per cent higher yields, especially in sugarcane and corn. The analysis of ground water samples showed that the quality of water was not affected due to land application of treated spentwash. Apart from realizing higher crop yields, the farmers were able to save money on N and K fertilisers as the applied spentwash met the crop requirement. Hence, it could be concluded that the bio-methanated distillery spentwash can be gainfully utilized in crop production without polluting the environment.

Keywords: bio-methanation, pollutant, potassium status, soil organic carbon

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Authors: Anna Stepien

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The paper presents the results of research on modifications of sand-lime bricks, especially using glass additives (glass fiber and glass sand) and other additives (e.g.:basalt&barite aggregate, lithium silicate and microsilica) as well. The main goal of this paper is to answer the question ‘How to use glass additives in the sand-lime mass and get a better bricks?’ The article contains information on modification of sand-lime bricks using glass fiber, glass sand, microsilica (different structure of silica). It also presents the results of the conducted compression tests, which were focused on compressive strength, water absorption, bulk density, and their microstructure. The Scanning Electron Microscope, spectrum EDS, X-ray diffractometry and DTA analysis helped to define the microstructural changes of modified products. The interpretation of the products structure revealed the existence of diversified phases i.e.the C-S-H and tobermorite. CaO-SiO2-H2O system is the object of intensive research due to its meaning in chemistry and technologies of mineral binding materials. Because the blocks are the autoclaving materials, the temperature of hydrothermal treatment of the products is around 200°C, the pressure - 1,6-1,8 MPa and the time - up to 8hours (it means: 1h heating + 6h autoclaving + 1h cooling). The microstructure of the products consists mostly of hydrated calcium silicates with a different level of structural arrangement. The X-ray diffraction indicated that the type of used sand is an important factor in the manufacturing of sand-lime elements. Quartz sand of a high hardness is also a substrate hardly reacting with other possible modifiers, which may cause deterioration of certain physical and mechanical properties. TG and DTA curves show the changes in the weight loss of the sand-lime bricks specimen against time as well as the endo- and exothermic reactions that took place. The endothermic effect with the maximum at T=573°C is related to isomorphic transformation of quartz. This effect is not accompanied by a change of the specimen weight. The next endothermic effect with the maximum at T=730-760°C is related to the decomposition of the calcium carbonates. The bulk density of the brick it is 1,73kg/dm3, the presence of xonotlite in the microstructure and significant weight loss during DTA and TG tests (around 0,6% after 70 minutes) have been noticed. Silicate elements were assessed on the basis of their compressive property. Orthogonal compositional plan type 3k (with k=2), i.e.full two-factor experiment was applied in order to carry out the experiments both, in the compression strength test and bulk density test. Some modification (e.g.products with barite and basalt aggregate) have improved the compressive strength around 41.3 MPa and water absorption due to capillary raising have been limited to 12%. The next modification was adding glass fiber to sand-lime mass, then glass sand. The results show that the compressive strength was higher than in the case of traditional bricks, while modified bricks were lighter.

Keywords: bricks, fiber, glass, microstructure

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Authors: Sairi Satari

Abstract:

Introduction: Six-sigma is a metric that quantifies the performance of processes as a rate of Defects-Per-Million Opportunities. Sigma methodology can be applied in chemical pathology laboratory for evaluating process performance with evidence for process improvement in quality assurance program. In the laboratory, these methods have been used to improve the timeliness of troubleshooting, reduce the cost and frequency of quality control and minimize pre and post-analytical errors. Aim: The aim of this study is to evaluate the sigma values of the Cobas 8000 analyzer based on the minimum requirement of the specification. Methodology: Twenty-one analytes were chosen in this study. The analytes were alanine aminotransferase (ALT), albumin, alkaline phosphatase (ALP), Amylase, aspartate transaminase (AST), total bilirubin, calcium, chloride, cholesterol, HDL-cholesterol, creatinine, creatinine kinase, glucose, lactate dehydrogenase (LDH), magnesium, potassium, protein, sodium, triglyceride, uric acid and urea. Total error was obtained from Clinical Laboratory Improvement Amendments (CLIA). The Bias was calculated from end cycle report of Royal College of Pathologists of Australasia (RCPA) cycle from July to December 2016 and coefficient variation (CV) from six-month internal quality control (IQC). The sigma was calculated based on the formula :Sigma = (Total Error - Bias) / CV. The analytical performance was evaluated based on the sigma, sigma > 6 is world class, sigma > 5 is excellent, sigma > 4 is good and sigma < 4 is satisfactory and sigma < 3 is poor performance. Results: Based on the calculation, we found that, 96% are world class (ALT, albumin, ALP, amylase, AST, total bilirubin, cholesterol, HDL-cholesterol, creatinine, creatinine kinase, glucose, LDH, magnesium, potassium, triglyceride and uric acid. 14% are excellent (calcium, protein and urea), and 10% ( chloride and sodium) require more frequent IQC performed per day. Conclusion: Based on this study, we found that IQC should be performed frequently for only Chloride and Sodium to ensure accurate and reliable analysis for patient management.

Keywords: sigma matrics, analytical performance, total error, bias

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Authors: Paulos Meles Yihdego

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To address the environmental impact of the cement industry and road building waste, the use of chemical stabilizers in conjunction with recycled asphalt and cement components was investigated. The silica-based chemical stabilizers and their potential effects on the base layer stabilized by cement are discussed in this paper. Strength, moisture compaction interaction, and microstructural characteristics are all examined. According to the outcome, using this stabilizer has improved the mechanical properties. The inclusion of chemical stabilizers in the combination, which is responsible for the mixture's improved strength, raised the intensity of the C-S-H (Calcium Silicate Hydrate) gel, according to a microstructural study. The design was demonstrated to be durable by the little ettringites found in the later phases. The application of this stabilizer ensures a strong, eco-friendly, durable base layer.

Keywords: ettringites, microstructure analysis, durability properties, cement stabilized base

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