Different methods of cutting fluid application on turning of a difficult-to-machine steel

Different methods of cutting fluid application are used on turning of a difficult-tomachine steel (SAE EV-8). A semi-synthetic cutting fluid was applied using a conventional method, minimum quantity of cutting fluid (MQCF), and pulverization. By the minimum quantity method was also applied a lubricant of vegetable oil (MQL). Thereafter, a cutting fluid jet under high pressure (3.0 MPa) was singly applied in the following regions: chip-tool interface; top surface of the chip; and tool-workpiece contact. Two other methods were used: an interflow between conventional application and chip-tool interface jet and, finally, three jets simultaneously applied. In order to carry out these tests, it was necessary to set up a high pressure system using a piston pump for generating a cutting fluid jet, a Venturi for fluid application (MQCF and MQL), and a nozzle for cutting fluid pulverization. The output variables analyzed included tool life, surface roughness, cutting tool temperature, cutting force, chip form, chip compression rate and machined specimen microstructure. It can be observed that the tool life increases and the cutting force decreases with the application of cutting fluid jet, mainly when it is directed to the chip-tool interface. Excluding the methods involving jet fluid, the conventional method seems to be more efficient than other methods of low pressure. © (2013) Trans Tech Publications, Switzerland.

Existence of solutions for the 3D-micropolar fluid system with initial data in Besov-Morrey spaces

In this paper, we show a local-in-time existence result for the 3D micropolar fluid system in the framework of Besov-Morrey spaces. The initial data class is larger than the previous ones and contains strongly singular functions and measures. © 2013 Springer Basel.

Analysis of the bioactive surface of Ti-35Nb-7Zr alloy after alkaline treatment and solution body fluid

The purpose of this work was to evaluate the Ti-35Nb-7Zr experimental alloy after surface treatment and soaking in solution body fluid (SBF) to form bonelike apatite. The Ti-35Nb-7Zr alloy was produced from commercially pure materials (Ti, Nb and Zr) by an arc melting furnace. All ingots were submitted to sequences of heat treatment (1100 °C/2 h and water quenching), cold working by swaging procedures and heat treatment (1100 °C/2 h and water quenching). Discs with 13 mm diameter and 3 mm in thickness were cut. The samples were immersed in NaOH aqueous solution with 5 M at 60 °C for 72 h, washed with distilled water and dried at 40 °C for 24 h. After the alkaline treatment, samples were heat treated in both conditions: at 450 and 600 °C for 1 h in an electrical furnace in air. Then, they were soaking in SBF for 24 h to form an apatite layer on the surface. The surfaces were investigated by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), infrared spectroscopy (FTIR) and contact angle measurements. The results indicate that calcium phosphate could form on surface of Ti-35Nb-7Zr experimental alloy. © Springer-Verlag Berlin Heidelberg 2013.

Physiological Concentrations of Acute-Phase Proteins and Immunoglobulins in Equine Synovial Fluid

Synovial fluid (SF) is capable of reflecting infectious, immunological, or inflammatory joint conditions in horses by altering its composition and appearance. Although plasma and SF compositions are quantitatively different, this latter compartment reflects changes in plasma macromolecules. Therefore, changes in serum immunoglobulin protein concentrations tend also to alter intracapsular levels. Therefore, it is necessary to know the physiological concentrations of proteins present in SF. The aim of this study was to determine the levels of total protein, albumin, transferrin, haptoglobin, α1-acid glycoprotein, ceruloplasmin, and immunoglobulins A and G in SF of six healthy horses. The synovial proteinogram was obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The SF proteins reached a maximum of 25% of serum concentrations, varying inversely with molecular weight of the protein, except for the ceruloplasmin. © 2013 Elsevier Inc.

Alkali activated materials based on fluid catalytic cracking catalyst residue (FCC): Influence of SiO2/Na2O and H 2O/FCC ratio on mechanical strength and microstructure

Reuse of industrial and agricultural wastes as supplementary cementitious materials (SCMs) in concrete and mortar productions contribute to sustainable development. In this context, fluid catalytic cracking catalyst residue (spent FCC), a byproduct from the petroleum industry and petrol refineries, have been studied as SCM in blended Portland cement in the last years. Nevertheless, another environmental friendly alternative has been conducted in order to produce alternative binders with low CO2 emissions. The use of aluminosilicate materials in the production of alkali-activated materials (AAMs) is an ongoing research topic which can present low CO2 emissions associated. Hence, this paper studies some variables that can influence the production of AAM based on spent FCC. Specifically, the influence of SiO 2/Na2O molar ratio and the H2O/spent FCC mass ratio on the mechanical strength and microstructure are assessed. Some instrumental techniques, such as SEM, XRD, pH and electrical conductivity measurements, and MIP are performed in order to assess the microstructure of formed alkali-activated binder. Alkali activated mortars with compressive strength up to 80 MPa can be formed after curing for 3 days at 65°C. The research demonstrates the potential of spent FCC to produce alkali-activated cements and the importance of SiO2/Na2O molar ratio and the H2O/spent FCC mass ratio in optimising properties and microstructure. © 2013 Elsevier Ltd. All rights reserved.

Fuzzy control embedded in microcontroller and applied to an experimental apparatus using magnetorheological fluid damper

This work focuses on applying fuzzy control embedded in microcontrollers in an experimental apparatus using magnetorheological fluid damper. The non-linear behavior of the magnetorheological dampers associated with the parametric variations on vehicle suspension models corroborate the use of the fuzzy controllers. The fundamental formulation of this controller is discussed and its performance is shown through numeric simulations. An experimental apparatus representing a two degree of freedom system containing a magnetorheological damper is used to identify the main parameters and to evaluate the performance of the closed-loop system with the embedded low-cost microcontroller-based fuzzy controller. © 2013 Brazilian Society for Automatics - SBA.

Three-dimensional transient complex free surface flows: Numerical simulation of XPP fluid

In this paper we present a finite difference MAC-type approach for solving three-dimensional viscoelastic incompressible free surface flows governed by the eXtended Pom-Pom (XPP) model, considering a wide range of parameters. The numerical formulation presented in this work is an extension to three-dimensions of our implicit technique [Journal of Non-Newtonian Fluid Mechanics 166 (2011) 165-179] for solving two-dimensional viscoelastic free surface flows. To enhance the stability of the numerical method, we employ a combination of the projection method with an implicit technique for treating the pressure on the free surfaces. The differential constitutive equation of the fluid is solved using a second-order Runge-Kutta scheme. The numerical technique is validated by performing a mesh refinement study on a pipe flow, and the numerical results presented include the simulation of two complex viscoelastic free surface flows: extrudate-swell problem and jet buckling phenomenon. © 2013 Elsevier B.V.

Energetic, ecologic and fluid-dynamic analysis of a fluidized bed gasifier operating with sugar cane bagasse

This work aims to study the thermodynamic, ecological and fluid-dynamic aspects of a circulating fluidized bed gasifier using sugar cane bagasse as biomass, in order to estimate a model of its normal operation. In the initial stage was analysed the composition of biomass selected (sugar cane bagasse) and its lower heating value (LHV) was calculated. The energy balance of the gasifier was done, being the volumetric flow of air, synthesis gas and biomass estimated. Also the power produced by this gasifier was theoretically estimated. Then the circulating fluidized bed gasifier was designed for operation with approximately 100 kg/h of processed biomass. Cross-sectional area of the reactor, feeder size, diameter of the exit zone of the gases and minimum height of the expanded bed were selected. Some bed gasifier hydrodynamic factors were also studied. The minimum fluidization velocity, fluidization terminal velocity, and average fluidizing velocity were calculated, in order to understand the fluid-dynamic behaviour of gasification of this fuel. It was obtained a theoretical model that can support a possible prototype of circulating fluidized bed gasifier biomass. Finally, there were studied the ecological aspects of the gasifier, through an overall methodology. Ecological efficiencies were estimated for two scenarios: first considering the carbon cycle and thereafter disregarding the carbon cycle. In both cases, it can be proved the ecological viability of the project. © 2013 Elsevier Ltd. All rights reserved.

Biochemical Profile of Amniotic and Allantoic Fluid During Different Gestational Phases in Mares

Fetal fluids have different vital functions that sustain both pregnancy and normal parturition. The biochemical composition of amniotic fluid during gestation is not well established; thus the purpose of the present study was to determine the biochemical profile of both amniotic and allantoic fluids from mares during initial, mid, and latter third phases of pregnancy. Samples were collected after slaughter, using allantocentesis and amniocentesis. Sixty samples of fetal fluids were analyzed. Alkaline phosphatase (AP), glucose, total protein (TP), urea, creatinine, Ca, chloride (Cl), Na, and K concentrations were measured using commercially available kits. The AP concentration in amniotic fluid was higher than that in allantoic fluid during the three gestational phases (P < .05). There were no differences between glucose mean values of allantoic and those of amniotic fluids (P < .05). However, glucose values were higher in the allantoic fluid in the last trimester of pregnancy. TP was higher in the amniotic fluid than in allantoic fluid (P < .05). Urea values varied among the phases; however, there were no differences between the amniotic and allantoic fluid values (P > .05). Creatinine values were higher in allantoic fluid (P < .05). Na and Cl concentrations were higher in amniotic fluid (P < .05). However, Ca and K concentrations were higher in the allantoic fluid. © 2013 Elsevier Inc. All rights reserved.

Opalas gemológicas do Piauí: gênese revelada por microtermometria e minerais associados

As opalas de Pedro II e Buriti dos Montes, no estado do Piauí, constituem as mais importantes ocorrências brasileiras dessa gema, tanto em termos de volume quanto pela qualidade gemológica, que é comparável à das famosas opalas australianas. No entanto, a informalidade na extração e comercialização destas opalas, assim como a falta de informações quanto à gênese destes depósitos não permitem a prospecção por novas jazidas e o estabelecimento de um certificado de procedência para as opalas do Piauí que permitisse sua inserção formal no mercado gemológico internacional. Alguns autores têm se dedicado ao estudo dessas opalas, revelando fortes evidências de sua origem hidrotermal, mas até então, nenhum trabalho abordou as características físico-químicas dos fluidos que teriam originado esses depósitos de opalas. Diante disso, o principal objetivo deste trabalho foi entender o sistema hidrotermal responsável pela gênese das opalas do Piauí, ou seja, caracterizar os fluidos que originaram a mineralização e mostrar sua relação com o contexto geológico da região. Os municípios de Pedro II e Buriti dos Montes se localizam na porção nordeste do estado do Piauí, a aproximadamente 230 km a leste da capital Teresina, e as ocorrências de opala se encontram na porção basal da Bacia do Parnaíba, constituindo veios e vênulas nos arenitos dos grupos Serra Grande (Buriti dos Montes) e Canindé (Pedro II), os quais são seccionados por soleiras e diques de diabásio da Formação Sardinha. Elas também ocorrem cimentando brechas e como depósitos coluvionares e de paleocanal. Associados às opalas, localmente encontram-se veios de quartzo, calcedônia, barita e hematita (ou goethita). De maneira geral, as opalas de Pedro II apresentam jogo de cores, são predominantemente brancas ou azuladas com aspecto leitoso, semitranslúcidas a opacas e com inclusões sólidas pouco aparentes. Em contrapartida, as opalas de Buriti dos Montes não apresentam jogo de cores, a cor varia entre amarelo claro e vermelho amarronzado, são semitransparentes a translúcidas e contêm grande variedade de inclusões sólidas. Os dados obtidos revelam que as opalas de Pedro II são tipicamente do tipo amorfo (opala-A), enquanto as opalas de Buriti dos Montes variam entre amorfas e cristobalita-tridimita (opala-CT). Na opala preciosa, o típico jogo de cores é causado pelo arranjo regular das esferas de sílica que as constituem. A ausência de cimento opalino entre as esferas reforça a beleza desse efeito. Em contrapartida, as opalas laranja não apresentam jogo de cores, mas têm maior transparência devido ao diminuto tamanho das esferas. As inclusões sólidas também produzem belos efeitos nas opalas estudadas, principalmente na variedade laranja, que é mais transparente. Além disso, o conjunto de inclusões sólidas revela características intrínsecas aos processos hidrotermais que originaram as opalas estudadas. Agregados botrioidais, dendríticos e nodulares são exemplos de inclusões formadas por fragmentos dos arenitos hospedeiros carreados pelos fluidos hidrotermais que geraram as opalas. As inclusões sólidas também têm relação direta com a cor das opalas. Nas opalas de Buriti dos Montes, os tons de vermelho, laranja e amarelo são produzidos pela dissolução parcial das inclusões constituídas por oxihidróxidos de Fe. De maneira semelhante, a cor verde nas opalas preciosas está relacionada aos microcristais de Co-pentlandita inclusos nas mesmas. O conjunto de minerais associados às opalas conduz a uma assinatura mineralógicogeoquímica marcada pelos elevados teores de Fe e Al nas opalas com inclusões de hematita/goethita e caulinita, e assim também com aumento considerável dos teores de elementos terras raras nas opalas em que se concentram as inclusões de caulinita e apatita. Entre os elementos-traço, Ba é o mais abundante, e provavelmente foi incorporado pelo fluido hidrotermal, tendo em vista que veios de barita são encontrados com frequência nessa região da Bacia do Parnaíba. Várias feições como estruturas de fluxo nas opalas, corrosão e dissolução parcial dos cristais de quartzo hialino e de inclusões mineralógicas, vênulas de quartzo hidrotermal sobrecrescidas aos grãos detríticos, e zoneamento dos cristais de quartzo confirmam que essas opalas têm origem hidrotermal. A ruptura do Gondwana teria provocado um vasto magmatismo básico fissural, que por sua vez foi responsável pelo aporte de calor que gerou as primeiras células convectivas de fluidos quentes. A água contida nos arenitos certamente alimentou o sistema e se enriqueceu em sílica através da dissolução parcial ou total dos próprios grãos de quartzo dos arenitos. Este fluido hidrotermal foi posteriormente aprisionado em sistemas de fraturas e nelas se resfriou, precipitando a opala e minerais associados.

Role of α2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

Dynamics of the interaction between body fluid and Ti cp: the influence of surface functionalization in the first stages of osseointegration

INTRODUCTION: Regenerative therapies using biomaterials require accurate information on interactions between the implanted material and the human body. To improve the process of bone regeneration it is necessary to obtain a better understanding of the influence of the surfaces on the early stages of osseointegration. This work aims to investigate the dynamic interaction between simulated body fluid (SBF) and titanium surfaces (Ti cp) immediately after their first contact. METHODS: Ti cp samples were passed through physicochemical treatments after immersion in acid solution, alkaline solution and solutions containing TiO2 and Ca2+, to obtain three different surfaces. These were characterized by electron microscopy and free energy estimates. The evaluation of the interaction with SBF was performed by measuring the dynamic contact angles after contacting the surfaces. RESULTS: The effects of SBF wettability were more significant on surfaces according to high energy estimates. A comparative analysis of the three types of surfaces showed that fluid spreading was greater in samples with greater polar components, indicating that the surface nature influences interactions in the early stages of osseointegration. CONCLUSION: The results indicate the influence of polar interactions in the dynamic wettability of the SBF. It is possible that these interactions can also influence cellular viability on surfaces. Based on these results, new experiments are being designed to improve the presented methodology as a tool for the evaluation of biomaterials without the need for in vivo experiments.

Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO2), as a function of plant provenance and plant parts

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. ¹H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO2 were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated.

Glucose, Cholesterol, Total Protein and Growth Factor Insulin-like Type I in Follicular Fluid of River Buffaloes (Bubalus bubalis)

In order to establish the concentrations of glucose, cholesterol, total protein and growth factor insulin-like type I (IGF-I) in the follicular fluid, 26 Murrah breed river buffaloes, between 45 and 70 days postpartum, empty, multiparous, with average live weight of 675 +/- 56 kg and average body condition of 3.5 points on a scale of 1-5, were used in this study. The fluid was collected from dominant follicles with diameters between 8 and 12 mm by OPU, and was not taken into account the stage of the estrous cycle. Using this technique, the wave of follicular development was synchronized six days prior to collection. Biochemical analysis was performed to glucose and cholesterol through the enzymatic colorimetric method using commercial kit glicose CHOLESTEROL GOD-PAP and CHOD-PAP (Kovalent), respectively. Determination of total protein was carried out by using total protein commercial kit (Kovalent) Biuret method, and the readings were performed using absorption spectrophotometry with visible light. Concentration of IGF-I was measured by Radioimmunoassay (RIA) technique using commercial IRMA Kit IGF-I (INMUNOTECH). Descriptive statistics were developed using the PROC MEANS procedure of SAS (2009). Concentration of glucose (4.0 +/- 0.75 mmol / L-1) and IGF-I (340 +/- 129.83 ng / mL (-1)) were higher than those reported by other authors in river buffaloes and cows, respectively. However, cholesterol levels (0.51 +/- 0.12 mmol / L (-1)) and total protein (58.4 +/- 4.43 g / L (-1)) behaved inferior to other studies in same species. The results indicated that there is relationship among the nutritional aspects, diameter of follicles aspirated and productive period in the concentration of biochemical indicators.

Extended Daily Dialysis in Acute Kidney Injury Patients: Metabolic and Fluid Control and Risk Factors for Death

Intermittent hemodialysis (IHD) and continuous renal replacement therapies (CRRT) are used as Acute Kidney Injury (AKI) therapy and have certain advantages and disadvantages. Extended daily dialysis (EDD) has emerged as an alternative to CRRT in the management of hemodynamically unstable AKI patients, mainly in developed countries.Objectives: We hypothesized that EDD is a safe option for AKI treatment and aimed to describe metabolic and fluid control of AKI patients undergoing EDD and identify complications and risk factors associated with death.Study Selection: This is an observational and retrospective study describing introduction of EDD at our institution. A total of 231 hemodynamically unstable AKI patients (noradrenalin dose between 0.3 and 1.0 ucg/kg/min) were assigned to 1367 EDD session. EDD consisted of 6-8 h of HD 6 days a week, with blood flow of 200 ml/min, dialysate flows of 300 ml/min.Data Synthesis: Mean age was 60.6 +/- 15.8 years, 97.4% of patients were in the intensive care unit, and sepsis was the main etiology of AKI (76.2). BUN and creatinine levels stabilized after four sessions at around 38 and 2.4 mg/dl, respectively. Fluid balance decreased progressively and stabilized around zero after five sessions. Weekly delivered Kt/V was 5.94 +/- 0.7. Hypotension and filter clotting occurred in 47.5 and 12.4% of treatment session, respectively. Regarding AKI outcome, 22.5% of patients presented renal function recovery, 5.6% of patients remained on dialysis after 30 days, and 71.9% of patients died. Age and focus abdominal sepsis were identified as risk factors for death. Urine output and negative fluid balance were identified as protective factors.Conclusions: EDD is effective for AKI patients, allowing adequate metabolic and fluid control. Age, focus abdominal sepsis, and lower urine output as well as positive fluid balance after two EDD sessions were associated significantly with death.