Tertiary Phase Research Articles

Characterization of Silica Derived from Rice Husk Ash and Nickel Oxide at Different Composition and Temperatures

Nickel supported on silica (SiO2) porous bodies have been found to be active for hydrogen and carbon in gas catalyst applications. In this study, the compatibility of naturally derived SiO2 derived from rice husk ash (RHA) and nickel oxide (NiO) at variable compositions and temperatures were highlighted. The compositions of SiO2 involved in this study were 50wt% and 90wt% sintered at temperatures of 800°C, 900°C, 1000°C and 1100°C. The properties of SiO2-NiO were determined through X-ray diffraction (XRD), X-ray fluorescence (XRF) and density. XRD analysis proven SiO2 derived from RHA was found to be amorphous and that mixtures of SiO2-NiO at all composition and temperatures yielded no tertiary phase of SiO2 and NiO. Density analyses indicated that density increased with increasing sintering temperature. Thus, this proves SiO2 derived from RHA is compatible with NiO even up to 1100°C, which indicates probability of applying SiO2 in gas catalyst application.

Enhancing Corrosion Resistance and Hardness Properties of Carbon Steel through Modification of Microstructure.

Steel has played a primary role as structural and fabricating materials in various industrial applications—including the construction sector. One of the most important properties of steel that required a constant improvement is corrosion resistance specifically in corrosive environment. For this purpose, various approaches have been conducted through different heat treatment parameters to compare its microstructural engineering on chemical and mechanical properties. In this paper, correlation of different microstructure on corrosion resistance and hardness properties have been investigated. Three different heat treatment cycle have been applied on carbon steel with same composition to prepare dual-structure (DS) steel that consisted of ferrite/pearlite and triple-structure (TS) with ferrite/pearlite/bainite and ferrite/bainite/martensite. Phase transformation during heat treatment process was analyzed through in-situ ultra-high temperature confocal microscopy. Effect of corrosion behavior on these steels was investigated by Tafel plot, Scanning Electron Microscopy (SEM), 3D laser scanning confocal microscopy (3DLSCM), and calculation of phase volume fraction by ImageJ. Mechanical test was conducted by Vickers hardness test. It has been found that TS steels that have improvement in corrosion resistance accounted around 5.31% and hardness value for up to 27.34% more than DS steel, because of tertiary phase—bainite/martensite. This corrosion rate was reduced due to decreased numbers of pit growth and lower level of boundary corrosion as bainite/martensite phases emerged.

Effect of surfactants on the degree of dispersion of MWNTs in ethanol solvent

The poor dispersibility of multiwalled carbon nanotubes (MWNTs) in organic solvents is a serious obstacle towards development of novel nanomaterials devices. Therefore, the addition of tertiary phase became necessary to promote such dispersion. In the present work, five surfactants were tested to evaluate the degree of dispersion of MWCNTs in Ethanol: Sodium Dodecyl Sulfate (SDS), Triton X-100, Span-60, Pluronic F-127 and Cetyl trimethyl Ammonium Bromide (CTAB). The concentration of MWNTs was kept constant to be around 1 g/l. Dispersion degree of surfactant coated MWNTs has been characterized with UV–vis spectroscopy, Zeta Potential (ξ-potential) and Transmission Electron Microscopy (TEM). According to ξ-potential, the SDS was found to enhance the MWNTs dispersibility in ethanol solvent compared to the other surfactants. The degree of dispersion was found in ascending order as follows: CTAB < Pluronic < Triton X-100< Span-60< SDS. The mechanism of the degree dispersion of MWNTs will be explained and proposed according to the functional groups and the geometry of such surfactant. The FTIR analysis and SEM observations are in good concordance with ξ-potential results.

English medium instruction: Comparing teacher beliefs in secondary and tertiary education

Learning content through the medium of a second language is a form of education which is growing rapidly in both secondary and tertiary educational phases. Yet, although considerable research now exists on these phases of education viewed separately, virtually no comparisons have been made between the two phases. This study compared beliefs about English medium instruction (EMI) held by 167 secondary and tertiary EMI teachers from 27 countries. Teachers’ beliefs were elicited in four key areas: EMI teachers’ goals, EMI policy, benefits and drawbacks to students, and challenges to teachers. The findings indicate that secondary teachers felt more strongly that EMI provides students with a high quality education. More secondary than tertiary teachers reported an institutional policy on the English proficiency level required of teachers to teach through EMI, yet in neither phase was there evidence of adequate support to reach a required proficiency level. Teachers deemed EMI beneficial to advancing students’ English but felt that EMI would affect academic content, with no clear difference between the phases. Our conclusions indicate that EMI is being introduced without thorough institutional stakeholder discussion and therefore without clear policies on levels of teacher expertise. Neither is there evidence of a dialogue between phases regarding the challenges faced by EMI teachers and students.

Managing hypoxic ischaemic encephalopathy in term newborn infant

Abstract Hypoxic–ischaemic encephalopathy (HIE) is a brain dysfunction resulting from inadequate blood flow and oxygenation to the whole body during the perinatal period. It is a major cause of brain injury and is associated with mortality and significant disabilities in later life. Following HIE acute, secondary and tertiary phases of brain injury lasting from hours to years occurs. Therapeutic hypothermia reduces death and improves the neurodevelopment in infants with moderate to severe HIE. Passive cooling can be initiated soon after birth in infants that fulfil criteria for the treatment. Active cooling with appropriate intensive and supportive care including respiratory and cardiovascular support, maintaining normoglycaemia, sedation, and seizure management is essential for minimising the brain injury. In cooled infants likely to have a worse prognosis re-orientation of care is often considered in the infant's best interests. This short review aims to explain the underlying pathophysiological effects of HIE and its management.

Peripheral facial palsy revealing neuroborreliosis

Introduction: Neuroborreliosis (NB) is a bacterial infection with Borrelia burgdorferi (Bb), targeting the peripheral and/or central nervous system. It appears on the secondary and tertiary phase of its evolution. Observation: T.M is a 40 years-old man, previously healthy. He presented 7 days before his admission, a facial asymmetry, with swallowing disorders. These signs were evolving rapidly during a stay in a village. There was no history of migrant erythema, tick’s spot, or fever. The clinical examination found a right peripheral facial palsy (PFP), hypoesthesia on the territory of the right Vth cranial nerve and hypokinesia of the right soft palate with dulled gag reflex. The clinical syndrome was unilateral cranial polyneuritis. The cerebral MRI showed a Gado enhancement of the right facial nerve above his emergence from the protuberance. The cerebro-spinal fluid (CSF) study found lymphocytic meningitis (14 Lymphocytes/mm3) with elevated CSF protein (0, 6 g/l). Exhaustive para clinical tests were performed and went negative. The Borreliosis serology was positive to IgM and negative to IgG, with specific antiborrelia immunoglobulin intrathecal synthesis. The patient was treated by Ceftriaxone 2g / 24h during 14 days. The evolution was favorable, with partial regression of the PFP, and the control of the intrathecal immunoglobulin synthesis was negative. Discussion: Lyme borreliosis is the most frequent ixodid tick-borne human disease in the world, with an estimated 85,500 patients annually. It is a multi-systemic disease caused by Borrelia burgdorferi sensu lato. A complete presentation of the disease is an extremely unusual observation, in which a skin lesion follows a tick bite, the lesion itself is followed by heart and nervous system involvement, and later on by arthritis; late involvement of the eye, nervous system, joints and skin may also occur. We reported an early Lyme neuroborreliosis case with atypical unilateral painless cranial meningo-polyneuritis. The diagnosis was confirmed biologically with favorable clinical and biological evolution after antibiotic treatment. Conclusion: The absence of Tick, classical migrant erythema or painful meningopolyneuritis did not exclude neuroborreliosis diagnosis. In presence of LNB suggestive neurological syndrome, the detection of specific antibody in blood and CSF stay the mainstay for diagnosis of the disease.

Developmental research of sustainable technologies to minimise problematic road embankment settlements

Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined.

Development of a rheological model for creep strain evolution in steel and aluminium at high temperature

SummaryThe paper presents a rheological model capable of reproducing the temperature‐, stress‐, and time‐dependent strain component, which occurs in steel and aluminium during exposure to high temperature. The model is capable of providing the creep strain output for the primary, secondary, and tertiary creep phases for both steel and aluminium. Constitutive parameters of the rheological model are calibrated using 2 recent coupon test studies based on the European steel grade S275JR and aluminium grade EN6082AW T6, both of which are currently used in the construction industry. The calibrated constitutive parameters are valid within the temperature range, within which creep is expected to occur (400‐600°C for steel and 200‐300°C for aluminium). The rheological model proposed in the paper can easily be used for application in finite element–based computer codes.

THE TREATMENT OF WASTE OIL-IN-WATER EMULSIONS IN THE METALWORKING PROCESS

Used water emulsions obtained in the metalworking process contain oils and grease, organic compounds as well as secondary oils and anti-corrosion fluids, metal ions and other things. Since they can have a negative effect on the environment before released into the recipients, they need to be processed through the primary, secondary and tertiary phase of treatment. The primary treatment procedure of waste oil-in-water emulsions is used for the separation of free and non-emulsifying oils as well as for balancing the course of wastewater and oil concentration. In the secondary phase of treatment of waste oil-in-water emulsions, the emulsifying oil and a large fraction of dissolved oil are carried out. What follows is the tertiary biological treatment based on the basic biological processes present in nature. Key words: metalworking, waste oil-in-water emulsions, treatment

Comparative thin-layer chromatographic studies and development of a high-performance thin-layer chromatography method for the quantification of lawsone in natural and micropropagated plant parts of Lawsonia inermis L.

A simple, sensitive, and precised high-performance thin-layer chromatography (HPTLC) method has been developed for the analysis of lawsone in natural vis-a-vis micropropagated plant parts of Lawsonia inermis L. Separation of the components was perfectly achieved on high-performance thin-layer chromatography (TLC) plates using optimized tertiary mobile phase of benzene‒ethyl acetate‒ acetic acid (7.5:2.5:0.1, v/v). Densitometric scanning was performed before derivatization of the plate in absorption/reflection mode, and lawsone was quantified at its maximum absorbance of wavelength of 275 nm. Linearity of the method was obtained in the concentration range of 50 to 350 ng spot−1 with a correlation coefficient (r2) of 0.9999, indicating good relationship between concentrations in opposition to the peak area. The limit of detection and limit of quantification were found to be 16 and 50 ng spot−1, respectively. The obtained recovery ranges from 95.09% to 96.90% with an average value of 96.02% proved the excell...

Communication—Investigation of Catalyst Ink Degradation by X-ray CT

X-ray computed tomography was used to visualize the interior of a catalyst ink composed of platinum/carbon black in water/1-propanol over time. Bubble expansion and the emergence of a tertiary phase were observed. Gas chromatography-mass spectrometry determined that propionaldehyde and propionic acid were produced in the ink. Analysis of the gases within the ink container indicated that the CO2 concentration was increased. These results indicate that the oxidation reaction of 1-propanol, as catalyzed by platinum, resulted in degradation of the ink. Thus, controlling the exposure of the catalyst ink to oxygen is an important aspect of managing the quality of the ink.

Perinatal brain injury: mechanisms and therapeutic approaches.

Brain damage resulting from perinatal hypoxia-ischemia evolves slowly over time. While a small number of brain cells may die during a sufficiently profound period of hypoxia-ischemia, many will show initial recovery during a "latent" phase characterized by actively suppressed neural metabolism and activity. Critically, this transient recovery may be followed after ~6 hours by a phase of secondary deterioration, with delayed seizures, failure of mitochondrial function, cytotoxic edema, and bulk cell death over ~72 hours. This is followed by a tertiary phase of remodeling and recovery. Understanding the mechanisms of injury that occur during each phase may allow for the development of more targeted treatments. This review discusses the mechanisms of injury that occur during the primary, latent, secondary and tertiary phases of injury and potential treatments that target one or more of these phases. Treatment during the latent phase has the greatest potential to prevent injury. In the secondary phase of injury, anticonvulsants can attenuate seizures but show limited neuroprotection. By contrast, there is increasing preclinical evidence that neurorestorative therapies may improve long-term outcomes.

Rutting Evaluation of Asphalt Mixtures Using Static, Dynamic, and Repeated Creep Load Tests

Flow tests (flow number and flow time) are explicatory indices for the evaluation of the rutting potential of asphalt mixtures. This study investigates the rutting susceptibility of various asphalt mixtures subjected to static and dynamic creep tests. Four wearing course gradations were selected; and asphalt mixture’s specimens were fabricated using Superpave gyratory compactor. The flow tests were performed at a single effective temperature of 54.4 $${^{\circ }}\hbox {C}$$ and a stress level of 300 kPa using asphalt mixture performance tester. Dynamic modulus ( $${\vert }{E}^{*}{\vert }$$ ) test was conducted at different temperatures and frequency levels. The test results indicate that specimens of mixtures experienced tertiary flow state in the flow number (FN) test, but no specimen achieved tertiary flow state in the flow time (FT) test. Data smoothening technique was employed for removing the resonance from the raw test data. The performance of mixtures was compared using: (a) FN values; (b) number of cycles at which the 50,000 microstrains occurred; and (c) intercept obtained from regression analysis of total permanent strain. The observed accumulated axial strains at time of termination were used for comparison purpose of mixtures as tertiary phase was not achieved in FT tests. Three statistical models were developed of the different functional formulation—i.e. Cobb–Douglas, power and first-order multiple linear regression—using $${\vert }{E}^{*}{\vert }$$ , FN, and mix volumetric data. The laboratory results were used to rank the mixtures based on their resistance to rutting. The findings of the study are envisaged to facilitate the implementation of performance-based mechanistic-empirical pavement design approach.

Analysis of the thermodynamic behavior of A355 and B319 alloys using the differentiation method

This work analyzes the thermodynamic behavior of two candidate aluminum alloys (A355 and B319) for SSM processing. Both alloys undergo a semisolid tertiary phase transformation below the main eutectic solidification temperature. The use of the differentiation method (DM) to identify critical points associated with the thixoformability of these alloys is evaluated. The method is compared with the conventional tangent method (TM) for determining the solidus and liquidus temperatures and with the visual recognition method for identifying the unstable “knee” of the liquid fraction-versus-temperature curve. For both alloys, numerical simulation is performed with Thermo-Calc® (Scheil condition), and experimental DSC data is generated for cooling (rheocasting) and heating (thixoforming) cycles under different kinetic conditions (5, 10, 15, 20 and 25°C/min) to compare the DM and the conventional approaches. The findings indicate that the DM is an efficient tool for identifying critical points such as the solidus, liquidus, knee and beginning and end of the SSM-processing working window for A355 and B319 alloys and that it not only yields results that agree well with those obtained using traditional techniques, but also, unlike the latter, provides accurate results even in the presence of tertiary phase transformations when the kinetic effects are strong. A correction to the Flynn method of integration of partial areas using two complementary baselines is introduced for rheocasting and thixoforming operations.

USE OF ARTIFICIAL AQUATIC FOOD-WEB FOR POST-TREATMENT OF DOMESTIC WASTEWATER IN COLD CLIMATE: A REVIEW

Eutrophication-promoting phosphorous loads originating from wastewater treatment plants are commonly controlled by chemical precipitation in the tertiary treatment phase. However, this approach is costly and generates additional waste. Therefore, inexpensive and sustainable methods for wastewater post-treatment are wanted. The artificial aquatic food-web that performs wastewater phycoremediation by algae and subsequent biomass harvest by filter-feeding organisms not only requires low energy consumption but also produces biomass for treatment process cost recovery. Still, the knowledge on its performance at different scales and under different climates are limited. In this review, the application possibilities of the artificial aquatic food-web for domestic wastewater post-treatment is discussed, focusing on its use in cold climate regions. Considering the reduced biological activity of aquatic organisms at low ambient temperature, possible solutions for its performance and prospect application at low temperatures are suggested. Finally, directions for future research regarding the practical use of artificial aquatic food-web are highlighted.

Centralisation for resection of the pancreatic head: A comparison of operative factors and early outcomes during the evolving unit and tertiary unit phases at a UK institution

AimsTo assess impact of centralisation on patients undergoing pancreatic head resections at a tertiary hepatobiliary (HPB) centre in the UK. MethodsData were analysed from a prospectively maintained database from 1998 to 2014 on all patients undergoing pancreatic head resections. Two specific time periods were defined; these were the evolving unit phase (EU) from 1998 to 2009 and finally the established tertiary unit phase (TU) from 2010 to 2014. Peri-operative factors and post-operative outcomes were analysed. Results395 resections were undertaken during the study period. Following establishment of our tertiary HPB unit, the volume of resections undertaken increased greater than three-fold with an associated increase in case-complexity (p = 0.004). Operating time was found to increase in the TU phase compared with EU phase (p=>0.0005) whilst there was no significant difference in the rate of peri-operative transfusion, or in post-operative morbidity rates. There was a significant reduction in the post-operative length of stay in the TU phase (p = 0.003) with a significantly higher proportion of patients being discharged within 9 days of their procedure (p=<0.0005). There was also a significant reduction in 30-day post-operative mortality in the TU phase (0.5%) compared with the EU phase (3%) (p = 0.029). ConclusionsData from our series of 395 cases suggests that centralisation of pancreatic cancer services to a tertiary centre does result in improved patient outcomes. The benefits of a multi-disciplinary and specialist HPB service results in a high volume, high quality unit with improved patient outcomes.

Optimization of Smart Water Chemical Composition for Carbonate Rocks Through Comparison of Active Cations Performance

Designing smart water (SW) by optimizing the chemical composition of injected brine is a promising low-cost technique that has been developed for both sandstone and carbonate reservoirs for several decades. In this study, the impact of SW flooding during tertiary oil recovery phase was investigated by core flooding analysis of pure limestone carbonate rocks. Increasing the sulfate ion concentration by using CaSO4 and MgSO4 of NaCl concentration and finally reducing the total salinity were the main manipulations performed to optimize SW. The main objective of this research is to compare active cations including Ca2+ and Mg2+ in the presence of sulfate ions (SO42−) with regard to their efficiency in the enhancement of oil production during SW flooding of carbonate cores. The results revealed a 14.5% increase in the recovery factor by CaSO4 proving its greater effectiveness compared to MgSO4, which led to an 11.5% production enhancement. It was also realized that low-salinity water flooding (LSWF) did not lead to a significant positive effect as it contributed less than 2% in the tertiary stage.

Durability of (La0.8Sr0.2)0.95MnO3-δ-(Er0.2Bi0.8)2O3 composite cathodes for low temperature SOFCs

(La0.8Sr0.2)0.95MnO3-δ (LSM) and (Er0.2Bi0.8)2O3 (ESB) composite has shown promise as a potential candidate for low temperature solid oxide fuel cell (LT-SOFC) cathodes. Here the stability of LSM-ESB composite cathode was tested under a range of temperature between 500 °C and 650 °C in symmetrical cell configuration, and the changes in cathode area specific resistance (ASR) was monitored in situ using electrochemical impedance spectroscopy (EIS). Two different mechanisms govern the LSM-ESB performance degradation in different temperature regions. At 600 °C and below the decrease in ESB conductivity due to the order-disorder transition of ESB significantly impacts the ohmic resistance of the cells. Moreover, the surface catalytic activity of LSM-ESB is directly affected by the order-disorder transition, possibly due to changes in the oxygen incorporation rate of ESB. At 650 °C, above the order-disorder transition, LSM and ESB react to form tertiary phases in as little as 180 h. Our results suggest that bismuth transports through vapor phase and deposits across the porous electrode surface. These results reveal the possible degradation mechanisms for bismuth-oxide based composite cathodes. These findings are important for the future development of SOFCs and the selection of potential cathode candidates that incorporate bismuth oxide.

Improvement of UNS S32205 Duplex Welds by GMAW and Controlled Magnetic Field for Offshore Pipelines and Flowlines Applications

Mechanical properties and corrosion resistance of UNS S32205 duplex stainless steel (DSS) welds obtained under the application of controlled magnetic fields were evaluated in the context of offshore pipelines and flowlines applications. Tensile tests, impact toughness, and hardness measurements were performed. Corrosion behavior was evaluated by linear polarization resistance (LPR) and potentiodynamic polarization curves (PCs) using a synthetic seawater solution at different temperatures. An improvement in tensile strength, impact toughness, and corrosion resistance was observed with the application of magnetic fields during welding. This effect is attributed to the refinement in the microstructure of the weld metal along with the suppression of detrimental intermetallic tertiary phases. Applying an axial magnetic field of 3 mT during DSS welding by the gas metal arc welding (GMAW) process is a potential technique for improving the performance of offshore pipeline welds and may be implemented in both, double-sided single pass and single-sided multipass butt joints.

Assessment of Landslide Pre-Failure Monitoring and Forecasting Using Satellite SAR Interferometry

In this work, the ability of advanced satellite interferometry to monitor pre-failure landslide behaviours and the potential application of this technique to Failure Forecasting Methods (FFMs) are analysed. Several limits affect the ability of the technique to monitor a landslide process, especially during the pre-failure phase (tertiary creep). In this study, two of the major limitations affecting the technique have been explored: (1) the low data sampling frequency and (2) the phase ambiguity constraints. We explored the time series of displacements for 56 monitored landslides inferred from the scientific literature and from different in situ and remote monitoring instruments (i.e., extensometers, inclinometers, distometers, Ground Base InSAR, and total station). Furthermore, four different forecasting techniques have been applied to the monitoring data of the selected landslides. To analyse the reliability of the FFMs based on the InSAR satellite data, the 56 time series have been sampled based on different satellite features, simulating the satellite revisit time and the phase ambiguity constraints. Our analysis shows that the satellite InSAR technique could be successful in monitoring the landslide’s tertiary creep phase and, in some cases, for forecasting the corresponding time of failure using FFMs. However, the low data sampling frequency of the present satellite systems do not capture the necessary detail for the application of FFMs in actual risk management problems or for early warning purposes.