CEC Process Research Articles

Clinical ethics consultations: a scoping review of reported outcomes

BackgroundClinical ethics consultations (CEC) can be complex interventions, involving multiple methods, stakeholders, and competing ethical values. Despite longstanding calls for rigorous evaluation in the field, progress has been limited. The Medical Research Council (MRC) proposed guidelines for evaluating the effectiveness of complex interventions. The evaluation of CEC may benefit from application of the MRC framework to advance the transparency and methodological rigor of this field. A first step is to understand the outcomes measured in evaluations of CEC in healthcare settings.ObjectiveThe primary objective of this review was to identify and map the outcomes reported in primary studies of CEC. The secondary objective was to provide a comprehensive overview of CEC structures, processes, and roles to enhance understanding and to inform standardization.MethodsWe searched electronic databases to identify primary studies of CEC involving patients, substitute decision-makers and/or family members, clinicians, healthcare staff and leaders. Outcomes were mapped across five conceptual domains as identified a priori based on our clinical ethics experience and preliminary literature searches and revised based on our emerging interpretation of the data. These domains included personal factors, process factors, clinical factors, quality, and resource factors.ResultsForty-eight studies were included in the review. Studies were highly heterogeneous and varied considerably regarding format and process of ethical intervention, credentials of interventionist, population of study, outcomes reported, and measures employed. In addition, few studies used validated measurement tools. The top three outcome domains that studies reported on were quality (n = 31), process factors (n = 23), and clinical factors (n = 19). The majority of studies examined multiple outcome domains. All five outcome domains were multidimensional and included a variety of subthemes.ConclusionsThis scoping review represents the initial phase of mapping the outcomes reported in primary studies of CEC and identifying gaps in the evidence. The confirmed lack of standardization represents a hindrance to the provision of high quality intervention and CEC scientific progress. Insights gained can inform the development of a core outcome set to standardize outcome measures in CEC evaluation research and enable scientifically rigorous efficacy trials of CEC.

Damping characterization and its underlying mechanisms in CNTs/AZ91D composite processed by cyclic extrusion and compression

The proper combination of strength and damping performance has been a major challenge for the wide use of Mg alloys/composites in many fields. In this regard, this research focused on the effect of the CEC process and the CNTs addition on the damping behavior of AZ91D alloy. The damping capacity of CEC-processed CNTs/AZ91D composite is significantly improved compared with the initial solid-solution state. Also, although 0.5 wt% addition of CNTs to AZ91D decreases the room-temperature damping of the base alloy, its performance can be improved by the addition of 2.0 wt% CNTs. Besides, the addition of CNTs, regardless of its amount regularly increases the high-temperature damping behavior compared to the base alloy. For the solid-solution alloy/composite, when the test temperature is lower than the critical temperature, the damping is mainly advanced by the movement of dislocations between a large number of weak pinning points and a low amount of strong pinning points. Contrarily, the damping mechanism of the same material at higher than critical temperatures is mainly progressed by grain boundary sliding.

Primary schools’ development in Somaliland – The role of Community Education Committees

The study sought to determine the methods used to participate the community in school infrastructure projects. It also examined the extent and effectiveness of the community education committee participation process. Done as a cross-sectional survey using mixed methods of inquiry, the study targeted 1002 respondents consisting of 920 headteachers and 82 officers in charge of District Education (DEOs) in Somaliland. The sample comprised 257 headteachers and 22 DEOs. Multi stage sampling was used. Purposive sampling was used to draw a sample of regions, stratified random sampling to draw a sample of headteachers while simple random sampling was used to draw a sample of DEOs. Pilot testing of the questionnaire was done on 28 headteachers. DEOs were interviewed while Headteachers filled questionnaires. Reliability of the questionnaire was ensured using Cronbach alpha. Empirical literature review, peer review and pilot testing were used to ensure validity. The response was received from 20 DEOs and 247 headteachers. Thematic analysis was used to analyse interview data collected from DEOs. Headteachers data collected by questionnaire were analysed using descriptive statistics. Participating the community in decision-making, offering free labour and and fundraising were the leading methods of participating communities in school infrastructure projects. Communities perceived full ownership of completed school infrastructure projects. Community members were satisfied with the schools‘ participation process. Most schools had realized their community participation goals. The CEC process was just one of the numerous ways the community participated in school infrastructure projects. The CEC participation method was largely working and realising its goals. More school development could be realised if the CEC participation process was further strengthened.

Environmental-friendly montmorillonite-biochar composites: Facile production and tunable adsorption-release of ammonium and phosphate

The cleaner production of environmentally friendly materials for the controlled adsorption and desorption of ammonium and phosphate in wastewater treatment and soil fertility maintenance is a challenge. Here we show that a class of clay mineral-biochar composites which were produced via a facile cleaner pyrolysis process starting from two abundant natural materials (montmorillonite and bamboo powder). The montmorillonite-biochar composites (MBC) were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, N2 adsorption/desorption isotherms, thermogravimetric analysis, and scanning electron microscopy. The adsorption and slow-release characteristics of MBC samples for NH4+ and PO43− in aqueous solution were evaluated. Montmorillonite (Mt) acted as a solid acidic catalyst and catalyzed the pyrolysis of bamboo powder to biochar and lower the pyrolysis temperatures. Both biochar and Mt contributed to the texture and structure, which provided varied surface and various adsorptive sites. The Langmuir maximum adsorption capacity of MBC samples for NH4+ and PO43− was 12.52 mg·g−1 and 105.28 mg·g−1. The adsorption of NH4+ onto the MBC sample was primarily controlled by surface adsorption and partially by a CEC process. The adsorption capacity of PO43− resulted from the electrostatic attraction or ionic bonding between PO43− and cations in the MBC samples such as Ca2+, Mg2+, Al3+ and Fe3+. The release of NH4+ and PO43− from the NH4+- and PO43−-laden MBC samples was merely 0.30–4.92% and 2.63–5.09% within 2–88 h. These findings implied that the MBC samples prepared from low-cost Mt and bamboo can remove NH4+ and PO43− from aqueous solution by adsorption and the resultant NH4+- and PO43−-laden MBC samples can be used as an effective slow-release fertilizer of N and P.

A study on continuous and batch electrocoagulation process for fluoride removal

AbstractContinuous and batch electrocoagulation processes (CEC and BEC) for treating fluoride-containing solution were investigated and compared. The poor mixture and uneven distribution of flocs during BEC lead to a lower removal efficiency, when compared with CEC. Under whole range of current densities, the superiority of CEC is obvious. However, at high residence time, CEC process, which has intense back mixing has a lower removal efficiency when compared with BEC. Also it was found that even at same charge loading, the CEC differ a lot with BEC. The influences of charge loading and initial pH on CEC process were investigated with the consideration of utilization rate of electro-generated Al element. The molar ratio of F/Al in sludge presents a trend of gradual decline with the increment of charge loading. The molar ratio of (OH + F) to Al element in sludge conforms the fact that the F− is removed not only by Al(OH)3-xFx(s) precipitation but also by the absorption of aluminum flocs. The influent at the...

New possibilities for intense plastic deformation of aluminium alloys on a special CEC press

The new machine for deformation of metals and alloys by Cyclic Extrusion Compression method has been presented. The special, 600 kN capacity press was designed and build to deform materials by the CEC way. The press is equipped by microprocessor control system for hydraulic steering and measurement of the forces exerted by tools. The microstructure of AlMgSi (6082) samples deformed by new CEC press showed the nanometric features such as dimension of grains below 100 nm and large disorientation between nanograins. The nanostructure was found after the 24 cycles of the CEC (ϕ = 16). The simulation of plastic flow in CEC process was performed by a DEFORM software. The process has been modelled in relation to the technically pure aluminium and 6082 aluminium alloys deformed with the reduction of sample diameter from 10 to 8.5 mm and next increase from 8.5 to 10 mm in a single CEC cycle. It was found that at suitably selected values of counterforce the tensile circumferential stresses occurred behind the matrix where radial extrusion took place. Increasing the level of hydrostatic pressure it was possible to prevent an increase of the dangerous tensile stresses. Based on the data from numerical simulation of the CEC processes a special diagram has been prepared, which facilitates suitable choice of the counterforce level.

Microstructure Evolution and Mechanical Properties of an AZ61 Mg Alloy through Cyclic Extrusion Compression

Microstructure evolution and mechanical properties of an AZ61 Mg alloy processed by cyclic extrusion compression were investigated. It is shown that CEC process may be applied successfully to AZ61 Mg alloys, and this leads to excellent grain refinement with grain size of ~0.8μm after 15 passes at 573K and to significant improvements in yield strength, ductility and hardness of AZ61 materials with slight compressive strength decreases. Dislocations were induced at initial stage of CEC process, and with increased deformation, tangled dislocations developed to form dislocation boundaries and subgrain boundaries, and then evolved into low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) which was regarded as continuous dynamic recovery and recrystallization (CDRR).

A contribution to the study of the electroreduction of 2-chloro-4,6-di(ethylamino)-1,3,5-triazine (simazine) on mercury electrodes

Abstract This paper presents polarographic (dc and DP) and voltammetric studies of the electroreduction of the s-triazine derivative simazine (2-chloro-4,6-di(ethylamino)-1,3,5-triazine) on mercury electrodes. The study is performed in the acidity range 2.25 M H2SO4 to pH 5. Above this last pH value no signals were obtained. In DP polarography, two main reduction peaks were observed, accompanied by a pre-peak, at less negative potentials, and a post-peak, at more negative potentials, due to the adsorption of simazine on the electrode. The main peaks corresponded to two-electron reduction processes. At pH below the protonation pK of the triazine ring (ca. 1.7), the results showed that in the first stage, simazine suffers a cleavage of the Cl atom via a CEC process to yield a dechlorinated intermediate, which is reduced through an irreversible two-electron process, the rate-determining step being the second electron transfer. At pH>pK, a protonation of the triazine ring precedes the reduction process, this reaction being also responsible for the observed decrease in limiting current. Linear-sweep voltammetry showed that simazine is adsorbed on the electrode with the triazine ring parallel to the electrode surface, as can be inferred from the value of the calculated area covered by one molecule. At pH values where both the protonated and unprotonated forms of simazine coexist, both forms are co-adsorbed on the electrode.

On the electroreduction of 4-chloro-2,6-diisopropylamino- s-triazine (propazine) on mercury electrodes

This paper presents a polarographic (dc and differential pulse (DP)) study of the reduction of the s-triazine derivative propazine (4-chloro-2,6-diisopropylamino- s-triazine). The study is performed in acidic media (from solutions 2.25 M in H 2SO 4 to pH 5) because no signals were obtained above pH 5 (even at pH values of 11–12). In the pH range 2–4 the polarograms decreased until they vanished. In DP polarography, two main reduction peaks were observed, accompanied by a pre-peak at less negative potentials, and a post-peak at more negative potentials, due to the adsorption of propazine on the electrode. The main peaks corresponded to two-electron reduction processes. At pH below the protonation p K of the triazine ring (about 1.7), the results showed that, in a first stage, propazine suffers a cleavage of the Cl atom via a CEC process (electron transfer placed between two chemical reactions) to yield a dechlorinated intermediate, which is reduced through an irreversible two-electron process, the rate-determining step (r.d.s.) being the second electron transfer. At pH above the p K, a protonation of the triazine ring precedes the reduction process, this reaction being also responsible for the observed decrease in limiting current.

Optimization of Drilling Mud Conditioning For Chemically Enhanced Centrifuging

Abstract Chemically-enhanced centrifuging, CEC, is a drill site environmental control process for drilling mud. The process makes use of mud dewaterability for recycling the mud liquid phase and minimizing volume of the waste mud discharge. In this process, mud is chemically conditioned to enhance dewaterability- the ability of drilling fluid to release its liquid phase. This paper introduces a simple method, the nine-point (9-P) experiment, for finding optimum chemical conditioning (i.e., combination of dilution water, coagulant and flocculent) that would maximize the mud volume reduction and minimize the cost of chemicals. The 9-P experiment is based on the statistical theory of factorial analysis and requires only nine tests to find optimum treatment. The paper explains how to design the experiment and analyse its results. Also presented is a comparison of 9-P (in terms of volume reduction) with the conventional trial-and-error approach. The comparison shows a significant, from 1.78 to 2.35 - fold, increase of the volume reduction efficiency, EV R, and up to 3.7 - fold reduction of chemical usage resulting from optimal selection of the most active flocculent. Introduction The process of chemically-enhanced centrifuging, CEC, also known as mud dewatering was introduced to drilling operations during the mid 1980s mostly in response to growing environmental regulations requiring minimization and recycling of drilling fluids (muds). In field operations, CEC is an extension of the drilling fluid processing system (solids control) and is either offered by a separate contractor or integrated with the complete mud engineering service. In environmentally-sensitive (zero-discharge) areas, the CEC or downhole injection technologies are the only alternatives to off-site disposal involving high cost of drilling waste handling, transportation and disposal. The importance of dewatering technology as an environmental control measure in drilling operations stems from a variety of its uses. In principle, CEC removes water from sludge so that the dewatered sludge volume is minimized (sludge densification). Alternatively, the process is viewed as the removal of solids from water suspensions (water clarification). Finally, CEC can be considered a recovery process in which an expensive liquid phase is recovered from waste (liquid phase recycling). In oilwell drilling operations, CEC is used in all these applications. In the reserve pit closures, water must be removed from sludge in the earthen mud pit to minimize the volume of sludge for onsite burial (sludge densification)(1,2). In the processing of the well site's wastewater ("gray" water, deck drainage, stormwater and run-off water), CEC is used for water clarification(3). The third oilfield application of CEC is a continuous dewatering of active drilling mud(4,5,6). In this application, the excess volume of drilling mud (resulting from solids control dilutions) is dewatered and the recovered liquid phase is used for further dilutions. The CEC process consists of three stages: chemical conditioning; forced settling; and mechanical expression. Chemical conditioning destabilizes the continuous suspension of fine solids in drilling mud and converts this suspension to a mixture of solid agglomerates (flocs, flocculates) and the free liquid phase. Then, this mixture is pumped into the centrifuge where the remaining two stages take place.

Discrimination between CEC, CE and EC mechanisms by using a sinusoidal current-time function

A theoretical treatment corresponding to a CEC process when a sinusoidal current is applied to static and dynamic electrodes is presented. The general equations obtained allow us to deduce as particular cases those corresponding to CE and EC mechanisms. The conditions under which the response of a CEC process may be discriminated from CE and EC mechanisms are discussed. Methods for determining heterogeneous and homogeneous kinetic parameters are also proposed.

Characterization of CE and CEC processes under pure kinetic conditions by linear‐sweep voltammetry

AbstractTheoretical equations applying to voltammetric curves corresponding to electrochemical processes preceded by a chemical reaction under pure kinetic conditions are derived. Logarithmic analyses for CrEr, CrEi, and CrErCi, processes are proposed. The equations are tested with the aid of well‐known reduction processes.

Investigation of the reduction of 1,2-cyclohexanedione and methylglyoxal on mercury electrodes under pure kinetic conditions by linear-sweep voltammetry

The electroreduction of both unhydrated 1,2-cyclohexanedione and methylglyoxal under pure kinetic conditions has been investigated using linear-sweep voltammetry. In acidic media, and for both compounds, the negative scans show S-shaped I - E curves at low scan rate values due to the dehydration reaction preceding the reductions. In the case of 1,2-cyclohexanedione the voltammograms correspond to a CEC process at very low pH values and to a CE irreversible process at neutral and basic pH values. The first one-electron transfer for methylglyoxal appears to be quasi-reversible.

Chronopotentiometry with several types of programmed current at most usual electrodes: General study of systems with coupled first-order chemical reactions

The general equations corresponding to CEC and catalytic processes when current-time functions of the forms I ( t) = I 0 t u ewt and I( t) = I 0( t 1 + t) v are applied to a DME were deduced taking into account the electrode sphericity and using a blank period t 1. From these expressions we deduce as particular cases those corresponding to other types of electrodes (for example expanding plane electrode, static mercury dropping electrode and stationary plane electrode), other well-known current-time functions (power current, exponential current and step current), other reaction schemes (CE, EC and E mechanisms) and those cases in which the blank period is zero. Moreover, methods for determining heterogeneous and homogeneous kinetic parameters are proposed in each reaction scheme.

Theoretical equations for electrochemical processes preceded by concurrent first-order chemical reactions in DC polarography: Application to the study of the interaction between guanine and diacetyl

Theoretical expressions are derived for electrochemical processes preceded by two concurent first-order chemical reactions in dc polarography by using both the approximation of convective diffusion under the steady state conditions and the dimensionless differential equations of the Nernst diffusion layer approximation. These equations are formally identical to those obtained for CE and CEC processes, with differences only in the kinetic terms. Study of the interaction between guanine and diacetyl shows the usefulness of these equations. A value of 7 × 104 M is obtained for the formation constant of the adduct guaninediacetyl at 25°C.

Etude electrochimique et spectrophotometrique des complexes d'inclusion du diazino-2-2′ bis(ethyl-3 sulfonate-6 benzothiazole) avec les cyclodextrines en milieu aqueux

The complexation of 2,2′-diazino bis (3-ethyl 6-sulfonate benzothiazole) (ABTS) by α-, β- and γ-cyclodextrin (CD) in aqueous media has been investigated by voltammetry and uv spectrophotometry. The inclusion process in CD was indicated by changes in the limiting current, the half-wave potential and the uv spectrum. Each of these effects was quantitatively evaluated and the characteristic parameters of the anodic oxidation of ABTS in the presence of CD were obtained. The 1:1 (guest:host) ratio inclusion complexes are the major species with natural CDs whereas the 1:2 complexes are also involved with modified CDs (methyl, hydroxyethyl and hydroxypropyl derivatives). Several methods have been used for the determination of association constants, whose values are sensitive to hydrophobic and electrical charge parameters of the substrate as well as to hydrogen bonding. The total anodic oxidation is a CEC process in which no direct electron transfer of the inclusion complex could clearly be detected.

Diagnosis of irreversible electron transfers and reversible CEC, CE, and EC processes from differential pulse polarographic criteria

Diagnosis of irreversible electron transfers and reversible CEC, CE, and EC processes from differential pulse polarographic criteria

CEC's process chromatograph

RETURN TO ISSUEPREVAdvertisementNEXTCEC's process chromatographCite this: Chem. Eng. News 1958, 36, 45, 76Publication Date (Print):November 10, 1958Publication History Published online6 November 2010Published inissue 10 November 1958https://doi.org/10.1021/cen-v036n045.p076Copyright © 1958 AMERICAN CHEMICAL SOCIETYArticle Views53Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (133 KB) SUBJECTS:Chromatography,Separation science Get e-Alerts