Gas holdup in a 32 cm bubble column

Air-water-fiber flows are found in the pulp and paper industry in a variety of unit operations such as flotation deinking of recycled paper and fiber bleaching. Vertical bubble column reactors are often used for these operations due to low cost, ease of operation, and high interfacial areas. The complex hydrodynamics of bubble columns are difficult to understand due to the presence of many different phenomena occurring in the flow. Therefore, it is difficult to scale up the information gathered from research for industrial sized applications. The current study experimentally investigates the effects of fiber mass fraction, superficial gas velocity, fiber type, fiber length, and distributor plate open area on gas flow regime, and overall and local gas holdup in a 32.1 cm diameter semi-batch bubble column. Three different Rayon fiber lengths (L = 3, 6, 12 mm) and three different cellulose (natural) fiber types are experimentally studied over a range of superficial gas velocities (U[Subscript g] [Less than or equal to] 20 cm/s), fiber mass fractions (0 [Less than or equal to] C [Less than or equal to] 1.8%), and distributor open areas (A = 0.49, 0.95, and 2.03%). Local gas holdup is determined by pressure drop measurements at several axial locations spanning a height of ten column diameters (H = 321 cm). Overall gas holdup is determined from the pressure difference between the top and bottom pressure transducers. The Zuber and Findlay drift flux model is used to determine the gas flow regime. Fiber mass fraction had the most significant influence on overall and local gas holdup, where increasing fiber mass fraction decreased gas holdup. Superficial gas velocity has different effects on gas holdup for flows that demonstrate three regimes (homogeneous, transitional, and heterogeneous) and flows that were heterogeneous for all superficial gas velocities (pure heterogeneous). Local gas holdup trends showed two local maximum gas holdup values and the existence of recirculation cells within the flow. Their location and size depends on fiber type and distributor plate open area

Structural and Behavioural Model for Social Computing Applications

Social Computing a new paradigm is causing transformational changes to societal and business processes resulting in new businesses models known as sharing economy, peer economy or collaborative consumption. The diffusion rates of these applications have surpassed any historical technological advancement and have reached millions and billions of users during a short period of time. To understand this phenomenon we analysed eight such popular applications using inductive and content analysis techniques which have helped us derive a structural and a behavioural model for Social Computing. Using these two models we were able to get a deeper understanding of how an application designed to assist a particular communication pattern give rise to a set of emergent characteristics within the user such as trust, empowerment, belongingness that motivate user to act to fulfil a need assisting the growth of these applications. This understanding can guide the design of new successful Social Computing applications

Reconceptualizing Indigeneity Within the Fraternity and Sorority Community

The purpose of this article provides fraternity and sorority communities with an understanding of the impact of a Native American sisterhood on the cultivation in how it conceptualized itself, its centering an Indigenous structure, and how it affirms the women who join through building relationality. Through the first research inquiry of a Native American sisterhood, the findings reveal/highlight how the sisterhood has centered Indigeneity in its conception to how it lives today. Fraternity and sorority communities need to shift their culture to honor Indigenous ways of being

U-drawing of Fortiform 1050 third generation steels. Numerical and experimental results

Elasto–plastic behavior of the third generation Fortiform 1050 steel has been analysed using cyclic tension–compression tests. At the same time, the pseudo elastic modulus evolution with plastic strain was analysed using cyclic loading and unloading tests. From the experiments, it was found that the cyclic behavior of the steel is strongly kinematic and elastic modulus decrease with plastic strain is relevant for numerical modelling. In order to numerically analyse a U-Drawing process, strip drawing tests have been carried out at different contact pressures and Filzek model has been used to fit the experimental data and implement a pressure dependent friction law in Autoform software. Finally, numerical predictions of springback have been compared with the experimentally ones obtained using a sensorized UDrawing tooling. Different material and contact models have been examined and most influencing parameters have been identified to model the forming of these new steels

Specific Human Astrocyte Subtype Revealed by Affinity Purified GFAP+1 Antibody; Unpurified Serum Cross-Reacts with Neurofilament-L in Alzheimer

The human GFAP splice variants GFAPΔ164 and GFAPΔexon6 both result in a GFAP protein isoform with a unique out-of-frame carboxy-terminus that can be detected by the GFAP+1 antibody. We previously reported that GFAP+1 was expressed in astrocytes and in degenerating neurons in Alzheimer's disease brains. In this study we aimed at further investigating the neuronal GFAP+1 expression and we started by affinity purifying the GFAP+1 antibody. The purified antibody resulted in a loss of neuronal GFAP+1 signal, although other antibodies directed against the amino- and carboxy-terminus of GFAPα still revealed GFAP-immunopositive neurons, as described before. With an in-depth analysis of a western blot, followed by mass spectrometry we discovered that the previously detected neuronal GFAP+1 expression was due to cross-reactivity of the antibody with neurofilament-L (NF-L). This was confirmed by double-label fluorescent immunohistochemistry and western blotting with the unpurified GFAP+1 antibody and an antibody against NF-L. Our data imply that NF-L can accumulate in some tangle-like structures in Alzheimer brains. More importantly, the purified GFAP+1 antibody clearly revealed a specific subtype of astrocytes in the adult human brain. These large astrocytes are present throughout the brain, e.g., along the subventricular zone, in the hippocampus, in the striatum and in the spinal cord of controls, Alzheimer, and Parkinson patients. The presence of a specific GFAP-isoform suggests a specialized function of these astrocytes

An assessment of validity and responsiveness of generic measures of health-related quality of life in hearing impairment

This article is made available through the Brunel Open Access Publishing Fund. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Purpose: This review examines psychometric performance of three widely used generic preference-based measures, that is, EuroQol 5 dimensions (EQ-5D), Health Utility Index 3 (HUI3) and Short-form 6 dimensions (SF-6D) in patients with hearing impairments. Methods: A systematic search was undertaken to identify studies of patients with hearing impairments where health state utility values were measured and reported. Data were extracted and analysed to assess the reliability, validity (known group differences and convergent validity) and responsiveness of the measures across hearing impairments. Results: Fourteen studies (18 papers) were included in the review. HUI3 was the most commonly used utility measures in hearing impairment. In all six studies, the HUI3 detected difference between groups defined by the severity of impairment, and four out of five studies detected statistically significant changes as a result of intervention. The only study available suggested that EQ-5D only had weak ability to discriminate difference between severity groups, and in four out of five studies, EQ-5D failed to detected changes. Only one study involved the SF-6D; thus, the information is too limited to conclude on its performance. Also evidence for the reliability of these measures was not found. Conclusion: Overall, the validity and responsiveness of the HUI3 in hearing impairment was good. The responsiveness of EQ-5D was relatively poor and weak validity was suggested by limited evidence. The evidence on SF-6D was too limited to make any judgment. More head-to-head comparisons of these and other preference measures of health are required.Medical Research Counci