Constant-angle surfaces in liquid crystals

We discuss some properties of surfaces in R3 whose unit normal has constant angle with an assigned direction field. The constant angle condition can be rewritten as an Hamilton-Jacobi equation correlating the surface and the direction field. We focus on examples motivated by the physics of interfaces in liquid crystals and of layered fluids, and discuss the properties of the constant-angle surfaces when the direction field is singular along a line (disclination) or at a point (hedgehog defect

Intensified extraction of uranium(VI) in impinging-jets contactors

The mass transfer performance of confined impinging-jets (CIJs) contactors was investigated for metal separations. In particular, the extraction of uranium(VI) from aqueous nitric acid solutions (3 M) into 30% v/v TBP/Exxsol D80, relevant to spent nuclear fuel reprocessing, was studied for different cell geometries, i.e. main chamber size (D = 2 and 3.2 mm) and jet diameter (d j = 0.25 and 0.5 mm), and different operating conditions, i.e. residence time (τ = 1–9 s), total jet velocity (u tot = 2.6–8.6 m/s), and reactor length (L = 7–85 cm). For all conditions investigated, the aqueous phase was the dispersed one. Drop sizes were also measured with high-speed imaging. It was found that the extraction efficiency increased by increasing residence time for a constant total jet velocity regardless of the chamber size. At a constant residence time, higher extraction efficiency was achieved at high total jet velocities, which are associated with larger interfacial areas (smaller drops). The extraction efficiency reached 70% in most of the cases investigated in less than 2 s. In addition, high overall volumetric mass transfer coefficients (up to 1 s −1 ) were obtained at short residence times. Using regression analysis, a correlation for the overall volumetric mass transfer coefficient was developed from the experimental data with an average deviation of 9%

Facial Mimicry of Spontaneous and Deliberate Duchenne and Non-Duchenne Smiles

Increasing evidence suggests that Duchenne (D) smiles may not only occur as a sign of spontaneous enjoyment, but can also be deliberately posed. The aim of this paper was to investigate whether people mimic spontaneous and deliberate D and non-D smiles to a similar extent. Facial EMG responses were recorded while participants viewed short video-clips of each smile category which they had to judge with respect to valence, arousal, and genuineness. In line with previous research, valence and arousal ratings varied significantly as a function of smile type and elicitation condition. However, differences in facial reactions occurred only for smile type (i.e., D and non-D smiles). The findings have important implications for questions relating to the role of facial mimicry in expression understanding and suggest that mimicry may be essential in discriminating among various meanings of smiles

Current and Future Therapeutic Approaches for Thymic Stromal Cell Defects

Inborn errors of thymic stromal cell development and function lead to impaired T-cell development resulting in a susceptibility to opportunistic infections and autoimmunity. In their most severe form, congenital athymia, these disorders are life-threatening if left untreated. Athymia is rare and is typically associated with complete DiGeorge syndrome, which has multiple genetic and environmental etiologies. It is also found in rare cases of T-cell lymphopenia due to Nude SCID and Otofaciocervical Syndrome type 2, or in the context of genetically undefined defects. This group of disorders cannot be corrected by hematopoietic stem cell transplantation, but upon timely recognition as thymic defects, can successfully be treated by thymus transplantation using cultured postnatal thymic tissue with the generation of naïve T-cells showing a diverse repertoire. Mortality after this treatment usually occurs before immune reconstitution and is mainly associated with infections most often acquired pre-transplantation. In this review, we will discuss the current approaches to the diagnosis and management of thymic stromal cell defects, in particular those resulting in athymia. We will discuss the impact of the expanding implementation of newborn screening for T-cell lymphopenia, in combination with next generation sequencing, as well as the role of novel diagnostic tools distinguishing between hematopoietic and thymic stromal cell defects in facilitating the early consideration for thymus transplantation of an increasing number of patients and disorders. Immune reconstitution after the current treatment is usually incomplete with relatively common inflammatory and autoimmune complications, emphasizing the importance for improving strategies for thymus replacement therapy by optimizing the current use of postnatal thymus tissue and developing new approaches using engineered thymus tissue

Investigation into the use of water based brake fluid for light loads

This paper addresses the possibility of using water based fluid as a bake. fluid for light loads. Characterization of.both standard and water based brruced fluids formulated was carried out. The properties of ttie latter were com pared with that of a standard commercial brake fluid. The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus· of University of Uyo and the· braking effiqiency obtained at test to its suitability for light loads.Keywords·: Water-based, Brake fluid properties, Light loads, Efficienc

Scale-up studies for intensified production of biodiesel from used cooking oil

In this paper the effect of channel size on the transesterification of used cooking oil (UCO) with methanol using KOH as catalyst to produce biodiesel was investigated for capillaries with internal diameter ranging from 1 to 3 mm. A T-junction was used as the mixing zone of the two liquid phases. The effects of different parameters such as, internal diameter, methanol-to-oil molar ratio, reaction time, temperature, and catalyst concentration were investigated. Results showed that the conversion efficiency to biodiesel is increased by decreasing the channel size, whilst the interactions of the other variables are also discussed

Intensified Liquid-Liquid Extraction Technologies in Small Channels: A Review

Solvent extraction is a key separation process in several industries. Mixer-settlers and agitated or pulsed columns are mainly used as liquid-liquid contactors. However, these units require large solvent inventories and long residence times, while flow fields are often not uniform and mixing is poor. These drawbacks can be overcome with process intensification approaches where small channel extractors are used instead. The reduced volumes of small units in association with the increased efficiencies facilitate the use of novel, often expensive, but more efficient and environmentally friendly solvents, such as ionic liquids. The small throughputs of intensified contactors, however, can limit their full usage in industrial applications, thus robust scale-up strategies need to be developed. This paper reviews promising intensified technologies for liquid-liquid extractions based on small channels. In particular, extractions in single channels and in confined impinging jets are considered. The increase in throughput via scale-out approaches with appropriate manifolds is discussed, based on the use of many channels in parallel. The combination of small channels and centrifugal forces is exploited in counter-current chromatography (CCC) systems where many mixing and settling steps are combined within the contactors. Scale up is possible via centrifugal partition chromatography (CPC) configurations

Oblique amplitude modulation of dust-acoustic plasma waves

Theoretical and numerical studies are presented of the nonlinear amplitude modulation of dust-acoustic (DA) waves propagating in an unmagnetized three component, weakly-coupled, fully ionized plasma consisting of electrons, positive ions and charged dust particles, considering perturbations oblique to the carrier wave propagation direction. The stability analysis, based on a nonlinear Schroedinger-type equation (NLSE), shows that the wave may become unstable; the stability criteria depend on the angle $\theta$ between the modulation and propagation directions. Explicit expressions for the instability rate and threshold have been obtained in terms of the dispersion laws of the system. The possibility and conditions for the existence of different types of localized excitations have also been discussed.Comment: 21 pages, 6 figures, to appear in Physica Script

Magnetized Domain Walls in the Deconfined Sakai-Sugimoto Model at Finite Baryon Density

The magnetized pure pion gradient ($\mathcal{5}\phi$) phase in the deconfined Sakai-Sugimoto model is explored at zero and finite temperature. We found that the temperature has very small effects on the phase. The thermodynamical properties of the phase shows that the excitations behave like a scalar solitonic free particles. By comparing the free energy of the pion gradient phase to the competing multiquark-pion gradient (MQ-$\mathcal{5}\phi$) phase, it becomes apparent that the pure pion gradient is less thermodynamically preferred than the MQ-$\mathcal{5}\phi$ phase. However, in the parameter space where the baryonic chemical potential is smaller than the onset value of the multiquark, the dominating magnetized nuclear matter is the pion gradient phase.Comment: 20 pages, 9 figure

Self Management and Telehealth: Lessons Learnt from the Evaluation of a Dorset Telehealth Program

Dorset Clinical Commissioning Group