Transitioning through the vapour-liquid equilibrium for low energy thermal stripping of ammonia from wastewater: Enabling transformation of NH3 into a zero-carbon fuel

Vacuum thermal stripping permits the recovery of ammonia from wastewater in a concentrated form, which is key to its exploitation in the circular economy, but the latent heat demand for thermal separation remains a critical barrier to exploitation. In this study, we investigate the vapor-liquid equilibrium (VLE) for ammonia-water as a mechanism to enhance recovered ammonia quality and minimise the thermal energy required for ammonia separation. Below the dew point (65 °C at 0.25 bar) a two-phase region of the VLE exists where 48 %wt gas-phase ammonia could be produced (61 °C) compared to only 2 %wt within the stripping region adopted widely in the literature. This was complemented by a 98 % reduction in thermal separation energy, since limited water vaporization can occur when the feed is maintained below the activation energy threshold for bulk evaporation. Operation within this practically unexplored region of the ammonia-water VLE fosters a gas-phase product suitable for energy generation in gas turbines or solid oxide fuel cells. Comparable product quality was achieved using concentrated wastewater, which validated the VLE for design in the presence of a broad range of dissolved gases and volatile inorganic compounds. Rapid desorption of CO2 occurred during vacuum stripping, subsequently increasing pH >9 without the requirement for alkali addition to shift the ammonia-ammonium equilibrium in favor of gaseous ammonia. Consequently, the two-phase region of the VLE defined for vacuum thermal stripping provides a synergistic strategy to mitigate chemical demand, minimise separation energy and recover gas-phase ammonia for zero carbon energy generation, constituting a significant advancement toward the net zero ambitions of the water sector.

Impact of changing from autopsy to post-mortem CT in an entire HM Coroner region due to a shortage of available pathologists

A significant problem facing routine medicolegal coroner-referred autopsies is a shortfall of pathologists prepared to perform them. This was particularly acute in Lancashire, where the coroner decided to initiate a service that relied on post-mortem computed tomography (PMCT). This involved training anatomical pathology technologists (APTs) to perform external examinations, radiographers to perform scans, and radiologists to interpret them. The service started in 2018 and now examines over 1,500 cases per year. This study outlines the PMCT process using NHS staff, with CT equipment and logistics managed by the commercial sector. It compares the demographics and outcomes of PM investigations for two 6-month periods: the autopsy service prior to 2018, and then the PMCT service. These data were then compared with previous UK PMCT data. Referrals for adult non-suspicious deaths were made in 913 cases of which 793 (87%) had PMCT between 01/10/2018 and 31/03/2019. Fifty-six cases had autopsy after PMCT, so 81% of cases potentially avoided autopsy. The PMCT service did not delay release of bodies to the next-of-kin. Comparing the cause of death given shows no difference in the proportions of natural and unnatural deaths. There was an increase in diagnosis of coronary artery disease for PMCT, with less respiratory diagnoses, a feature not previously demonstrated. These data suggest PMCT is a practical solution for potentially failing autopsy services. By necessity, this involves changes in diagnoses, as PMCT and autopsy have different strengths and weakness, but the ability to pick up unnatural death appears unaffected.

Distal intestinal obstruction syndrome and colonic pathologies in cystic fibrosis

The management of abdominal pain in cystic fibrosis can be complicated. Distal intestinal obstruction syndrome is a common cause of pain and obstruction in these patients. Knowledge of the diagnosis and management and of similar presenting symptoms is essential for the hospital doctor.

Anatomical siting of the splenic flexure using computed tomography

INTRODUCTION Often, left-sided colorectal surgery requires splenic flexure mobilisation (SFM) to allow a tension-free anastomosis to be carried out. This step is difficult and not without risk. We investigated a system of anatomical siting of the splenic flexure using computed tomography (CT). METHODS The Shrewsbury Splenic Flexure Siting (SSFS) system involves siting of the splenic flexure using the vertebral level (VL) as a reference point. We asked three surgical registrars (SRs) to analyse 20 CT scans of patients undergoing colonic resection to ascertain the anatomical site of the splenic flexure using the SSFS system. The distance from the centre of the vertebral body to the lateral edge (CVBL) of the splenic flexure was measured, as was the distance from the centre of the vertebral body to the inner abdominal wall (CVBI) along the same line, on axial images. RESULTS VL assessment demonstrated substantial inter-observer agreement with a kappa (κ) value of 0.742 (95% confidence interval (CI), 0.463-0.890). CVBL and CVBI demonstrated very strong inter-observer agreement (CVBL: κ = 0.905 (95% CI, 0.785-0.961); CVBI: 0.951 (0.890-0.979) (p<0.001). Overall, there was strong correlation between assessments by all three SRs across the three variables measured. CONCLUSIONS The SSFS system is an accurate method to site the splenic flexure anatomically using CT. We can use the SSFS system to develop a validated scoring system to help colorectal surgeons assess the difficulty of SFM.

Separation of Protein Crystals from Spores of Bacillus thuringiensis by Ludox Gradient Centrifugation

A method is described for the purification of Bacillus thuringiensis protein crystals by Ludox gradient centrifugation. This method is simple, inexpensive, fast, and efficient compared with other techniques. It has been successfully used to purify and characterize the protein crystals from several B. thuringiensis strains.

Integrating decision tools for the sustainable management of land contamination

The approach to taking decisions on the management of land contamination has changed markedly over 30 years. Change has been rapid with policy makers and regulators, practitioners and researchers having to keep pace with new technologies, assessment criteria and diagnostic methods for their measurement, techniques for risk analysis and the frameworks that support decision-makers in their efforts to regenerate historically contaminated land. Having progressed from simple hazard assessment through to 'sustainability appraisal' we might now consider piecing together the experience of decision-making for managing land contamination. Here, we critically review recent developments with a view to considering how better decisions can be made by integrating the decision tools available. We are concerned with the practicality of approach and the issues that arise for practitioners as decision criteria are broadened.

Methods for understanding organic fouling in MBRs

The identification and quantification of foulants in membrane bioreactors present a major challenge due to their complexity resulting from biomass heterogeneity. Fouling is normally characterised with respect to the critical flux, this being conventionally viewed as being the flux below which a reduction in membrane permeability does not take place. However, recent studies have revealed that such fouling arises even at very low fluxes. Moreover, fouling rates can differ substantially between different experiments, trials and installations even when operated under apparently similar conditions of biomass and soluble organic carbon concentrations. The methods available for quantifying and analysing fouling are reviewed with specific reference to recent data on sub-critical flux behaviour. It is concluded that HPSEC analysis of extracted biomass fractions may provide the most valuable data towards the determination of differences in fouling propensity between different biomasses, as inferred in conventional flux step analysis.

Women's voices: prenatal diagnosis and care for the disabled

The development and implementation of prenatal diagnosis has changed the experience of pregnancy for many women. How women make decisions about prenatal diagnosis PD is an important question that challenges us both individually and as a community. The question of care is central to many women's decision-making process. How much care a child will require, how much care a woman feels confident to provide, and the level of care available for children with genetic conditions and families from their communities all impact on women's decisions to undertake prenatal diagnosis as well as how to use the information available from testing. Interviews with women making these decisions explored, among other things, the role that caring and access to care played in women's ethical deliberations. Before PD can widen women's reproductive choices and counter criticisms that its use is eugenically oriented, the central role that provision of, and access to, care holds for participants in PD programmes must be acknowledged and addressed.

Pharyngeal abscess presenting with upper airway obstruction and atlanto-axial subluxation in a small infant

We describe an infant who presented with a combination of upper airway obstruction and atlanto-axial subluxation, secondary to a pharyngeal abscess resulting from cosmetic ear piercing. This combination posed a number of difficulties for the anasthetist and a detailed plan was formulated to prepare the child for anasthesia.

Pantoprazole-based 10-day triple therapy is effective in Helicobacter pylori eradication

AIM

To investigate the efficacy of a short course of pantoprazole-based triple therapy in Helicobacter pylori eradication in a single-centre pilot study.

METHODS

Patients with active or healed duodenal ulcer or with gastric erosions or gastritis, all of whom were H. pylori-positive, received 10 days of twice-daily open treatment with pantoprazole 40 mg, plus clarithromycin 250 mg and tinidazole 500 mg. H. pylori was assessed at entry and 28-35 days after the end of treatment by rapid urease test (at entry only), culture and antimicrobial sensitivity, histology and 13C urea breath test. The criterion for eradication was a negative result in all three tests.

RESULTS

Seventy patients were treated, of whom four were excluded from analysis due to major deviations from the study protocol. Eradication of H. pylori was achieved in 57/66 patients (per protocol analysis 86% (95% CI: 78-95%)) and was higher in patients with organisms sensitive to nitroimidazole before treatment (sensitive: 47/53 (89%), insensitive: 10/13 (77%)). There was marked reduction in acute gastritis throughout the stomach while chronic gastritis decreased only in the corpus. Healing was achieved in all 24 patients with active duodenal ulcer. Treatment was complied with; only one patient missed one of the 20 doses. Adverse events were of mild or moderate intensity and did not require withdrawal from treatment.

CONCLUSION

A short course of pantoprazole-based triple therapy is well tolerated and effective in eradicating H. pylori.

Cloning of a gene bearing missense mutations in early-onset familial Alzheimer's disease

Some cases of Alzheimer's disease are inherited as an autosomal dominant trait. Genetic linkage studies have mapped a locus (AD3) associated with susceptibility to a very aggressive form of Alzheimer's disease to chromosome 14q24.3. We have defined a minimal cosegregating region containing the AD3 gene, and isolated at least 19 different transcripts encoded within this region. One of these transcripts (S182) corresponds to a novel gene whose product is predicted to contain multiple transmembrane domains and resembles an integral membrane protein. Five different missense mutations have been found that cosegregate with early-onset familial Alzheimer's disease. Because these changes occurred in conserved domains of this gene, and are not present in normal controls, they are likely to be causative of AD3.

Apolipoprotein E epsilon 4 allele frequency in patients with Lewy body dementia, Alzheimer's disease and age-matched controls

Genotypes of apolipoprotein E (ApoE) were determined by polymerase-chain reaction (PCR) amplification and restriction-sizing of brain DNA from 39 cases of Lewy body dementia (LBD), 68 senile Alzheimer's disease (AD) patients and 47 neuropathologically validated non-demented controls. There was a 3-fold increase in the epsilon 4 allele frequency in both LBD and AD groups compared with controls. These results indicate that LBD and AD share the epsilon 4 allele of ApoE as a major risk factor for the development of disease and suggest a similarity in disease aetiology.

Combining binocular and monocular curvature features

A study is reported of the perception of visual surfaces in wire-frame stimuli generated by combinations of monocular surface contours and binocular disparity that provide differing information about 3-D relief. Observers vary considerably in the relative contribution made by the binocular and monocular cues to the perception of overall 3-D form. Without training, many observers may entirely fail to perceive surface curvature from the binocular disparity patterns, interpreting the form of the surface only according to the monocular information. For other observers, both cues contribute to the end percept, with the monocular interpretation dominating where the disparity information indicates planarity and with disparity dominating where disparity information suggests curvature and the monocular interpretation suggests planarity. Where stereo and monocular interpretations indicate inconsistent surface curvature features at a common location, more complex resolution strategies are suggested.

The analogy between stereo depth and brightness

Apparent depth in stereograms exhibits various simultaneous-contrast and induction effects analogous to those reported in the luminance domain. This behavior suggests that stereo depth, like brightness, is reconstructed, ie recovered from higher-order spatial derivatives or differences of the original signal. The extent to which depth is analogous to brightness is examined. There are similarities in terms of contrast effects but dissimilarities in terms of the lateral inhibition effects traditionally attributed to underlying spatial-differentiation operators.

Binocular depth from surfaces versus volumes

Subjects were asked to compare the relative depths of two binocular targets embedded in different random dot stereogram backgrounds. The disparities of the background points were either randomized, corresponding to a scattering of points within a volume, or arranged according to a sawtooth (triangle-wave) disparity profile (i.e., a set of slanted planar surfaces separated by sharp depth discontinuities). When the targets were embedded in the random volume, their depths were perceived in accordance with their relative disparities. But when the target points were embedded in the sawtooth surfaces their depths were systematically misperceived in a manner predicted by the incorrect depth interpretation of the background points. Rather than seeing a sawtooth pattern, the background points resembled a staircase in depth, and the targets, which appeared embedded in different steps, were misjudged in depth accordingly. The effect suggests a distinction between the depth processing of isolated binocular features and those associated with continuous surfaces.

Binocular depth from surfaces versus volumes

Subjects were asked to compare the relative depths of two binocular targets embedded in different random dot stereogram backgrounds. The disparities of the background points were either randomized, corresponding to a scattering of points within a volume, or arranged according to a sawtooth (triangle-wave) disparity profile (i.e., a set of slanted planar surfaces separated by sharp depth discontinuities). When the targets were embedded in the random volume, their depths were perceived in accordance with their relative disparities. But when the target points were embedded in the sawtooth surfaces their depths were systematically misperceived in a manner predicted by the incorrect depth interpretation of the background points. Rather than seeing a sawtooth pattern, the background points resembled a staircase in depth, and the targets, which appeared embedded in different steps, were misjudged in depth accordingly. The effect suggests a distinction between the depth processing of isolated binocular features and those associated with continuous surfaces.

The concave cusp as a determiner of figure-ground

The tendency to interpret as figure, relative to background, those regions that are lighter, smaller, and, especially, more convex is well known. Wherever convex opaque objects abut or partially occlude one another in an image, the points of contact between the silhouettes form concave cusps, each indicating the local assignment of figure versus ground across the contour segments. It is proposed that this local geometric feature is a preattentive determiner of figure-ground perception and that it contributes to the previously observed tendency for convexity preference. Evidence is presented that figure-ground assignment can be determined solely on the basis of the concave cusp feature, and that the salience of the cusp derives from local geometry and not from adjacent contour convexity.

Integrating stereopsis with monocular interpretations of planar surfaces

Experiments are reported that involved spatial judgments of planar surfaces that had contradictory stereo and monocular information. Tasks included comparing the relative depths of two points on the depicted surface and judging the surface's apparent spatial orientation. It was found that for planar surfaces the 3D perception was dominated by the monocular interpretation, despite the strongly contradictory stereo information. We propose that stereo information is effectively integrated only where the surface exhibits curvature features or edge discontinuities, i.e. where the second spatial derivatives of disparity are nonzero. Planar surfaces induce constant gradients of disparity and are thus effectively featureless to stereopsis. Further observations are reported regarding nonplanar surfaces, where contradictory monocular information can still be effectively rivalrous with that suggested stereoscopically.

A microiontophoretic study of the actions of mu-, delta- and kappa-opiate receptor agonists in the rat brain

The actions of mu-, delta- and kappa-opiate receptor agonists have been compared on the activity of single neurones in the brain stem, caudate nucleus and hippocampus of the rat, using the technique of microiontophoresis. In the brain stem and caudate nucleus the predominant effect of all the opiate agonists tested was depression of neuronal activity which was antagonized by naloxone. The selectivity of naloxone as an opiate receptor antagonist was indicated by its lack of effect on gamma-aminobutyric acid (GABA)-induced responses. In the hippocampus both mu- and delta-agonists mainly caused an increase in neuronal firing rates, though some neurones were depressed. In contrast, all the kappa-agonists, including the proposed endogenous ligand for the kappa-receptor, dynorphin, caused depression of neuronal activity. All of these effects were antagonized by naloxone. There was a clear distinction in the areas within the hippocampus in which the mu- and delta-agonists produced different effects. Neurones in the pyramidal cell layer were always excited by these drugs, whereas neurones in the granule cell layer of the dentate gyrus were always depressed by the same drug.

Electrophysiological evidence for kappa-agonist activity of dynorphin in rat brain

Dynorphin (1-13) and the mu-agonist, FK 33,824, have been applied microiontophoretically to single neurones in the hippocampus of the rat. Whereas FK 33,824 predominantly caused an increase in neuronal firing rates, dynorphin (1-13) decreased activity. Both effects were blocked by the opiate antagonist naloxone, whereas the effects induced by GABA and glutamate were not. This action of dynorphin (1-13) is comparable to that of other kappa-agonists in this brain region and suggests that dynorphin (1-13) may be a ligand for the kappa opiate receptor.