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OBJECTIVE The prevalence of epilepsy in the older adult population is increasing. While surgical intervention in younger patients is supported by level I evidence, the safety and efficacy of epilepsy surgery in older individuals is less well established. The aim of this study was to evaluate seizure freedom rates and surgical outcomes in older epilepsy patients. METHODS The authors’ institutional electronic database was queried for patients older than 50 who had undergone epilepsy surgery during 2002–2018. Cases were grouped into 50–59, 60–69, and 70+ years old. Seizure freedom at the last follow-up constituted the primary outcome of interest. The institutional analysis was supplemented by a literature review and meta-analysis (random effects model) of all published studies on this topic as well as by an analysis of complication rates, mortality rates, and cost data from a nationwide administrative database (Vizient Inc., years 2016–2019). RESULTS A total of 73 patients (n = 16 for 50–59 years, n = 47 for 60–69, and n = 10 for 70+) were treated at the authors’ institution. The median age was 63 years, and 66% of the patients were female. At a median follow-up of 24 months, seizure freedom was 73% for the overall cohort, 63% for the 50–59 group, 77% for the 60–69 group, and 70% for the 70+ group. The literature search identified 15 additional retrospective studies (474 cases). Temporal lobectomy was the most commonly performed procedure (73%), and mesial temporal sclerosis was the most common pathology (52%), followed by nonspecific gliosis (19%). The pooled mean follow-up was 39 months (range 6–114.8 months) with a pooled seizure freedom rate of 65% (95% CI 59%–72%). On multivariable meta-regression analysis, an older mean age at surgery (coefficient [coeff] 2.1, 95% CI 1.1–3.1, p < 0.001) and the presence of mesial temporal sclerosis (coeff 0.3, 95% CI 0.1–0.6, p = 0.015) were the most important predictors of seizure freedom. Finally, analysis of the Vizient database revealed mortality rates of 0.5%, 1.1%, and 9.6%; complication rates of 7.1%, 10.1%, and 17.3%; and mean hospital costs of $31,977, $34,586, and $40,153 for patients aged 50–59, 60–69, and 70+ years, respectively. CONCLUSIONS While seizure-free outcomes of epilepsy surgery are excellent, there is an expected increase in morbidity and mortality with increasing age. Findings in this study on the safety and efficacy of epilepsy surgery in the older population may serve as a useful guide during preoperative decision-making and patient counseling.

To interrogate the association of tumor-associated syrinxes with postoperative neurological and oncological outcomes in patients surgically treated for WHO grade 2 spinal ependymomas.Adults treated for primary spinal intramedullary ependymomas between 2000 and 2020 were identified and data were gathered on preoperative neurological exam, radiographic characteristics, operative details, and postoperative neurological outcome. Neurological status was graded on the modified McCormick Scale (MMS). Neurological worsening immediately postoperatively and at last follow-up were defined by ≥ 1 MMS grade deterioration. Decision-tree analyses were also performed to identify independent predictors of new neurological deficits.Seventy patients were identified; mean age 45.4 ± 12.7; 60% male. Forty-eight patients (68.6%) had tumor-associated syrinxes, were more common among males (68.8%) and cervical lesions (68.8 vs. 31.8%; P = 0.005). Postoperatively patients with syrinxes had better MMS (P = 0.035) and were less likely to require a gait aid (39.6 vs. 81.8; P = 0.002). This latter difference persisted to last follow-up (22.9 vs. 59.1%; P = 0.006). On decision-tree analysis the strongest predictors of long-term neurological worsening were advanced age (≥ 63 years) and worse baseline neurological function. Worsened neurological status in the immediate postoperative period was best predicted by thoracic localization, the presence of a hemosiderin cap, and longer craniocaudal extension.For spinal ependymomas, tumor-associated syrinxes may portend decreased risk for immediate postoperative neurologic deficits but do not predict long-term neurological outcomes (MMS) or odds of successful gross total resection. Thoracic localization appears to best predict new immediate postoperative deficits, and worse baseline neurological function and advanced age best predict long-term deficits.

In the present study, the effect of dolomite and olivine as catalysts on the carbon dioxide (CO2) gasification of a candidate renewable solid recovered fuel, known as Subcoal™ was determined. Thermogravimetric analysis (TGA) was used to produce the TGA curves and derivative thermogravimetry (DTG) for the gasification reaction at different loadings of the catalyst (5, 10, 15 wt.%). The XRD results showed that the crystallinity proportion in Subcoal™ powder and ash was 42% and 38%, respectively. The Arrhenius constants of the gasification reaction were estimated using the model-fitting Coats–Redfern (CR) method. The results showed that the mass loss reaction time and thermal degradation decreased with the increase in catalyst content. The degradation reaction for complete conversion mainly consists of three sequences: dehydration, devolatilisation, and char/ash formation. The complete amount of thermal degradation of the Subcoal™ sample obtained with dolomite was lower than with olivine. In terms of kinetic analysis, 19 mechanism models of heterogeneous solid-state reaction were compared by the CR method to identify the most applicable model to the case in consideration. Among all models, G14 provided excellent linearity for dolomite and G15 for olivine at 15 wt.% of catalyst. Both catalysts reduced the activation energy (Ea) as the concentration increased. However, dolomite displayed higher CO2 gasification efficiency of catalysis and reduction in Ea. At 15 wt.% loading, the Ea was 41.1 and 77.5 kJ/mol for dolomite and olivine, respectively. Calcination of the mineral catalyst is substantial in improving the activity through enlarging the active surface area and number of pores. In light of the study findings, dolomite is a suitable mineral catalyst for the industrial-scale of non-recyclable waste such as Subcoal™ gasification.

Although stereotactic EEG (sEEG) has become a widely used intracranial EEG technique, the significance of subclinical seizures (SCS) recorded on sEEG is unclear and studies examining this finding on sEEG are limited. We investigated (1) the prevalence of SCS in patients undergoing sEEG and clinical factors associated with their presence, (2) how often the subclinical seizure onset zone (SOZ) colocalizes with clinical SOZ, (3) the association of SCS and surgical outcomes, and (4) the influence of resection of the subclinical SOZ on surgical outcome.We reviewed all patients who underwent intracranial monitoring with sEEG at our institution from 2015 through 2020 (n=169). Patient and seizure characteristics were recorded, as was concordance of subclinical and clinical seizures and post-surgical outcomes.SCS were observed during sEEG monitoring in 84 of 169 patients (50%). There was no difference in the prevalence of SCS based on imaging abnormalities, temporal vs extratemporal SOZ, number of electrodes, or pathology. SCS were more common in females than males (62% vs 40%, p=0.0054). SCS had complete concordance with clinical SOZ in 40% of patients, partial concordance in 29%, overlapping in 19%, and discordant in 12%. Eighty-three patients had surgery, 44 of whom had SCS. There was no difference in excellent outcome (ILAE 12 or 2) based on the presence of SCS or SCS concordance with clinical SOZ; however, there were improved outcomes in patients with complete resection of the subclinical SOZ compared with patients with incomplete resection (p =0.013).These findings demonstrate that SCS are common during sEEG and colocalize with the clinical SOZ in most patients. Discordance with clinical SOZ does not necessarily predict poor surgical outcome; rather, complete surgical treatment of the subclinical SOZ correlates with excellent outcome. For unclear reasons, subclinical seizures occurred more commonly in females than males.

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Pulverised coal injection (PCI) is used in ironmaking to replace expensive and energy intensive coke with coal, reducing overall costs and greenhouse gas emissions. As the coke making process removes some of the sulphur present in coal, the utilisation of PCI results in the admission of greater levels of sulphur into the blast furnace. The increased sulphur levels could potentially lead to an increase in costs and energy usage related to hot metal sulphur removal processes. In an increasingly volatile market, the ability to make use of higher sulphur coals is also of both financial and logistical relevance.\ud\udThis work aims to produce a more thorough understanding of the transformation of sulphur introduced through PCI into the blast furnace, leading to changes in coal selection, blending, or mitigation efforts.\ud\udThe volatilisation of sulphur from four coals used in PCI was investigated using a drop tube furnace (DTF) to produce conditions similar to a blast furnace raceway. Chars and flue gases were analysed using a range of techniques, including X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, and wet chemistry methods.\ud\udThe coal’s burnout was found to be the biggest factor in coal sulphur volatilisation. It was found that a coal’s volatile matter content was a key indicator into the volatility of a coal’s sulphur content; it influences the rate of a coal’s burnout, the availability of hydrogen for the formation of H2S, and the reactivity of the produced chars. Coals with higher volatile matter contents are more likely to volatilise their sulphur component at shorter residence times than coals with lower volatile matter contents. The bonding of volatilised sulphur to nascent char was seen in coals with lower volatile matter contents. The sulphur forms present in the initial coal samples were shown to influence the sulphur forms found in the collected chars.

The injection of coal through tuyeres into a blast furnace is widely adopted throughout the industry to reduce the amount of coke used and to improve the efficiency of the iron making process. Coals are selected depending on their availability, cost, and the physical and chemical properties determined by tests, such as the volatile matter content, fixed carbon, and ash content. This paper describes research comparing the laboratory measured properties of injection coals that were used over a two-month production period compared to the process variables and measurements of the blast furnace during that study period. In addition to the standard tests, a drop tube furnace (DTF) was used to compare the burnout of coals and the char properties against the production data using a range of statistical techniques. Linear regression modelling indicated that the coal type was the most important predictor of the coal rate but that the properties measured using laboratory tests of those coals were a minor feature in the model. However, comparisons of the Spearman’s correlations between different variables indicated that the reverse Boudouard reactivity of the chars, prepared in the DTF from the coals, did appear to be related to some extent to the coal and coke rates on production. It appears that the constant process adjustments made by the process control systems on the furnace make it difficult to identify strong correlations with the laboratory data and that the frequency of coal sampling and the coal blend variability are likely to contribute to this difficulty.

The global net emissions of the Kyoto Protocol greenhouse gases (GHG), such as carbon dioxide (CO2), fluorinated gases, methane (CH4), and nitrous oxide (N2O), remain substantially high, despite concerted efforts to reduce them. Thermal treatment of solid waste contributes at least 2.8–4% of the GHG in part due to increased generation of municipal solid waste (MSW) and inefficient treatment processes, such as incineration and landfill. Thermal treatment processes, such as gasification and pyrolysis, are valuable ways to convert solid materials, such as wastes into syngas, liquids, and chars, for power generation, fuels, or for the bioremediation of soils. Subcoal™ is a commercial product based on paper and plastics from the source segregated waste that is not readily recyclable and that would otherwise potentially find its way in to landfills. This paper looks at the kinetic parameters associated with this product in pyrolysis, gasification, and combustion conditions for consideration as a fuel for power generation or as a reductant in the blast furnace ironmaking process. Thermogravimetric Analysis (TGA) in Nitrogen (N2), CO2, and in air, was used to measure and compare the reaction kinetics. The activation energy (Ea) and pre-exponential factor A were measured at different heating rates using non-isothermal Ozawa Flynn Wall and (OFW) and Kissinger-Akahira-Sonuse (KAS) model-free techniques. The TGA curves showed that the thermal degradation of Subcoal™ comprises three main processes: dehydration, devolatilization, and char and ash formation. In addition, the heating rate drifts the devolatilization temperature to a higher value. Likewise, the derivative thermogravimetry (DTG) results stated that Tm degradation increased as the heating rate increased. Substantial variance in Ea was noted between the four stages of thermal decomposition of Subcoal™ on both methods. The Ea for gasification reached 200.2 ± 33.6 kJ/mol by OFW and 179.0 ± 31.9 kJ/mol by KAS. Pyrolysis registered Ea values of 161.7 ± 24.7 kJ/mol by OFW and 142.6 ± 23.5 kJ/mol by KAS. Combustion returned the lowest Ea values for both OFW (76.74 ± 15.4 kJ/mol) and KAS (71.0 ± 4.4 kJ/mol). The low Ea values in combustion indicate shorter reaction time for Subcoal™ degradation compared to gasification and pyrolysis. Generally, TGA kinetics analysis using KAS and OFW methods show good consistency in evaluating Arrhenius constants.

Net outcome‐type biodiversity policies are proliferating globally as perceived mechanisms to reconcile economic development and conservation objectives. The UK government's Environment Bill will mandate that most new developments in England demonstrate that they deliver a biodiversity net gain (BNG) to receive planning permission, representing the most wide‐ranging net outcome type policy globally. However, as with many nascent net‐outcome policies, the likely outcomes of mandatory BNG have not been explored empirically. We assemble all BNG assessments (accounting for ∼6% of England's annual housebuilding and other infrastructure) submitted from January 2020 to February 2021 in six early‐adopter councils who are implementing mandatory no net loss or BNG requirements in advance of the national adoption of mandatory BNG, and analyze the aggregate habitat changes proposed. Our sample is associated with a 34% reduction in the area of nonurban habitats, generally compensated by commitments to deliver smaller areas of higher quality habitat years later in the development project cycle. Ninety‐five percent of biodiversity units delivered in our sample come from habitats within or directly‐adjacent to the development footprint managed by the developers. However, we find that these gains fall within a governance gap whereby they risk being unenforceable, a challenge that is shared with other net outcome type policies implemented internationally.

Renewably generated ammonia offers a form of carbon-free chemical energy storage to meet the differences between uncertain renewable supply and fluctuating demand, and has the potential to support future energy requirements as a power-to-X concept. The storage and transportation characteristics of NH3 are favorable compared with H2, however there are significant combustion research challenges to enhance fuel reactivity whilst reducing harmful emissions production. The purpose of the presented work was to evaluate different fuel delivery concepts for a representative GT combustor. An experimental and numerical comparison was made between swirl-stabilized premixed and diffusion NH3-air flames at elevated inlet temperature (473 K). The exhaust NOx and unburned NH3 emissions generated from each concept were quantified to optimize operational combustor performance. High-speed OH* and NH2* chemiluminescence was employed to characterize the change in flame topology with variation in fuel-air equivalence ratio, and the resultant influence on measured emission concentrations. Chemiluminescence intensities were shown to elucidate changes in sampled exhaust emissions, enabling detailed analysis of intermediate chemistry. A comparison was made between experimental data and chemical kinetic simulations with a reactor network model, demonstrating the sensitivity of NOx emissions to premixed fuel-air equivalence ratio. A comparison was also made between exclusive primary airflow, and the staged introduction of secondary air, to quantify the change in NOx production between each configuration and improve fuel burnout. Secondary air loadings were incrementally increased through the combustor, and the change in exhaust emissions mapped. In addition, reactant humidification was employed as a secondary process for NOx reduction, having shown favorable performance with NH3/H2 mixtures to limit thermochemical NO production. The efficacy of humidification was compared for both premixed and diffusion configurations.

The majority of spinal meningiomas are grade I tumors, as defined by World Health Organization (WHO) classification making atypical (grade II) or anaplastic (grade III) tumors extremely rare lesions to encounter in clinical practice. Here, we present our institutional experience of management of grade II and III spinal meningiomas. Following IRB approval, we queried all available institutional electronic medical records for patients undergoing surgical resection of pathology-proven spinal meningiomas, with further review of patients with grade II and III. Variables of interest included age, sex, histological type, tumor size, symptoms at baseline, treatment characteristics, symptom resolution at the last follow-up, recurrence, NF-2 status, concurrent intracranial meningioma, and mortality. Kaplan Meier curves were constructed to study time to progression/recurrence. A total of 188 patients undergoing surgical resection of spinal meningioma between 1988 and 2018 were identified. Among those, 172 (91.5%) patients had grade I meningioma and 16 (8.5%) patients had high grade meningiomas [grade II (15) and III (1)]. Over a median (IQR) follow-up of 8.0 years (5.1–13.0), mortality and recurrence rates were 18.8% (n = 3) and 47.1% (n = 8), respectively. In univariate analysis, adjuvant radiotherapy and thoracic segment involvement were associated with lower rates of recurrence while male sex was associated with a higher rate of recurrence. Results showed variations in clinical outcomes for patients with high grade spinal meningiomas, especially the recurrence. Adjuvant radiotherapy and thoracic segment involvement was associated with lower rates of recurrence while recurrence ocurred at a higher rate in males.

Energy storage is one of the highest priority challenges in transitioning to a low-carbon economy. Fluctuating, intermittent primary renewable sources such as wind and solar require low-carbon storage options to enable effective load matching, ensuring security of supply. Chemical storage is one such option, with low or zero carbon fuels such as hydrogen, alcohols and ammonia having been proposed. Ammonia provides zero-carbon hydrogen storage whilst offering liquefaction at relatively low pressures and atmospheric temperatures, enabling ease of transportation in a pre-existing infrastructure. Ammonia can also be used directly as a fuel in power plants such as gas turbines to avoid complete conversion back to hydrogen. It is a relatively unreactive fuel, and so it is of interest to explore the potential utilisation of ammonia/hydrogen mixtures. Hence, the goal of this paper is to provide a first assessment of the suitability of a chosen 70%NH330%H2 (%vol) blend for utilisation within a gas turbine environment, based on primary combustion diagnostics including combustion stability – via OH chemiluminescence - and emissions (NOx and NH3). An established optical generic swirl-burner enabled studies of the influence of equivalence ratio (φ > 1), ambient temperature (

The majority of spinal meningiomas are grade I tumors, as defined by World Health Organization (WHO) classification making atypical (grade II) or anaplastic (grade III) tumors extremely rare lesions to encounter in clinical practice. Here, we present our institutional experience of management of grade II and III spinal meningiomas.Following IRB approval, we queried all available institutional electronic medical records for patients undergoing surgical resection of pathology-proven spinal meningiomas, with further review of patients with grade II and III. Variables of interest included age, sex, histological type, tumor size, symptoms at baseline, treatment characteristics, symptom resolution at the last follow-up, recurrence, NF-2 status, concurrent intracranial meningioma, and mortality. Kaplan Meier curves were constructed to study time to progression/recurrence.A total of 188 patients undergoing surgical resection of spinal meningioma between 1988 and 2018 were identified. Among those, 172 (91.5%) patients had grade I meningioma and 16 (8.5%) patients had high grade meningiomas [grade II (15) and III (1)]. Over a median (IQR) follow-up of 8.0 years (5.1-13.0), mortality and recurrence rates were 18.8% (n = 3) and 47.1% (n = 8), respectively. In univariate analysis, adjuvant radiotherapy and thoracic segment involvement were associated with lower rates of recurrence while male sex was associated with a higher rate of recurrence.Results showed variations in clinical outcomes for patients with high grade spinal meningiomas, especially the recurrence. Adjuvant radiotherapy and thoracic segment involvement was associated with lower rates of recurrence while recurrence ocurred at a higher rate in males.

Steelmaking is energy intensive, with manufacturing facilities representing some of the biggest point-source carbon dioxide (CO2) emitters in the UK. Efficiency improvements are essential with rising energy costs, driving significant investment from the UK iron and steel sector. However, the industry still finds it difficult to justify waste heat recovery (WHR) projects, as individual schemes incorporating waste heat capture and an end-use for the waste heat often incur high capital costs, resulting in long payback times. This paper describes the conceptual and numerical development of a strategy for the deployment of WHR using a large integrated steel works as a case study. An existing asset was utilised to link individual waste heat schemes together with a single end-user; thereby reducing the capital requirement for each subsequent project. The proposed strategy and its development is discussed, followed by the resultant carbon dioxide and energy savings (estimated to be 2.3 Mt and equivalent to £45 million), over the 6-year period since its implementation.

With developing interest in NH3 as a prospective energy carrier, combustor designs and fuelling concepts require optimisation to reduce NOx emissions. Through the introduction of staged combustor concepts, pathways have previously been identified that limit NOx production whilst improving combustor efficiency and reducing unburned NH3. However, the efficacy of secondary air staging is sensitive to the primary flame behaviour, and whilst low NOx emissions can be achieved at rich conditions, high unburned NH3 leads to greater global NOx concentrations from downstream production. Here, time-resolved OH*, NH2* and NH* chemiluminescence were employed together for the first time for NH3-air and NH3-H2-air flames to investigate a primary flame configuration that produced the lowest combined emissions concentration. A generic, fuel-flexible burner was developed to enable partial and full premixing, together with operation of a swirl-stabilised non-premixed flame. Initially, NH3-H2-air flames were employed in a range of configurations and produced markedly different chemiluminescence and emissions results as functions of global equivalence ratio. The performance of a pure NH3-air flame was subsequently investigated and compared to the blended fuel results. Optical trends complemented changes in sampled exhaust emissions, enabling analysis of intermediate chemistry. Burner inlet temperature and pressure were then increased proportionally to maintain equivalent bulk nozzle exit velocities. Contrasting trends were identified as functions of fuel composition and equivalence ratio, with a comprehensive database of optical and analytical results generated. Results obtained for NH3-H2-air suggest the most favourable configuration resulted from a partially premixed flame employing H2 as a pilot, operating under rich conditions (Φ=1.2). However, at higher temperatures and pressures, the trends observed for non-premixed NH3-air flames will lead to uperior performance, particularly with a small increase in equivalence ratio.

Modern gas turbines operate with large amounts of excess air for cooling and dilution of the combustion gases, in order to maintain gas turbine blade integrity. Selective recycling of CO2 into the gas turbine compressor inlet, also referred as Selective Exhaust Gas Recirculation (SEGR), can reduce the large volumetric flow rate through a CO2 capture system caused by the gas turbine excess air requirements, by 70 - 77%. It also increases CO2 concentrations to 14-18 vol% from 3-4% vol, increasing the driving force for post-combustion capture systems. This paper provides a comprehensive assessment of the concept and presents research outcomes from the UK-funded SELECT project, including power plant and process modelling, techno-economic assessments, pilot-scale gas turbine experimental work and experimental combustion tests on a representative combustor. Using an integrated model of turbomachinery, power cycles and a generic post-combustion CO2 capture technology with a 30%wt MEA solvent, we show that a reduction of up to 50% of the absorber of the capture plant – the most capital intensive part of the process – can be achieved. The compressor and gas turbine operate without any significant deviation from their design point, and a marginal increase of 0.5% point in the net electrical efficiency can be achieved. Pilot-scale testing - conducted at the Pilot Scale Advanced Capture Technologies (PACT) facilities at the University of Sheffield - show that CO2 injection at the compressor inlet of a 100 kW micro gas turbine (mGT) connected to a 1 tonne per day CO2 capture plant reduces net electrical efficiency by 1-2 %point. This is caused by lower flame temperatures, and, unlike in larger gas turbines, the control system of the micro gas turbine. Combustion tests at Cardiff University’s Gas Turbine Research Centre (GTRC) in a pilot-scale high-pressure generic premixed swirl burner, representative of modern dry-low emissions (DLR) gas turbine burners, show the effect of CO2 as diluent on the operational premixed CH4/air flame stability, chemical kinetics and measured exhaust gas composition. CO2 acts as a combustor inhibitor, causing downstream migration of the premixed flame zone, leading to eventual blow-off, instability and extinction, requiring a change in the operation equivalence ratio. The effect of adding CO2 leads to a reduction in the adiabatic flame temperature due to thermal quenching, which results in higher CO emissions and smaller thermal NOx emissions. Increasing pressure has a significant reducing effect on CO emissions, yet it results in higher NOx production, which may require mitigation if this trend is found to continue towards pressures approaching that of the F-class gas turbine. Finally, a conceptual design assessment of a regenerative adsorption wheel with structured adsorbents is proposed for the selective recycling of CO2 in combined cycle gas turbine (CCGT) power plants. It has the advantage of a relatively small pressure drop to reduce the derating of the gas turbine compared to selective CO2 membrane systems. An equilibrium model of a rotary adsorber with commercially available activated carbon adsorbents shows that four rotary wheels of 24 m diameter and 2 m length would be required in an 820MW CCGT plant. A reduction of 50% in the mass of adsorbent would be possible with an adsorbent with a higher capacity, such as Zeolite X13, with upstream dehydration of the flue gases.

A study has been undertaken to experimentally and numerically evaluate the use of carbon dioxide or steam as premixed fuel additive in hydrogen-air flames to aid in the development of lean premixed (LPM) swirl burner technology for low NOx operation. Chemical kinetics modelling indicates that the use of CO2 or steam in the premixed reactants reduces H2-air laminar flame speed and adiabatic flame temperature within the well-characterized range of preheated LPM methane-air flames, albeit in markedly different proportions; for example, nearly 65 %vol CO2 as a proportion of the fuel is required for a reduction in laminar flame speed to equivalent CH4-air values, while approximately 30 %vol CO2 in the fuel is required for an equivalent reduction in adiabatic flame temperature, significantly impacted by the increased heat capacity of CO2. The 2nd generation high-pressure generic swirl burner, designed for use with LPM CH4-air, was therefore utilized to experimentally investigate the influence of CO2 and steam dilution on pressurized (up to 250 kW/MPa), preheated (up to 573 K), LPM H2-air flame stability using high-speed OH* chemiluminescence. In addition, exhaust gas emissions, such as NOx and CO, have been measured in comparison with equivalent thermal power conditions for CH4-air flames, showing that low NOx operation can be achieved. Furthermore, pure LPM H2-air flames are characterized for the first time in this burner, stabilized at low equivalence ratio (approximately 0.24) and increased Reynolds number at atmospheric pressure compared to the stable CH4-air flame (equivalence ratio of 0.55). The influence of extinction strain rate is suggested to characterize, both experimentally and numerically, the observed lean flame behavior, in particular as extinction strain rate has been shown to be non-monotonic with pressure for highly-reactive and diffuse fuels such as hydrogen.

OBJECTIVE Insular lobe epilepsy is a challenging condition to diagnose and treat. Due to anatomical intricacy and proximity to eloquent brain regions, resection of epileptic foci in that region can be associated with significant postoperative morbidity. The aim of this study was to review available evidence on postoperative outcomes following insular epilepsy surgery. METHODS A comprehensive literature search (PubMed/MEDLINE, Scopus, Cochrane) was conducted for studies investigating the postoperative outcomes for seizures originating in the insula. Seizure freedom at last follow-up (at least 12 months) comprised the primary endpoint. The authors also present their institutional experience with 8 patients (4 pediatric, 4 adult). RESULTS A total of 19 studies with 204 cases (90 pediatric, 114 adult) were identified. The median age at surgery was 23 years, and 48% were males. The median epilepsy duration was 8 years, and 17% of patients had undergone prior epilepsy surgery. Epilepsy was lesional in 67%. The most common approach was transsylvian (60%). The most commonly resected area was the anterior insular region (n = 42, 21%), whereas radical insulectomy was performed in 13% of cases (n = 27). The most common pathology was cortical dysplasia (n = 68, 51%), followed by low-grade neoplasm (n = 16, 12%). In the literature, seizure freedom was noted in 60% of pediatric and 69% of adult patients at a median follow-up of 29 months (75% and 50%, respectively, in the current series). A neurological deficit occurred in 43% of cases (10% permanent), with extremity paresis comprising the most common deficit (n = 35, 21%), followed by facial paresis (n = 32, 19%). Language deficits were more common in left-sided approaches (24% vs 2%, p < 0.001). Univariate analysis for seizure freedom revealed a significantly higher proportion of patients with lesional epilepsy among those with at least 12 months of follow-up (77% vs 59%, p = 0.032). CONCLUSIONS These findings may serve as a benchmark when tailoring decision-making for insular epilepsy, and may assist surgeons in their preoperative discussions with patients. Although seizure freedom rates are quite high with insular epilepsy treatment, the associated morbidity needs to be weighed against the potential for seizure freedom.

ObjectivesThe study objective was to investigate the prevalence and clinical characteristics of phenobarbitone-associated adverse effects in epileptic cats.MethodsThe medical records of two veterinary referral clinics from 2007 to 2017 were searched for cats fulfilling the inclusion criteria of a diagnosis of epilepsy, treatment with phenobarbitone and available follow-up information on the occurrence of adverse effects. Follow-up information was obtained from the medical records of the primary veterinarian and referral institutions and a questionnaire completed by the cats’ owners.ResultsSeventy-seven cats met the inclusion criteria. Fifty-eight were affected by idiopathic epilepsy and 19 by structural epilepsy. One or more of the following adverse effects were reported in 47% of the cats: sedation (89%); ataxia (53%); polyphagia (22%); polydipsia (6%); polyuria (6%); and anorexia (6%). Logistic regression analyses revealed significant associations between adverse effect occurrence and both phenobarbitone starting dosage and administration of a second antiepileptic drug (AED). For each 1 mg/kg q12h increment of phenobarbitone, the likelihood of adverse effects increased 3.1 times. When a second AED was used, the likelihood of adverse effects increased 3.2 times. No association was identified between epilepsy aetiology and adverse effect occurrence. An idiosyncratic adverse effect, characterised by severe neutropenia and granulocytic hypoplasia, was diagnosed in one cat. This resolved following phenobarbitone discontinuation.Conclusions and relevanceThe prevalence of phenobarbitone-associated adverse effects was 47%. Sedation and ataxia were most common. These are type A adverse effects and are predictable from phenobarbitone’s known pharmacological properties. In the majority of cases, adverse effects occurred within the first month of treatment and were transient. Idiosyncratic (type B) adverse effects, which were not anticipated given the known properties of the drug, occurred in one cat. Increased phenobarbitone starting dosage and the addition of a second AED were significantly associated with the occurrence of adverse effects.

Background The English setter (ES) is predisposed to congenital sensorineural deafness (CSD). CSD prevalence and association with phenotype in the UK ES population are previously unreported. Methods The database of the authors’ institution was searched for ES puppies undergoing brainstem auditory evoked response (BAER) testing for CSD screening (2000–2018). Inclusion criteria were BAER performed at 5–10 weeks of age, testing of complete litters and available phenotypic data. The age, sex, presence of patches at birth, coat colour, iris colour, hearing status and BAER-determined parental hearing status of each puppy were recorded. Multivariable binary logistic regression was performed to determine the significance of these variables as predictors for the likelihood of puppies being unilaterally or bilaterally deaf. Results Inclusion criteria were met for 447 puppies. Hearing was bilaterally normal in 427 (95.5 per cent) puppies. The prevalence of unilateral and bilateral CSD was 3.6 per cent and 0.9 per cent, respectively. Females were 3.3 times more likely to be deaf than males, and puppies with both parents of unknown hearing status were 4.6 times more likely to be deaf than those with at least one normal parent. Conclusion The prevalence of CSD was 4.5 per cent, with female puppies and those with two parents of unknown hearing status at greatest risk.

OBJECTIVE Surgical site infection (SSI) is a rare but significant complication after vagus nerve stimulator (VNS) placement. Treatment options range from antibiotic therapy alone to hardware removal. The optimal therapeutic strategy remains open to debate. Therefore, the authors conducted this retrospective multicenter analysis to provide insight into the optimal management of VNS-related SSI (VNS-SSI). METHODS Under institutional review board approval and utilizing an institutional database with 641 patients who had undergone 808 VNS-related placement surgeries and 31 patients who had undergone VNS-related hardware removal surgeries, the authors retrospectively analyzed VNS-SSI. RESULTS Sixteen cases of VNS-SSI were identified; 12 of them had undergone the original VNS placement procedure at the authors’ institutions. Thus, the incidence of VNS-SSI was calculated as 1.5%. The mean (± standard deviation) time from the most recent VNS-related surgeries to infection was 42 (± 27) days. Methicillin-sensitive staphylococcus was the usual causative bacteria (58%). Initial treatments included antibiotics with or without nonsurgical procedures (n = 6), nonremoval open surgeries for irrigation (n = 3), generator removal (n = 3), and total or near-total removal of hardware (n = 4). Although 2 patients were successfully treated with antibiotics alone or combined with generator removal, removal of both the generator and leads was eventually required in 14 patients. Mild swallowing difficulties and hoarseness occurred in 2 patients with eventual resolution. CONCLUSIONS Removal of the VNS including electrode leads combined with antibiotic administration is the definitive treatment but has a risk of causing dysphagia. If the surgeon finds dense scarring around the vagus nerve, the prudent approach is to snip the electrode close to the nerve as opposed to attempting to unwind the lead completely.

In this study, two Inconel 625 swirl nozzle inserts with identical bulk geometry were constructed via additive layer manufacturing (ALM) for use in a generic gas turbine swirl burner. Further postprocessing by grit blasting of one swirl nozzle insert results in a quantifiable change to the surface roughness characteristics when compared with the unprocessed ALM swirl nozzle insert or a third nozzle insert which has been manufactured using traditional machining methods. An evaluation of the influence of variable surface roughness effects from these swirl nozzle inserts is therefore performed under preheated isothermal and combustion conditions for premixed methane-air flames at thermal power of 25 kW. High-speed velocimetry at the swirler exit under isothermal conditions gives evidence of the change in near-wall boundary layer thickness and turbulent fluctuations resulting from the change in nozzle surface roughness. Under atmospheric combustion conditions, this influence is further quantified using a combination of dynamic pressure, high-speed OH* chemiluminescence, and exhaust gas emissions measurements to evaluate the flame stabilization mechanisms at the lean blowoff and rich stability limits. Notable differences in flame stabilization are evident as the surface roughness is varied, and changes in rich stability limit were investigated in relation to changes in the near-wall turbulence intensity. Results show that precise control of in-process or postprocess surface roughness of wetted surfaces can positively influence burner stability limits and NOx emissions and must, therefore, be carefully considered in the ALM burner design process as well as computational fluid dynamics (CFD) models.

OBJECTIVEThe sitting or semisitting position in neurosurgery allows for several technical advantages, including improved visualization of the surgical field. However, it has also been associated with an increased risk of venous air embolisms and positioning-related complications that limit its commonplace adoption. The authors report a large, single-center series of cervical spine procedures performed with patients in the sitting or prone position in order to assess the perceived risk of intraoperative and postoperative complications associated with the sitting position.METHODSNoninstrumented, single-level posterior cervical spine procedures performed with patients in the sitting/semisitting or prone position from 2000 to 2016 at a single institution were reviewed. Institutional abstraction tools (DataMart and Chart Plus) were used to collect data from the medical records. The two positions were compared with regard to preoperative factors, intraoperative variables, and postoperative outcomes. Multivariable logistic regression models were fitted for 30-day readmission, 30-day return to the operating room, and complication rates.RESULTSA total of 750 patients (sitting, n = 480; prone, n = 270) were analyzed. The median age was 53 years for those who underwent surgery in the prone position and 50 years for those who underwent surgery in the sitting position (IQRs 45–62 years and 43–60 years, respectively), and 35% of the patients were female. Sitting cases were associated with significantly longer anesthetic times (221 minutes [range 199–252 minutes] vs 205 minutes [range 179–254 minutes]) and operative times (126 minutes [range 101–163 minutes] vs 149 minutes [120–181 minutes]). Cardiorespiratory events in the postanesthesia care unit (PACU) were comparable between the two groups, with the exception of episodes of apnea (2.6% vs 0.6%, p = 0.041) and hypoventilation (4.4% vs 0.8%, p < 0.003), which were more frequent in the prone-position cohort. On multivariable analysis, the effect of the sitting versus the prone position was not significant for 30-day readmission (OR 0.77, 95% CI 0.34–1.71, p = 0.52) or reoperation (OR 0.71, 95% CI 0.31–1.60, p = 0.40). The sitting position was associated with lower odds of developing any complication (OR 0.31, 95% CI 0.16–0.62, p < 0.001).CONCLUSIONSBased on the intraoperative and postoperative complications chosen in this study, the sitting position confers a similar safety profile to the prone position. This can be explained by a more anatomic positioning accounting for reduced temporary neurological deficits and reduced PACU-associated hypoventilation noted in this series. Nevertheless, the findings may also reflect institutional familiarity, experience, and mastery of this position type, and outcomes may not reflect practices in general.

Gas products from gasified solid recovered fuel (SRF) have been proposed as a replacement for natural gas to produce electricity in future power generation systems. In this work, the life cycle assessment (LCA) of SRF air gasification to energy was conducted using the Recipe2016 model considering five environmental impact categories and four scenarios in Qatar. The current situation of municipal solid waste (MSW) handling in Qatar is landfill with composting. The results show that using SRF gasification can reduce the environmental impact of MSW landfills and reliance on natural gas in electricity generation. Using SRF gasification on the selected five environmental impact categories—climate change, terrestrial acidification, marine ecotoxicity, water depletion and fossil resource depletion—returned significant reductions in environmental degradation. The LCA of the SRF gasification for the main four categories in the four scenarios gave varying results. The introduction of the SRF gasification reduced climate change-causing emissions by 41.3% because of production of renewable electricity. A reduction in water depletion and fossil resource depletion of 100 times were achieved. However, the use of solar technology and SRF gasification to generate electricity reduced the impact of climate change to almost zero emissions. Terrestrial acidification showed little to no change in all three scenarios investigated. This study was compared with the previous work from the literature and showed that on a nominal 10 kg MSW processing basis, 5 kg CO2 equivalent emissions were produced for the landfilling scenarios. While the previous studies reported that 8 kg CO2 produced per 10 kg MSW is processed for the same scenario. The findings indicate that introducing SRF gasification in solid waste management and electricity generation in Qatar has the potential to reduce greenhouse gas (GHG) emission load and related social, economic, political and environmental costs. In addition, the adoption of the SRF gasification in the country will contribute to Qatar’s national vision 2030 by reducing landfills and produce sustainable energy.

The hydrodynamic behaviour of gas-solid mixtures inside Bed Fluidised Beds (BFB) gasifiers has a major impact on the gasification process due to particles - gas and particle - particle contact mechanisms. The Discrete Phase Model DPM with Multiphase Particle-in-Cell method MPPIC was used as a CFD approach to study the hydrodynamic behaviour of an 800 height x 83 mm φ prototype fluidised bed gasifier with 4 different perforated plate distributors. In terms of bubble forming, pressure drop and superficial velocity, the type D distributor, i.e. triangular, had the best performance among the other types and in turn better bed height and bed movement, thus allowing best fluidisation performance as a consequence of better flow distribution.

Experimental trials have been conducted using an optical swirl burner to compare the heat release and emission profiles from the application of four different aviation fuel blends with changing inlet conditions. The mixtures comprised fossil Jet A-1 and a HRJ (Hydrotreated Renewable Jet fuel) batch produced from used cooking oil processing, and blended in discrete ratios. Changes in the produced emissions were quantified with varying combustor pressure and equivalence ratio, in addition to analysing the distribution of combustion heat release using OH∗ chemiluminescence, and monitoring operational rig temperatures. Results suggest the presence of HRJ can reduce emissions and lead to a more compacted and homogenous heat release zone, beneficial as localised hot-spots can lead to the generation of soot and thermal NOx. An increase in pressure was also shown to compact the flame brush at constant thermal power, due to density changes in the combustion air, and reduced bulk flow. The presented heat release distributions and experimental data are useful for the validation of numerical simulations, particularly for the use of alternative fuels. The work also highlights the correlation of flow/acoustic perturbations with heat release, crucial in characterising global combustion behaviour.

Tritium is ubiquitous in and around nuclear plants, being formed via neutron capture by 2H, 6Li, 10B and 14N and via ternary fission. The highly mobile nature of 3H species results in widespread distribution of the radionuclide. Predictive modeling of 3H activity concentrations is challenging and direct measurement of 3H activities in materials is the preferred approach to underpin waste and environmental assessments. For well over a decade, the UK nuclear industry has engaged in a significant program of site decommissioning of its first generation reactors. This has resulted in a high demand for the rapid characterization of 3H in a diverse range of matrices, including concretes, metals, plastics, sludges, resins, soils and biota. To support such assessments, it has been necessary to develop dedicated instrumentation in parallel with robust radioanalytical methodologies; namely a multi-tube furnace and a high-capacity, closed (pressurized) oxygen combustion system. Data are presented on the development and validation of these instruments, designed specifically to enable the quantitative extraction of 3H (and other volatile radionuclides) from diverse sample types. Furthermore the furnace system has been employed as a tool to gain insights into the 3H association in decommissioning and environmental matrices exposed to 3H arising from nuclear power plant operations through tritium evolution with temperature profiling. The impact of the chemical speciation of 3H on analytical strategy is discussed. A major benefit of the multi-sample furnace is its ease of use and applicability to 3H determination in virtually any sample type. The complementary HBO2 oxygen combustion system has been developed for the quantitative oxidation of organic-rich samples (e.g. wood, plastic, oil, biota) and analytical data prove its effectiveness.

There is a perceived need for multi-fuel burner geometries capable of operating with variable composition fuels from diverse sources to achieve fuel flexibility in gas turbines. The objective of the research covered herein is a comparison study between two liquid fuels, a biodiesel (in a pure form) and the biodiesel as a saturated mixture with a pyrolysis by-product; these two fuels were compared against a standard kerosene as a baseline. The research methodology involved two stages: firstly atomization patterns and injection regimes were obtained using a high speed imaging method, secondly a combustion test campaign was undertaken using a swirl burner to quantify the operational behaviour, species production and exhaust gas compositions of the fuels. Emissions, flame stability trends and power outputs were measured at gas turbine relevant equivalence ratios. Excess oxygen and atomization trends in the biodiesel seem to be playing a major role in the production of emissions and flame stability when compared to kerosene. Also, heavy organics seem to be acting as catalytic substances for OH production close to the burner mouth. In terms of stability and combustion, it is proposed that the saturated blend would be a viable candidate for power generation. © 2016

The choice of subdural grid (SDG) or stereoelectroencephalography (sEEG) for patients with epilepsy can be complex and in some cases overlap. Comparing postoperative pain and narcotics consumption with SDG or sEEG can help develop an intracranial monitoring strategy.A retrospective study was performed for adult patients undergoing SDG or sEEG monitoring. Numeric Rating Scale (NRS) was used for pain assessment. Types and dosage of the opioids were calculated by converting into milligram morphine equivalents (MME). Narcotic consumption was analyzed at the following three time periods: I. the first 24 h of implantation; II. from the second postimplantation day to the day of explantation; and III. the days following electrode removal to discharge.Forty-two patients who underwent SDG and 31 patients who underwent sEEG implantation were analyzed. After implantation, average NRS was 3.7 for SDG and 2.2 for sEEG (P .001). After explantation, the NRS was 3.5 for SDG and 1.4 in sEEG (P .001). Sixty percent of SDG patients and 13% of sEEG patients used more than one opioid in period III (P .001). The SDG group had a significantly higher MME throughout the three periods compared with the sEEG group: period I: 448 (SDG) vs. 205 (sEEG) mg, P = .002; period II: 377 (SDG) vs. 102 (sEEG) mg, P .001; and period III: 328 (SDG) vs. 75 (sEEG) mg; P = .002. Patients with the larger SDG implantation had the higher NRS (P = .03) and the higher MME at period I (P = .019). There was no correlation between the number of depth electrodes and pain control in patients with sEEG.Patients undergoing sEEG had significantly less pain and required fewer opiates compared with patients with SDG. These differences in perioperative pain may be a consideration when choosing between these two invasive monitoring options.

This chapter explains why protecting one’s intellectual property is important and describes the various protections available for intellectual property commonly developed by digital health companies. A discussion of key considerations in developing a comprehensive intellectual property plan is also provided.

The use of metallic Additive Layer Manufacturing (ALM) is an active area of development for gas turbine components, particularly concerning novel combustor prototypes for micro gas turbines. However, further study is required to understand the influence of this manufacturing technique and subsequent post-processing on the resulting burner component surface roughness and its effect on flame stability. In this study, two Inconel 625 swirl nozzle inserts with identical bulk geometry (swirl number, Sg = 0.8) were constructed via ALM for use in a generic gas turbine swirl burner. Further post-processing by grit blasting of one swirl nozzle insert results in a quantifiable change to the surface roughness characteristics in the burner exit nozzle when compared with the unprocessed ALM swirl nozzle insert or a third nozzle insert which has been manufactured using traditional machining methods. An evaluation of the influence of variable surface roughness effects from these swirl nozzle inserts is therefore performed under preheated isothermal and combustion conditions for premixed methane-air flames at thermal power of 25 kW. High-speed velocimetry at the swirler exit under isothermal air flow conditions gives evidence of the change in near-wall boundary layer thickness and turbulent fluctuations resulting from the change in nozzle surface roughness. Under atmospheric combustion conditions, this influence is further quantified using a combination of dynamic pressure, high-speed OH* chemiluminescence, and exhaust gas emissions measurements to evaluate the flame stabilization mechanisms at the lean blowoff and rich stability limits. Notable differences in flame stabilization are evident as the surface roughness is varied, and changes in rich stability limit were investigated in relation to changes in the near-wall turbulence intensity. Results show the viability of using ALM swirl nozzles in lean premixed gas turbine combustion. Furthermore, precise control of in-process or post-process surface roughness of wetted surfaces can positively influence burner stability limits and must therefore be carefully considered in the ALM burner design process as well as CFD models.

This paper is an experimental study of the kinetics of gasification of olive kernel by using a\ud thermogravimetric fluidized bed reactor technique. Gasification of ‘as received’ and torrefied\ud olive kernels were investigated in a lab-scale bubbling fluidized bed gasifier, operating at up\ud to 3.2 kg/hr. The effect of bed temperature between 550°C and 750°C in 50°C increments on\ud the gasification product gas at mass-based equivalence ratios of 0.15 and 0.2 was studied. To\ud explore the potential of torrefied biomass, the gasification results were compared to that of the\ud ‘as received’ biomass. The product gas from torrefied biomass produced higher H2, CO and\ud CH4 concentrations at identical oxidant flow rates in addition to higher cold gas efficiency and\ud higher product gas heating value. The influence of equivalence ratio in gasification was also\ud investigated at reactor temperatures of 750°C and five equivalence ratios (0.15, 0.2, 0.25, 0.3,\ud and 0.35). The results revealed that the torrefied biomass has the highest HHV at an\ud equivalence ratio of 0.2 with a value of 6.09 MJ/Nm3\ud , while ‘as received’ biomass 4.72\ud MJ/Nm3\ud . Kinetic experiments under isothermal conditions were performed for the gasification\ud of the materials in continuous mode. A mass balance model was successfully used to provide\ud the capability of separately determining the rate constant of the reactions taking place. The\ud kinetic parameters were calculated by a first order reaction model giving activation energies\ud for ‘as received’ olive kernels of 84 kJ/mole and for torrefied olive kernels of 106 kJ/mole.

Case summary An 8-year-old neutered female domestic longhair cat was presented for investigation of a 48 h history of lethargy and pelvic limb ataxia. MRI of the spinal cord and vertebral column (C1 to sacrum) and brain was unremarkable. Lumbar cerebrospinal fluid analysis revealed pleocytosis and increased protein concentration. Thoracic radiographs and abdominal ultrasound were unremarkable. Anti-inflammatory doses of prednisolone were administered. Clinical deterioration occurred over the following 2 days, with the development of lower motor neuron deficits in both thoracic limbs. On repetition of the MRI, bilateral enlargement, T2-weighted hyperintensity, and marked contrast enhancement of the C7, C8 and T1 nerve roots, spinal nerves and brachial plexuses were observed. Infectious disease testing was negative. An immune-mediated inflammatory process was suspected and immunosuppressive doses of prednisolone were commenced. The clinical signs improved transiently, but marked deterioration occurred after 2 weeks. The patient was euthanased and a post-mortem examination was performed. A lymphocytic inflammatory infiltrate was detected in the C7, C8 and T1 nerve roots and dorsal root ganglia, and neoplastic plasma cells were identified in multiple organs. A diagnosis of non-cutaneous extramedullary plasmacytoma with multiorgan involvement and paraneoplastic ganglioradiculoneuritis was reached. Relevance and novel information Paraneoplastic ganglioradiculoneuritis in association with a plasma cell neoplasia has not been previously reported in the cat and should be considered as a differential diagnosis for cats with clinical or imaging evidence of an inflammatory process affecting the nerve roots, spinal nerves or brachial plexuses.

Background Laser interstitial thermal therapy (LITT) has emerged as a safe and effective approach to the treatment of temporal lobe epilepsy (TLE). The relationship of ablation volume with postoperative outcomes remains an area of contention. Methods We conducted a systematic review and meta-analysis of available studies on LITT for TLE. Seizure freedom and complication rates were meta-analyzed using a random-effects model. Meta-regression of seizure freedom rate for the overall cohort and mesial temporal sclerosis (MTS) subset (n = 384) was performed adjusting for overall ablation volume as well as percentage of hippocampal and amygdala ablation. Results A total of 13 studies (551 patients) were analyzed. Pooled mean ablation volume was 5376 mm3 (range, 2900–7110 mm3), pooled mean hippocampal ablation was 67.5% (range, 56%–78.3%) and pooled mean amygdala ablation was 58.8% (range, 43%–73.7%). Overall seizure freedom rate was 58% (95% confidence interval [CI], 54%–62%) and was not significantly associated with total ablation volume (P = 0.42), hippocampal ablation (P = 0.67), or amygdala ablation (P = 0.33). Seizure freedom rate for patients with MTS was 66% (95% CI, 58%–74%) and was also not found to be significantly associated with total ablation volume (P = 0.15), hippocampal ablation (P = 0.73), or amygdala ablation (P = 0.43). Overall complication rate was 17% (95% CI, 13%–22%). Conclusions The findings show a pooled seizure freedom rate of 58% for all patients with TLE and 66% for patients with MTS undergoing LITT. The evidence is insufficient to support a significant relationship of seizure freedom rate with total ablation volume as well as hippocampal or amygdala ablation.

The ever-increasing importance of energy efficiency has given rise to numerous areas of concern for operators and developers of combustion plants; as the need to utilise fuel gases of increasingly poor quality and variability is essential for sustainability, while emission standards continuing to become more stringent. Swirl combustors are ubiquitous in industry owing to their great stability range which occurs due to the formation of a CRZ, which through the recycling of heat and active chemical species to the root of the flame enhances stability over a wide range of operating conditions. Alternative fuels containing hydrogen offer the possibility of reduced greenhouse gas emissions; however flashback is of special concern with hydrogen enriched fuels, owing to the very high flame speed of hydrogen. Many by-products of process and waste industries can include a high proportion of hydrogen, for example Coke Oven Gas. Alternatively, many by-product process gases can contain a high proportion of non-combustible species such as nitrogen and carbon dioxide which can substantially reduce their flame speed and as a consequence increase the possibility of the flame extinguishing through blow-off. This paper examines the blow-off and flashback potential of common steelworks process gases (including one which contains hydrogen) in a compact, premixed swirl burner in swirl number regimes representative of those found in practical systems. Methane is used as a base fuel for comparison. All results are obtained at atmospheric pressure without air preheat. The Peclet number modelling approach incorporating a flame quenching parameter was applied to the results obtained for each of the fuel gases. Using this model, the quench factor value was seen to be dependent on burner configuration as well as fuel composition. It was found that the stable burner operating conditions significantly change from fuel to fuel; with the operating points at which flashback occurs with Coke Oven Gas producing blow-off with weaker process gases such as Blast Furnace Gas and Basic Oxygen Steelmaking gas.

The use of thermogravimetric analysis to describe biomass kinetics often uses bench top thermogravimetric analyser (TGA) analysers which are only capable of low heating rates. The aim of this research was to compare experimental fast pyrolysis of Olive kernels in a bespoke laboratory thermogravimetric fluidised bed reactor (TGFBR) characterised by rapid heating rates at high flow rates, compared to a smaller bench scale fixed bed TGA system. The pyrolysis in the TGFBR was analysed by using the isothermal kinetic approach and it was theorised that the pyrolysis decomposition reactions occurred by two mechanisms depending on the temperature, resulting in an activation energy of 67.4 kJ/mol at temperatures below 500 °C. For comparison, a bench scale TGA was used to look at the thermal behaviour in different fixed bed thermal conditions giving a higher activation energy of 74.4 kJ/mol due to the effect of external particle gas diffusion. The effect of biomass particle size (0.3–4.0 mm) on the conversion of biomass at different temperatures, was investigated between 300 and 660 °C in the TGFBR. The results suggested inhibition of internal gas diffusion was more important at lower temperatures, but in comparison had no significant effect when measured in the fixed bed TGA at lower heating rates. Bench top TGA analysis of pyrolysis is a rapid and valuable method, but is limited by smaller sample sizes and lower heating rates. In comparison, the conditions encountered with the laboratory scale TGFBR are more likely to be relevant to larger scale systems where heat distribution, heat transfer and mass diffusion effects play major roles in the reactivity of biomass.

Objective Women with epilepsy (WWE) have lower birth rates than expected. The reasons for this are multifactorial and involve a complex interaction between reproductive endocrine and psychosocial factors. The effect of epilepsy surgery on reproduction in women with drug-resistant focal epilepsy has not previously been studied. Methods Adult women of childbearing age (18–45 years old) with drug-resistant focal epilepsy who had undergone a focal cortical resection between 1997 and 2008 at the Mayo Clinic in Rochester, MN were included in the study. Patients who had a history of hysterectomy or tubal ligation or who were menopausal at the time of surgery were excluded. Data on prior pregnancies and births, epilepsy history, surgical treatment, hormonal dysfunction, and socioeconomic status were obtained using a retrospective chart review. Associations between various clinical and demographic variables with changes in pregnancies and births from pre- to postsurgery were assessed using Chi-square or Fisher's exact test for categorical variables and Wilcoxon rank sum test for continuous variables. All tests were 2-sided, and p-values less than 0.05 were considered statistically significant. All analyses were performed using SAS software version 9.2 (SAS INC, Cary NC). Results One hundred and thirteen women (average age: 30.5 years) were included in the study. Average length of follow-up was 5.7 years (SD-3.90). Sixty-four patients (57.5%) were nulliparous at the time of surgery. Sixty-one patients (54%) had never been married. Average number of pregnancies per patient prior to surgery was 0.93, and average number of births prior to surgery was 0.73. After surgery, a total of 17 women had a total of 35 pregnancies and 25 births. The average number of pregnancies and births after surgery was 1.27 and 0.96, respectively. Infertility was reported in one patient postoperatively. Patients who were younger at the time of surgery experienced a greater change in the number of pregnancies and births after surgery (p = 0.0036 and 0.0060, respectively). Patients who received fewer antiepileptic drug medication trials by the time of surgery also had a greater change in the number of births after surgery (p = 0.0362). Seizure onset localization and lateralization, presurgical seizure frequency, age at seizure onset, duration of epilepsy, and postoperative seizure outcome were not statistically significant factors. Conclusion The present retrospective observational study provides additional evidence for the importance of early surgical treatment in women with drug-resistant focal epilepsy. Patients who had received fewer medications prior to surgery were more likely to experience an increase in births following surgery. The significance of these findings requires further investigation but may support a role for earlier surgical intervention in the management of drug-resistant focal epilepsy.

Grinding coals to a pulverised coal specification for blast furnace injection can be costly, which is why some iron manufacturers choose a larger granulated coal size specification. However, there is a concern that these coals may have lower burnout in the raceway region so there is a technical and economic balance with coal grinding. This paper investigates how the process of grinding alters the physical properties, plus the surface chemistry, of coals and their chars formed in a drop tube furnace; it was found that in many cases the larger particle size coals gave improved combustion burnout compared to smaller sizes. The physical properties of the chars, formed from grinding coals to different sizes, resulted in char swelling in the smaller particle sizes, compared to char fragmentation for the larger size classifications. Minerals phases associated with better coal reactivity were found to undergo higher conversion to other chemical forms with the larger size coals, suggesting a potential catalytic or synergistic contribution to their burnout. A closer look at the surface chemistry suggests that the action of grinding coals has an important effect on the surface chemistry. The XPS spectra of the chars, formed in a drop tube furnace, indicated that grinding the coals to a smaller particle size reduced the carbon–oxygen and carbon–mineral interactions compared to the larger sizes and correlated with the higher burnouts. An increasing trend was identified for the carbon sp2 bonding with larger size and higher rank coals which correlated with their burnout at low carbon conversions; however, this did not hold at higher conversions, suggesting other factors were more dominant.

The Legacy It was a woman’s hand. In life, in its proper place at the end of a woman’s arm, I could easily believe that it had been beautiful. But as it lay before me on the table, amidst the heap of papers in...

A four-year-old female neutered greyhound was presented for investigation of back pain and cough one week after an episode of extreme exertion. Investigations revealed severely elevated creatine kinase (CK), but no other haematological, biochemical or urinary abnormalities. MRI of the thoracolumbar spine showed diffuse, bilaterally symmetrical signal changes of the longissimus and iliocostalis muscles. These muscles were mildly hyperintense on T1W and markedly hyperintense on T2W and short tau inversion recovery (STIR) images, with strong contrast enhancement. The signal changes were consistent with muscle oedema, which was attributed to exertional myopathy. MRI of the pharynx demonstrated ceratohyoid-epihyoid subluxation. This dog made a complete recovery with two weeks of conservative management, which consisted of strict rest and analgesia (carprofen and gabapentin).

Blast furnace coal injection is a vital part of modern ironmaking, reducing the amount of coke reductant required in the process and increasing its efficiency. However the injection of different coals or their blends, into the raceway formed by the hot blast, has technical issues due to the very short particle residence times and the limited availability of oxygen in this region. This makes complete burnout difficult and limits the range of coals suitable for this application, leading to partially burnt chars being carried out of the raceway into the blast furnace shaft and potentially into the off-gas system.\ud \ud This paper explores the fate of these chars, from a range of different coals, looking at how this influences the selection for injection and the implication of these on the blast furnace. In particular, we have looked beyond the limitations of selecting coals based on proximate analysis alone by examining in more detail other physical and chemical properties and their potential effect on the process. A drop tube furnace (DTF) has been used to synthesise chars in a high heating rate environment, and although burnout and volatile loss values suggest suitability of some coals for blast furnace injection, additional problematic effects have been identified and measured such as char swelling and agglomeration which may impact the gas permeability of the furnace. A TGA/DSC has been used to measure the gasification of chars by the Boudouard reaction and compare the thermal impact of more reactive samples.\ud \ud While other studies have concentrated on the combustion of injection coals to determine their suitability, this one focuses on the implications of the partially burnt chars formed by incomplete reaction in the raceway.

It has become increasingly cost-effective for the steel industry to invest in the capture of heavily carbonaceous BOF (Basic Oxygen Furnace) or converter gas, and use it to support the intensive energy demands of the integrated facility, or for surplus energy conversion in power plants. As industry strives for greater efficiency via ever more complex technologies, increased attention is being paid to investigate the complex behavior of by-product syngases. Recent studies have described and evidenced the enhancement of fundamental combustion parameters such as laminar flame speed due to the catalytic influence of H2O on heavily carbonaceous syngas mixtures. Direct formation of CO2 from CO is slow due to its high activation energy, and the presence of disassociated radical hydrogen facilitates chain branching species (such as OH), changing the dominant path for oxidation. The observed catalytic effect is non-monotonic, with the reduction in flame temperature eventually prevailing, and overall reaction rate quenched. The potential benefits of changes in water loading are explored in terms of delayed lean blowoff, and primary emission reduction in a premixed turbulent swirling flame, scaled for practical relevance at conditions of elevated temperature (423 K) and pressure (0.1–0.3 MPa). Chemical kinetic models are used initially to characterize the influence that H2O has on the burning characteristics of the fuel blend employed, modelling laminar flame speed and extinction strain rate across an experimental range with H2O vapor fraction increased to eventually diminish the catalytic effect. These modelled predictions are used as a foundation to investigate the experimental flame. OH* chemiluminescence and OH planar laser induced fluorescence (PLIF) are employed as optical diagnostic techniques to analyze changes in heat release structure resulting from the experimental variation in water loading. A comparison is made with a CH4/air flame and changes in lean blow off stability limits are quantified, measuring the incremental increase in air flow and again compared against chemical models. The compound benefit of CO and NOx reduction is quantified also, with production first decreasing due to the thermal effect of H2O addition from a reduction in flame temperature, coupled with the potential for further reduction from the change in lean stability limit. Power law correlations have been derived for change in pressure, and equivalent water loading. Hence, the catalytic effect of H2O on reaction pathways and reaction rate predicted and observed for laminar flames, are compared against the challenging environment of turbulent, swirl-stabilized flames at elevated temperature and pressure, characteristic of piratical systems.

Ammonia has been identified as a sustainable fuel for transport and power applications. Similar to hydrogen,\ud ammonia is a synthetic product that can be obtained either from fossil fuels, biomass or other renewable sources.\ud Since the 1960’s, considerable research has taken place to develop systems capable of burning the material in gas\ud turbines. However, it is not until recently, that interest in ammonia has regained some momentum in the energy\ud agenda as it is a carbon free carrier and offers an energy density higher than compressed hydrogen. . Therefore, this\ud work examines combustion stability and emissions from gaseous ammonia blended with methane or hydrogen in gas\ud turbines. Experiments were carried out in a High Pressure Combustion Rig under atmospheric conditions employing\ud a bespoke generic swirl burner. OH* Chemiluminescense was used for all trials to determine reactivity of the radical.\ud Emissions were measured and correlated to equilibrium calculations using GASEQ. Results show that efficient\ud combustion can be achieved with high power but at very narrow equivalence ratios using both hydrogen and methane\ud blends. Moreover, low concentrations of OH radicals are observed at high hydrogen content, probably as a\ud consequence of the high NH2 production.