Development of new catalysts for methane oxidation in dual-fuel HGV engines

1.4 billion tonnes of cargo is transported in the UK every year, using 1,445,000 heavy goods vehicles (HGVs) over a collective distance of 19 billion km and these figures are likely to increase in the future. For example, the number of trucks is expected to rise by 75% by 2040, and the demand for transport fuels will also grow rapidly. In view of that, natural gas has become subject to big investments for new businesses lines, such as dual-fuel engines. This type of engine typically utilises diesel as a primary fuel with the substitutions of natural gas in order to reduce running costs, as well as for environmental benefits. However, the main downside of the utilisation of natural gas is that it has a higher combustion enthalpy per unit mass, when compared to other conventional fuels. Also, it is not fully burned in the engine, thus results in increased methane emissions in the exhaust. The aim of this project is, therefore, to develop new catalysts to manage emissions of methane to meet the requirements established by the Euro VI regulations. This thesis reports the synthesis and full characterisation of hydroxyapatite (HAP) as the support for a range of catalysts, using several methods and templates to improve its porosity. Moreover, carbon nanorods were employed for the first time as a hard-template in the synthesis of HAP, obtaining high BET surface areas that corresponded to 242.2± 2.3 m2g-1. Then, the thermal, chemical and mechanical stability of HAP was investigated by reproducing possible environmental conditions, which the catalyst would be exposed to in real exhausts from HGV engines. The main findings were that mesoporous HAP is fully stable to any change of pH and any mechanical disturbance, and only started to dehydroxylate at temperatures above 650ᵒC, which is, nonetheless, higher than the engine operating temperature. In consequence, HAP was confirmed as an extremely powerful catalyst support. Additionally, new methods for doping HAP with Pd and Ni metals were explored in order to improve the metal distribution on the support and, hence its catalytic activity. Ultrasound was utilised to assist conventional ion exchange (IE) and incipient wetness impregnation (IW) methodologies. The results for IW revealed that the ultrasound breaks down metal clusters and subsequently improves their distribution, when compared to the standard IW protocol, and in the case of IE, even though the distribution remains stable, the utilisation of ultrasound significantly accelerated the process from 3 days to 3 hours. Furthermore, pretreatment of HAP with different pH before doping with Pd using the IW protocol considerably enhanced the metal distribution when compared to the conventional IW procedure, and remained the high metal distribution when IE took place in a different pH buffer solution instead of neutral water. All synthesised and characterised samples were tested towards dry reforming of methane (DRM) and oxidation of methane, reproducing the oxygen lean and rich conditions found in an exhaust of a HGV, respectively. Products of the reactions were analysed using an in-house built catalysis rig equipped with GC-TCD. For DRM, the most active catalyst impressively exceeded the commercially available catalyst tested under same conditions; converting 100% at a temperature of 250ᵒC, and still achieving 80% conversion after 88 hours continuous reaction. On the other hand, it was found that the oxidation of methane in the presence of oxygen species proceeds through a redox cycle between reduced metal and metal oxide. Based upon the catalytic profiles of previously synthesised catalysts, the metal oxide was more active and revealed more stable conversions when compared to the reduced metal. The results obtained, therefore, suggest that the adsorbed lattice oxygen plays a key role in the catalysis reaction. Lastly, coking process was also studied via TGA as a preliminary deactivation process of the catalysts. It was found that all Pd and Ni based catalysts were resistant to the formation of carbon on their surface

Metalloproteinase-2 in failed back surgery syndrome caused by epidural fibrosis: can it play a role in persistent pain?

PurposeFailed Back Surgery Syndrome (FBSS) occurs in 10–40% of patients treated surgically due to disk herniation (DH). There are several factors that can cause a predisposition to FBSS, but the exact pathomechanism has not been elucidated. The aim of this study was to investigate Metalloproteinase-2 (MMP-2) and Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) activities in a homogeneous group of FBSS patients with epidural fibrosis in comparison to its activity in patients with surgically treated DH.MethodsDH, FBSS, and control (CG) groups consisted of 30 subjects. The patients were assessed clinically by the Numerical Rating Scale (NRS), McGill Pain Questionnaire (SF -MPQ), Oswestry Disability Index (ODI), and Beck Depression Inventory (BDI). Serum concentrations of MMP-2 and TIMP-2 were measured by using the immunoenzymatic method.ResultsThere was a significantly higher MMP-2 expression (medians: 4797.49 vs. 2656.65; p < 0.0001) and TIMP-2 concentration (medians: 166.40 vs. 109.60; p < 0.0001) in the DH compared to the CG. Significantly higher MMP-2 expression (4219.95 vs. 2656.65; p < 0.0001) and TIMP-2 concentration (medians: 150.17 vs. 109.60; p = 0.0003) were also found in the FBSS compared to the CG. The activity of MMP-2, measured as MMP-2/TIMP-2, did not significantly change between the DH, FBSS, and CG. MMP2 expression (p < 0.0001) and TIMP-2 concentration (p < 0.0001) were significantly higher in the DH than FBSS.ConclusionResults indicate the presence of a contribution of MMP-2 and TIMP-2 in DH and FBSS. Unchanged activity of MMP-2 can indicate an insufficiency in the MMP-2 repair system in both diseases. Lower MMP-2 expression and TIMP-2 concentration in the FBSS group can reflect the chronicity of the process

Carpal Tunnel Syndrome - treatment

Litak Jakub, Grochowski Cezary, Litak Joanna, Szmygin Paweł, Kulesza Bartłomiej, Kamieniak Piotr. Carpal Tunnel Syndrome – treatment. Journal of Education, Health and Sport. 2017;7(1):141-146. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.238710 http://ojs.ukw.edu.pl/index.php/johs/article/view/4160 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 754 (09.12.2016). 754 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Author (s) 2017; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 05.12.2016. Revised 20.12.2016. Accepted: 11.01.2017. Zespół cieśni nadgarstka – leczenie Jakub Litak [1], Cezary Grochowski [2], Joanna Litak [3], Paweł Szmygin [1], Bartłomiej Kulesza [1], Piotr Kamieniak [1] [1] Klinika Neurochirurgii i Neurochirurgii Dziecięcej SPSK-4 w Lublinie [2] Katedra i Zakład Anatomii Prawidłowej Człowieka Uniwersytetu Medycznego w Lublinie [3] Centrum Onkologii Ziemii Lubelskiej im. Jana z Dukli Carpal Tunnel Syndrome – treatment Jakub Litak [1], Cezary Grochowski [2], Joanna Litak [3], Paweł Szmygin [1], Bartłomiej Kulesza [1], Piotr Kamieniak [1] [1] Department of Neurosurgery and Pediatric Neurosurgery SPSK-4 in Lublin [2] Department of Human Anatomy Medical University of Lublin [3] St. John`s Cancer Center in Lublin Słowa kluczowe: Zespół cieśni nadgarstka Key words: Carpal Tunnel Syndrome Abstrakt Zespół cieśni nadgarstka jest częstym schorzeniem spotykanym w praktyce lekarskiej. Obraz kliniczny i diagnostyka przewodnictwa nerwowego są podstawą rozpoznania. Leczenie dobrane adekwatnie do nasilenia dolegliwosci daje ulgę w bólu . Zaniki mięśniowe w obrębie kłębu kciuka są wskazaniem do zabiegu operacyjnego . Abstract Carpal Tunnel Syndrome is a common disease in General Practice. Clinical symptoms and Nerve Conduction Evaluation are crucial for proper diagnosis. Adequate treatment leads to pain relief. Thenar dystrophy indicates surgical treatment

Mechanical, pH and Thermal Stability of Mesoporous Hydroxyapatite

The stability of mesoporous hydroxyapatite (HAP) powder was studied following treatments of ultrasound, pH and heating. HAP was found to be mechanically stable up to (and including) 1 h continuous ultrasonic treatment in water. The HAP structure was also stable to pH, evidenced by practically identical XRD and FTIR spectra over the pH range 2–12. The surface area increased progressively with increasing acidity, reaching a maximum of 121.9 m 2 g −1 at pH 2, while alkaline conditions decreased the surface area to a minimum of 55.4 m 2 g −1 at pH 12. Heating in air had a significant influence on the structural and morphological properties of HAP, which underwent dehydroxylation to form oxyhydroxyapatite (OHAP) at temperatures ≥ 650 °C, and β-tricalcium phosphate (β-TCP) ≥750 °C. The surface area decreased at elevated temperatures due to agglomeration of HAP crystals by sintering, which was associated with an increased particle size

Can Ultrasound or pH Influence Pd Distribution on the Surface of HAP to Improve Its Catalytic Properties in the Dry Reforming of Methane?

The influence of ultrasound and different pH pre-treatments during the metal doping/modification of a hydroxyapatite (HAP) support is investigated. HAP is first synthesised via a hard-template synthetic route using carbon nanorods followed by their full physiochemical characterisation. The HAP was found to be crystalline and comprised a mesoporous structure as observed via XRD and nitrogen adsorption with a BET surface area of 97.57 (±1.16) m2 g−1. Ultrasound-assisted ion exchange (IE) and incipient wetness impregnation (IW) methodologies were employed to decorate the surface of HAP with Pd0 and are compared to previous procedures. The influence of pH upon the distribution of Pd0 throughout the samples during the doping process is also studied. All the prepared samples were evaluated for their catalytic activity towards dry reforming of methane (DRM) and the reaction was monitored via a thermal conductivity detector, coupled with gas chromatography (GC-TCD). It was found that ultrasound-assisted IE significantly accelerated the process from 3 days to 3 h and with the Pd0 metal remaining highly distributed upon the HAP with minor changes in catalytic conversions. Moreover, the ultrasound-assisted IW method successfully improved the Pd0 distribution and catalytic performance. On the other hand, the dispersion of the metal was unaffected after pH treatments in IE with no catalytic improvements observed, in contrast to IW, where considerable increase in metal distribution and subsequently catalytic performance was observed

Methane emission management in a dual-fuel engine exhaust using Pd and Ni hydroxyapatite catalysts

© 2017 Elsevier Ltd While dual-fuel engines reduce transportation costs and CO 2 emissions by using alternative energy sources e.g. natural gas, the exhaust streams often contain quantities of emissions that exceed limits and therefore require removal. Pd- and Ni-hydroxyapatite (HAP) catalysts were prepared using a soft-templating method and tested in the dry reforming of methane (DRM) in a fixed bed reactor that simulates an exhaust from a diesel-natural gas dual-fuel engine. XRD revealed the characteristic HAP crystal structure of all the prepared materials. The HAP phase was further confirmed by TEM, which also showed the presence of submicron sized particles. The BET surface areas of HAP prepared using a single surfactant was 27.7 m 2  g −1 and increased to 84.9 m 2  g −1 when mixed surfactants were used. Active metals were added to HAP using either incipient wetness impregnation, ion-exchange or solid dispersion. All the catalysts tested were active in DRM with the optimal samples converting over 85% of methane at 650 °C

Diagnosis and Management of Neuropathic Pain in Spine Diseases

Neuropathic pain is generally defined as a non-physiological pain experience caused by damage to the nervous system. It can occur spontaneously, as a reaction to a given stimulus, or independently of its action, leading to unusual pain sensations usually referred to as firing, burning or throbbing. In the course of spine disorders, pain symptoms commonly occur. According to available epidemiological studies, a neuropathic component of pain is often present in patients with spinal diseases, with a frequency ranging from 36% to 55% of patients. Distinguishing between chronic nociceptive pain and neuropathic pain very often remains a challenge. Consequently, neuropathic pain is often underdiagnosed in patients with spinal diseases. In reference to current guidelines for the treatment of neuropathic pain, gabapentin, serotonin and norepinephrine reuptake inhibitors and tricyclic antidepressants constitute first-line therapeutic agents. However, long-term pharmacologic treatment often leads to developing tolerance and resistance to used medications. Therefore, in recent years, a plethora of therapeutic methods for neuropathic pain have been developed and investigated to improve clinical outcomes. In this review, we briefly summarized current knowledge about the pathophysiology and diagnosis of neuropathic pain. Moreover, we described the most effective treatment approaches for neuropathic pain and discussed their relevance in the treatment of spinal pain

Brain metastases from rectal cancer – case report

Colorectal  origin of  brain metastases (BM) are relatively  rare in oncological practice.  Represent 0,6% to 3,2% of all brain metastatic lesions with median survival time of 2.8–5.4 months. Only very few patients survive more than 1 year. Metastases spread to the brain reflecting  the vascular anatomy.  Colorectal metastases appear early and more frequently  in pulmon and liver. BM use to be called late metastases. Thanks to highier availability of diagnostic methods as a CT or MRI detectability of BM  raised significantly. Early diagnosis and treatment of BM  provide proper quality of life for patient  ,  in addition to adequate control of prime colorectal cancer

Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) represents a cluster of various vascular disorders with different pathological backgrounds. The advanced vasculature net of cerebral vessels, including small arteries, capillaries, arterioles and venules, is usually affected. Processes of oxidation underlie the pathology of CSVD, promoting the degenerative status of the epithelial layer. There are several classifications of cerebral small vessel diseases; some of them include diseases such as Binswanger’s disease, leukoaraiosis, cerebral microbleeds (CMBs) and lacunar strokes. This paper presents the characteristics of CSVD and the impact of the current knowledge of this topic on the diagnosis and treatment of patients