New materials for electrochemical synthesis of ammonia

This thesis was previously held under moratorium from 8th May 2014 until 8th May 2016.This thesis has mainly focused on the electrochemical synthesis of ammonia at atmospheric pressure using three different catalyst types (nitride, spinel and perovskite). Attention also has been given to developing new electrolyte materials based on oxide-carbonate composites, with the aim of exploring their application in ammonia synthesis at low operating temperature (< 500 °C). Ammonia was synthesised from H₂ and N₂ using an electrolyte supported cell based on LiAlO₂-(Li/Na/K)₂CO₃ as electrolyte, Ag-Pd as anode and either nitride (e.g. Co₃Mo₃N) or spinel (CoFe₂O₄) as cathode. The maximum rate of ammonia formation (3.27 x 10⁻¹⁰10 mol s⁻¹ cm⁻² at 450 °C and 0.8 V) was obtained when Co₃Mo₃N was used as a cathode. Ammonia was also synthesised from H₂ and N₂ in an electrolytic cell based on Sm-doped ceria-carbonate composite (SDC-(Li/Na/K)₂CO₃) as an electrolyte, NiO-SDC as anode and perovskite oxide La₀.₆Sr₀.₄Fe₀.₈Cu₀.₂O₃-δ (LSFCu) catalyst as a cathode. The maximum rate was found to be 5.39 x 10⁻⁹ mol s⁻¹ cm⁻² at 450 °C and 0.8 V. Ammonia was also synthesised successfully from water vapour (3% H₂O) and nitrogen, using a new electrolyte material based on Ca and Gd co-doped ceria-carbonate composite (CGDC-(Li/Na/K)₂CO₃). Perovskite oxide Sm₀.₅Sr₀.₅CoO₃-δ (SSCo) was used as an anode and either spinel or perovskite based catalysts were used as cathodes. The maximum rate of ammonia formation (4.0 x 10⁻¹⁰ mol s⁻¹ cm⁻² at 375 °C and 1.4 V) was attained with a La₀.₇₅Sr₀.₂₅Cr₀.₅Fe₀.₅O₃-δ (LSCrF) cathode. Ammonia was synthesised directly from air and water vapour (3% H₂O) in a symmetrical cell composed of LSCrF as electrodes (cathode and anode) and CGDC-(Li/Na/K)₂CO₃ composite as electrolyte. The maximum rate was found to be 1.94x10⁻¹¹ mol s⁻¹ cm⁻² at 375 °C with an applied voltage of 1.2 V.This thesis has mainly focused on the electrochemical synthesis of ammonia at atmospheric pressure using three different catalyst types (nitride, spinel and perovskite). Attention also has been given to developing new electrolyte materials based on oxide-carbonate composites, with the aim of exploring their application in ammonia synthesis at low operating temperature (< 500 °C). Ammonia was synthesised from H₂ and N₂ using an electrolyte supported cell based on LiAlO₂-(Li/Na/K)₂CO₃ as electrolyte, Ag-Pd as anode and either nitride (e.g. Co₃Mo₃N) or spinel (CoFe₂O₄) as cathode. The maximum rate of ammonia formation (3.27 x 10⁻¹⁰10 mol s⁻¹ cm⁻² at 450 °C and 0.8 V) was obtained when Co₃Mo₃N was used as a cathode. Ammonia was also synthesised from H₂ and N₂ in an electrolytic cell based on Sm-doped ceria-carbonate composite (SDC-(Li/Na/K)₂CO₃) as an electrolyte, NiO-SDC as anode and perovskite oxide La₀.₆Sr₀.₄Fe₀.₈Cu₀.₂O₃-δ (LSFCu) catalyst as a cathode. The maximum rate was found to be 5.39 x 10⁻⁹ mol s⁻¹ cm⁻² at 450 °C and 0.8 V. Ammonia was also synthesised successfully from water vapour (3% H₂O) and nitrogen, using a new electrolyte material based on Ca and Gd co-doped ceria-carbonate composite (CGDC-(Li/Na/K)₂CO₃). Perovskite oxide Sm₀.₅Sr₀.₅CoO₃-δ (SSCo) was used as an anode and either spinel or perovskite based catalysts were used as cathodes. The maximum rate of ammonia formation (4.0 x 10⁻¹⁰ mol s⁻¹ cm⁻² at 375 °C and 1.4 V) was attained with a La₀.₇₅Sr₀.₂₅Cr₀.₅Fe₀.₅O₃-δ (LSCrF) cathode. Ammonia was synthesised directly from air and water vapour (3% H₂O) in a symmetrical cell composed of LSCrF as electrodes (cathode and anode) and CGDC-(Li/Na/K)₂CO₃ composite as electrolyte. The maximum rate was found to be 1.94x10⁻¹¹ mol s⁻¹ cm⁻² at 375 °C with an applied voltage of 1.2 V

Aspergillus section Flavi and aflatoxins in Algerian wheat and derived products

Wheat and its derivatives are a very important staple food for North African populations. The aim of this study was to analyze populations of Aspergillus section Flavi from local wheat based on aflatoxins (AFs),cyclopiazonic acid (CPA) and sclerotia production, and also to evaluate AFs-contaminated wheat collected from two different climatic regions in Algeria. A total of 108 samples of wheat were collected during the following phases: pre-harvest, storage in silos and after processing. The results revealed that among the Aspergillus species isolated, those belonging to section Flavi were predominant. Of the 150 strains of Aspergillus section Flavi isolated, 144 were identified as Aspergillus flavus and 6 as Aspergillus tamarii. We showed that 72% and 10% of the A. flavus strains produced AFs and CPA, respectively. Among the 150 strains tested, 60 produced amounts of AFB1 ranging from 12.1 to 234.6 lg/g of CYA medium. Also, we showed that most strains produced large sclerotia. AFB1was detected by HPLC in 56.6% of the wheat samples and derived products (flour, semolina and bran) with contamination levels ranging from 0.13 to 37.42 lg/kg

A web content mining application for detecting relevant pages using Jaccard similarity

The tremendous growth in the availability of enormous text data from a variety of sources creates a slew of concerns and obstacles to discovering meaningful information. This advancement of technology in the digital realm has resulted in the dispersion of texts over millions of web sites. Unstructured texts are densely packed with textual information. The discovery of valuable and intriguing relationships in unstructured texts demands more computer processing. So, text mining has developed into an attractive area of study for obtaining organized and useful data. One of the purposes of this research is to discuss text pre-processing of automobile marketing domains in order to create a structured database. Regular expressions were used to extract data from unstructured vehicle advertisements, resulting in a well-organized database. We manually develop unique rule-based ways of extracting structured data from unstructured web pages. As a result of the information retrieved from these advertisements, a systematic search for certain noteworthy qualities is performed. There are numerous approaches for query recommendation, and it is vital to understand which one should be employed. Additionally, this research attempts to determine the optimal value similarity for query suggestions based on user-supplied parameters by comparing MySQL pattern matching and Jaccard similarity

Remote Control of Mobile Robot using the Virtual Reality

In this paper we present the simulation and manipulation of  teleoperation system for remote control of mobile robot using the Virtual Reality (VR). The objective of this work is to allow the operator to control and supervise a unicycle type mobile robot. In this research we followed three ways: The use of articulated robotic mobile on the Web, the design of remote environment for the experimentation using the network for the mobile robot and the  architecture of control is proposed to facilitate the piloting of the robot. This work proposes a hardware and software architecture based on communication and information technologies to control the virtual robot to improve the control towards the remote robot. A path planning method is integrated to the remote control system. Results show the real possibilities offered by this manipulation, in order to follow a trajectory of the robot and to create applications with a distance access to facilities through networks like the Internet and wireless

Note from the Editors

The Editors reflect on Issue XXII

Evaluation of Serum Copper, Zinc and Copper/Zinc Ratio in Psoriatic Patients

Backgrounds: Psoriasis is a hyper proliferative coetaneous disease of multi-factorial etiologies, genetic background, environmental factors, vascular and immune system disturbances. Copper and zinc are very importance trace elements and essential to biochemical processes in the body and are involved in immunological and inflammatory reactions. Objective: The objective of the present study was to evaluate the relationship between zinc (Zn) and copper (Cu) ion and copper/zinc with the pathogenesis of psoriasis disease. Materials and Methods: an analytical case control hospital based study conducted in Khartoum dermatology and venerology teaching hospital, Khartoum state, Sudan. During the period from September to December 2018. A total of 100 subjects were enrolled in the study, 50 psoriatic patients as case group and 50 apparently healthy as control group with match age and sex. The age ranged from 12 and 60 years and their average mean 32 years. Three ml of venous blood were collected from each volunteer, serum was obtained and analyzed using colorimetric method in fully Automated Biochemistry Analyzer and the data was analyzed using SPSS version (21). P-value of &lt;0.05 was considered significant. And also psoriatic patients the severity of psoriasis was assessed by ‘Psoriasis Area Severity Index’ (PASI score). Results: The study revealed a significantly increase (p = 0.000) of serum copper in psoriatic patients compared to control group and a significantly decrease (p = 0.040) of serum zinc in psoriatic patients compared to control group. And the copper/ zinc was significantly increase (p = 0.000) in patients than controls. Moreover, serum copper was &nbsp;significantly increased (p = 0.012) in psoriatic patients infected &gt;1 year compared to patients infected 6 months to 1 year. The serum zinc was significantly decreased (p = 0.030) in psoriatic patients infected &gt;1 year compared to patients infected 6 month-1 year. And also the copper/ zinc significantly increased (p = 0.027) in psoriatic patients infected &gt;1 year compared to patients infected 6 month to 1 year. The serum copper was a significantly different (p =0.001) between severity of psoriatic disease compared to mild and moderate. Moreover, the serum zinc was&nbsp; significantly different (p =0.001) between mild and moderate and also a significantly different (p =0.022) between severity of psoriatic disease compared to mild and moderate. The copper/ zinc was a significantly different (p =0.000) between severity of psoriatic disease compared to mild and moderate. Conclusion: The psoriatic patients had a significantly increased serum copper, copper/ zinc and a significantly decrease of serum zinc. The study observed that, the common in male than female and also in moderate a stage of severity

ASPECT TOXICOLOGIQUE ET PHYSICOCHIMIQUE DU 1,5-DIPENTANAL

The 1,5-dipentanal is an important organic molecule: pedagogically, the molecule provides a range of interesting chemical reactions (Aldolisation, Michael, glycolysis, Cannizzaro, Mannich ...). It has the same reaction mechanisms for teaching the fundamentals of ecotoxicology in particular and chemistry in the environment in general. The extent of these applications between the fine disciplines (medical sciences, pharmacological chemistry, enzyme technology, technology of biological membranes and tissues, cytochemistry, histochemistry, immunochemistry, microscopy, X-ray ...) generates a rich multidisciplinary education first. Glutaraldehyde reacts with proteins, sugars and lipids feature free groups (-NH2). The amine group (NH2) reacts with the nucleophilic carbonyl electrophilic aldehyde (- CHO). The consequences of this mechanism in vivo are at the heart important pathophysiological (diabetes, renal failure, ...). Moreover, the miscibility with water (100%), high reactivity in physiological, highly evaporable terms (air contamination), chemical intermediate in industry and a must for all disinfection and sterilization of equipment. A good compromise between advantage and disadvantage impose a regulated management of the molecule as effluent or residue. It can not be rejected in sanitation, or natural mitan. The development of processes requested by the practical interest of the molecule and its management as harmful liquid waste is required

Stray Dogs and Wild Cats Tracking Down Information Systems in Government

This paper explores the body of e-government research surfaced during 1998-2003 in Web of Science and ProQuest. The search identified 158 scholarly papers. Using a classification model developed by Andersen and Danziger (1995), the predominately part of the research addresses improvements of services and products (72%), better data access (67%) and public-Government interaction (64%). Less frequent are studies on values. Comparing data with literature review on the Golden Age of transformation of the public sector (1988-2000), the authors suggest that e-government so far has not altered the balance between existing domains of applications or introduced new areas

Impact of the underlying cause and co-morbid conditions on the outcome of hepatic encephalopathy

Background: Hepatic encephalopathy (HE) is a serious neuropsychiatric complication of acute and chronic liver diseases. This study aimed at identifying liver diseases and co-morbidity conditions associated with hepatic encephalopathy (HE) and their impact on patient`s mortality (the outcome).Methods: A hospital-based, prospective study enrolled 76 patients admitted with HE conducted at Ibn Sina specialized gastroenterology hospital, Sudan, from January 2010 to May 2011. Personal data, clinical presentation, underlying liver disease, precipitants, co-morbid conditions and the outcome of HE were obtained from the inpatients’ hospital records.Results: A total of 76 patients were included, 62 males (81.5%) and 14 females (18.5%) aged between 13 and 84 years old. Hepatitis B virus (HBV) was the most common cause of the liver disease (36.8%), followed by HCV (11.8%). Clinically, 53 patients (69%) had impaired level of consciousness. Infection was the most common risk factor for HE (54%) followed by electrolyte disturbance (42%). Overall mortality within one to three weeks following the admission was (50%). The higher percentage of mortality was seen inpatients with late stage autoimmune hepatitis, followed by HCC and in co-morbid conditions like renal impairment (58.8%).Conclusion: HE is associated with a high mortality despite proper management in specialized hospitals. The mortality tends to increase in the presence of comorbid condition.