Synthesis of Porous Monoclinic Tungsten Oxides and Their Application in Sensors

Semiconducting metal oxide sensors are limited in their usage because of their poor detection selectivity. The current approach to achieve better selectivity in SMO detection uses prefiltering/preconcentration schemes to reduce the number of gases in contact with the sensor in combination with array-based detection. In this thesis we have investigated different materials and approaches for use as elements in an array based detection system. One approach we have investigated involves the use of porous monoclinic WO3 to obtain size selectivity in detection within the sensing element itself. In chapter 3 we describe the synthetic protocol used to generate high surface area porous monoclinic tungsten oxide. Mesoporous oxides are produced by a sol-gel polymerization in the presence of a self-assembled surfactant structure. This approach has not been applied to the synthesis of WO3 based oxides because the presence of salts leads to mixtures of WO3 and tungstates. By minimizing the presence of Na+ ions, it is shown that ordered porous monoclinic WO3 can be prepared. The sodium tungstate is first passed through an ion exchange resin to remove the sodium and tungstic acid thus formed is then added to solution containing a cationic surfactant, n-cetyltrimethylammonium bromide (CTAB) to template the structure. While a salt is formed with the CTAB cation, it does not lead to stable tungstates because these salts are easily decomposed during the calcination step. It is also shown that the need for ion-exchange can be avoided by using ammonium tungstate as a precursor in place of sodium tungstate. As with CTAB cations, the NH4+ ions are easily decomposed during the calcination step. While the surfactant template collapses during the calcination step, the morphology and properties of the product is controlled by the initial template structure. Using these cationoic surfactant based receipies unique high surface area and porous monoclinic WO3 powders are prepared. In Chapter 4, we examine the sensor properties of the various porous W03 powders. The sensors were tested to a series of alcohols of various size as well as dimethyl methyl phosphonate (DMMP, a nerve agent stimulant) and it was found that there was a size dependent response signal on the porous WO3 relative to sensors fabricated with nonporous WO3 powders. IR spectroscopic measurements shows that the difference in sensor responses on porous material was due to a size dependent control over the amount of alcohol absorbed on the surface. A key aspect of this approach is to operate the sensors in a difference mode in which a gas pulse is simultaneously exposed to several sensors composed of both porous and nonporous powders. By comparing the response on a porous sensor to that of a nonporous sensor it is possible to separately distinguish the signal of DMMP from methanol. The ability to distinguish the response of DMMP from methanol has been a longstanding goal to demonstrate selectivity in nerve agent detection. In chapter 5 we examined a different approach to achieve selectivity in an array based SMO sensor. Specifically, the approach involves the use of UV illumination to selectively decompose adsorbed molecules from the surface of WO3. In infrared studies, it is found that adsorbed DMMP decomposes under UV illumination at room temperature to form a stable methyl phosphate species on the surface. However, the decomposition under UV does not occur with the lattice oxygen but rather with the ozone or surface 0\u27 sites oxygen radicals produced in the gas phase and this is and this is unlikely to lead to a change in sensor response. In addition, it is found that the sensor base conductivity is also very sensitive to UV illumination at room temperature. The UV generates electron-hole pairs that decompose surface water and these results in the intercalation of H+ into the material to produce tungsten bronzes and a resulting change in base conductivity

Practical Approaches to USO Costing and Financing

In this paper we set out a holistic approach that incorporates recent developments in assessing the net cost of the USO and presents a robust methodology for practical implementation. We analyse the issues relating to assessing the net costs of the USO with particular focus on the benefits associated with USO and current empirical approaches to calculating the net costs. We then present an overview of approaches that have been applied in various countries and highlight their strengths and shortcomings in light of the necessarily theoretical aspects discussed in the first part of the paper. Finally, we present a practical approach that we believe assesses robustly the net cost of the USO.Regulation, Post, Universal service obligation, Financing

First record of the genus \u3cem\u3eCompsobuthus\u3c/em\u3e (Scorpiones: Buthidae) from Maharashtra, India, with description of a new species

A new species of the genus Compsobuthus Vachon, 1949 (Buthidae) belonging to the werneri group is described from two localities in Jalgaon District, Maharashtra, India. The new species can be easily distinguished from all four members of the werneri group known from India and Pakistan by combination of nonoverlapping morphological characters. Compsobuthus satpuraensis sp. n. is the first species of this genus to be reported from the state of Maharashtra and fourth to be reported from India

PENERAPAN SUPERVISI KLINIS OLEH KEPALA SEKOLAH SEBAGAI UPAYA MENINGKATKAN KEMAMPUAN GURU MENGGUNAKAN MODEL PEMBELAJARAN KOOPERATIF DI SEKOLAH DASAR KATOLIK PIGASEMSTER GANJIL TAHUN 2018/2019

Tujuan penelitian tindakan  sekolah ini adalah untuk meningkatkan kemampuan guru dalam menggunakan model pembelajaran kooperatif  di SDK Piga, Kecamatan Soa. Jenis penelitian yang digunakan adalah penelitian tindakan sekolah. Kegiatan dalam penelitian ini terdiri atas tahapan perencanaan tindakan, pelaksanaan tindakan,observasi, dan refleksi. Penelitian ini dilakukan dalam dua siklus. Tempat penelitian di SDK Piga, Kecamatan Soa, Kabupaten Ngada. Subyek dalam penelitian ini adalah  guru  - guru di SDK Piga    yang berjumlah 8 orang, yang terdiri dari 6 orang guru kelas dan 2 orang guru mata pelajaran.  Metode pengumpulan data menggunakan metode  obeservasi kelas. Analisis data yang digunakan adalah teknik analisis deskriptif komparatif. Data kuantitatif yang diperoleh dideskripsikan dalam bentuk kata-kata atau penjelasan. Selanjutnya dilakukan komparasi data untuk memastikan ada tidaknya peningkatan kinerja guru dalam pelaksanaan pembelajaran di Kelas. Hasil penelitian  diketahui pada  kondisi awal nilai supervisi klinis kepala sekolah dalam kegiatan pembelajaran diperoleh  rata-rata  69,81, pada Siklus I mengalamai peningkatan dengan rata – rata peroleh nilai pada supervisi klinis sebesar 76,92 mengalami peningkatan sebesar 7,11. Pada siklus II nilai supervisi klinis diperoleh rata – rata  83,08. Mengalami peningkatan dari siklus I ke Siklus II sebesar 6, 16. Dari data ini berarti terjadi peningkatan nilai supervise klinis kepala sekolah dalam kegiatan pembelajaran dari kondisi awal hingga akir siklus II sebesar 13, 93%.Hal ini dapat disimpulkan bahwa dengan Penerapan Supervisi Klinis Oleh Kepala Sekolah dapat Meningkatkan Kemampuan Guru Menggunakan Model Pembelajaran Kooperatif  di Sekolah Dasar Katolik Piga semster Ganjil Tahun  2018/201

Role of Maternal Dietary Intake on Fatty Acids in Human Milk: A Systematic Review

Human milk is the main source of food for young infants up to 6 months of age. During initial period of lifecycle, lipids in human milk predominate the health of an individual as a whole. Lipids form the principle source of nutrition in an infant .Therefore, the sort of fatty acids in human milk directs the growth and development of infants.   Lipids in human milk vary based on the dietary intake of the mothers. This paper strives to summarize accessible studies related to maternal dietary intake during pregnancy and lactation and its impact on composition of fatty acids in human milk. On the whole11 studies were selected to review. These studies basically examined maternal dietary intake and its effect on essential fatty acids, vitamin A and vitamin D in human milk. Results: Maternal Dietary intake of vitamin A, DHA positively influences its level in human milk. Supplementation of DHA in prenatal and postnatal mothers increases DHA levels in milk for both preterm and term infants

Les erreurs et les stratégies d'orthographe chez les élèves du premier cycle du secondaire du Gabon

Dans le domaine éducatif, le phénomène des erreurs d'orthographe est l'une des préoccupations majeures dans les pays francophones. Au Gabon, où nous avons réalisé notre investigation, les élèves éprouvent de difficultés à orthographier correctement des mots. C'est au constat de leurs faibles performances en orthographe que nous sommes parvenu à poser la problématique des erreurs d'orthographe au premier cycle du secondaire. Cette recherche vise à identifier et à classer, à partir de la typologie des erreurs de Catach (1980), les différentes erreurs d'orthographe que les jeunes scripteurs commettent dans leurs écrits. Pour, y parvenir, nous avons organisé, pour un échantillon de 783 élèves de 6e (lere année secondaire au Québec) et de 3 e (4eme année secondaire au Québec) de niveau collège du Gabon, une dictée et un entretien métacognitif tel que le conçoit Jaffré (1999 et 2003). Il en ressort, comme l'avaient déjà, ailleurs, démontré certaines études (Bétrix, 1991), que la zone morphogrammique, notamment la grammaire, reste celle qui serait la moins bien maîtrisée chez les jeunes scripteurs gabonais

Role of Maternal Dietary Intake on Fatty Acids in Human Milk: A Systematic Review

Human milk is the main source of food for young infants up to 6 months of age. During initial period of lifecycle, lipids in human milk predominate the health of an individual as a whole. Lipids form the principle source of nutrition in an infant .Therefore, the sort of fatty acids in human milk directs the growth and development of infants.   Lipids in human milk vary based on the dietary intake of the mothers. This paper strives to summarize accessible studies related to maternal dietary intake during pregnancy and lactation and its impact on composition of fatty acids in human milk. On the whole11 studies were selected to review. These studies basically examined maternal dietary intake and its effect on essential fatty acids, vitamin A and vitamin D in human milk. Results: Maternal Dietary intake of vitamin A, DHA positively influences its level in human milk. Supplementation of DHA in prenatal and postnatal mothers increases DHA levels in milk for both preterm and term infants

Foreign languages assessment practices in Senegal: Spanish as foreign lan-guage case in end of high school exam

[EN] This paper results from a research on the evaluation of Spanish as foreign language’s device in the high school diploma exam. It investigates critically the organizational system as well as the tests, activities and items proposed. At last it offers a package of assessment grids and evaluation tools in accord with the new theories of language teaching, the bases of the Common European Framework of Reference for Languages and The competency-based approach[ES] Este artículo es fruto de una investigación sobre el dispositivo de evaluación del ELE en el Bachillerato en Senegal. Indaga tanto en el sistema organizativo del mismo como en las pruebas, actividades y consignas propuestas. Por último, facilita un conjunto de herramientas didácticas y evaluativas conforme con las nuevas tendencias en Didáctica de las lenguas extranjeras, los fundamentos del Marco Común Europeo de Referencia para las Lenguas (MCERL) y el enfoque por competencias.Diop, PM. (2016). Las prácticas evaluativas en lenguas extranjeras en Senegal: el caso del ELE en el examen estatal del bachillerato. Lenguaje y Textos. (44):1-17. doi:10.4995/lyt.2016.6629SWORD11744Altet, M. (2001). Pratiques d'évaluation et communication en classe. En Fijari, G. y Achouche, M. (eds.) L'activité évaluative réinterrogée. Redards scolaires et socioprofessionnels (pp. 78-107). Bruxelles: De Boeck Université.Astolfi, J-P. (1995). Evaluer, oui, mais pas trop! En Goulet, J.-P. (dir.) Enseigner au collégial (pp. 415-417). Québec:Association québécoise de pédagogie collégiale.Auger, R. (2000). Formation de base en Evaluation des apprentissages. En FERNÁNDEZ DÍAZ, J.-M. y EYEANG, E (coords.) Lengua, Literatura y Ciencias de la Educación en los sistemas educativos del África subsahariana (pp. 63- 72). Salamanca: Ediciones Universidad de Salamanca.Boutolini, G. (2014). Evaluation des capacités lexicales entre 3 et 11 ans: adaptation au contexte gabonais . En Fernández Díaz, J.-M. y Eyeang, E. (coords.) Lengua, Literatura y Ciencias de la Educación en los sistemas educativos del África subsahariana (pp. 63-72). Salamanca: Ediciones Universidad de Salamanca.De Ketele, J.-M. y Ruzibiza, A. D. (2007). Apprentissage par intégration des compétences de base et évaluation critériée du savoir-résumer en français langue étrangère. Porta Lingarum, Revista Internacional de Didáctica de las Lenguas Extranjeras, 7, 13-30.Diop, P. M. (2007). El análisis de errores de espa-ol en alumnos del contexto escolar de Senegal y propuestas de intervención didáctica. Revista Lenguaje y Textos, 25, 205-227.Diop, P. M. (2008). Autonomía y profesionalización de los profesores de lenguas en Senegal: estudio de los actos profesionales docentes desde las estrategias de formación continua. Tesis doctoral. Universidad de Valladolid.Ducrot, J.-M. (2010). La pédagogie du projet en Français langue étrangère. En Guillén, C. (coord.) Didáctica del Francés. El dise-o del currículo de Francés Lengua extranjera en la educación secundaria obligatoria y el bachillerato. Aspectos metodológicos y técnicos (39-52). Barcelona: Grao.Eyeang, E. (2012). La pratique de l'évaluation et l'autoévaluation dans la formation des élèves-professeurs d'espagnol au Gabon. Echos du Formateur, Revue de Sciences de l'Education, 0, 5-15.Gerard, F.-M. (2008). Evaluer des compétences. Guide pratique. Bruxelles: De Boeck.González Piñeiro, M., Guillén Díaz, C. y Vez, J. M. (2010). Didáctica de las lenguas modernas. Competencia plurilingüe e intercultural, Madrid: Editorial Síntesis.Larruy Marquillo, M. (2003). L'interprétation de l'erreur. Paris: Clé International.Mangada, B. (2010). « Ecouter, parler et converser ». En Guillén, C. (coord.) Francés complementos de formación disciplinar. La configuration du curriculum du français langue étrangère dans l'Enseignement Secondaire Obligatoire et le Baccalauréat. Aspects théorico-conceptuels (pp. 91-105). Barcelona: Grao.Martín Vegas, R. A. (2009). Manual de Didáctica de la Lengua y la Literatura, Madrid: Editorial Síntesis.Mata, F. S., Rodríguez Diéguez, J. L. y Bolívar Botía, A. (2004). Diccionario Enciclopédico de Didáctica. Volumen II, Málaga: Ediciones Aljibe.Nze-Waghe, A.-D. (2014). Problématique de l'évaluation en dictée dans le système éducatif gabonais. En Fernández Díaz, J.-M. y Eyeang, E. (coords.) Lengua, Literatura y Ciencias de la Educación en los sistemas educativos del África subsahariana. (pp. 261-273). Salamanca: Ediciones Universidad de Salamanca.Santos Maldonado, M. J. (2003). El error en las producciones léxicas de francés lengua extranjera: Análisis y tratamiento didáctico. Tesis doctoral. Universidad de Valladolid.Thiam, A. B. (2015). Les préstamos léxicos en la lengua ouolof: un estudio tipológico. Tesis doctoral. Universidad de La Laguna

Semiconducting Metal Oxide Based Sensors for Selective Gas Pollutant Detection

A review of some papers published in the last fifty years that focus on the semiconducting metal oxide (SMO) based sensors for the selective and sensitive detection of various environmental pollutants is presented