Diversity and path coefficient analysis of Southern African maize hybrids

Detailed knowledge on genetic diversity among germplasm is important for hybrid maize ( Zea mays L.) breeding. The objective of the study was to determine genetic diversity in widely grown hybrids in Southern Africa, and compare effectiveness of phenotypic analysis models for determining genetic distances between hybrids. Fifty hybrids were evaluated at one site with two replicates. The experiment was a randomized complete block design. Phenotypic and genotypic data were analyzed using SAS and Power Marker respectively. There was significant (p < 0.01) variation and diversity among hybrid brands but small within brand clusters. Polymorphic Information Content (PIC) ranged from 0.07 to 0.38 with an average of 0.34 and genetic distance ranged from 0.08 to 0.50 with an average of 0.43. SAH23 and SAH21 (0.48) and SAH33 and SAH3 (0.47) were the most distantly related hybrids. Both single nucleotide polymorphism (SNP) markers and phenotypic data models were effective for discriminating genotypes according to genetic distance. SNP markers revealed nine clusters of hybrids. The 12-trait phenotypic analysis model, revealed eight clusters at 85%, while the five-trait model revealed six clusters. Path analysis revealed significant direct and indirect effects of secondary traits on yield. Plant height and ear height were negatively correlated with grain yield meaning shorter hybrids gave high yield. Ear weight, days to anthesis, and number of ears had highest positive direct effects on yield. These traits can provide good selection index for high yielding maize hybrids. Results confirmed that diversity of hybrids is small within brands and also confirm that phenotypic trait models are effective for discriminating hybrids.

Avaliação da técnica de dispersão da matriz em fase sólida assistida por vórtex para análise de fármacos em peixes

Os fármacos classificados como contaminantes orgânicos emergentes tornaramse tópico de discussão ambiental pois estes são capazes de atingir diferentes matrizes do meio ambiente, como água, solo e organismos aquáticos, e estudos demonstrando a toxicidade tem despertado o interesse científico. Neste estudo um método analítico foi otimizado e validado para determinação de quinze fármacos em amostras de peixes empregando preparo de amostras por dispersão da matriz em fase sólida (MSPD) assistida por vórtex e determinação por cromatografia líquida acoplada a espectrometria de massas sequencial (LC-MS/MS). O estudo ainda focou na aplicação de diferentes suportes sólidos na etapa de dispersão da MSPD, sendo que três (quitina, quitosana e concha de mexilhão dourado) foram utilizados pela primeira vez para esta finalidade, O método otimizado foi validado seguindo os parâmetros do INMETRO, ANVISA, SANCO e FDA. A curva analítica e linearidade foram avaliados através da calibração externa e superposição na matriz. Os compostos demonstraram linearidade dentro da faixa recomendada, com coeficiente de correlação maior do que 0,99. Os limites de detecção do método variaram de 1 a 100 ng g -1 , e os limites de quantificação a variaram de 5 a 1000 ng g -1 . Os valores de recuperação variaram de 68% a 108%, com RSD menores que 13% para todos os compostos. O efeito de matriz foi avaliado e quatro dos quinze compostos apresentaram efeito maior que ±20%. Na aplicabilidade o método demonstrou ser eficiente para extração de fármacos de diferentes espécies de peixe, apresentando exatidão e precisão adequados. Não foram encontrados resíduos de fármacos nas amostras analisadas.

On the temperature dependence of the rate coefficient of formation of C2+ from C + CH+

[EN] We carry out quasi-classical trajectory caculations for theC + CH+ → C2+ + H reaction on an ad hoc computed high-level ab initio potential energy surface. Thermal rate coefficients at the temperatures of relevance in cold interstellar clouds are derived and compared with the assumed, temperature-independent estimates publicly available in kinetic databases KIDA and UDfA. For a temperature of 10 K the database value overestimates by a factor of two the one obtained by us (thus improperly enhancing the destruction route of CH+ in astrochemical kinetic models) which is seen to double in the temperature range 5–300 K with a sharp increase in the first 50 K. The computed values are fitted via the popular Arrhenius–Kooij formula and best-fitting parameters α = 1:32 X 10-9 cm3s-1, β = 0:10 and γ = 2:19 K to be included in the online mentioned databases are provided. Further investigation shows that the temperature dependence of the thermal rate coefficient better conforms to the recently proposed so-called ‘deformed Arrhenius’ law by Aquilanti and Mundim.

Motion compensation with minimal residue dispersion matching criteria

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnoloigia, 2016.

Community satisfaction with indoor residue spraying for Malaria control in Karonga, Northern Malawi

Background The Malawi National Malaria Control Program conducted Indoor Residual Spraying (IRS) in 2010 and 2013 in selected hot districts along the valleys including Karonga, but no study has been done to measure community satisfaction levels in these areas. Aim To assess satisfaction levels of community with IRS in both rural and urban settings, in Karonga district. Methods A cross-sectional study was conducted in urban village of Mwahimba and rural village of Fundi. Qualitative and quantitative data was collected from households’ representatives through Focus Group Discussions (FGDs) using De Wets’s Schutte tool. Qualitative data was analysed using thematic analysis while numbers and percentages were generated using Microsoft excel. Results Overall level of satisfaction in Fundi was estimated at 69% while that of Mwahimba was at 60.9%. In Fundi village, 66.1 % (37) of the household representatives were satisfied while in Mwahimba village, 60.7 % (34) were satisfied with the IRS programme. Factors that led to satisfaction were minimal adverse effects of the chemical on people after spraying, killing of other insects, sprayer’ courtesy and good communication. Factors behind dissatisfaction include: short residual effect of the chemical used, over-dilution of the chemical and minimal community involvement. Conclusion Despite finding high satisfaction levels in rural village than in an urban village, overall all the villages reported low levels of satisfaction with IRS due to various factors some of which common to both villages. Karonga District Health Office needs to involve the community in the process of spraying by recruiting sprayers from the target area and also explaining the purpose of dilution and the dilution factor to community members.

Evaluation of the conductor-like screening model for real solvents for the prediction of the water activity coefficient at infinite dilution in ionic liquids

Ionic liquids (ILs) have attracted great attention, from both industry and academia, as alternative fluids for very different types of applications. The large number of cations and anions allow a wide range of physical and chemical characteristics to be designed. However, the exhaustive measurement of all these systems is impractical, thus requiring the use of a predictive model for their study. In this work, the predictive capability of the conductor-like screening model for real solvents (COSMO-RS), a model based on unimolecular quantum chemistry calculations, was evaluated for the prediction water activity coefficient at infinite dilution, gamma(infinity)(w), in several classes of ILs. A critical evaluation of the experimental and predicted data using COSMO-RS was carried out. The global average relative deviation was found to be 27.2%, indicating that the model presents a satisfactory prediction ability to estimate gamma(infinity)(w) in a broad range of ILs. The results also showed that the basicity of the ILs anions plays an important role in their interaction with water, and it considerably determines the enthalpic behavior of the binary mixtures composed by Its and water. Concerning the cation effect, it is possible to state that generally gamma(infinity)(w) increases with the cation size, but it is shown that the cation-anion interaction strength is also important and is strongly correlated to the anion ability to interact with water. The results here reported are relevant in the understanding of ILs-water interactions and the impact of the various structural features of its on the gamma(infinity)(w) as these allow the development of guidelines for the choice of the most suitable lLs with enhanced interaction with water.

Determination of the Side-Reaction Coefficient of Desferrioxamine B in Trace-Metal-Free Seawater

Partial funding for open access provided by the UMD Libraries' Open Access Publishing Fund.

Análise da descarga sólida em suspensão na Bacia do Riacho Fundo, Brasília - DF

Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, 2015.

Confronto tra le tecniche XRD e IHD per la misura di tensioni residue

Le rotture a fatica dei componenti sono dovute principalmente alle tensioni di trazione generate da carichi ciclici e variabili nel tempo. Le cricche causate da questo tipo di tensioni possono propagarsi e crescere fino a causare danni catastrofici nel componente. La fatica costituisce uno dei fattori principali di rottura delle strutture aeronautiche; in campo aeronautico sono quindi molto diffusi dei trattamenti superficiali che permettono di indurre tensioni di compressione che contrastano quelle di trazione, in modo tale da ritardare o prevenire le rotture dovute al fenomeno della fatica. Esistono diverse tecniche per raggiungere questo risultato e permettere di prolungare la vita a fatica di un componente metallico, la più nota è sicuramente il Laser Shock Peening (LSP). Nel corso degli ultimi anni la maggior parte delle ricerche condotte rispetto a questa tecnica sono state incentrate sugli effetti meccanici che questo trattamento ha sul materiale in modo da determinare la configurazione ottimale per ottenere una distribuzione delle tensioni il più efficace possibile ai fini della vita a fatica; sono state svolte diverse prove sperimentali per studiare il ruolo dei parametri del laser e ottimizzare la procedura del LSP. Tra le tecniche utilizzate per valutare gli effetti del LSP in termini di tensioni residue, spiccano, oltre ai metodi computazionali, l'X-ray Diffraction (XRD) e l'Incremental Hole Drilling (IHD). L'elaborato di tesi qui presentato ha come scopo il confronto tra i livelli di tensioni residue riscontrate all'interno di provini sottili in lega di alluminio, sottoposti a differenti trattamenti laser, attraverso i suddetti metodi XRD e IHD. I risultati, già noti, ottenuti con la tecnica l'XRD sono stati posti a verifica attraverso dei test svolti con l'IHD presso i laboratori MaSTeRLab della Scuola di Ingegneria dell'Università di Bologna.

Performance of concrete incorporating amorphous silica residue and biomass fly ash

L'industrie du ciment est l'une des principales sources d'émission de dioxyde de carbone. L'industrie mondiale du ciment contribue à environ 7% des émissions de gaz à effet de serre dans l'atmosphère. Afin d'aborder les effets environnementaux associés à la fabrication de ciment exploitant en permanence les ressources naturelles, il est nécessaire de développer des liants alternatifs pour fabriquer du béton durable. Ainsi, de nombreux sous-produits industriels ont été utilisés pour remplacer partiellement le ciment dans le béton afin de générer plus d'économie et de durabilité. La performance d'un additif de ciment est dans la cinétique d'hydratation et de la synergie entre les additions et de ciment Portland. Dans ce projet, deux sous-produits industriels sont étudiés comme des matériaux cimentaires alternatifs: le résidu de silice amorphe (RSA) et les cendres des boues de désencrage. Le RSA est un sous-produit de la production de magnésium provenant de l'Alliance Magnésium des villes d'Asbestos et Thedford Mines, et les cendres des boues de désencrage est un sous-produit de la combustion des boues de désencrage, l'écorce et les résidus de bois dans le système à lit fluidisé de l'usine de Brompton située près de Sherbrooke, Québec, Canada. Récemment, les cendres des boues de désencrage ont été utilisées comme des matériaux cimentaires alternatifs. L'utilisation de ces cendres comme matériau cimentaire dans la fabrication du béton conduit à réduire la qualité des bétons. Ces problèmes sont causés par des produits d'hydratation perturbateurs des cendres volantes de la biomasse quand ces cendres sont partiellement mélangées avec du ciment dans la fabrication du béton. Le processus de pré-mouillage de la cendre de boue de désencrage avant la fabrication du béton réduit les produits d'hydratation perturbateurs et par conséquent les propriétés mécaniques du béton sont améliorées. Les approches pour étudier la cendre de boue de désencrage dans ce projet sont : 1) caractérisation de cette cendre volante régulière et pré-humidifiée, 2) l'étude de la performance du mortier et du béton incorporant cette cendre volante régulière et pré-humidifiée. Le RSA est un nouveau sous-produit industriel. La haute teneur en silice amorphe en RSA est un excellent potentiel en tant que matériau cimentaire dans le béton. Dans ce projet, l'évaluation des RSA comme matériaux cimentaires alternatifs compose trois étapes. Tout d'abord, la caractérisation par la détermination des propriétés minéralogiques, physiques et chimiques des RSA, ensuite, l'optimisation du taux de remplacement du ciment par le RSA dans le mortier, et enfin l'évaluation du RSA en remplacement partiel du ciment dans différents types de béton dans le système binaire et ternaire. Cette étude a révélé que le béton de haute performance (BHP) incorporant le RSA a montré des propriétés mécaniques et la durabilité, similaire du contrôle. Le RSA a amélioré les propriétés des mécaniques et la durabilité du béton ordinaire (BO). Le béton autoplaçant (BAP) incorporant le RSA est stable, homogène et a montré de bonnes propriétés mécaniques et la durabilité. Le RSA avait une bonne synergie en combinaison de liant ternaire avec d'autres matériaux cimentaires supplémentaires. Cette étude a montré que le RSA peut être utilisé comme nouveaux matériaux cimentaires dans le béton.

Assessment of sugarcane harvesting residue effects on soil spectral behavior

When the harvesting of sugarcane involves a mechanized process, plant residues remain on the soil surface, which makes proximal and remote sensing difficult to monitor. This study aimed to evaluate, under laboratory conditions, differences in the soil spectral behavior of surface layers Quartzipsamment and Hapludox soil classes due to increasing levels of sugarcane?s dry (DL) and green (GL) leaf cover on the soil. Soil cover was quantified by supervised classification of the digital images (photography) taken of the treatments. The spectral reflectance of the samples was obtained using the FieldSpec Pro (350 to 2500 nm). TM-Landsat bands were simulated and the Normalized Difference Vegetation Index (NDVI) and soil line were also determined. Soil cover ranged from 0 to 89 % for DL and 0 to 80 % for GL. Dry leaf covering affected the features of the following soil constituents: iron oxides (480, 530 and 900 nm) and kaolinite (2200 nm). Water absorption (1400 and 1900 nm) and chlorophyll (670 nm) were determinant in differentiating between bare soil and GL covering. Bands 3 and 4 and NDVI showed pronounced variations as regards differences in soil cover percentage for both DL and GL. The soil line allowed for discrimination of the bare soil from the covered soil (DL and GL). High resolution sensors from about 50 % of the DL or GL covering are expected to reveal differences in soil spectral behavior. Above this coverage percentage, soil assessment by remote sensing is impaired.

Progettazione di un sistema di taratura per dispositivi di misura delle tensioni residue mediante hole-drilling

Nel seguente elaborato è stato sviluppato un metodo di validazione per dispositivi di misura delle tensioni residue mediante la tecnica dell'hole drilling. Esso si basa sul confronto tra tensioni residue ottenute per via teorica e sperimentale su un provino soggetto a carico imposto. Inizialmente si è proceduto attraverso lo studio della normativa di riferimento ASTM E837-20. In essa viene definito il metodo sperimentale di esecuzione dei test di hole drilling e di calcolo delle tensioni residue. In seguito è stata progettata un'attrezzatura di prova in grado di indurre un gradiente di tensione noto nello spessore del provino sollecitato. L'attrezzatura di prova in questione è stata verificata sia mediante calcoli numerici, che mediante software di simulazione agli elementi finiti. La fase di prototipazione seguente ha consentito di realizzare l'attrezzatura necessaria per l'esecuzione dei test sperimentali. Le forature sono state effettuate prima su provini scarichi, al solo scopo di scongiurare la presenza di tensioni residue e, in seguito, su provini soggetti a momento flettente noto. Le deformazioni ottenute tramite le letture degli estensimetri sono state impiegate per il calcolo delle tensioni secondo normativa ASTM E837-20. infine è stato possibile valutare l'efficacia del metodo paragonando tali risultati con quelli teorici.