Use of essential oils of cinnamon (Cinnamomum zeylanicum L.), lavender (Lavandula spp.) and peppermint (Mentha x piperita L.) for weed control

The indiscriminate use of synthetic chemical compounds for weed control has been often responsible of damage to both the environment and the human health. To challenge these problems, in the last years research has increased its effort to find out alternatives farming strategies. A feasible alternative could be the identification of natural substances with allelopathic effects for the realization of natural herbicides. Some research has already highlighted the possibility of using essential oils, extracted from aromatic plants, for weed control. The advantage in the utilization of such natural compounds is the quickly breaking down process into the environment and so the possible application in sustainable agriculture like organic farming. Objective of this research was the evaluation of the inhibition effect exerted by the essential oils of cinnamon, peppermint and lavender on seeds germination of some of the most common weeds species of the Mediterranean environment (pigweed, wild mustard and ryegrass). The results have highlighted a control in the weeds germination. Among the essential oils tested, cinnamon oil has exerted the highest inhibition effect compared with lavender and peppermint ones. The dicotyledonous species have been more susceptible compared with the monocotyledonous, even if it has been recorded only for redroot pigweed a dose able to inhibit totally the seed germination

Estudio de las condiciones de agitación por oleaje en un puerto mediante simulación numérica

Se describe una aplicación del sistema computacional DIFRAC para estudiar la s condiciones de agitación por oleaje dentro de un puerto, teniendo en cuenta el efecto combinado de difracción, refracción y reflexión de las olas . Se presentan resultados para la amplitud y dirección de propagación del oleaje en su interior y de las condiciones de resonancia en la s distintas dársenas del puerto .Peer Reviewe

Estudio de las condiciones de agitación por oleaje en un puerto mediante simulación numérica

Se describe una aplicación del sistema computacional DIFRAC para estudiar la s condiciones de agitación por oleaje dentro de un puerto, teniendo en cuenta el efecto combinado de difracción, refracción y reflexión de las olas . Se presentan resultados para la amplitud y dirección de propagación del oleaje en su interior y de las condiciones de resonancia en la s distintas dársenas del puerto .Peer Reviewe

A busca de justiça social em tempo de pandemia

This article seeks to carry out a synthetic and philosophical analysis of the methods of negotiating the conflicts generated by the global hecatomb. In times of pandemic, caused by the coronavirus, society was affected in several segments. The article creates two characters who talk about the most just governmental measures, to try to satisfy society in the sanitary and economic aspects, with support in the communitarian ideals and also, on the other hand, in the liberal ideals. It does not address technical issues in the health and economic sciences, but how to seek a more just decision, based on philosophical foundations of social justice.O presente artigo busca realizar uma análise sintética e filosófica dos métodos de negociação dos conflitos gerados pela hecatombe mundial. Em tempo de pandemia, causada pelo coronavirus, a sociedade foi atingida em diversos seguimentos. O artigo cria dois personagens que dialogam sobre as medidas governamentais mais justas, para tentar satisfazer a sociedade nos aspectos sanitários e econômicos, com apoio nos ideais comunitaristas e também, de outro lado, nos ideais liberais. Não aborda questões técnicas das ciências sanitárias e econômicas, mas como se buscar uma decisão mais justa, sob fundamentos filosóficos da justiça socia

High resolution spectroscopy in the XUV with pairs of mutually coherent and time-delayed laser harmonics

We present a Ramsey technique using high-order harmonics for high-resolution atomic spectroscopy in the extreme ultraviolet. Pairs of time-delayed and phase-coherent harmonic pulses generated by the interaction of ultrashort and intense laser pulses with a noble gas are used to study excited states of krypton

Optical delay control of large-spectral-bandwidth laser pulses

In this letter we report the first experimental observation of temporal delay control of large-spectral-bandwidth multimode laser pulses by means of electromagnetically induced transparency (EIT). We achieved controllable retardation with limited temporal distortion of optical pulses with an input spectral bandwidth of 3.3 GHz. The experimental results compare favorably with theoretical predictions.Comment: Submitted to Optics Letters (January 2009

Analysis, design and construction of copper vapor laser system

In this work construction characteristics and performance of a small scale self-heating copper vapor laser are presented. Analytical design of the thermal isolator is reported in some detail. Particular attention has been given to the knowledge of power deposition in the discharge to evaluate the component losses. In the optimized conditions the laser mean power is over 5 W, confirming the expected values. Details of the measurements on the system are also reported

Influência do teor de água e da digestibilidade de alimentos industrializados sobre o balanço hídrico de gatas

Dietary adjustment has been studied for the control and prevention of the Feline Lower Urinary Tract Disease. This work studied the influence of the amount of water and food digestibility on water intake and excretion (urinary and fecal). Ten adult female cats housed in metabolic cages were used. Four treatments were tested: low price dry food, low price dry food with 50% added water, super-premium dry food and canned food. Water intake with food and by drinking, fecal and urinary water excretion and food's digestibility coefficient were determined, in a Latin square experimental design with repetitions over time. The results were submitted to variance analysis; to Tukey's test to compare means and to Pearson's Correlation to test the association between variables (p<0.05). Moist food led to the highest water intake and the largest urine volume with the lowest density. The cats balanced the higher water intake with food by drinking less water. Adding 50% water to the food did not result in a higher total water intake and urine excretion. The lowest consumption of dry matter and highest food digestibility resulted in lower fecal water excretion. Dry foods with high and low digestibility had a urine:feces water excretion rate of 0.7:1 and 1.6:1, respectively. Among the nutrients, fat intake had a positive correlation with the urine volume. Foods with higher digestibility resulted in lower fecal water loss. Canned food (high water:dry matter ratio) led to the highest total water intake and urinary volume excretion, and lower urinary density.A modificação dietética tem sido estudada e empregada no controle e prevenção da Doença do Trato Urinário Inferior dos Felinos. Este trabalho estudou a influência do teor de água e da digestibilidade das rações sobre a ingestão, excreção urinária e excreção fecal de água. Utilizaram-se 10 gatas adultas castradas, alojadas em gaiolas metabólicas.Testaram-se quatro tratamentos: ração enlatada; seca super-premium; seca econômica e seca econômica acrescida de 50% de água. Determinou-se a ingestão de água via alimento e bebedouro, a excreção de água via fezes e urina e o coeficiente de digestibilidade das rações. Foi empregado um quadrado latino com repetições no tempo. Os resultados foram avaliados por análise de variância seguido pelo teste de Tukey para a comparação de médias e a Correlação de Pearson para se verificar a associação entre variáveis (p<0,05). O consumo de ração enlatada proporcionou uma maior ingestão total de água e uma maior excreção de urina, que apresentou menor densidade. Os gatos compensaram a maior ingestão de água alimentar bebendo menos água. Quanto menor a ingestão de matéria seca e maior a digestibilidade do alimento, menor a excreção fecal de água, pois as rações secas de baixa e alta digestibilidade obtiveram, respectivamente, relação excreção de urina:excreção de água fecal de 0,7:1 e 1,6:1. A ingestão de gordura apresentou correlação positiva com o volume urinário. Rações de maior digestibilidade promovem menor perda fecal de água, mas somente a ração enlatada (alta relação água:matéria seca) proporcionou maiores ingestão total de água e volume urinário