Treatment of domestic wastewater using the nutrient film technique (NFT) to produce horticultural roses

Removal of organic matter, nitrogen and phosphorus was investigated in a pilot based on the nutrient film technique system used for horticultural production. Rosebushes producing commercial roses were set on an inclined impermeable surface over which a thin film of domestic wastewater flowed directly through the root matrix. The roses produced with wastewater as nutrient solution were qualitatively and quantitatively similar to those produced traditionally and can be marketable. In the presence of the rosebushes, the lowering of chemical oxygen demand (COD), biological oxygen demand (BOD5) and suspended solids (SS) increased with their influent strengths in a linear fashion correlation. Whatever the pollutant load of the influent, within the range studied, the level of organic pollution required to allow the discharge of the effluent into water courses was reached after 24 h of treatment. At this time, the COD reached 39 +/- 13 mg L(-1), the BOD5 7 +/- 4 mg L(-1) and the SS 8 +/- 6 mg L(-1). The removal percentages were 89, 95 and 94, respectively, whereas without plants they were 55, 33 and 53, respectively. The rosebushes had a beneficial effect on the removal of phosphorus from 20% to 23% greater in their presence than without. In presence of plants, the nitrate was the principal form of nitrogen from 48 h of treatment whereas without rosebushes, nitrite represent more than 20% of initial nitrogen whatever the treatment duration. The root matrix served not only as a filter for the organic matter, but also provided a microhabitat suitable for nitrifying bacteria and heterotrophic micro-organisms, which responded rapidly to the pollutant load.     

Effects of mineral wool insulation on electric cables in buildings

Since the seventies, energy conservation in all its forms has grown. This mindset has lead to the addition of thermal insulation in existing buildings, without concern for the existing electric cables. The addition over-insulates the cables, inhibiting heat dissipation, and possibly creating a hazardous situation.Our laboratory performed, between 1981 and 1990, a series of technical tests to determine the effect of this additional thermal insulation on the electric cables.This paper is the result of a research program giving the risks of fires caused by cables submitted to over-insulation, as a function of the type of thermal insulation and the current.Nomenclature L cable life expectancy (years) - A constant which depends on the specific chemical reaction - B constant which depends on the specific chemical reaction - T temperature (°C or °K) - T _I initial conductor temperature (°C) - T _F final conductor temperature (°C) - t time (seconds) - I current (amperes) - W heat dissipation (Watt-seconds) - R resistance (ohms)     

北方乡村生态屋设计实践

本论文给出在恶劣条件下,改善北方乡村居民居住质量、创造舒适与生态的人居环境的设计策略与技术手段,论文通过对当地传统民居与生态屋进行的同步测试、评估与比较分析,验证了生态屋生态技术的有效性,为北方乡村住宅建设的可持续发展指明了方向。     

Speciation (including adsorbed species) of copper, lead, nickel and zinc in the Meuse River: Observed results compared to values calculated with a chemical equilibrium computer program

The adsorption of trace metals on sediments of the Meuse River was interpreted in terms of competition between metals and protons for surface sites. Surface constants (^*β₁^surf) were determined for Cu, Zn and Cd (10^−1.8, 10^−3.6 and 10^−3.7). The constants for Pb, Ni, Ca and Mg (10^−1.7, 10^−3.8, 10^−6.5 and 10^−5.2) were estimated using a correlation between hydrolysis and surface constants. A chemical equilibrium computer program in which surface sites (for adsorption reactions) are treated as conventional ligands was used to calculate the speciation of Cu, Pb, Ni and Zn in the Meuse River. Calculated values of the adsorbed/dissolved distribution agreed well with observed values, after some realistic data manipulation. This work indicates that dissolved trace metal concentrations in the Meuse River are controlled by adsorption and not by precipitation mechanisms. The relationship between organic matter and suspended matter greatly influences the adsorption of metals like Cu and Pb.     

New generation photon-counting cameras: algol and CPNG

Algol and Comptage de Photons Nouvelle Génération (CPNG) are new generation photon counting cameras developed for high angular resolution in the visible by means of optical aperture synthesis and speckle interferometry and for photon noise limited fast imaging of biological targets. They are intensified CCDs. They have been built to benefit from improvements in photonic commercial components, sensitivity, and personal computer workstations processing power. We present how we achieve optimal performances (sensitivity and spatiotemporal resolution) by the combination of proper optical and electronics design, and real-time elaborated data processing. The number of pixels is 532 x 516 and 1024(2) read at a frame rate of 262 and 100 Hz for CPNG and Algol, respectively. The dark current is very low: 5.5 x 10(-4) e(-) .pixel(-1). s(-1). The saturation flux is approximately 7 photon events /pixel/s. Quantum efficiencies reach up to 36% and 26% in the visible with the GaAsP photocathodes and in the red with the GaAs ones, respectively, thanks to the sensitivity of the photocathodes and to the photon centroiding algorithm; they are likely the highest values reported for intensified CCDs.     

Determination of the correlation between physical measurements of roughness, optical properties, and perception of frosted glass surfaces

Chemical frosting is used as a surface decorating method by many glass package producers. After immersion in an acid frosting bath, glass items present the desired frosted effect. The perception of this particular effect is due to the formation of a microscopic crystalline pattern on the glass surface, which scatters light passing through the glass surface. The chemical composition of the frosting bath influences these properties by modifying the surface roughness, the depth, and the average slopes of the crystalline pattern. Perception of the final aspect can be modified according to the chemical composition of the frosting bath. Different correlations between all these parameters exist and have been quantified.     

Update of line parameters of ozone in the 2550-2900 cm(-1) region

An update of spectroscopic line parameters for the 3.45-3.92 microm ozone bands is reported. The line list includes the parameters of 15 bands of the main isotopic species and of the v1+v2+v3 band of 16O16O18O and 16O18O16O. The results are based on previous high resolution laboratory studies. Comparisons of experimental spectra with an absorptance simulation of ozone based on the reported line list shows that the latter one is accurate enough for strong, medium, and weak transmittance in the 2550-2900 cm(-1) spectral range. The data are available on the Web in the Spectroscopy and Molecular Properties of Ozone (S&MPO, http://smpo.iao.ru and http://ozone.univ-reims.fr) and HITRAN (http://cfa-www.harvard.edu/hitran/) databanks.     

Priority pesticides and their degradation products in river sediments from Portugal

A multiresidue gas chromatography-mass spectrometry method was developed to determine 28 priority pesticides of different chemical families (organochlorine, organophosphorus, triazines, anilides) together with some of their transformation products in river sediment. Ultrasonic, Soxhlet and pressurized liquid extraction (PLE) methods were compared in spiking experiments using acetone:hexane (1:1) followed by alumina solid phase extraction cartridges or in-cell alumina clean-up for PLE. All extraction techniques produced acceptable recoveries for the pesticides under study, although Soxhlet extraction produced the lowest recoveries for 2,4-DDE, trifluralin, lindane, and hexachlorobenzene (<50%) whereas ultrasonic extraction resulted in low recoveries for hexachlorobenzene and lindane (<50%). However, PLE using in-cell alumina clean-up produced an overestimation of more apolar compounds, given the amount of coextracted compounds. Limits of detection at the low microg L(-1)-ng L(-1) levels were obtained with Soxhlet and ultrasonic extraction, while PLE produced higher variability due to the lack of exhaustive clean-up. Given the simplicity of ultrasonic extraction, this method was further employed to determine target compounds in river sediments collected in Portugal. Lindane was detected in practically all samples, followed by trace levels of the pesticides simazine, diazinon, fenitrothion, and parathion-methyl.     

Effect of the Fiber Size on the Physicochemical and Mechanical Properties of Composites of Epoxy and Date Palm Tree Fibers

Lignocellulosic fibers from date palm trees were employed to reinforce an epoxy matrix. Two fiber sizes were used, with the length and diameter in the range of 20–30 and 1.5–3 mm, respectively, for the so‐called long fibers, and in the range of 5–15 and 0.25–0.75 mm, respectively, for the so‐called short fibers. The morphologies of the resulting composites, as well as their thermal, mechanical, and water sorption properties were evaluated. Strong interactions between both components and etherification reactions may occur between the hydroxyl groups of the fibers and the epoxy groups of the epoxy‐amine reactive mixture. These effects are emphasized when decreasing the size of the fibers.

     

Profiles of volatile compounds in milk containing fish oil analyzed by HS‐SPME‐GC/MS

Long‐chain polyunsaturated fatty acids (LC‐PUFA) have various positive biological effects. Fish oil represents a major source of LC‐PUFA; therefore it is extensively used to enrich food products as, for example, infant formulae, dairy products and fruit juices. However, in the presence of oxygen and metals, LC‐PUFA readily degrade, producing off‐flavors and decreasing the nutritional value of the product. The deterioration of sensory properties (taste and odor) can be easily perceived by the consumer, due to the formation of volatile compounds that are formed by decomposition of lipid hydroperoxides, also known as primary oxidation products. In this study, we used the headspace solid‐phase microextraction‐gas chromatography/mass spectrometry technique (HS‐SPME‐GC/MS) to characterize and quantify volatile compounds in a food matrix supplemented with fish oil. We demonstrated that the HS‐SPME‐GC/MS method is a valuable tool to monitor lipid oxidation at early stages. We identified t‐2‐hexenal and c‐4‐heptenal as possible oxidation markers during the storage of milk enriched with 5% of cod oil.