Kinetic and morphology study of alginate-vineyard pruning waste biocomposite vs. non modified vineyard pruning waste for dye removal

In this work a comparative bioadsorption study between a biocomposite consisting of hydrolysed vineyard pruning waste entrapped in calcium alginate spheres and non entrapped vineyard residue was carried out.Results have demonstrated that the biocomposite based on lignocellulose-calcium alginate spheres removed 77.3% of dyes,while non entrapped lignocellulose eliminated only removed 27.8% of colour compounds.The experimental data were fitted to several kinetic models(pseudo-first order,pseudo-second order,Chien–Clayton model,intraparticle diffusion model and Bangham model); being pseudo-second order the kinetic model that better described the adsorption of dyes onto both bioadsorbents.In addition,a morphological study(roughness and shape) of alginate-vineyard biocomposite was established under extreme conditions,observing significant differences between hydrated and dehydrated alginate-vineyard biocomposite.The techniques used to carry out this morphological study consisted of scanning electron microscopy(SEM),perfilometry and 3D surface analysis.     

Using Count Data and Ordered Models in National Forest Recreation Demand Analysis

This research addresses the need to improve our knowledge on the demand for national forests for recreation and offers an in-depth data analysis supported by the complementary use of count data and ordered models. From a policy-making perspective, while count data models enable the estimation of monetary welfare measures, ordered models allow for the wider use of the database and provide a more flexible analysis of data. The main purpose of this article is to analyse the individual forest recreation demand and to derive a measure of its current use value. To allow a more complete analysis of the forest recreation demand structure the econometric approach supplements the use of count data models with ordered category models using data obtained by means of an on-site survey in the Bussaco National Forest (Portugal). Overall, both models reveal that travel cost and substitute prices are important explanatory variables, visits are a normal good and demographic variables seem to have no influence on demand. In particular, estimated price and income elasticities of demand are quite low. Accordingly, it is possible to argue that travel cost (price) in isolation may be expected to have a low impact on visitation levels.     

Radiocarbon dating of archaeological samples (sambaqui) using CO(2) absorption and liquid scintillation spectrometry of low background radiation

Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO(2) absorption on Carbo-sorb and (14)C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H(3)PO(4) in a closed vessel in order to generate CO(2). The produced CO(2) was absorbed on Carbo-sorb. On saturation about 0.6g of carbon, as CO(2), was mixed with commercial liquid scintillation cocktail (Permafluor), and the (14)C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the (14)C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained.     

突发性气象灾害监测系统的设计

本文探讨了一种以新一代多普勒天气雷达为探测手段,应用GIS技术,借助Surfer等值线分析功能,获取灾害性天气落区、面积等定量化信息的方法,并据此以VB及VBA开发了一套突发性气象灾害监测系统,并给出了该系统一次典型冰雹过程的应用实例.     

Short-term variability in the photosynthetic activity of microphytobenthos as detected by measuring rapid light curves using variable fluorescence

Short-term variability in the photosynthetic activity of microphytobenthos assemblages was studied by measuring chlorophyll fluorescence rapid light curves (RLC), using pulse amplitude modulated (PAM) fluorometry. Measurements carried out on undisturbed samples under dark–light cycles revealed large diel oscillations in both the initial slope of the RLC () and in the maximum relative electron transport rate (ETR_m). Short-term variations in RLC parameters were also observed, closely following changes in incident photon irradiance (E). Increases in irradiance were followed by decreases in and increases in ETR_m, resulting in significant correlations between the light-saturation parameter E_k and E. These results were interpreted as resulting from the onset of reversible energy-dissipating, non-photochemical quenching mechanisms and of compensatory high light-induced activation of carbon metabolism activity. Short-term RLC variability was shown to result mainly from physiological causes and to be detectable only by using short (10–20 s) light steps during RLC construction. Dark-adapted samples kept under constant conditions exhibited apparently endogenous rhythms in RLC parameters and in the maximum quantum yield, F_v/F_m, coincident with vertical migratory movements occurring during subjective photoperiods. These fluctuations appeared to result from the interaction between migratory rhythms and the physiological responses, and from the endogenous activation of processes affecting both the efficiency of energy transfer from light-harvesting antennae to the photosystem II (PSII) reaction centres or from non-radiative pathways (F_v/F_m, ) and the reactions downstream of PSII (ETR_m).Communicated by M. Kühl, Helsingør     

Mineralization of major lateral teeth in the radula of a deep-sea hydrothermal vent limpet (Gastropoda:Neolepetopsidae)

Radular teeth of a neolepetopsid patellogastropod limpet, Paralepetopsis ferrugivora, from a deep-sea hydrothermal vent site have similar elemental composition (O, Si, P, S, Cl, K and Fe) to radular teeth of the shallow-waters patellogastropod limpets. However, in contrast to shallow waters limpets, the fully mature teeth of P. ferrugivora do not show any crystalline phases. Amorphous silica was found in the cusp of the teeth and amorphous iron oxide in the junction zone and base of the teeth. Ferritin-rich vesicles were observed in cells adjacent to the junction zone of the early mature teeth, suggesting that these vesicles can mediate the delivery of iron to the tooth matrix. The similarity in the elemental composition between the hydrothermal limpet P. ferrugivora and shallow-waters patellogastropod limpets shows that the extreme hydrothermal environment did not alter the elemental composition of the radular teeth in the deep-sea species.Communicated by P. W. Sammarco, Chauvin     

工作价值观、调节焦点与安全绩效的关系研究——基于煤矿企业新生代员工的实证分析

为了从价值观和调节焦点的双重视角给煤矿企业新生代员工的安全管理提供科学依据,在文献研究和问卷调查的基础上,对 244 个有效样本进行分析,揭示煤矿企业新生代员工工作价值观的具体内容,结合动机理论和调节焦点理论,构建煤矿企业新生代员工工作价值观、调节焦点和安全绩效的结构方程模型。研究结果表明:煤矿企业新生代员工的工作价值观包含发展导向、自我导向、关系认同、独立自主、利益导向和创造导向6个因子结构;煤矿企业新生代员工的工作价值观、调节焦点和安全绩效两两之间均显著相关;煤矿企业新生代员工的工作价值观不仅可以直接预测安全绩效,还可以通过调节焦点的中介作用间接影响煤矿员工的安全绩效。