Urethane Modified Hydrophobic Compact Wood Pulp Paper for Oil Spill Cleanup: A Preliminary Study

Oil spills and oil/water wastewater are among the great concerns regarding oil pollution.Existing technologies face many limitations and in some cases are responsible for causing secondary pollution,therefore there is as seek for environmental friendly solutions.Biomass,from which celluloses are highlighted,are being employed for oil/water separation or oil absorbents membranes.Usually,these membranes are obtained by freeze drying of CNF(cellulose nano-fibrils)suspensions followed by chemical modification for hydrophobization,which involves expensive process as chemical vapor deposition and expensive reactants as sylanes,turning these processes hardly scalable.Here,we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping and heating process in a blocked diisocyanate solution.After the surface treatment,contact angle with water reached 144°and water absorption reduced seven times,keeping the good oil absorbance.The chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt%based on cellulose.The good mechanical properties of the material allows its use in non usual conditions which can be of great importance depending on the environmental conditions.

Effect of Ce-base mischmetal addition on the microstructure and mechanical properties of hot-rolled ZK60 alloy

Mg-Zn-Zr(ZK)alloys exhibit notably high mechanical strength amongst all magnesium alloy grades.However,due to the formation of low melting point Mg_3Zn_7-precipitates,these alloys are susceptible to hot cracking,thus compromising their metallurgical processing.The addition of rare earths to ZK alloys is an alternative to form higher melting point intermetallic compounds,speed up dynamic recrystallization,refine grain size,enhance corrosion resistance and extend the service temperature due to improved creep resistance.This work deals with the effect of Ce-base mischmetal addition on the hot rolling behaviour of as-cast ZK60 alloy.The microstructure investigation conducted using electron microscopy and X-Ray diffraction shows that precipitation of Mg_(7)Zn_(3) intermetallics occur during hot rolling,whereas no further precipitation is observed for the ZK60-Mm alloys.The fragmentation of the intermetallic compounds occur during hot rolling and finer particles of Mg_(7)Zn_(3) are observed for the ZK60,whereas Mg_(7)Zn_(3) and Mg Zn_(2) Ce intermetallics are formed in the alloy modified with mischmetal addition.A higher fraction of dynamically recrystallized grains is observed for the ZK60-Mm in comparison to the ZK60.Continuous recrystallization takes place in ZK60 with the formation of sub-grains near to the intermetallics and the addition of mischmetal promotes the occurrence of discontinuous recrystallization with the nucleation of new grains close to the precipitates.The mechanical strength and,in particular,the ductility of the hot-rolled alloys are notably improved when compared to the same alloys in the as-cast condition.The mechanical strength is,however,higher for the ZK60 alloy.Less solid solution strengthening,softer Mg Zn_(2) Ce intermetallics and more extensive recrystallization contribute to reduce the mechanical strength of ZK60-Mm.Failure in both alloys are initiated at coarse intermetallics and propagate through intermetallic-rich regions.

固体渗硼对AISI H13钢耐磨和耐蚀性能的影响

研究了固体渗硼的时间和温度对AISI H13工具钢耐磨和耐蚀性能的影响。将900℃和1 000℃固体渗硼2 h和4 h的渗硼试样和未渗硼试样进行无磨料固定球的微量磨损试验,耐蚀性能则通过0.1 mol HCl溶液中进行的动电位极化试验测定。渗硼试样中均形成了高硬度的渗层,钢的成分对渗层的硬度、厚度、渗层/基体界面的形貌和形成相等特性均有影响。对于合金元素含量比碳钢高的AISI H13钢,所形成的渗层硬度较高,渗层较薄,渗层/基体界面较平坦。在上述工艺条件下获得的渗层中,均发现有Fe_2B、FeB和CrB等硼化物。渗硼试样的耐磨和耐蚀性能得到了显著的改善,且在1 000℃渗硼的效果最佳。

渗硼对沉淀硬化铌不锈钢的影响

沉淀硬化不锈钢是含铝、钛、铌和铜等沉淀硬化元素的铁-镍-铬合金。沉淀硬化过程包括非常细小的金属间相的形成(析出),如Laves相Fe_2(Mo,Nb),Ni_3M(M:Al,Ti,Nb,Cu,V,Mo,W),Nb(C,N)和碳氮化物Ti(C,N)及碳化物Fe_3Nb_3C(M_6C)。本文对沉淀硬化钢进行了渗硼处理,为了提高硬度和耐磨性,该钢以铌作硬化剂。钢的成分为0.03C-0.22Si-17.86Cr-3.91Ni-2.14Mo-1.96Nb(质量分数,%)。渗硼在添加10%Al的熔融硼砂中进行,温度1 100℃,时间4 h,油冷,随后于500℃时效。结果获得了硬度高、耐磨性好的硼化物层。

Elimination of Quench Cracking by Controlling Agitation Uniformity

Uniform agitation of the quenchant is a critically important control parameter in optimizing distortion control and reducing steel cracking. Quenching with ultrasonic agitation or in the presence of electrical and magnetic fields provide uniform agitation leading to improved uniformity of the stress fields within the metal not readily achievable with more traditional agitation methods such as propeller pumps and sprays. These methods provide the additional potential advantage of varying agitation throughout the cooling cycle to achieve a wide range of cooling profiles not readily achievable with quenchants and more traditional agitation systems currently in use.

2011欧洲设计大奖揭晓

欧洲设计大奖是由欧洲经济与社会委员会（简称欧洲经社委，EESC）倡议笈起的设计奖。欧洲经社委是于1957根据《罗马条约》成立的欧盟咨询机构，它的主要工作是向欧洲议会、欧盟理事会和欧洲委员会这三个主要机构提出建议。2009年，欧洲经社委发起这一设计竞赛，旨在设计出创新，可持续的设计作品及产品包装，传达出欧洲政府所倡导的社会文化。

Feeding Strategies for Enrichment and Characterization of Anammox Biomass in a Sequencing Batch Reactor

Anammox bacteria represent a promising alternative for treating ammonium-rich wastewater. In this work reported, biomass performing anaerobic oxidation of ammonium was enriched in a sequencing batch reactor, from sludge used for the treatment of high-nitrogen waste from an amino acid-producing industry. After 89 days of operation, both ammonium and nitrite were consumed. During operation under a 24-hour cycle, the applied nitrogen load (ANL) was increased from 155 to 802 mg N/L·d. This strategy resulted in efficiencies of nitrogen removal and nitrogen conversion rate of 91.7% and 98.5%, respectively. Specific anammox activity increased proportionally to ANL and it was partially inhibited at 802 mg N/L·d. Sequencing analysis using 16S rRNA anammox primers, after 170 days of operation, showed that 21 clones were grouped into two OTUs (operational taxonomic units). The identity of the 16S rRNA gene of OTU esp 1 showed similarity to Brocadia species, and OTU esp 2 displayed 99% similarity to Anammoxoglobus propionicus. After 450 days of operation, sequencing analysis using universal primers showed that 48 clones were grouped into 19 OTUs representing six major groups of bacteria: Planctomycetes, beta-Proteobacteria, green sulfur bacteria of the Chlorobi phylum, Nitrospira, Chloroflexi and OP 11. Brocadia sp. was the only anammox bacteria in the biomass at this time.

Using Computer Vision and Intelligent Classification Techniques for the Classification and Selection of Brazilian Nuts

Aiming to improve the processes involved in the industrial beneficiation of the Brazilian nuts, this work used a new methodology based on concepts of computer vision and intelligent classification, with a focus on two of the various stages of the processing： classification according to the origin and selection. Using the proposed methodology for the selection of the nuts it was possible to distinguish between intact and broken nuts and between good and spoiled nuts with a very high percentage of correct identifications. Also to evaluate the efficiency of the proposed methodology, visual tests by human subjects were performed for the classification of the nuts, the results demonstrated that the intelligent techniques performed the same or better than the visual classification.

Nanostructural Evolution of Sugarcane Rind and Pith Submitted to Hydrothermal Pretreatments

Lignocellulose conversion into cellulosic ethanol and coproducts starts with a pretreatment step.Most current industrial plants of cellulosic ethanol use thermochemical pretreatments under hydrothermal conditions,with or without addition of acid catalyst.Such pretreatments modify biomass chemistry and morphology,particularly at the nanoscale.In this work,we use X-ray diffraction,dynamic vapor sorption and calorimetric thermoporometry to investigate the biomass nanostructural changes promoted by hydrothermal conditions.We compare and differentiate the rind and pith fractions of sugarcane stalks in order to contribute to the understanding of rind-pith contrasting recalcitrance.Moreover,for both cane fractions our results point consistently to cellulose co-crystallization,lignin aggregation,and opening of nanoscale pores as the main nanostructural phenomena occurring during hydrothermal treatments.

金刚石车床上带固态执行器的微定位装置——一个初步实验

在超精密设计中,很可能没有可供选择的设计方案。在超精细进给情况下,压电执行器是一种潜在选择。目前,欧洲和日本刀具制造商为此正致力于磁致伸缩执行器的研究。压电材料和磁致伸缩材料都存在磁滞型非线性,以致这些系统的输出依赖于以前的输入,绝对定位仅通过反馈控制才能得到。本文采用模拟技术对脆性材料的超精密加工中(微米级)刀架定位的几种现代控制技术作了一番比较。

Microstructure and mechanical behavior of similar butt-joints of ZK60 and ZK60-1.5RE magnesium alloys produced by linear friction stir welding

The microstructure and mechanical properties of butt-joints produced by linear friction stir welding of similar plates of as-cast ZK60 and modified ZK60 with 1.5 wt.%RE(ZK60-1.5 RE)are investigated.The thermomechanical affected zone is investigated in both advancing and retrieving sides,and the microstructure is compared to the base metal and the stirred zone.Electron backscattered diffraction measurements provide the average microstructural features of the transformed microstructure.The mechanical properties are assessed using hardness,tensile testing,and surface residual stress measured using X-ray diffraction.Higher torque and heat input are obtained for the ZK60-1.5 RE compared to the ZK60.The thermomechanical affected zone is notably larger for the ZK60 compared to the ZK60-1.5 RE.A gradient microstructure is formed in thermomechanical affected zones where deformed grains are progressively more recrystallised towards the stirred zone.There is no visible interface between the thermomechanical affected zone and the stirred zone.A fine and partially recrystallised microstructure is formed in the stirred zone.The retrieving side of the ZK60-1.5 RE has a slightly more refined microstructure compared to the other investigated zones.Anisotropy measured with increment in the maximum intensity of the(0001)increases towards to stirred zone.The formed microstructure is correlated with the role of twinning,recovery,static,and dynamic recrystallisation that can occur during friction stir welding.Twinning and grains with large misorientation spread are more pronounced in the thermomechanical affected zone and regions towards the base metal.Sharp low angle grain boundaries are observed towards the stirred zone.From refined recrystallised grains decorating the grain in the thermomechanical affected zone,a mosaic-like of low and high angle grain boundaries are observed in the stirred zone.The joints have comparable surface residual stresses.The friction stir welding improved the ductility and strength of the as-cast ZK60-1.5 RE alloy since the tensile samples fractured in the BM.

Drainage Bed:A Natural System for WTP Sludge Dewatering and Drying with Different Coagulant Chemicals in Tropical Countries

This study seeks to evaluate the mechanisms for dewatering sludge from Water Treatment Plants (WTP) in a natural system that uses nonwoven polyester geotextile blankets named Drainage Bed (DB). Dewatering mechanisms are divided into two stages: Drainage and Drying Phases. For the Drainage Phase, the results showed that the solids content of the Aluminum Sulfate sludge reached 8.9% to 18.3% and the PACl sludge 1.8% to 6.5%, the volume reduction on this phase exceeding 50% and 74%, respectively. The final solids content, after the Drying Phase, was greater than 28%, reaching 90%. In the Drainage Phase the lower the Surface Application Rate—SAR [kg/m2] is, the greater the drainage flow will be. In the Drying Phase, moisture and insolation were key factors in drying sludge. Thus, the Drying Phase in the DB takes special attention for being virtually nonexistent in dewatering technologies in a closed system (confined) without exposure to solar energy. The use of the DB as a natural system for dewatering WTP sludge in tropical countries proved to be a promising alternative, because of its efficient removal of water from sludge coupled with operational simplicity and low costs, provided there is area available.

Eutrophication Indexes Used as Fish Production Parameters in the Itaipu Reservoir(Brazil)

The knowledge of liminology can be applied in studies of trophic state indexes and morfoedaphic indexes as factors for determining the inference fish production in reservoirs. This work is based on the hypothesis of the trophic cascade relations, particularly related to bottom-up and top-down effect in Itaipu Reservoir (Brazil). Using the data available by Itaipu, from 1999 to 2004, analyzes of multiple regressions were accomplished to determine the relationships of the dependent and independent variables. We applied the trophic state indices (TSI) based on readings Secchi disk, total phosphorus and chlorophyll-a density for obtaining TSI medium. Morfoedaphic index was calculated based on the reading of the concentration of dissolved solids and the inference of fishing yield, from this index. The average results of the trophic state indices indicate an oligotrophic status for the entire reservoir as well as for the riverine, transition and lacustrine zones separately. The fish was yieldn Estimated by the relation with cyanobacteria concentration, and this was the best variable que explained this prediction. The use of the morfoedaphic index (MEI), with the recorded catch data, predictive models can generate que estimate the fishing yield in the Itaipu Reservoir. The relations of MEI with chlorophyll-a and water transparency que Indicate this index may be a good predicting factor for future fish captures.

Performance evaluation of a water erosion tracer using plot-scale experiments and process-based modeling

Socioeconomic and environmental losses caused by water erosion have highlighted the importance of quantifying and understanding the dynamics of soil redistribution in the landscape to develop effective soil management practices.Several methods are applied to estimate erosion/deposition rates and identify sources of sediments,among them,the one that uses rare earth elements(REE)as a tracer stands out.However,an alternative not yet explored that can benefit the accuracy of the estimates provided by the method is using a tracer containing a chemical signature composed of more than one REE.The present study aimed to evaluate the performance of a new water erosion tracer based on montmoril-lonite labeled with rare earth elements(La40-MMT).The innovative aspects of this La40-MMT tracer include its highly stable multi-chemical signature(Nd^(3+),La^(3+),and Pr^(3+)),which enhances tracer detection in the environment,and its low production cost due to the use of an industrial residue in the synthesis process.The tracer was evaluated for a typical soil of the Cerrado biome,using a natural rainfall field-scale plot-NRFP(5 m × 20 m)and a physical predictive erosion model(WEPP).The results showed that the La40-MMT tracer could be used to estimate erosion/deposition rates,with agreement between the values observed with the tracer and the WEPP model.Thus,this study confirmed the great potential of La40-MMT as a tool to identify patterns of soil redistribution at the field scale and aid in the validation of erosion models.

R eview of Soil and Water Assessment Tool(SWAT)applications in Brazil:C hallenges and prospects

The geographical extent of Brazil exceeds 8.5 million km2 and encompasses a complex mix of biomes and other environmental conditions.Multiple decision support tools are needed to help support management of these diverse Brazilian natural resources including ecohydrological models.The use of the Soil and Water Assessment Tool(SWAT)ecohydrological watershed-scale model in Brazil has increased greatly during the past decade.Well over 100 SWAT studies were identified in this review which have been published during 1999 to 2015 in Brazilian and international journals,conference proceedings,and as theses or dissertations,many of which are written in Portuguese.The majority of these studies(102 total)are reviewed here as part of an extensive survey covering the 1999 to 2013 time period.Temporal and spatial distributions,a summary of hydrologic calibration and validation results and a synopsis of the types of applications that were performed are reported for the surveyed studies.A smaller subset of recent Brazilian studies published in English between 2012 and 2015 in scientific journals are also reviewed,with emphasis on hydrologic and sediment transport testing results as well as scenario applications that were performed.The majority of the surveyed SWAT studies was performed for watersheds located in the South and Southeast regions of Brazil(67%)and was conducted in the context of academic research.Nearly 50%of the surveyed studies reported only hydrologic results.Similar trends were found for the subset of more recent English publications.Limited studies have been reported that describe applications of SWAT in Brazil by private firms or government agencies;this review indicates that the potential exists for increased numbers of such studies in the future.However,there is evidence that a lack of accessibility to adequate quality input data is a possible hindrance to the more general use of SWAT for watershed applications in Brazil.