办公废纸DCS的分离及其对脱墨浆性能的影响

本文对混合办公废纸回用过程中产生的DCS进行了分离分析,并初步研究了DCS及其单独的DS和CS对脱墨剂性能的影响。结果发现,DCS的电导率和CODcr主要由DS贡献,而浊度主要由CS贡献。与碎浆段相比,漂白段DCS及DS上述参数的值要低的多。纸浆白度的降低主要是由溶解物质引起的,而纸浆裂断长的降低主要是由胶体物质引起的。     

Independent histogram pursuit for segmentation of skin lesions

In this paper, an unsupervised algorithm, called the Independent Histogram Pursuit (IHP), for segmenting dermatological lesions is proposed. The algorithm estimates a set of linear combinations of image bands that enhance different structures embedded in the image. In particular, the first estimated combination enhances the contrast of the lesion to facilitate its segmentation. Given an N-band image, this first combination corresponds to a line in N dimensions, such that the separation between the two main modes of the histogram obtained by projecting the pixels onto this line, is maximized. The remaining combinations are estimated in a similar way under the constraint of being orthogonal to those already computed. The performance of the algorithm is tested on five different dermatological datasets. The results obtained on these datasets indicate the robustness of the algorithm and its suitability to deal with different types of dermatological lesions. The boundary detection precision using k-means segmentation was close to 97%. The proposed algorithm can be easily combined with the majority of classification algorithms.     

FAME--a flexible appearance modeling environment

Combined modeling of pixel intensities and shape has proven to be a very robust and widely applicable approach to interpret images. As such the active appearance model (AAM) framework has been applied to a wide variety of problems within medical image analysis. This paper summarizes AAM applications within medicine and describes a public domain implementation, namely the flexible appearance modeling environment (FAME). We give guidelines for the use of this research platform, and show that the optimization techniques used renders it applicable to interactive medical applications. To increase performance and make models generalize better, we apply parallel analysis to obtain automatic and objective model truncation. Further, two different AAM training methods are compared along with a reference case study carried out on cross-sectional short-axis cardiac magnetic resonance images and face images. Source code and annotated data sets needed to reproduce the results are put in the public domain for further investigation.     

Nitrogen fertilizer replacement value of digestates from three green manures

Green manure mixtures including legumes and forbs can help to increase N availability in organic arable systems. Anaerobic digestion of green manures may provide ammonium rich digestate, which can be redistributed as fertilizer. The aim of this study was to investigate the effect of plant species composition, cutting strategy and anaerobic digestion on the N fertilizer replacement value (NFRV) of different green manures. Digestates obtained from silages of pure stand lucerne (four cuts/year) and a mixture including lucerne, grass and forbs (two or four cuts/year) were used to fertilize winter wheat (surface banding) and spring barley (injection). In general, NFRV was 46–173% higher in spring barley than winter wheat, due to the different application method and timing, which reflect the common practices in Denmark. NFRV of digestates were 25–63% higher than the corresponding silages, with the largest increase with the most fibrous material (mixture at two cuts/year). Total N concentration (DM based) in the silages largely explained NFRV of the digestates. To obtain NFRV above 60%, total N concentration of silage should exceed 3.5 g 100 g^?1 DM, achievable with silages from four-cut strategies. Silages of plant materials with different composition and N content may be similar in terms of biomethane production, but the fertilizer value of the digestates varies considerably depending on total N concentration.     

Lignin and Other Aromatic Substances Released from Spruce Wood During Pressurized Hot-Water Extraction,Part 1: Extraction,Fractionation and Physico-Chemical Characterization

Ground spruce wood was extracted with pressurized hot water in an accelerated solvent extractor (ASE) at 170°C during 20, 60, and 100 min. Released aromatic substances (from 2.2 to 2.5% on wood basis) were isolated on XAD-7 resin and fractionated into lignin, oligomeric aromatic substances (OAS), and compounds insoluble in methanol (IMC). The separated aromatic fractions, and the ground wood before and after extraction, were characterized by physico-chemical methods (GC, GC-MS, HPLC-SEC, TG, DSC). The major part of the aromatic substances was oligomeric aromatic substances (OAS). This fraction increased significantly with the extraction time, while the yield of dissolved lignin increased only slightly with extraction time. Isolated lignins had a lower molar mass and differed considerably from spruce milled wood lignin (MWL). The isolated lignins were more stable against oxidative thermodegradation than spruce MWL. The UV-extinction coefficients at 280 nm were lower for the isolated lignins than for MWL.     

Hemicellulose Hydrolysis in the Presence of Heterogeneous Catalysts

A prominent autocatalytic effect in the hydrolysis of hemicelluloses was observed in the presence of heterogeneous cation-exchange catalysts, Amberlyst 15 and Smopex 101. The kinetic models proposed were based on the reactivities of the non-hydrolysed sugar monomer units and the increase of the rate constant as the reaction progresses and the degree of polymerization decreases. General kinetic models were derived and the kinetic parameters, describing the autocatalytic effect, were determined by non-linear regression analysis. The kinetic model explained very well the overall kinetics, as well as the product distribution in the hydrolysis of hemicelluloses.     

NaOH用量对旧报纸碎浆过程中DCS主要组分的影响

对旧报纸碎浆过程中NaOH用量对其释放出的碳水化合物、亲脂性抽出物、合成聚合物的影响进行了研究.GC、HPLC分析结果表明,旧报纸碎浆过程中随着NaOH用量的增加,溶解性碳水化合物、亲脂性抽出物、合成聚合物的量均有所增加.NaOH用量在0.5%～2.0%范围内所释放的溶解与胶体物的量变化较小,当NaOH用量＞2.0%时,溶解性碳水化合物总量剧烈增加.溶出糖基主要为葡萄糖、木糖、半乳糖醛酸和阿拉伯糖.亲脂性抽出物中树脂酸的含量远高于脂肪酸的含量,脂肪酸中十六碳酸和11-十八碳烯酸的含量比较高,而树脂酸中脱氢枞酸和枞酸的含量较高.