Estimating Glucan,Xylan, and Methylglucuronic Acids in Kraft Pulps of Eucalyptus globulus Using FT-NIR Spectroscopy and Multivariate Analysis

Abstract

Fourier transform near infrared (FT-NIR) associated with multivariate analysis was used to estimate glucan, xylan, 4-O-Methyl-α -D-glucuronic acid (MeGlcA) content, and pulp yield in kraft pulps of Eucalyptus globulus Labill. Several models were applied to correlate chemical composition in samples with the NIR spectral data by means of principal components regression (PCR) or partial least square (PLS) algorithms. Calibration models were built and validated by using all the spectral data and cross-validation methodology. The r_c ² values for the best calibration models for quantification of glucan, xylan, MeGlcA contents and pulp yield were between 0.71–0.92. The model was validated using a set of external samples. The amount of glucan (64–77%), xylan (12–18%), and MeGlcA (204–363 mmol kg pulp^–1) in pulps were predicted with a root mean square error of prediction (RMSEP) of 0.91%, 0.46%, and 15.21% for glucan, xylan, and MeGlcA, respectively. Pulp yield (in the range of 46–70%) was also predicted with good accuracy with a RMSEP of 1.63%. These results suggest that glucan, xylan, MeGlcA composition, and pulp yield in kraft pulps of E. globulus can be adequately estimated by NIR spectroscopy for laboratory or industrial applications. NIR predictions can also provide useful and cost-effective tools for the rapid screening of large numbers of samples.     

Remediation revisited.

This article replies to comments by J. C. Gonsiorek (see record 84-33291), P. Orr (see record 84-33300), and L. S. Brown (see record 84-33284 ) on M.J. Layman and J.R. McNamara's (see record 84-33293) work on remediation and ethics violations. The authors acknowledge various distinctions they have introduced but continue to argue that sexual violations are outstandingly egregious. They agree that making amends is important but wonder about the practicalities of working this into rehabilitation. Lack of empirical knowledge about what is prescribed for remediation is reemphasized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

美国印刷业的现状与发展趋势

各位上午好。我非常高兴又一次来到了北京。在此，我代表NPES(印刷、出版及纸品加工技术供应商协会)的400多家会员企业，向中国印刷及设备器材工业协会表示衷心的感谢，感谢您们邀请我来参加北京国际印刷发展论坛。     

Remediation for ethics violations: Focus on psychotherapists' sexual contact with clients.

The field of psychology has only recently begun to recognize the extent and impact of professional impairment of its members, whereas several other professions have established formal identification and treatment plans for impaired colleagues. Impairment in psychologists may be caused by various factors, but it has the same result: diminished levels of care and, frequently, ethics violations. Sexual contact with clients is considered in particular. Several alternate avenues for remediation exist, including mandatory psychotherapy for ethics offenders. Although the majority of psychologists value personal therapy for training purposes, it is the authors' opinion that mandated therapy is not an appropriate form of rehabilitation for such violations of the ethics code. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The lateral deformation of cross-linkable PPXTA fibres

The lateral deformation properties of oriented polymer fibres were examined by transverse compressive and torsional experiments. A modified interfacial test system machine was used to study the transverse compressive deformation behaviour of thermally cross-linkable poly(p-1,2-dihydrocyclobutaphenylene terephthalamide) (PPXTA) fibres and of a number of commercially available polymers (Nomex, nylon, Kevlar, Dacron) and ceramic (Nicalon and FP) fibres. The torsional (shear) modulus G of PPXTA and Kevlar poly(p-phenylene terephthalamide) (PPTA) fibres was measured by pendulum experiments. During both fibre torsion and transverse compression, the deformation involves materials slip on (h k 0) planes, in the [0 0 1] direction for the torsion and the [h k 0] directions for transverse compression. The intermolecular crosslinks in PPXTA did not significantly modify the elastic transverse modulus Et and caused only slight (13%) increase in shear modulus G. However, the plastic transverse properties of cross-linked PPXTA were significantly different than those of uncross-linked PPXTA. The stress at the proportional limit σp, determined from the transverse load–displacement curves, was substantially higher for the cross-linked fibres than for the uncross-linked fibres. In addition, the cross-linked PPXTA fibres exhibited a large strain recoverable response reminiscent of elastomers, whereas the PPTA and uncross-linked PPXTA fibres exhibited a large strain irreversible response. This revised version was published online in November 2006 with corrections to the Cover Date.     

Soil organic carbon dynamics of improved fallow-maize rotation systems under conventional and no-tillage in Central Zimbabwe

Fallowing increases soil organic carbon (SOC) during the fallowing phase. However, this benefit is lost quickly during the cropping phase. The objective of this study was to evaluate SOC dynamics of an improved fallow-maize rotation under no-tillage (NT) and conventional tillage (CT) from time of fallow termination, through the next two cropping seasons. The treatments studied were improved fallows of Acacia angustissima (A. angustissima) and Sesbania sesban (S. sesban), natural fallow and continuous maize. Our hypothesis is that fallowing maintained higher SOC and lower soil bulk densities through the cropping phase when compared with continuous maize system and that NT maintained higher SOC when compared with CT. Soil organic carbon was significantly greater under fallows than under continuous maize from fallow termination to the end of the second cropping season. Soil organic carbon for the 0–5 cm depths was 11.0, 10.0, 9.4 and 6.6 g kg⁻¹ for A. angustissima, S. sesban, natural fallow and continuous maize, respectively at fallow termination. After two cropping seasons SOC for the same depth was 8.0, 7.0, 6.1, 5.9 g kg⁻¹ under CT and 9.1, 9.0, 8.0, 6.0 g kg⁻¹ under NT for A. angustissima, S. sesban, natural fallow and continuous maize, respectively. Total SOC stocks were also higher under fallows when compared with continuous maize at fallow termination and after two cropping seasons. Soil bulk densities were lower under fallows when compared with continuous maize during the period of study. We concluded that fallows maintained greater SOC and NT sequestered more SOC than CT. Acacia angustissima was the better tree legume fallow for SOC sequestration when compared with S. sesban or natural fallow because it maintained higher SOC and lower bulk densities after two seasons of maize cropping.     

Wavelength dependence of irreversible photobleaching of dye-doped polymer waveguide materials

We report the irreversible bleaching characteristics of 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran (DCM) doped into perfluorocyclobutene (PFCB) and a new material known as DH-6 doped into amorphous polycarbonate (APC) by a monochromatic bleaching source. The wavelength dependent rate constants for the irreversible bleaching process are found, and the experimental bleaching characteristics are compared to the theoretical bleaching characteristics determined from a kinetic model of the bleaching process.     

Rapid Analysis of Abietanes in Conifers

Diterpene resin acids are major constituents of conifer oleoresin and play important roles in tree defense against insects and microbial pathogens. The tricyclic C-20 carboxylic acids are generally classified into two groups, the abietanes and the pimaranes. The abietanes have conjugated double bonds and exhibit characteristic UV spectra. Here, we report the analysis of abietanes by reversed-phase high-performance liquid chromatography using multiwavelength detection to optimize quantification of underivatized abietic, neoabietic, palustric, levopimaric, and dehydroabietic acids. The utility of the method is demonstrated with methanol extracts of white spruce (Picea glauca) phloem, and representative concentrations are reported.