Effects of Temperature on the Compressive Strength Parallel to the Grain of Bamboo Scrimbe.

The objective of this study was to investigate the compressive strength parallel to the grain of bamboo scrimber during and after exposure to various temperatures, in a range from 20 to 225 °C. These data were used to provide a basis for the evaluation of the fire performance of bamboo structures. A total of 152 specimens, assembled as group "during-fire" and "post-fire", were tested during and after exposure to high temperatures. The experimental results indicated that there were significant differences in compressive properties between the "during-fire" and "post-fire" groups. At one temperature level, the compressive strength and modulus of elasticity of the "post-fire" group were significantly higher than those properties of the "during fire" group, but the ductility coefficient was reversed. FTIR analysis results showed that 175 °C was a key turning point, at which thermal decomposition occurred in the cellulose of the bamboo and phenolic resin.

Experimental and Statistical Evaluation of the Size Effect on the Bending Strength of Dimension Lumber of Northeast China Larch.

This study investigated the size effect on the bending strength (modulus of rupture-MOR) of dimension lumber of Northeast China larch (Larix gmelinii); providing a basis for the further application in light wood frame construction. Experimental and statistical evaluations were conducted on the bending strength. A total of 2409 full-size dimension lumber samples were tested by static bending tests; which included three different sizes: 2 × 3; 2 × 4; and 2 × 6. Results indicate that the size has a significant effect on the MOR. Both the chi-square (χ²) and Kolmogorov-Smirnov (K-S) test results show that the lognormal distribution generally fits to the MOR better than to the normal distribution. Additionally; the effects of partial safety factor (γR) and live-to-dead load ratio (ρ) were studied by reliability analysis. Reliability analysis results indicate that the reliability index increases nonlinearly with the decrease of γR and the rise of ρ. Finally; the design value of bending strength and its adjusting factor of size effect of 2 × 3; 2 × 4; and 2 × 6 larch dimension lumber were obtained according to the Chinese National Standards' requirements of the reliability index.

Pollen Typhae total flavone improves insulin resistance in high-fat diet and low-dose streptozotocin-induced type 2 diabetic rats.

Pollen Typhae total flavone (PTF), the extract from Pollen Typhae, is reported to enhance glucose uptake in C2C12 myotubes in vitro, but the convincing evidence is lacking in vivo. In this study, PTF ameliorated insulin resistance and dyslipidemia, but failed to significantly increase body weight in type 2 diabetic rats induced by high-fat diet and low-dose streptozotocin.

[Investigation of near infrared spectroscopy of rosewood].

Rosewood is a kind of precious wood which include many wood species. It's difficult to most people to identify rosewood species. Near infrared spectroscopy (NIR) of eight rosewood species was investigated in the present paper. The results showed that (1) there was significant correlation between near infrared spectroscopy and color parameters expressed by L*, a* and b* values of rosewood, the correlation coefficients between NIR predicted and laboratory measured L* , a* and b* values were 0.988, 0.991 and 0.993, respectively; (2) The eight rosewood samples can be distinctly divided into eight categories by principal component analysis (PCA), the differences in the NIR among the eight rosewood species were more distinctly revealed by the three-dimensional PCA score plot than that of the two-dimensional. The results illustrated that it was feasible to identify rosewood species by near infrared spectroscopy coupled with chemometrics, and also provided a new method to rapidly identify or classify rosewood.

[Measuring the density of wood and bamboo using computed tomography].

CT is widespread non-destructive detection technique for wood materials, and the density measurement is a key role during this application. In the present report, the use of CT for air-dry density measurement of wood and bamboo is described. The authors found that there were marked linear correlations between air-dry density (0.303-1.061 g x cm(-3)) of 24 kinds of woods and their respective CT value, as well as 25 kinds of lignin materials (including 24 kinds of woods and 1 kind of bamboo) and the CT value, both with correlation coefficient of 0.99, which belonged to the CT technological breakthrough for wood quantitative detection These research results show that CT is an appropriate way to measure density for wood and bamboo, and would provide technical support for CT used in the field of wood science research and wood processing.

[Study on chemical compositions and crystallinity changes of bamboo treated with gamma rays].

The structures and qualities of main chemical compositions in cell wall of bamboo treated with gamma rays were tested by nuclear magnetic resonance spectrometer (NMR) and X-ray Diffraction (XRD). The result indicated that the bamboo crystallinity increased at the beginning of irradiation process, while the crystallinity reduced when the irradiation dose was raised to about 100 kGy. During the whole irradiation process, hemicellulose degraded, and with the irradiation doses increased the non-phenolic lignin changed to the phenolic.

[Study on bamboo treated with gamma rays by X-ray diffraction].

The microfibril angle and crystallinity of bamboo treated with gamma rays were tested by X-ray diffraction (XRD). The result indicated that crystallinity in bamboo increased when irradiation dose was less than 100 kGy, while the irradiation dose was raised to about 100 kGy, crystallinity in bamboo reduced. But during the whole irradiation process, the influence on microfibril angle was not obvious, so it was not the dominant factors on variation in physical-mechanical properties of bamboo during the process of irradiation.

Complete genome sequence of the bacterium Ketogulonicigenium vulgare Y25.

Ketogulonicigenium vulgare is characterized by the efficient production of 2KGA from L-sorbose. Ketogulonicigenium vulgare Y25 is known as a 2-keto-L-gulonic acid-producing strain in the vitamin C industry. Here we report the finished, annotated genome sequence of Ketogulonicigenium vulgare Y25.

[Analysis of effects of irradiation on the crystal size of daemonorops margaritae with X-ray diffractometry].

In order to find the relationships between the crystal size and the physical & mechanical properties, and to improve the levels of high value-added processing and utilizing for Chinese rattan resources, the daemonorops margaritae, Chinese unique rattan, was chosen as the research material, then the crystal size was measured and analyzed through the X-ray diffraction method before and after gamma-ray irradiation. The results show that the crystal width is in the range between 1.901 and 3.019 nm, and the average width is 2.403 nm. The crystal length is in the range between 4.118 and 28.824 nm with an average length of 10.907 nm. After irradiation, the width of daemonorops margaritae is in the range between 2.139 and 3.540 nm, and the average width is 2.569 nm, and the crystal length dramatically changes in the range between 5.765 and 38.432 nm with a mean of 15.530 nm. Both of the scope and the mean value of the crystal width and length increase after irradiation.

[Analysis of the microfibrilla angles & crystallinity index of Daemonorops Margaritae with X-ray diffractometry and the effects of gamma-ray irradiation].

In order to find out the properties and improve the levels of high value-added processing and utilization of Chinese rattan resources, the Daemonorops Margaritae, a Chinese unique rattan, was chosen as the research material, then the microfibril angles (MFA) & crystallinity index (CrI) were measured through the X-ray diffraction method, and the effects of gamma-ray irradiation upon the MFA & CrI were analyzed. The results show that the MFA of the cane varied from 33.4 degrees to 38.7 degrees with the average value of 36.1 degrees, and the MFA of the coretex were not larger than that of the core. The MFA were 36.2 and 35.8 degrees, 35.9 and 35.4 degrees, and 36.2 and 35.4 degrees before and after irradiation with a radiation dose rate of 2.5 x 10(3) Gy x h(-1) and radiation dose of 3, 9 and 15 kGy, and decreased 1.10%, 1.39% and 2.21% respectively compared with the former. The CrI was in the range of 24.8%-32.0%, and the average CrI was 28.6%. The CrI of coretex was larger than that of the core. Under the same radiation conditions, the CrI was 28.1% and 26.0%, 28.1% and 26.9%, and 28.5% and 27.1% before and after irradiation, and the latter decreased 7.58%, 4.34% and 4.70% respectively compared to the former. With the radiation dose of 3 kGy, the differences in CrI between with and without irradiation were most notable in the 0.001 level.

[Nano TiO2 modification of bamboo and its antibacterial and mildew resistance performance].

Bamboo, a kind of forest resources only less important than wood, is especially easy to mildew during outdoor service. In this work, TiO2 sols were synthesized under low-temperature condition by sol-gel method. The crystalline TiO2 film with a diameter of approximate 40-90 nm was used to coat bamboo at low temperature. The TiO2 films were characterized by nuclear magnetic resonance spectrometer (NMR), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The effects of temperature on film crystal forms, its antibacterial, and mildew resistance properties were mainly investigated. The results showed that the modified bamboo in low temperature solution (20, 60 and 105 degrees C) was mainly covered with anatase nano TiO2 film. The nano-TiO2-modified bamboo maintained the natural wood color, texture and structure, and improved its anti-bacterial property from non-anti-bacterial to anti-Escherichia coli, and the bactericidal rate reached over 99%. Meanwhile its mildew resistance property increased over 10 times. So this method is expected to become the new way of functional improvement on bamboo, and has the reference meaning for the protection and improvement of wood and other biologic materials.

[Determination of metal elements in paper sludges by ICP-AES].

Metal elements, especially the heavy metal element, need to be considered for resource utilization of paper sludge. Seventeen kinds of metal elements were determined by ICP-AES method, which were form two kinds of paper sludge from Anhui Shanying paper mill, one kind of paper sludge from Fujian Qingshan paper mill, and one kind of paper sludge from Fujian Zhongzhu paper mill. The results show that there are different amounts of metal elements in the 4 kinds of paper sludge including poisonous metal elements, such as Cr, etc, metal element which is poisonous when excessive, such as Fe, etc, and P and K which are beneficial for plant growth Al and Ca contents are maximal. The recovery ratio for Fujian Zhongzhu paper mill obtained by standard addition method is 94.4%-107.3%. Heavy metal elements content lower than the national standard GB/4284-84 "Control standards for pollutions in sludge form agricultural use". The order of heavy metal elements content is paper sludge from Fujian Zhongzhu paper mill

[Determination of lignin distribution during ageing of bamboo culms (Phyllostachys pubescens) with visible-light spectrophotometry].

The lignin distribution in different anatomical regions of developing moso bamboo Phyllostachys pubescens f. lutea Wen was investigated by means of optical microscope and visible-light microspectrophotometry coupled with the Wiesner and Maule reaction. The lignin is widely distributed in different tissues, in which there is a difference in lignin content between different ages, tissues and anatomical regions. Guaiacyl lignin and Syringyl lignin unit can be found in cell wall of fibre, parenchyma and vessel. Lignin content of secondary wall, cell corner and compound middle lamellae of fibre increased gradually within 12 months, then almost remained in the same level or decreased slowly in the culms with an age from 12 to 78 months. The lignification rate in secondary wall, cell corner and compound middle lamellae of fibre changed with age until they reached a relative steady value. There is no regular variation in lignin content with different radial location of culms and different location in fibre strands within one age. The secondary wall, compound middle lamellae of parenchyma and vessel secondary wall lignified rapidly within 12 months, and then changed slowly.

[Discrimination of wood biological decay by NIR and partial least squares discriminant analysis (PLS-DA)].

Extensive research has demonstrated that near infrared spectroscopy (NIR) and partial least squares discriminant analysis (PLS-DA) can be used to rapidly discriminate or detect a wide variety of food, medicine and agricultural products. The use of NIR coupled with PLS-DA to detect wood biological decay was investigated in the present paper. The results showed that the correlation between the predicted category variable of calibration and validation and the measured category variable is significant with a correlation coefficient (r) over 0.94 and low SEC and SEP (< 0.17); the discriminant accuracy for the non-decay, white-rot and brown-rot decay samples are 100% (deviation < 0.5) by the PLS-DA model based on the test set of samples; the discriminant accuracy by PLS-DA model is better than that by SIMCA model. It's suggested that NIR spectroscopy coupled with PLS-DA could be used to rapidly detect wood biological decay.

[Influence of sample surface roughness on mathematical model of NIR quantitative analysis of wood density].

Near infrared spectroscopy is widely used as a quantitative method, and the main multivariate techniques consist of regression methods used to build prediction models, however, the accuracy of analysis results will be affected by many factors. In the present paper, the influence of different sample roughness on the mathematical model of NIR quantitative analysis of wood density was studied. The result of experiments showed that if the roughness of predicted samples was consistent with that of calibrated samples, the result was good, otherwise the error would be much higher. The roughness-mixed model was more flexible and adaptable to different sample roughness. The prediction ability of the roughness-mixed model was much better than that of the single-roughness model.

[Determination of holocellulose and lignin content in Chinese fir by near infrared spectroscopy].

The contents of holocellulose and lignin of wood are important determinants of the pulping quality of wood. The determination of holocellulose and lignin contents using traditional chemical methods is a costly and time-consuming process. Near infrared reflectance (NIR) analysis offers a fast, nondestructive testing and low cost alternative for prediction of wood quality. In the present article, the total amounts of holocellulose and lignin contents of 48 samples were analyzed according to standard wet-chemical method. All samples were milled using a Standard Wiley knife mill with a 2 mm screen. The 2 mm material was sieved with a 40-60 mesh sieve. Then, near infrared (NIR) spectra were collected in diffuse reflectance from samples of meal contained in a spinning cup by an analytical spectral devices (ASD) Lab Spec at wavelengths between 350 nm and 2 500 nm. The raw spectra were pretreated by the second derivative and smoothing, then the NIR model was built using partial least-squares statistical analysis and full cross validation. The coefficients of correlation (r) of calibration and validation for holocellulose were 0. 96 and 0.93, respectively; the standard error of calibration (SEC) and the standard error of prediction (SEP) were 0.39 and 0.50, respectively. For lignin, the values for r of calibration and validation were 0.99 and 0.90, while the SEC and SEP were 0.10 and 0.28, respectively. It was concluded that NIR analysis is a reliable, fast and nondestructive testing predictor of holocellulose and lignin content of wood in Chinese fir.

[Rapid prediction of annual ring density of Paulownia elongate standing tress using near infrared spectroscopy].

Rapid prediction of annual ring density of Paulownia elongate standing trees using near infrared spectroscopy was studied. It was non-destructive to collect the samples for trees, that is, the wood cores 5 mm in diameter were unthreaded at the breast height of standing trees instead of fallen trees. Then the spectra data were collected by autoscan method of NIR. The annual ring density was determined by mercury immersion. And the models were made and analyzed by the partial least square (PLS) and full cross validation in the 350-2 500 nm wavelength range. The results showed that high coefficients were obtained between the annual ring and the NIR fitted data. The correlation coefficient of prediction model was 0.88 and 0.91 in the middle diameter and bigger diameter, respectively. Moreover, high coefficients of correlation were also obtained between annual ring density laboratory-determined and the NIR fitted data in the middle diameter of Paulownia elongate standing trees, the correlation coefficient of calibration model and prediction model were 0.90 and 0.83, and the standard errors of calibration (SEC) and standard errors of prediction(SEP) were 0.012 and 0.016, respectively. The method can simply, rapidly and non-destructively estimate the annual ring density of the Paulownia elongate standing trees close to the cutting age.

[Discrimination of wood biological decay by soft independent modeling of class analogy (SIMCA) pattern recognition based on principal component analysis].

Wood, as a biomass materials, tends to be attacked by microorganisms, and its structure could be rapidly destroyed by biological decay. Therefore, it's significant to rapidly and accurately detect or identify biological decay in wood. Recently, extensive research has demonstrated that near infrared spectroscopy (NIR) and soft independent modeling of class analogy (SIMCA) can be used to discriminate or detect a wide variety of food, medicine and agricultural products. The use of NIR coupled with principal component analysis (PCA) and SIMCA pattern recognition to detect wood biological decay was investigated in the present paper. The results showed that NIR spectroscopy coupled with SIMCA pattern recognition could be used to rapidly detect the biological decay in wood. The discrimination accuracy by the SIMCA model based on the training set for the non-decay, white-rot and brown-rot decay samples were 100%, 82. 5% and 100%, respectively; and that for the samples for the test set were 100%, 85% and 100%, respectively. However, some white-rot decay samples were mis-discriminated as brown-rot decay, for which the main reasons might be that the training set does not have enough typical samples, and there's a slight difference between white-rot and brown-rot decay during the early stage of decay.

[Effects of spectral pretreatment on the prediction of crystallinity of wood cellulose using near infrared spectroscopy].

The crystallinity of wood has an important effect on the physical, mechanical and chemical properties of cellulose fibers. The aims of this study were to investigate the ability of near infrared spectroscopy (NIR) to predict the crystallinity of wood cellulose and the effect of spectral pretreatment on the prediction of crystallinity in wood cellulose using near infrared spectroscopy (NIR). Near infrared diffuse reflectance spectra were collected from wood powder with a fiber-optical probe and the crystallinity of wood was determined by X-ray diffractometer (XRD) in this experiment. The results showed that near infrared spectroscopy coupled with partial least square (PLS) regression could be correlated with the crystallinity of plantation wood, and the ability of NIR prediction based on original spectra was better than that based on the first derivative or second derivative treated spectra. There was a significant correlation between NIR spectra and XRD determined crystallinity with a correlationcoefficient of 0.950 and a low RMSEP. Near infrared spectroscopy coupled with multivariate data anlaysis has proven to be an accurate and fast method for rapid prediction of wood crystallinity.

[Rapid determination of Klason lignin content in bamboo by NIR].

Lignin is one of the main components of lignocellulosic materials. The main purpose of wood cooking and bleaching is to remove lignin by chemical agent in paper industry. Whereas the lignin content shows wide variations depending on its tree specie, site condition, part and so on, it is essential to analyze the lignin content of different raw material. The aim of this paper is to develop a rapid near infrared (NIR) reflectance spectroscopic method to characterize the Klason lignin content of bamboo. Fifty four samples from three growth years, two positions along the longitudinal directions and three positions along the radial directions within a bamboo pole were prepared. The Klason lignin contents of 54 samples were analyzed according to traditional chemical method, the spectra of these samples were collected by NIR in the range of 350 to 2500 nm, and the relationship between the lignin content and the spectra of these samples was established by multivariate statistical technique. After second derivative pretreatment of raw spectra, the Klason lignin contents of the bamboo samples were quantified using partial least-squares statistical analysis (PLS1) and full cross validation in the range of 1011-1675 nm and 1930-2488 nm. High coefficients of correlation (r) were obtained between the predicted NIR results and those obtained from traditional chemical method. The correlation coefficient of calibration model and prediction model was 0.99 and 0.97, respectively. The standard error of calibration (SEC) and standard error of prediction (SEP) was 0.36% and 0.59%, respectively. It was found that the lignin content in bamboo could be determined rapidly with reasonable accuracy by the NIR method.