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The effect of copper on the corrosion properties of mooring chain steel in synthetic seawater at room temperature were investigated by weight loss tests, electrochemical methods and corrosion product analysis. The results indicated that the mooring chain steel exhibited active dissolution behavior in synthetic seawater. Corrosion potential shifted to noble direction and corrosion current decreased with copper contents. Therefore, the weight loss reduced and the polarization resistance was increased with increasing copper addition. The improvement of corrosion with copper was attributed to the change of corrosion rust that became smaller granules with higher adhesion strength as well as thicker layer when the steel was added more copper content. Meanwhile, the microcrack of inner rust was prevented to grow.

The aim of this study was to detect the expression of transforming growth factor-s1 (TGF-s1) in neonatal rats with hyperoxia-induced bronchopulmonary dysplasia (BPD) and to explore its relationship with lung development. Forty-eight rats (2-3 days old) were randomly divided into a hyperoxia group and a control group (N = 24) which were then fed in ≥95% oxygen atmosphere and air, respectively. On the 1st, 3rd and 7th days of hyperoxia exposure, morphological changes of lung tissues were observed under an optical microscope. TGF-s1 mRNA and protein levels in lung tissues were detected by real-time quantitative polymerase chain reaction and western blot, respectively. With increasing time of hyperoxia exposure, the hyperoxia group gradually suffered from pathological changes such as poor development of lung tissues, alveolar simplification, decrease in the number of alveoli, and hindered pulmonary microvascular development. On the 7th day of hyperoxia exposure, TGF-s1 mRNA and protein levels (relative to b-actin) of the hyperoxia group (0.34 ± 0.19 and 0.21 ± 0.09, respectively) were significantly lower than those of the control group (0.83 ± 0.45 and 0.57 ± 0.45, respectively; P < 0.05). TGF-s1 participates in the pathogenesis of BPD as an important regulatory factor during pulmonary vascular development.

In this article, a protective Ni–Co alloy coating was prepared on AZ91D magnesium alloy which was pretreated with electroless plating. The surface morphologies, microstructure and chemical composition of the coatings were studied using environmental scanning electron microscope, X-ray diffraction and energy dispersive spectroscopy respectively. The surface morphologies and microstructure analysis showed that the Ni–Co alloy coating possessed cone shaped grain congeries and formed face centred cubic solid solution. The energy dispersive spectroscopy analysis revealed that the content of cobalt element in the alloy coating was ∼31 wt-%. Potentiodynamic polarisation curves and electrochemical impedance spectroscopy were employed to investigate the corrosion resistance of different corrosive systems in neutral 3·5 wt-%NaCl and 0·5 mol L–1 Na2SO4 solutions, which were chosen to simulate the effects of marine and industrial environments respectively. The results showed that the corrosion resistance of t...

Analysis of residual stress in archaeological copper alloy artefacts by neutron diffraction has considerable potential for the investigation of early fabrication processes. However, residual stresses in metals are known to relax due to conditions similar to those encountered during burial, corrosion and conservation. In this pilot study, we investigate the effects of corrosion and conservation on a small group of replica copper ingots. Although corrosion and light cleaning do indeed cause some relaxation of stresses in the metal, corrosion having the most significant effect, the basic patterns and major features of the stress profiles may still be seen.

In this article, possible improvement related to the AGS 6-3-1 bunch merge test is presented. After that, relevant issues for beams with larger longitudinal emittance at RHIC are discussed.

Giardia duodenalis and Enterocytozoon bieneusi are two common protozoa that parasitize the intestinal epithelium of animals and humans. Calves have been identified as important reservoirs of these two pathogens, but limited data is available for these two pathogens in calves in China. In the present study, the prevalence and assemblages/genotypes of both parasites in calves of dairy and native beef (Qinchuan) cattle in Shaanxi province, northwestern China, were analyzed using multilocus genotyping (MLST). Of 371 fecal samples collected from calves (including 198 dairy calves and 173 Qinchuan calves), the respective overall prevalence of G. duodenalis and E. bieneusi was 18.87 (70 of 371) and 19.68 % (73 of 371). Both the zoonotic G. duodenalis assemblage A and animal adapted assemblage E were found in dairy and Qinchuan calves. Seventeen, eight, five, and two G. duodenalis subtypes were detected at the triose phosphate isomerase (tpi), β-giardin (bg), glutamate dehydrogenase (gdh), and small subunit ribosomal RNA (SSU-rRNA) loci, with five and two novel subtypes detected at the tpi and bg loci, forming 25 multiple genotypes (MLGs) (15 and 11 in dairy and Qinchuan calves, respectively). Of 73 samples that were positive for E. bieneusi at the ribosomal RNA internal transcribed spacer (ITS) locus, five ITS genotypes were found, including three known zoonotic genotypes (I, J, CHN1) and two novel genotypes (CSX1 and CSX2). MLST analysis of three microsatellite loci (MS1, MS3, MS7) and one minisatellite locus (MS4) detected six, two, two, and two genotypes at the MS1, MS3, MS4, and MS7 loci, respectively, forming ten MLGs (seven and four in dairy and Qinchuan calves, respectively). These results indicate complex population structures of G. duodenalis and E. bieneusi in calves in Shaanxi province and the zoonotic potential of these two pathogens in calves in this province.

The ability to resolve the wavelength in neutron transmission experiments has opened up a wide range of applications investigating crystallographic structures and properties. The investigations presented in this paper apply the Bragg edge transmission technique to the study of texture in a cylindrical aluminium specimen. The feasibility of this method is the main focus of this work; hence, conventional pole-figure measurements have been conducted with neutron diffraction to provide reference data for the evaluation of the transmission results. Furthermore, a Monte Carlo simulation has been developed to emulate the experimental conditions and allow investigations of instrument effects. The results have been compared and are discussed with respect to quantitative texture analysis.

The buckling behaviour and collapse mechanism of elastic–plastic cylindrical shells subjected to longitudinal impact were studied by impact experiments and computer simulations. Attention was focused on the influence of the geometry and material property of the shell and loading condition on dynamic buckling response. Varieties of bucking models and the switching between the modes in buckling process were observed. Particularly, the phenomenon of so called dynamic plastic buckling in relatively low impact velocity was captured by high speed photograph in impact test of cooper specimen. This experimentally confirms that the dynamic plastic buckling does not necessarily require high impact velocity. The whole process of impact buckling was simulated by LS‐DYNA code. The effects of the stress wave and the transverse inertia and plastic hardening modulus, etc. on initiation of wrinkle in earlier phase of buckling are analysed.

In order to study the effects of sweepback of inducer on cavitation performance of pump, based onthe experimental results, the Reynolds N-S equation, RNG k-? turbulent model and Schnerr&Sauer cavitation model, a three-dimensional numerical calculation is employed to study the flow characteristics of one certain LNG pump. Laws of the variation of cavitation performance, head and efficiency with the change of sweepback are studied. The numerical analysis of the eight inducer projects with sweepback angle from 120? to 290? is carried out. The results show that the cavitation bubbles appear at the suction surface near the inlet side at first. With the decrease of NPSHa, the bubbles spread to the outlet side of the inducer and the pressure surface, finally they fill the entire channel. When the inducer sweepback angle increases from 120? to 270?, NPSHr of the pump reduces gradually. That means the anti-cavitation performance of the pump has been improved. However, NPSHr of the pump raises gradually when the inducer sweepback angle increases from 270? to 290?. The efficiency and head of pump tend to be stable within the larger range near the optimal sweepback.

High-order correction terms to the expression of the field of circularly po- larized Gaussian laser are derived. Terms up to seventh order in the small dimen- sionless spatial parameter are explicitly presented. Using the test particle simulation programs, the CAS (Capture & Acceleration Scenario) phenomenon in the circularly polarized field has been proved, and the difference efficiency of CAS scheme between the circularly polarized field and linearly polarized field has been investigated, further more the electron dynamics obtained by the paraxial approximation, the fifth-order correction, and the seventh-order correction are compared in detail. The numerical calculations show that the results of three corrected models coincide with each other very well for kw0>60, and the difference of the three corrected models is very conspic- uously for kw0• 50. Then the ranges of the electron incident momentum for the CAS scheme in circularly polarized field to emerge are examined. This study is of signifi- cance in designing experimental setup to test CAS and helpful in understanding the basic physics of CAS.

Steam explosion treatments were used to modify straw fiber attributes for panel manufacturing. In particular, the effect of steam temperature and retention time on morphology, acidity, wettability, and ash and silicon contents of wheat straw was studied. After steam explosion treatments, proportion of large particles decreased, while fiber bundles increased. Higher steam temperature and longer retention time resulted in more homogeneous fiber-like material. The results showed that the pH value of the untreated wheat straw fiber was nearly 7 and the pH values and acid buffer capacities of straw were greatly reduced after steam explosion treatments. This indicated that the acidity of straw increased after steam explosion treatments. The dynamic contact angle of the straw before the treatment was nearly 90°, indicating that the straw material without treatment is more hydrophobic. After steam explosion treatments, the contact angle of straw was significantly reduced, showing that the surface wettability of the treated straw was improved. The ash and silicon contents of straw were also significantly reduced by steam explosion treatments. The improved acidity and wettabillity as well as decreased silicon content would contribute to the improved bondability between straw particles and water-soluble adhesive binders.

Composites made of polypropylene (PP) and wheat straw fiber treated by alkalization, acetylation, and maleic anhydride polypropylene (MAPP) were prepared, and the dynamic mechanical, thermal, and rheological properties of the treated composites have been investigated. The PP composites reinforced with the treated wheat straw fiber exhibited higher brittleness. The melt flow studies were carried out at the temperature of 170, 180, and 190°C and shear rate of 0.01—0.1 s—1. The PP composites reinforced with the alkalized wheat straw fiber showed the high melt viscosity due to the strong chemical interaction among polymer and wheat straw fiber. The introduction of MAPP to the system increased the flow behavior of the polymer dispersed the wheat straw fiber uniformly, and decreased the melt viscosity. The PP composites introduced by 2 wt% MAPP showed the lowest storage flexural modulus (E′) over the entire temperature range from 25—150°C, due to better compatibility between the wheat straw fiber and matrix. The PP composites made of with 20 wt% alkalized and MAPP treated wheat straw fiber showed the highest E′. The differential scanning calorimeter (DSC) study revealed that introducing the wheat straw fiber to PP matrix increased the melting temperature and crystallization temperature. The PP composites reinforced with the alkalized and MAPP treated fiber had the highest rate of crystallization as a consequent of the co-effect of alkalization and esterfication.

Effects of alkalization, acetylation, and maleic anhydride grafted polypropylene (MAPP) treatments on the thermal and chemical properties of the wheat straw fiber were investigated using thermogravimetric analysis, infrared spectrophotometer, X-ray diffraction, and scanning electric microscopy techniques. It was found that the wheat straw fiber was not prone to weight loss at 170°C and the treated wheat straw fiber exhibited more thermal stability than the untreated wheat straw fiber. Alkalization increased relative cellulose content and exhibited more crystalline due to a rearrangement of the crystalline regions. It also prolonged the degradation of the wheat straw fiber at higher temperatures due to the increased crystallinity of cellulose. Compared with alkalization, acetylation had more effect on the thermal and chemical stability in the wheat straw fiber contributing to a formation of ester bonding. MAPP improved the thermal stability partly because of a lower grafted ratio of maleic anhydride. Acetylation and MAPP treatment both decreased the crystallinity of the wheat straw fiber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

To improve the precision of sawing simulations, 4 regression models were developed to predict simulated lumber volume recovery using tree size variables. Simulated lumber volume recoveries from natural balsam fir trees based on the sawing simulator Optitek were different from real lumber volume recoveries from a stud sawmill because the simulation method only takes wane into consideration. Therefore, 2 methods were developed to correct estimated lumber volume recoveries. The results indicate that the lumber volume correction models for stem deformations could adjust the predictions of lumber volume recovery from the simulation and directly from the sawing simulator to obtain more accurate estimates. With the correction models, the lumber volume recovery from natural balsam fir trees could be estimated directly using easily measured tree DBH and height from the forest resource inventory. Key words: balsam fir, stem deformation, product recovery, sawing simulation, correction models, regression model

Precommercial thinning (PCT) is often used to improve stand growth and value. While PCT may accelerate tree growth and reduce mortality, it may also have a negative effect on product quality. This study examined the effect of moderate and heavy thinning on tree growth, lumber recovery and quality in a natural balsam fir [Abies balsamea (L.) Mill.] PCT trial 35 years after thinning. Compared with the control, the heavy thinning increased merchantable tree diameter, stem volume per tree and lumber volume recovery per tree by 41.1%, 100.9% and 92.7%, respectively, reduced the Select Structural grade (the best grade) recovery by 33.7%. Thinning did not affect the no. 2 and better grade yield. There was a 12.2% and 15.0% difference, respectively, in the lumber bending modulus of elasticity (MOE) and modulus of rupture (MOR) between the control and heavy thinning. Moderate thinning had little impact on the visual grade recovery, lumber bending MOE and MOR. Heavy thinning is recommended if the goal is t...

Summary Black spruce is one of the most important boreal tree species in Canada. In the current ecosystembased management context, commercial thinning (CT) could be a sound choice for attaining sustainable forest management while still achieving maximum returns on competitive timber markets. Through stand density regulation, CT aims to increase tree growth and enhances stand productivity, but the pattern and level of treatment responses are still unknown. This study examined the radial growth response of roots and stems to CT in 10 thinned stands and their controls. A split-plot unbalanced model was developed to describe growth variations over time. The study shows that CT leads to an increase in the radial growth of stems and roots for at least 10 years after the treatment. The 10-year post-treatment radial growth increment of stems is from 20 to 100 per cent higher than the pre-treatment 10-year mean growth. Response depends upon tree diameter and competition, with the biggest trees exhibiting the lowest response to the treatment. Nevertheless, these variables only explain a fraction of the response ( R 2 = 0.0511), suggesting that much of the observed variation may be due to variability between the stands and between trees within a stand. Moreover, stem growth response is correlated with, but lags behind root growth response. This study suggests that CT results may be enhanced by the selection of retained trees based on initial diameter at breast height.

Three black spruce plantations in northwestern Ontario, with varied stand densities and site indices were studied to determine lumber properties and yield. Based on visual grading rules, each stand produced at least 87% No. 2 and Better grade lumber. Wane and skip were the 2 most prominent defects causing lumber downgrades. The compliance of visually graded No. 2 and Better lumber with bending modulus of elasticity (MOE) design values for visual grades varied among stands, as did the proportion that qualified as machine stress-rated (MSR) lumber. MOE and Modulus of Rupture (MOR) differed among stands, consistent with differences in MSR yield. The stand with the highest density and the lowest site index produced the highest yield of MSR grade lumber, but not the highest compliance with bending MOE design values. Regardless of the grading scenario, the most productive stand with the largest average tree size produced the highest value per hectare ($28K per ha) under an MSR grading scenario. These results suggest that MSR grading can improve revenues, and that it will be needed to maintain market confidence in the quality of lumber from second-growth black spruce stands. Key words: lumber quality, Picea mariana (Mill.) BSP, market value, density regulation, stand-level effects, intensive silviculture

Wheat straw fiber-polypropylene (PP) composites were prepared to investigate the effects of wheat straw fiber content (10, 20, 30, 40, and 50 wt %), fiber size (9, 28, and 35 mesh), and maleic anhydride grafted polypropylene (MAPP) concentration (1, 2, 5, and 10 wt %) on the static and dynamic mechanical properties of the wheat straw fiber-PP composites in this study. The tensile modulus and strength of the composites increased linearly with increasing wheat straw fiber content up to 40%, whereas the elongation at break decreased dramatically to 3.78%. Compared with the composites made of the longer wheat straw fiber, the composites made of the fines (>35 mesh) had a slightly higher tensile strength of 31.2 MPa and tensile elongation of 5.39% at break. With increasing MAPP concentration, the composites showed an increase in tensile strength, and the highest tensile strength of 34.0 MPa occurred when the MAPP concentration reached 10 wt %. As wheat straw fiber content increased from 0 to 40%, the flexural modulus of the composites increased gradually from 1335 to 3437 MPa. The MAPP concentration and wheat straw fiber size distribution had no appreciable effect on the static flexural modulus of the composites. The storage flexural modulus of the composites increased with increasing wheat straw fiber content. The scanning electron microscopy (SEM) observation on the fracture surface of the composites indicated that a high wheat straw fiber content (>30 wt %) resulted in fiber agglomeration and a reduction in interfacial bonding strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Wheat straw fibers were modified via a pressurized steam treatment. The effect of steam pressure (i.e., 0.2, 0.4, 0.6, 1.0 MPa) and treatment time (i.e., 5 and 10 min) on chemical composition, sorption isotherm, thermal and mechanical properties of the treated fibers was investigated. Differential scanning calorimetry analysis showed that thermal characteristics of the treated straw samples were shifted indicating the improved thermal stability. The ash and extractive content of the treated straw was reduced; and the materials were likely removed when the steam was released. The removal of ash and extractives could improve the wettability of wheat straw when it is used in combination with polymer matrices. Sorption behavior study showed that steam treatment reduced the hydrophilic characteristic of wheat straw. Tensile strength of the treated straw was significantly enhanced. The tensile strength of straw after treatment at a steam pressure of 1.0 MPa for 5 min was more than twice higher than that of the control group. The study demonstrated that pressurized steam treatment is an effective pre-treatment process for wheat straw fibers as possible reinforcement element in polymer matrices.

In 2007 Forintek Canada Corp merged with the other forest research institutes—Paprican, FERIC and the newly formed Canadian Wood Fibre Centre (CWFC)—to become FPInnovations. This merger offers opportunities for synergies across a range of research activities from the forest to final product markets, and the first step to achieving these synergies is to provide a better understanding of past and current research roles. This paper chronicles delivered results from the Resource Program in response to Forintek member priorities. Of necessity due to limited resources, the Resource Assessment Program at Forintek was built on both internal and external collaboration. It was also built on a legacy of wood quality research inherited from the Eastern and Western Wood Product Laboratories of the Canadian Forest Service from which it was formed through privatization in 1979. FPInnovations now has custody of this legacy. This paper was prepared as a contribution to a workshop organized by the CWFC to promote better understanding of research capabilities residing within FPInnovations. It is aimed at identifying opportunities for future collaboration by describing Forintek's resource characterization program and our members' priorities for future wood quality research in Canada. Key words: resource characterization, wood quality, stand management, future forests, present forests, CT imaging, product Recovery

The objectives of this study were (1) to compare six methods for predicting parameters of the Weibull probability density function (PDF) for diameter at breast height (dbh) distribution in the unthinned white spruce plantations in eastern Canada with respect to their applicability, and (2) to evaluate their predictive abilities in terms of error index (EI) and Kolmogorov–Smirnov (K-S) statistic. The reasons for undertaking this study were (1) there are no available models for the dbh distributions of the studied species and (2) to determine the best method for projecting dbh distributions of white spruce plantations. A total of 113 sample plots which consisted of the commonly measured stand-level variables [stand age (A), site index at 25-year base age (SI), average height of dominant and co-dominant trees (H d), and stand density (SD)] and associated diameter frequency distributions were used in this study. Of all the six prediction methods, the moment-based and percentile-based parameter recove...

Different pretreatment procedures were investigated, and alkaline cleaning and acid picking pretreatment techniques were developed, for the first time, to achieve a phosphating conversion coating on a sintered NdFeB magnet. The effects of different additives on the pretreatment procedures are illustrated by several visual schematics. Corrosion immersion tests showed that NdFeB substrates with optimum pretreatment and phosphating conversion coating procedures can endure at least 17 h before pitting occurs in 5 wt-% neutral NaCl solution. Potentiodynamic polarisation tests in 3·5 wt-% NaCl solution show that corrosion potential E corr increases nearly 60 mV by combination of pretreatment and phosphating conversion coating, and the corresponding polarisation impedance value R is increased by 50%. The corrosion weight loss tests also confirm that compact and anticorrosive phosphating conversion coating could be formed on the NdFeB substrate with the optimum pretreatment.

The aim of this study was to develop and validate a method of determining the warm and cold edges of the Vegetation Temperature Condition Index (VTCI) drought monitoring approach, and to analyse the time series profiles of the VTCI in croplands under both rainfed and irrigated conditions. The linear correlation coefficients between the VTCI and the cumulative precipitation at one or two periods of 10-day intervals are the highest. There are significant linear correlations between the VTCI and soil moisture at the 0-10-cm layer for each 10-day interval during the winter wheat growing seasons. These results indicate that the VTCI is an effective approach for monitoring drought occurrence after the crops turn green. The time series analysis of the VTCI in the 10-day intervals shows that the VTCI profiles are different for irrigated and rainfed conditions. The time series VTCI values under rainfed conditions have a good response to recent precipitation, while those under irrigated conditions have less agreement with recent precipitation due to irrigation practices. The results show that the VTCI is a better indicator of droughts than indices developed from precipitation data.

Stem form is often used as a sawlog assortment criterion and has an important effect on lumber recovery and mechanical properties. Based on 7018 stems collected from the natural stands in 3 regions in eastern Canada, this study quantified the variations in stem form (taper, sweep and eccentricity) for five major commercial softwood species, viz., jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana), white spruce (Picea glauca), red spruce (Picea rubens) and balsam fir (Abies balsamea). The majority of the stems had a diameter at breast height (DBH) ranging from 10 to 32 cm and total tree height from 10 to 20 m. Stem taper and butt taper increased steadily from 0.38 to 1.75 cm/m and from 0.74 to 4.23 cm/m, respectively, with DBH increasing from 8 to 48 cm. Stem sweep and basal sweep ranged from 0.12 to 7.28 cm/m and from 0.12 to 9.85 cm/m, respectively, with mean values of 0.87 and 0.95 cm/m. There were no significant differences in stem sweep and basal sweep between DBH classes and both sweeps distributed over a wide range within DBH classes, species and regions. About 0.77% of the stems and 1.2% of the butt logs had seriously curved shapes (sweep >3.0 cm/m). Eccentricity (ratio of smaller diameter to larger diameter) at the breast height (0.96) was very close to 1. Balsam fir and jack pine had the best and worst stem forms, respectively, while stem forms in black spruce were in-between. Butt logs were most seriously curved in red spruce and most tapered in white spruce. Region C (mainly eastern Quebec and the Atlantic Provinces) produced stems with smaller butt taper, basal sweep and stem sweep and larger eccentricity compared with other regions in eastern Canada. Overall stems in eastern Canada have a good stem form in terms of taper, sweep and eccentricity. The evaluation of stem form provides valuable timber quality information for the wood industry to optimize wood processing as well as for forest managers to define appropriate silvicultural regimes to improve stem form and economic value.

This paper examined the impact of commercial thinning on selected wood properties of jack pine ( Pinus banksiana Lamb.). Wood properties evaluated include wood density (ring density, earlywood ring density, and latewood ring density), percentage of latewood in the ring, and wood bending properties. Nonlinear, mixed-effect models have been developed using data from three commercially thinned sites in eastern Canada. Ring density followed the same pattern as percentage of latewood, in which cambial age, relative height, and ring width were found to have important effects. Earlywood and latewood ring densities changed within the juvenile wood zone until a plateau was reached. Ring width affected earlywood and latewood ring densities mainly in narrow rings. Wood bending stiffness (measured by modulus of elasticity) and strength (measured by modulus of rupture) increased with cambial age and wood density; whereas, wood strength was also affected by ring width. Commercial thinning did not influence the developed models, but it had an indirect effect through increased ring width.

The kelp bed of Gouqi Island lies in the east of the East China Sea, in the Shengsi Archipelago. It is a key component of the island-reef ecosystem. This study evaluated kelp beds on intertidal and subtidal zones from 2004 to 2006. We evaluated seasonal variations in the community structure of macroalgae, and their relationship with water temperature, nitrogen and phytoplankton. The Gouqi Island kelp bed consists mainly of species of Sargassum. Sargassum horneri was the dominant species in subtidal zones, representing 90% of the total biomass. The dominant species in intertidal zones were S. fusiforme, S. horneri, S. thunbergii and Undaria pinnatifida. Fifty-four phytoplankton species were found in the Gouqi Island kelp bed, of which 51 species were found inside the kelp beds, 43 species outside the kelp beds, and 40 species were present both inside and outside the kelp beds. Diatoms were dominant both inside and outside the kelp beds. Except in winter, Skeletonema costatum was dominant, and its abundance in autumn was over 98% of the total abundance. Water temperature was found to be the primary factor influencing the growth of S. horneri in the Gouqi Island kelp bed. S. horneri grew slowly from November to March, and rapidly from March to June. The upper temperature limit for growth of S. horneri was about 18°C. Higher water temperatures can result in a decline in the kelp bed. Nitrogen seemed to be a limiting factor for macroalgal growth. This was particularly true for S. horneri and phytoplankton. Since nitrate is the primary nutrient for S. horneri, its absorption by S. horneri resulted in seasonal changes of nitrate in the ecosystem.

Wood polymer nanocomposites have been prepared from aspen wood using melamine-urea-formaldehyde (MUF) and montmorillonite nanoclay. The nanoparticles were ground with a ball-mill and mixed with the prepolymer to form suspensions that were subsequently impregnated into the wood and in situ polymerized. The influence of the nature of nanofillers and interphase interactions between nanoparticles and MUF on the physical/mechanical properties of the resulting wood polymer nanocomposites was investigated, using SEM, TEM and Electron Probe Micro-Analysis (EPMA) methods. Significant improvements in wood properties, including surface hardness, modulus of elasticity, dimensional stability and water repellence, were obtained with the addition of hydrophobic nanoparticles into the wood. The improved properties could be ascribed to inherent properties as well as better interphase between MUF and nanoparticles, and their co-reinforcement on the wood. Ball-mill treatment favored the dispersion of the nanoparticles into the wood, but broke down functional groups on the hydrophobic nanoclay surface, which was detrimental for the bonding between the nanoparticles and the MUF matrix.

Three major types of paper mill sludge, primary sludge (PS), secondary sludge (SS) and de-inking paper sludge (DPS) were characterized and evaluated as adhesive fillers. Plywood panels were made of formulations with phenol formaldehyde (PF) and sludges. Panels with PF/PS and PF/SS formulations had higher dry and wet shear strengths than those made with PF/Cocob® formulation. All wood failure values were comparable. Dry and wet shear strengths of the panels with PF/DPS formulation were comparable to those of the PF/Cocob® panels (with Cocob® as a commercial filler), but the former displayed a much lower wood failure value. Owing to this fact and its high ash content, DPS was not evaluated further as a potential component of adhesive formulations. Compared with SS, PS resulted in higher dry and wet shear strengths and higher wood failure values. However, granular SS was easier to disperse into the resin component than fibrous PS, and the PF/SS formulation was more easily dispensed on aspen veneer sheets than the PF/PS formulation. SS alone displayed adhesive properties with 0.87 MPa of dry shear strength, but PS alone did not exhibit any bond strength. PS and SS were further evaluated for their general thermal behavior and major functional groups using differential scanning calorimetry and Fourier transform infrared spectrometry, respectively.

Simulation methods exist to predict lumber volume recovery based on tree size. In most cases, however, they do not account for stem deformations, leading to possible overestimations of product recovery. This study calculated differences in lumber volume recovery between a stud sawing simulator and a real stud sawmill for natural black spruce trees. Virtual stems were reconstructed from diameter at breast height (dbh) and tree height data. They were processed with Optitek simulator and results were used to build equations predicting product recovery based on the tree size. Predictions from these equations as well as direct results from the Optitek were used to develop correction models predicting the difference between simulated values and observed values from the real sawmill. Four methods were developed to correct estimated lumber volume recoveries. The results indicated that the lumber volume correction models for stem deformations could adjust the predictions of lumber volume recovery from the...

This study evaluated the impacts of partial cutting on stand characteristics, product recovery, and financial return in mature black spruce-balsam fir stands in Quebec. Four harvesting strategies (clearcut with advance growth protection, irregular shelterwood cutting leaving small merchantable stems, and two patterns of selection cutting) were each applied four times in 20 ha harvest blocks representing irregular black spruce-balsam fir stands. Before the four harvesting strategies were applied, there were no significant differences in stand characteristics (i.e., quadratic mean DBH, basal area, and merchantable stem volume) or expected product recoveries (i.e., lumber volume and value, chip volume and value, and total product recovery) estimated using the Optitek sawing simulation package. There was no significant difference in stand characteristics or product recovery values of the harvested stems between the selection cutting approaches (p > 0.05). However, significant differences in stand characteristics and product recovery values of the harvested stems existed between these treatments and both of the two other treatments. After cutting, the two selection cutting treatments had the lowest impacts on stand characteristics, as compared to the two other treatments. The selection cutting approach which used temporary skidding trails and where cutting was initially concentrated over half of the stand resulted in the highest benefit/cost ratio, relatively high net income and high total product value of residual trees.

Static bending modulus of rupture (MOR) and modulus of elasticity (MOE) were measured on lumber from trees in the natural and mature black spruce stands grown in Eastern Canada. A sample of total 157 trees from the 90–100-year-old black spruce natural stands covering a range of sites and growing conditions was used for the model development ( n = 102) and validation ( n = 55). A stepwise regression method was employed to identify the best variables for predicting MOE and MOR using stand/tree characteristics and wood properties. Then, regression equations with different explanatory variables were developed to predict lumber bending stiffness and strength. Based on the results of model validation from the independent dataset, the regression models developed were able to predict the lumber bending MOE and MOR satisfactorily, especially for small- and middle-sized trees. The results (equation parameter estimates and predictions) obtained in this study, along with those for plantation-grown black spruce in Eastern Canada, will be highly useful in predicting lumber bending static stiffness and strength for both natural and managed black spruce stands.

The effects of using 100% black spruce (Picea mariana) bark fibers as core layer material accounting for up to 70% of the board and its resin content (between 6 and 10%) on the properties of three-layer medium-density fiberboard (MDF) were investigated using a full factorial experimental design with two independent variables and three levels. Five response variables, namely internal bond strength, modulus of rupture, modulus of elasticity, thickness swelling and water absorption were statistically analyzed using a response surface methodology and two-way analysis of variance. The effects of the proportion of core layer (bark fibers) and its resin content on panel properties were significant. All properties studied were positively affected by increasing core layer resin content. The effects of the proportion of core layer (bark fibers) on mechanical properties and water absorption were negative, but positive on thickness swelling. Simultaneous optimization of panel properties indicated that at a density of 850 kg/m3, a three-layer MDF with a core layer resin content of 6.5%, a face resin content of 12 and 60% of core layer proportion (spruce bark fibers) would satisfy the minimum requirements of ANSI standard for 130-grade MDF. Overall, black spruce bark, a major residue source in the Eastern Canada, should be considered as a supplemental furnish for the core layer materials of a three-layer MDF.

Wood polymer nanocomposites were prepared from solid aspen wood, water-soluble melamine-urea-formaldehyde (MUF) resin, and silicate nanoclays. The nanofillers were ground with a ball-mill before being mixed with the MUF resin and impregnated into the wood. The water-soluble prepolymer was mixed with the nanoclays at a mixing speed of 3050 rpm for 20 min to form impregnation solutions. Wood was impregnated with resin, which polymerized in situ under certain conditions. The physical and mechanical properties of the composite and the effect of ball-milling treatment of nanofillers on these properties were investigated. Significant improvements in physical and mechanical properties, such as density, surface hardness, and modulus of elasticity, were obtained for specimens impregnated with MUF resin and nanoclay-MUF resin mixtures. Ball-mill treatment favors dispersion of the nanofillers into the wood, but also appears to interfere with particle-resin adhesion.

Wood density is considered as one of the most important wood properties which affects the properties and value of both fibrous and solid wood products. The present study was intended for evaluating the possibilities of improving wood quality and growth of poplar hybrids. Wood density components of individual growth rings (minimum and maximum wood density, average ring density) and growth traits (tree height, dbh, stem volume) were measured in four 10- and 12-year-old clonal trials of four poplar hybrids, Populus deltoides × P. nigra, P. trichocarpa × P. deltoides, P. maximowiczii × P. balsamifera, and P. balsamifera × P. nigra, as well as P. deltoides. Wood density components of individual growth rings were obtained from microdensitometeric profiles measured with a direct reading X-ray densitometer. Site had a moderately significant effect on wood density and a highly significant effect on tree growth. The hybrid effect was highly significant (P

The susceptibility to hydrogen embrittlement in high strength mooring chain steel with different boron content (0, 0.003 %, 0.008 %) were investigated by electrochemical hydrogen charging technique and tensile test. The results revealed that appropriate boron content can effectively depress hydrogen induced embrittlement. Precharged with a low current density, this effect seemed to be unobvious. It gradually became clearly with the increasing current density. The increase of resistance to the hydrogen embrittlement for 3B and 8B after adding appropriate boron was attributed to three facts. The first was that the segregation of boron atoms along grain boundaries reduced the grain boundary segregation of phosphorus, which prohibited hydrogen concentration at the grain boundaries, depressing the possibility of the intergranular fracture due to H. The second was that the segregation of boron increased intergranular cohesion, enhanced grain boundary strength, and refined the final microstructure. The third was that the addition of boron changed the state of hydrogen traps, leading to the small amount of diffusible hydrogen. That is to say, hydrogen transferred to these defects by dislocations was accordingly decreased, which led to the low sensitive of hydrogen induced cracking.

Signal transducer and activator of transcription 3 (STAT3) is an important regulator of cardiac survival pathways. Decreased expression or activity of STAT3 in patients with end-stage heart failure demonstrated a clinical relevance of STAT3 in cardiac diseases. Betulin, a pentacyclic triterpene, has drawn extensive attention towards its beneficial effects. However, little is known about its roles in cardiac cells.We investigated the effects of betulin on the pro-inflammatory processes in human cardiac AC16 cells. Genes expression of pro-inflammatory cytokines and activation of NF-κB signaling were analyzed. Besides, levels of phosphorylated STAT3 and its down-stream target genes were measured to evaluate the activation of STAT3. Finally, STAT3 inhibitor and small interfering RNA (siRNA) oligos were used to determine the roles of STAT3 in AC16 cells treated with betulin.Our results revealed that betulin inhibited pro-inflammatory cytokines expression and NF-κB signaling activation through STAT3 signaling. Besides, betulin treatment also induced the expression of Bcl-xL, an anti-apoptotic downstream effector of STAT3.Our results, for the first time, uncovered the cardioprotective roles of betulin, which may be useful to reduce the occurrence of adverse cardiovascular events.

We aimed to investigate the correlation between the disc status in MRI and the different types of traumatic temporomandibular joint (TMJ) ankylosis.51 consecutive patients (69 joints), diagnosed with traumatic TMJ ankylosis with a residual condyle (Types A2 and A3), were included in this study. All patients had pre-operative MRI, which was reviewed to determine the disc shape, length and position. The results were compared using the Mann-Whitney test.There were 37 joints of Type A2 ankylosis and 32 joints of Type A3. All joints of Type A2 and 27 joints of Type A3 (84.4%) definitely had a discernible disc, while 5 joints of Type A3 had no discernible discs. Among the discernible discs, the lateral disc of Type A2 and the whole disc of Type A3 had severe deformity, while the medial disc of Type A2 had mild deformity. The mean (standard deviation) disc length was 10.88 (1.19) mm in Type A2, but 7.50 (0.82) mm in Type A3. There was a significant difference between Types A2 and A3 (p 0.05). As for the disc position, the intermediate position was found in all joints.There is a correlation between the disc status and the different types of traumatic TMJ ankylosis. Therefore, MRI examination is needed to help treatment planning and predict post-operative TMJ function.

Black spruce bark from a lumber mill in eastern Canada was characterized for its chemical composition and suitability for the manufacture of fiberboard. The high holocellulose content and low lignin content indicated it contained a considerable amount of wood fibers. The bark was treated with 1% NaOH solution, pre‐heated with steam, and subsequently steam‐pressurized refined to produce fibers. The untreated bark was also pre‐heated and refined for comparison purposes. The fiberboards made from alkaline‐treated bark showed lighter color, higher internal bonding strength, higher modulus of rupture, and higher modulus of elasticity in comparison with the control panels. The thickness swelling of the panels made from treated and untreated bark was comparable. Pre‐heating before refining was an important stage for the manufacture of binderless fiberboards from treated and untreated bark.

We studied the lumber characteristics of 148 trees acquired for that purpose during commercial thinning operations in three Norway spruce (Picea abies [L.] Karst.) plantations, aged from 32 to 34 years, which had been attacked repeatedly by the white pine weevil (Pissodes strobi [Peck]). The trees, with diameters ranging from 14 to 23 cm, were grouped into three quality classes according to the number of major deformations caused by the weevil. The effects of the deformations on bending strength and stiffness, wood density and lumber defects were examined. Results show that in general deformations caused by the weevil do not affect the lumber properties of Norway spruce on sites of medium to high quality. For the three Norway spruce plantations, the mean values of the modulus of elasticity (MOE) of the lumber varied between 8510 and 9357 MPa, and for the modulus of rupture (MOR) they ranged from 36.0 to 42.5 MPa, whereas wood density varied from 324 and 343 kg·m-3. For comparison purposes, the same measurements were taken on lumber from 38 trees in a white spruce (P. glauca [Moench] Voss) plantation that was unaffected by the weevil, but comparable to the Norway spruce plantation on one of the sites studied. The lumber properties from Norway spruce taken from deformed or undeformed stems were 34% superior to white spruce for MOE, 20% for MOR and 8% for wood density. The smaller knots in Norway spruce could explain this difference. On the other hand, a visual grading of this type of wood reveals few differences in lumber strength and stiffness. Key words: Norway spruce, Picea abies, wood characteristics, MOE, MOR, wood density, lumber, white pine weevil, Pissodes strobi, white spruce, Picea glauca

To investigate the effects of recombinant human growth hormone (rhGH) on rat acute lung injury (ALI).ALI was mimicked by intraperitoneal (i. p.) injection of E. coli. Female Sprague-Dawley rats were randomized into three groups: control group, injected with physiologic saline (i. p.); ALI group, received a bolus injection of E. coli (1 x 10(10) cfu/l, 15 ml/kg, i. p.) followed by intramuscular physiologic saline injection; and ALI + GH group, received a bolus administration of E. coli, and then treated with intramuscular rhGH injection (2.25 U/kg/d). ALI group and ALI + GH group were subdivided into day 1 and day 3 subgroups, respectively. Left lungs were lavaged and bronchial alveolar lavage fluid (BALF) was harvested. Lung injury score, lung wet-to-dry weight (W/D) ratio, percentage of neutrophils (PMNs) in BALF, lung permeability index (LPI), intercellular adhesion molecule-1(ICAM-1) expression and activation of nuclear factor-kappa B (NF-kappaB) in the lungs were determined.(1) On day 1 and day 3, the lung injury score, lung W/D ratio, LPI and protein content in BALF were significantly higher in the ALI group than in the control and ALI + GH groups. rhGH attenuated lung injuries significantly. (2) Compared with the control group, the percentage of PMNs in BALF was elevated significantly in the ALI and ALI + GH groups, especially in ALI group. (3) Nuclear positive rate of NF-kappaB and ICAM-1 expression at the levels of protein and mRNA in the lung in the ALI group on day 1 and day 3 were higher than in the control group. rhGH diminished activation of NF-kappaB and expression of ICAM-1 in the lung markedly.Treatment with rhGH can significantly attenuate lung injury in the endotoxemic rats, which may be attributed to the reduction of the expression of ICAM-1, the influence on the adhesion and activation of PMNs, the inhibition of the activation of NF-kappaB and the regulation of the transcription of certain proinflammatory cytokines.

The effects of thermo-mechanical refining conditions on the properties of medium density fiberboard (MDF) made from black spruce (Picea mariana) bark were evaluated. The bark chips were refined in the MDF pilot plant of Forintek Canada Corporation under nine different refining conditions in which preheating retention time was adjusted from 3 to 5 to 7 min and steam pressure was set at either 0.6, 0.9 or 1.2 MPa. The resulting bark fibers were blended with 12% UF resin (based on oven-dry fiber weight) using a mechanical blender. The resinated fibers were manually formed into fiber mats and hot-pressed into MDF panels using consistent parameters. Two panels for each refining condition were produced, resulting in a total of 18 panels. Analysis of variance (ANOVA) was used to analyze the significance of factors. Regression coefficients and 3D contour plots were used to quantify the relationship between panel properties and the two test factors. The results from this study indicated that the preheating retention time was a significant factor for both modulus of rupture (MOR) and modulus of elasticity (MOE), the steam pressure was a significant factor for internal bond strength (IB), MOR and MOE, whereas both factors were insignificant for thickness swelling, water absorption and linear expansion. The properties of MDF panels were quadratic functions of retention time and steam pressure. Compared to the ANSI standard for 120-grade MDF, most panels with a nominal density of 950 kg/m3 had very high IB (>1 MPa) and acceptable MOR, MOE and dimension stabilities. These results suggest that black spruce bark residues can be considered as a potentially suitable raw material for manufacturing MDF products.

We studied the lumber characteristics of 148 trees taken for that purpose during commercial thinning operations in three Norway spruce (Picea abies [L.] Karst.) plantations, aged from 32 to 34 years, which had been attacked by the white pine weevil (Pissodes strobi [Peck]). The trees, with diameters ranging from 14 to 23 cm, were grouped into three quality classes according to the number of major deformations caused by the weevil. The effects of the deformations on rigidity, bending strength, wood density and lumber defects were examined. Results show that in general the deformations caused by the weevil do not affect the lumber properties of Norway spruce on sites of medium- to high-quality. For the three Norway spruce plantations, the mean values of the modulus of elasticity (MOE) of the lumber vary from 8510 to 9357 MPa, and for the modulus of rupture (MOR) range from 36.0 to 42.5 MPa, whereas wood density varies from 324 to 343 kg·m-3. For comparison purposes, the same measurements were taken on lumber from 38 trees in a white spruce (P. glauca [Moench] Voss) plantation that was unaffected by the weevil, but otherwise comparable to the Norway spruce plantation on one of the sites studied. The lumber properties from the Norway spruce taken from deformed or undeformed stems are 34% superior to the white spruce for the MOE, 20% for the MOR and 8% for wood density. The smaller knots in the Norway spruce could explain this difference. On the other hand, a visual classification of this type of wood reveals few differences in the lumber's bending strength or rigidity. Key words: Norway spruce, Picea abies, wood characteristics, MOE, MOR, wood density, lumber, white pine weevil, Pissodes strobi, white spruce, Picea glauca

The establishment of the relationship between tree-level product value and tree characteristics will allow for predicting the potential value of individual trees and a stand directly using tree characteristics. Using statistical and elasticity analysis methods this study examined the relationship of tree-level product value with selected tree characteristics in black spruce (Picea mariana). The study was based a sample of 139 trees from 48-year-old black spruce plantations grown in Ontario, Canada. The sample trees showed large variation in tree characteristics and tree-level product value. Models were developed and compared on the basis of statistics of the estimated and predicted criteria. Results show that the model, including only tree DBH, tree height and stem taper, is the best in describing the relationship of the tree-level product value with tree characteristics. Furthermore, relationships including input-output and interaction factors in the model were analyzed by calculating the elasticity of production and scale and the cross partial derivative of output with respect to the inputs. The analyses indicate that tree DBH has the largest and positive influence on tree-level product value, followed by tree height; however, stem taper has a negative effect on tree-level product value. When tree DBH, tree height and stem taper each increase by 1%, the quantities of output elasticity show 2.53%, 0.64% and -0.37% changes in the product value, respectively; while the scale elasticity shows a 2.81% increase in tree-level product value with a simultaneous 1% change in tree DBH, tree height and stem taper. Results indicate that the model is suitable for predicting tree-level product value using those tree characteristics from forest inventory and also reflects biological behaviour.Key words: black spruce, regression models, elasticity analysis, product value, tree characteristics