bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of Rubberwood Medium-Density Fiberboard Bonded with Starch and Urea-Formaldehyde
Authors: Jarusombuti Songklod , Bauchongkol Piyawade , Hiziroglu Salim , Fueangvivat Vallayuth
Published: October 2013

The objective of this study was to evaluate some of the properties of experimental medium-density fiberboard panels made from rubberwood (Hevea brasiliensis) using a combination of cassava (Manihot utilissima) starch and a low percentage of urea-formaldehyde (UF) resin as a binder. Experimental panels with density levels of 0.65 and 0.80 g/cm3 were made using 10 percent starch, 10 percent starch and 3 percent UF, and 10 percent UF for the control samples. The panels manufactured with 10 percent starch did not have satisfactory physical and mechanical properties based on Japanese Industrial Standards. However, average modulus of elasticity, modulus of rupture, and thickness swelling values of the sample types E and F manufactured using a combination of starch and UF were 2,044 MPa, 22.49 MPa, and 35.50 percent, respectively, which met required limits listed in Japanese Industrial Standard A-5908. The results of this study indicated that starch can be used as a viable alternative binder with limited addition of UF resin without having any significant adverse influence of bending properties of the samples. Based on formaldehyde emission tests, specimens made with 3 percent UF had an average value of 18.5 mg/100 g, while control samples having 10 percent UF resulted in 38.5 mg/100 g.
Changes in Tennessee's Secondary Hardwood Processing and Sawmill Industries from 2005 to 2009
Authors: Luppold William G. , Alderman Delton , Schnabel Doug
Published: October 2013

Tennessee is in the center of the Eastern hardwood region and has experienced large declines in employment by primary and secondary hardwood processors since 2005 in a pattern similar to the one these processors have experienced nationally. The objective of this article is to examine changes in national hardwood processing industries between 2005 and 2009 and compare these changes with changes in secondary manufacturing employment and hardwood lumber production in Tennessee. The decline in employment in Tennessee's furniture industry was caused by increased imports of wooden furniture from Asia and reduced domestic furniture demand as the result of the 2009 recession. Reduced employment in Tennessee's flooring and kitchen cabinet industry was a function of the decline in home construction, large firms shifting production to other states, and the 2009 recession. Employment in the millwork industry was less affected perhaps because of shifts in production by larger firms from northern and western states to Tennessee. Declines in hardwood lumber consumption caused most large and very large sawmills in Tennessee to downsize and several medium and small mills to go out of business. The short-term outlook for Tennessee's secondary and primary hardwood manufacturers continues to be bleak except for pallets, crossties, and exports.
Energy Consumption and Efficiency of Appalachian Hardwood Sawmills
Authors: Lin Wenshu , Wang Jingxin , Grushecky Shawn T. , Summerfield David , Gopalakrishnan Bhaskaran
Published: October 2013

A study of energy consumption and efficiency for Appalachian hardwood sawmills was conducted in the Appalachian region. Primary data were collected through a mail survey on sawmills in the region in 2010, while secondary data were obtained from site audits at 17 sawmills over the last 10 years in West Virginia. The results from the mail survey showed that hardwood lumber production volume ranged from 700 to 600,000 board feet (BF) per wk, and monthly electricity consumption per mill averaged 220 kWh per thousand board feet (MBF) with an average electric bill of $17.78/MBF/mo. The energy audit results indicated that hardwood lumber production volume ranged from 4,250 to 400,000 MBF/y, and the energy use and total cost per thousand board feet of lumber production averaged 160.89 kWh/MBF and $10.04/MBF, respectively. The average marginal cost for all energy audits was $17.87/MMBtu (¢6.10/kWh). The annual carbon dioxide emission conserved was 587,045 pounds per mill. On average, engineers on site visits proposed changes that could save approximately 14.89 percent of the annual energy used. The results presented in this article provide energy profiles for Appalachian hardwood sawmills and reveal some potential techniques for reducing energy consumption.
Effects of Postlayup Borate Treatment on Appearance and Flexural Properties of Douglas-Fir Glued Laminated Beams
Authors: Long Brady , Morrell Jeffrey J.
Published: October 2013

Preservative treatments are required whenever glued laminated beams are exposed outdoors. Treatments can be either water-based systems applied to individual laminations prior to layup or organic solvent–borne systems applied after the beams are fabricated. Water-based systems are not recommended for posttreatment because of concerns over checking and the potential for reductions in flexural properties, but there are few data on the effects of these treatments. The effects of pressure treatment with disodium octaborate tetrahydrate (boron) on flexural properties, glue-line shear, and visual appearance were investigated using Douglas-fir (Pseudotsuga menziesii) glued laminated beams. While treatment did result in the presence of drying checks on some beams, boron treatment followed by air seasoning or mild kiln drying did not produce any significant effects on modulus of rupture, modulus of elasticity, or glue-line shear. The results indicate that boron treatment does not affect load-bearing properties.
Vibration Method for the Prediction of Aging Effect on Properties of Particleboard and Fiberboard
Authors: Maldonado Ignacio Bobadilla , González Guillermo Iñiguez , Herrero Miguel Esteban , Martitegui Francisco Arriaga
Published: October 2013

The physical and mechanical properties (density, modulus of elasticity, and modulus of rupture) of standard and humidity-resistant types of particleboard and fiberboard were determined by standardized test and wave propagation velocity, obtained from the natural frequency in a nondestructive longitudinal vibration test. Four batches of 66 specimens for each type of panel (particleboard and fiberboard) and for each kind of panel (standard and humidity resistant) were tested under initial conditions and after each one of the three aging cycles defined in European Standard EN 321:2001. Each aging cycle consisted of immersion in water, freezing, and high-temperature drying. The decreasing ratio of wave velocity was used to predict the decreasing ratio of properties. There was a strong relationship between both variables, and an exponential regression model is proposed to predict physical and mechanical properties, with a determination coefficient (R2) from 0.93 to 0.98.
Impact of Industrial Source on the Chemical Composition of Loblolly Pine Bark
Authors: Eberhardt Thomas L.
Published: October 2013

The chemical compositions of loblolly pine (Pinus taeda L.) bark samples from two industrial sources were determined for whole bark as well as the inner and outer bark components. Differences in extractive contents of the whole bark samples were primarily attributed to the different debarking methods which afforded different proportions of inner and outer bark. Treatment of the extractive-free bark samples with 1 percent NaOH to remove interfering phenolic compounds impacted the lignin contents determined by the Klason method, but not those determined by the acetyl bromide method. Upon determining the proportions of inner and outer bark, the data provided here can be used to estimate the chemical compositions of other southern yellow pine bark resources.
Life-Cycle Inventory of Wood Pellet Manufacturing and Utilization in Wisconsin*
Authors: Katers John F. , Snippen Adam J. , Puettmann Maureen E.
Published: October 2013

This study summarizes environmental impacts of “premium” wood pellet manufacturing and use through a cradle-to-grave life-cycle inventory. The system boundary began with growing and harvesting timber and ended with use of wood pellet fuel. Data were collected from Wisconsin wood pellet mills, which produce wood pellets from a variety of feedstocks. Three groups of manufacturers were identified, those who use wet coproduct, dry coproduct, and harvested timber. Pellet mill data were weight averaged on a per unit basis of 1.0 short ton of “premium” wood pellets, and burdens for all substances and energy consumed were allocated among the products on a 0 percent moisture basis. Wood pellets produced from dry coproduct required 60 percent less energy at the pellet mill. However, when considering all cradle-to-gate energy inputs, producing wood pellets from whole logs used the least energy. Pellets from wet coproduct and dry coproduct used 9 and 56 percent more energy across the life cycle, respectively. This study also compared environmental impacts of residential heating fuels with wood pellet fuel. Environmental impacts were measured on net atmospheric carbon emissions, nonrenewable energy use, and global warming potential (GWP). Assuming “better than break-even” forest carbon management, cordwood and wood pellet fuels emitted 67.3 and 26.6 percent less atmospheric carbon emissions per megajoule of residential heat across the life cycle than natural gas, the best fossil fuel alternative. Cordwood and wood pellets consumed fewer nonrenewable resources than natural gas, which consumed fewer resources than petroleum-based residual fuel oil. However, wood pellet fuels had a smaller GWP and effect on respiratory health because they have more efficient combustion.
Modeling Biomass Collection and Woods Processing Life-Cycle Analysis*
Authors: Johnson Leonard , Lippke Bruce , Oneil Elaine
Published: October 2013

A deterministic spreadsheet model developed in an earlier Consortium for Research on Renewable Industrial Materials (CORRIM) project that calculates cost, fuel, and chemical outputs of forest management and harvesting activities was modified to include logic for systems used to recover forest residue. Two illustrative biomass recovery systems with variations were modeled. A system to recover residues after whole-tree harvesting operations was applied to a representative forest stand in the Inland West. Whole-tree chipping in an early thinning was applied to a representative forest stand in the Southeast United States. Emission factors and life-cycle outputs were developed for the systems through the SimaPro v7.3 model using one if its environmental impact methodologies called TRACI2. Most environmental outputs, including global warming potential, had a direct relationship to fuel consumption of the recovery systems. These outputs were subsequently used as inputs to life-cycle analysis in biofuel conversion facilities. Fuel consumption for recovery of residues from the log landing was 8.10, 12.0, and 16.0 liters per bone dry metric ton (BDmT) at haul distances of 48, 97, and 145 km, respectively. Corresponding fuel consumption for whole-tree chipping and hauling at these distances was 10.5, 16.0, and 21.5 liters/BDmT. Shuttling ground residue from the landing for reload and a subsequent long haul of 145 km increased fuel consumption 32 percent over the residue recovery base case. Shuttling loose residue for centralized processing with a long haul distance of 145 km increases fuel consumption by 86 percent over recovery directly from the landing.
Life-Cycle Assessment for the Production of Bioethanol from Willow Biomass Crops via Biochemical Conversion*
Authors: Budsberg Erik , Rastogi Mohit , Puettmann Maureen E. , Caputo Jesse , Balogh Stephen , Volk Timothy A. , Gustafson Richard , Johnson Leonard
Published: October 2013

We conducted a life-cycle assessment (LCA) of ethanol production via bioconversion of willow biomass crop feedstock. Willow crop data were used to assess feedstock production impacts. The bioconversion process was modeled with an Aspen simulation that predicts an overall conversion yield of 310 liters of ethanol per tonne of feedstock (74 gal per US short ton). Vehicle combustion impacts were assessed using Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) models. We compared the impacts of bioconversion-produced ethanol with those of gasoline on an equivalent energy basis. We found that the life-cycle global warming potential of ethanol was slightly negative. Carbon emissions from ethanol production and use were balanced by carbon absorption in the growing willow feedstock and the displacement of fossil fuel–produced electricity with renewable electricity produced in the bioconversion process. The fossil fuel input required for producing 1 MJ of energy from ethanol was 141 percent less than that from gasoline. More water was needed to produce 1 MJ of ethanol fuel than 1 MJ of gasoline. The life-cycle water use for ethanol was 169 percent greater than for gasoline. The largest contributors to water use were the conversion process itself and the production of chemicals and materials used in the process, such as enzymes and sulfuric acid.
Trends in Lumber Processing in the Western United States. Part III: Residue Recovered versus Lumber Produced
Authors: Blatner Keith A , III Charles E. Keegan , Daniels Jean M , Morgan Todd A
Published: October 2013

This article presents changes in proportions of wood fiber residue or by-products generated in lumber production in the western United States over the last 40 years. The results show the proportion of logs remaining as residue has dropped from 59 percent in the 1970s to 51 percent in the 2000s. Technology and its improved application have led to decreased proportions of wood fiber residue in lumber production even as log size has decreased. West wide the proportion of the log converted to both sawdust and planer shavings has decreased substantially over the last 40 years with no change in the proportion recovered in coarse residue. Coarse residue was 31 percent of log volume processed in the 1970s and 2000s. Sawdust generated was 15 percent of log volume in the 1970s and 11 percent in the 2000s, with planer shavings moving from 13 to 9 percent.
Research on Properties of Reconstituted Bamboo Lumber Made by Thermo-Treated Bamboo Bundle Curtains
Authors: Qin Li , Wen-ji Yu , Yang-lun Yu
Published: October 2013

Untreated and 160°C, 180°C, and 200°C thermo-treated bamboo bundle curtains were reconstructed to make high-density board by impregnation with phenol–formaldehyde resin. The physical and mechanical properties of the boards were examined to evaluate the effect of temperature on their qualities. The modulus of rupture decreased with the increase in thermo-treatment temperature and was reduced by nearly 50 percent after 200°C treatment; however, the modulus of elasticity and bonding shear strength did not change much between untreated and thermo-treated specimens. Thermo-treatment improved the dimensional stability of the boards. Thickness swelling after water immersion and wet–dry cyclic testing decreased with increasing thermo-treatment temperature. Compared with the control specimens, the total color difference (ΔE*) changed greatly as the thermo-treatment temperature increased. The chemical and Fourier transform infrared spectroscopy results showed that the major component content and functional groups in the major components changed after thermo-treatment.
Efficacy of Pentachlorophenol in Biodiesel versus Diesel
Authors: Langroodi Saeed Keshani , Borazjani Hamid , Nicholas Darrel D , Prewitt Lynn M , Diehl Susan V
Published: October 2013

Pentachlorophenol (PCP) is widely used as a wood preservative for utility poles and other wood products. It has been proposed that a modified PCP carrier system based on a diesel/biodiesel mixture should be used in place of the conventional diesel/KB3 carrier, but questions exist as to whether this modified carrier system can provide the same service life as wood products treated with PCP/diesel/KB3. The main objective of this research was to evaluate the comparative decay resistance of wood treated with carrier formulations containing either diesel/KB3 or diesel/biodiesel. A 2-year efficacy study using an accelerated soil contact decay test was initiated to compare the performance of southern yellow pine wood treated with the conventional diesel/KB3 carrier and a modified diesel/biodiesel carrier, both with and without PCP. The residual hydrocarbon levels, PCP reduction, toxicity, and leaching of PCP of the samples remained approximately at the same level for treatments with similar PCP retention values for both carriers. For wood treated with PCP in these two different carriers, there was no evidence of differences in the average modulus of elasticity. Overall, this study recommends long-term field stake tests to determine the practical significance of these results.
Estimation and Analysis of Sanding Length in Brush Sanding Specially Shaped Wood Products
Authors: Baogang Wang , Zhankuan Zhang , Xiaorui Peng
Published: October 2013

Sanding is an important process in furniture production. Components with unconventional shapes are usually sanded by hand rather than by machine because heavy sanding makes machine sanding more difficult. However, manual sanding is inefficient and costly. Thus, a machine capable of sanding unconventionally shaped surfaces is needed.

In this study, we defined the cumulative sanding length L of a brush sander and built a numerical simulation model of L to analyze the problem of heavy sanding during surface brush sanding of specially shaped wood products. Based on our analysis of the motion and sanding process of a sander roller, we propose that the sanding strip should be bent when sanding flat surfaces and straight when sanding bulging surfaces. We also analyzed the effects of specific sanding parameters and the causes of heavy sanding. This research shows the following results: L increases with increasing theoretical contact length, the radius and rotational speed of the sander roller are proportional to L, feed rate is inversely proportional to L, and the L of a bulging point is 7.5 times greater than that of a flat surface. This difference is the main cause of heavy sanding, which is, in turn, mainly caused by different sanding strip patterns used when various parts of the component are sanded. This study provides a theoretical basis for using surface brush sanding for specially shaped wood products.
Crack Detection in Computer Tomographic Scans of Softwood Tree Discs
Authors: Wehrhausen Martin , Laudon Norvin , Brüchert Franka , Sauter Udo Hans
Published: October 2013

Cracks in softwood are an important defect that reduces the quality of sawn timber for construction purposes. As with all other quality reducing features in wood, it is of significant interest to know about their number and position in a log before sawing. On one hand, cracks are relatively easy to distinguish from wood by means of computer tomographic (CT) scanning owing to the large differences in density. The fact that they tend to be irregular and very thin, however, complicates detection. This study describes a method for automated crack detection in single CT slices and evaluates its precision in terms of both detection rate and length measurement. Twenty tree discs were sampled from spruce (Picea abies) and silver fir (Abies alba) logs and scanned with a computer tomograph. The results of the automated detection are compared with data from manual reference measurements on the physical discs and with data from visual inspection of the CT images. Under optimal conditions, the detection rate is 84 percent. The average underestimation of crack length is 18 mm for heart checks and 15 mm for radial checks. There is no sharp threshold of crack width that limits the detection. The overall precision of this crack detection method can be seen as sufficient for practical purposes, when the standard errors in length measurement are considered.
Formaldehyde Emissions from Urea-Formaldehyde– and No-Added-Formaldehyde–Bonded Particleboard as Influenced by Temperature and Relative Humidity
Authors: Frihart Charles R. , Wescott James M. , Chaffee Timothy L. , Gonner Kyle M.
Published: October 2013

It is well documented that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF)–type adhesives. This work investigates the effect of temperature and humidity on newer commercial California Air Resources Board (CARB) phase II–compliant particleboard produced with UF-type adhesives. These results were compared with laboratory particleboards prepared with the no-added-formaldehyde (NAF) Soyad adhesive technology. A modified version of EN 717‐3 (“Formaldehyde Release by the Flask Method,” ÖNORM 1996) was used to collect formaldehyde emissions that were quantified using the acetylacetone method. The formaldehyde emissions from the commercial particleboard panel bonded with a UF-type resin increased greatly when panels were exposed to higher heat and humidity than in normal testing protocols. Furthermore, the rate of emission for these UF-bonded panels increased with longer exposure at 100 percent relative humidity. In contrast, formaldehyde emissions from particleboard bonded with the NAF adhesive were relatively stable and significantly lower compared with those bonded with UF at all temperature and relative humidity conditions. This work highlights the potential for increased long-term formaldehyde emissions even from the new UF CARB phase II–compliant adhesive systems.
Modeling Air Drying of Sitka Spruce (Picea sitchensis) Biomass in Off-Forest Storage Yards in Ireland
Authors: Murphy Glen , Kent Tom , Kofman Pieter D.
Published: October 2013

Moisture management, through storage and drying in the supply chain between harvesting and use, is key to improving both transportation costs and market values of woody biomass. Storage can take place at sites within the forest or in off-forest storage yards. A model for predicting the moisture content of Sitka spruce roundwood and energy wood under an open, off-forest, environment was developed for Ireland. Experimental data for the model were gathered over a 16-month period beginning in April 2007. The major factors affecting biomass moisture content change are cumulative precipitation and evapotranspiration (ET0), biomass type, and type of cover. ET0 was computed using the FAO Penman-Monteith method, which requires temperature, solar radiation, wind, and relative humidity data. The model was easily used in a spreadsheet to estimate drying times for different locations in Ireland, different starting seasons for drying, different biomass types, and different types of cover. The model should not be used for estimating drying times for in-forest biomass storage because it will overestimate drying rates considerably.
Educational Needs of the Forest Products Industry in Minnesota and Virginia in 2012
Authors: Espinoza Omar , Smith Robert , Lyon Scott , Quesada-Pineda Henry , Bond Brian H.
Published: October 2013

The forest products industry has been greatly impacted by the Great Recession, with many firms reducing output or closing operations to remain competitive. Educational training has also been a casualty of cost reduction efforts by firms. Yet, we know that a well-trained workforce is better prepared to compete, is more innovative, and is a long-term competitive advantage for companies. This research looked at current educational needs in Minnesota and Virginia by conducting an electronic survey and personal interviews with management personnel in the forest products industry. A key finding was that the factors that have impacted firms since the start of the recession (2008) were similar between states and included the housing market, transportation costs, energy costs, and changing customer demand. Results by size of firm and type of firm varied significantly, and training needs differed by state and size and type of firm. The identified training needs included quality/process control, process improvement, marketing, sales, motivating personnel, and total quality management. Firms rated personal visits and short courses as the primary methods of providing training. During the in-person interviews, managers were asked about the reasons for their companies' success during the recession. In Virginia, they felt that being customer focused, flexible, and diversified and having good financial management were the key issues. In Minnesota, they believed having high-quality products and good customer relationships, being “lean,” controlling costs, and being flexible were their success factors.
Potential for Utilizing Western Juniper (Juniperus occidentalis) Biomass for Oil Extraction and as a Fermentation Medium
Authors: Sichamba Kennedy , Morrell Jeffrey J. , Leavengood Scott
Published: October 2013

Steam-distilled essential oils from western juniper (Juniperus occidentalis) foliage and twigs were tested for activity against subterranean termites and fungi. Foliage residues were pretreated with dilute sulfuric acid and enzymatically treated to determine their digestibility. Essential oil recovery and sugar yields were higher for foliage than twigs. Foliage essential oil exhibited excellent antifungal and termiticidal activities at the concentrations tested. These results highlight the potential for integrating steam distillation of western juniper foliage to remove essential oil with enzymatic digestion of extraction residues. Additional studies to optimize distillation and pretreatment conditions for foliage are recommended.
Input–Output Modeling of Wood-Based Bioenergy Industries in Mississippi
Authors: Joshi Omkar , Grebner Donald L. , Henderson James E. , Grado Stephen C. , Munn Ian A.
Published: October 2013

The southern region of the United States, which includes Mississippi, has abundant forest resources that provide an opportunity to establish a wood-based bioenergy industry in the region. This study estimated the direct, indirect, and induced economic impacts associated with establishment of wood-based bioenergy facilities in Mississippi. Three potential wood-based bioenergy facilities, wood pellets, bio-oil, and methanol-based gasoline, were considered. The requisite cost information pertaining to the construction and operation of selected wood-based bioenergy facilities were obtained from various secondary sources. Construction activities would impact the economy for a shorter period of time. Results showed operation of a wood pellet facility, having an annual production capacity of 75,000 dry tonnes, would contribute 8,282 full- and part-time jobs and US$12 million worth of economic output to the state economy. Likewise, operation of a bio-oil facility, having an annual production capacity of 66,224.5 dry tonnes, would provide 112 new full- and part-time jobs and an economic output of US$13 million. Similarly, an economic output of US$96 million and 795 more full- and part-time jobs would be added to the Mississippi economy by establishing a methanol-based gasoline facility. Clearly, these impacts are likely to draw the attention of policy makers and investors toward developing wood-based bioenergy opportunities in Mississippi.
Properties of Bamboo–Wood Hybrid Glulam Beams
Authors: Sinha Arijit , Clauson Milo
Published: October 2013

Bending and shear characteristics of bamboo–wood hybrid glulam (BWHG) beams were investigated to evaluate the possibility of using laminated bamboo lumber (LBL) as a lamstock for glulam beams in structural application. Moreover, two different resin types were also evaluated for bamboo–wood bond strength. Isocyanate-based resin performed better in terms of bond performance and resulted in higher bending strength and comparable stiffness to that of phenol-resorcinol-formaldehyde resin. The BWHGs performed better than the reported values on Douglas-fir (Pseudotsuga menziesii) glulam beams. Initial results indicate there is potential for LBL to be used as lamstock for glulam beams, which should be investigated further.
Latino Youths’ Sexual Values and Condom Negotiation Strategies
Authors: Deardorff Julianna , Tschann Jeanne M. , Flores Elena , de Groat Cynthia L. , Steinberg Julia R. , Ozer Emily J.
Published: October 2013

Context

Young Latinos in the United States are at high risk for STDs and are less likely than other youth to use condoms. To our knowledge, no studies have examined the relationship between sexual values and condom negotiation strategies among young Latinos.

Methods

Cross‐sectional data collected in 2003–2006 from 571 Latino women and men aged 16–22 in the San Francisco Bay Area were used to examine associations between sexual values (e.g., considering sexual talk disrespectful or female virginity important) and use of strategies to engender or avoid condom use. Linear regression analyses were used to identify such associations while adjusting for potential covariates and gender interactions.

Results

Among women, sexual comfort and comfort with sexual communication were positively associated with frequency of direct communication to foster condom use; the importance of female premarital virginity and levels of sexual self‐acceptance were positively associated with expressing dislike of condoms to avoid using them; and levels of sexual self‐acceptance were negatively associated with expressing dislike of condoms to avoid using them. Moreover, the degrees to which women considered sexual talk disrespectful and female virginity important were positively associated with the frequency with which they shared risk information as a condom use strategy. Among both sexes, the importance that respondents placed on premarital female virginity was negatively associated with use of direct communication strategies.

Conclusion

Researchers designing interventions to influence Latino youths’ sexual decision making and behaviors should consider including program components that address sexual values.
Ecological dynamics of Zostera marina (eelgrass) in three adjacent bays in Atlantic Canada
Authors: Wong Melisa C. , Bravo Monica A. , Dowd Michael
Published: October 2013

We obtained and analyzed a baseline dataset of Zostera marina (eelgrass) dynamics in three adjacent bays in Nova Scotia, Canada. The field sites were Kejimkujik National Park Seaside (Keji), Port l’Hebert (PH), and Port Joli (PJ). Measures of Z. marina growth and production, including shoot density, aboveground and belowground biomass, and shoot productivity, were sampled monthly for 1 year. Physical parameters, including water temperature, suspended solids, nutrients, ice cover, and algal presence, were also measured. Seasonal cycles in shoot density, leaf length, and aboveground biomass of Z. marina were evident at all sites. Shoots persisted throughout the winter; however, shoot density was lowest at PH and Keji due to ice cover. Belowground biomass at all sites did not show seasonal signals. Greatest differences in measured Z. marina parameters were observed at Keji compared with PH and PJ. Restricted water exchange at Keji caused high water temperatures, low flushing rates, and prolific algal growth, probably resulting in lower shoot densities and biomass than in PH and PJ. Our study provides some of the first data on Z. marina dynamics in the Atlantic Canadian region, and will provide a critical baseline for future comparisons of plant condition and estimates of variability in potential monitoring parameters.
Caffeic acid inhibits organic anion transporters OAT1 and OAT3 in rat kidney
Authors: Uwai Yuichi , Kawasaki Tatsuya , Nabekura Tomohiro
Published: October 2013

Background: Some food components influence drug elimination. Previously, we found that caffeic acid, present in coffee, fruits, and vegetables, strongly inhibited human homologs of organic anion transporters (OATs) OAT1 and OAT3, which are responsible for renal tubular secretion of anionic drugs. In this study, we examined the effect of caffeic acid on drug transport by OAT1 and OAT3 in the rat kidney.

Methods: The inhibitory effect of caffeic acid on rat OAT1 and OAT3 was assessed by drug uptake experiment using Xenopus laevis oocytes. Urinary excretion of phenolsulfonphthalein (PSP), a diagnostic agent secreted by renal OATs, was examined in rats, and the influence of caffeic acid was evaluated.

Results: Expression of rat OAT1 (rOAT1) and rOAT3 stimulated uptake of their typical substrates, p-aminohippurate and estrone sulfate, respectively, into oocytes, and caffeic acid inhibited them dose dependently. After intravenous injection of PSP in rats, 42.7% of the dose was excreted into urine up to 60 min, and the simultaneous administration of caffeic acid reduced it to 32.0%.

Conclusions: These findings show that caffeic acid inhibits OAT1 and OAT3 in the rat kidney.
Influence of Rare-Earth Yttrium on High-Temperature Oxidation Behavior of Fe-Si Alloys
Authors: Su Yong , Desong Meng , Liu Qun , Fu Guangyan , Wu Jingdong , Yu Sijie , Yu Zhenhui
Published: October 2013

The high-temperature oxidation behavior of Fe-Si-Y alloys has been studied at 1173 and 1273 K in 0.1 MPa flowing pure O2. Results show that as the content of rare-earth yttrium raises, the grain size of Fe-Si-Y alloys decreases obviously, which increases grain boundaries in the alloys. The grain size of the oxides formed on the grain-fined alloys is also decreased. These enhance the diffusion rate of the alloying elements through the alloy matrix and oxide scales, and promotes the formation of SiO2 and Y2O3. However, a single and continuous SiO2 or Y2O3 scale still does not form on yttrium-containing alloys when being oxidized at 1173 or 1273 K, but their rapid formation and partial lateral connection due to the grain refinement can restrain the element diffusion in the alloys to some extents, and thus the oxidation resistance of the alloys is improved. The mechanism related with the effect of the grain refinement resulting from the addition of rare-earth yttrium on high-temperature oxidation behavior of Fe-Si alloys is also discussed.
The Influence of Thermal Exposure and Hydrogen Charging on the Notch Tensile Properties and Fracture Behaviour of Dissimilar T91/TP316H Weldments
Authors: Blach Juraj , Falat Ladislav
Published: October 2013

The effects of ageing and hydrogen charging on the notch tensile properties and fracture behaviour of individual heat-affected zones (HAZ) and Ni-based weld metal (Ni WM) of T91/TP316H weldments were investigated. After the post-weld heat treatment at 750 °C for 1 h the weldments were annealed at 600 °C for 1000 h and 5000 h, respectively. All heat-treated states were studied in condition without as well as with hydrogen charging. Thermal expositions led to additional precipitation and microstructure coarsening but their influence on tensile strength was insignificant. In contrast, remarkable plasticity decrease and the fracture mode transition from ductile dimple tearing to transgranular cleavage were observed. The combined effects of thermal exposure and hydrogen charging were more complex. Whereas the regions of Ni WM and TP316H HAZ did not show any significant change in strength, the hydrogen effect caused the strength increase in T91 HAZ. Although the hydrogen embrittling effects were clearly manifested by decreasing plasticity, their significance was getting smaller with increasing annealing duration. The fracture behaviour of thermally exposed and hydrogen charged regions exhibited mixed fracture modes including transgranular cleavage, intergranular dimple fracture and intergranular decohesion.
Organic Montmorillonite Modified Asphalt Materials: Preparation and Characterization
Authors: Pei Jianzhong , Wen Yong , Li Yanwei , Zhang Zengping , Shi Xin , Zhang Jiupeng , Li Rui , Cao Leilei , Du Qunle
Published: October 2013

Organic montmorillonite (OMMT) modified asphalt was prepared with the melting intercalation technology. The distribution of OMMT layers in matrix asphalt was characterized through x-ray diffraction (XRD) and transmission electron microscope (TEM), and the effect of OMMT on physical properties and dynamic rheology of matrix asphalt were studied as well. It was found that OMMT homogeneously dispersed in the modified asphalt and intercalated OMMT/asphalt nanocomposites were prepared by means of melt extrusion. Additionally, from the penetration, softening point, and dynamic shear rheometer (DSR) testing result, it was observed that the OMMT obviously improved the high-temperature stability, temperature serviceability, and rut resistance of the matrix asphalt. The bending beam rheometer (BBR) results indicated that the OMMT modified asphalt with OMMT dosage of 3 % exhibited the lowest stiffness and highest resistance to low temperature cracking, and had less effect on the relaxation of stress in low temperature in comparison with OMMT modified asphalt with OMMT dosage of 1 % and 5 %. Furthermore, it was found that the optimal dosage of OMMT was 3 %.
Threshold Strain for Postcyclic Shear Strength Change of Mississippi River Valley Silt Due to Cyclic Triaxial Loading
Authors: Wang Shuying , Onyejekwe Site , Yang Junsheng
Published: October 2013

Soil microstructure is affected by cyclic loading, leading to changes in postcyclic shear strength. It is generally observed that the postcyclic shear strength of a given soil increases substantially after reconsolidation above a threshold strain for that soil. In this study, we investigated the threshold strain for change in the postcyclic shear strength of reconsolidated soil by conducting cyclic triaxial tests on reconstituted Mississippi River Valley silt with a plasticity index (PI) of 5.8. To this end, the effects of the cyclic stress ratio, overconsolidation ratio, effective consolidation pressure, and PI on the threshold cyclic axial strain were assessed. The postcyclic shear strength decreased slightly when the cyclic axial strain (εa,c) was less than 0.4 %, but it increased substantially when the cyclic axial strain was greater than 0.4 %. The threshold cyclic axial strain was determined as 0.4 %, which was close to the yield cyclic axial strain, equal to the strain at the intersection of two envelopes in εa,c versus p′ space. The threshold strain did not vary substantially with either the cyclic stress ratio or the overconsolidation ratio, but it decreased with the effective consolidation pressure. Within the PI range of 5.8 to 9.4, there was no obvious change in threshold cyclic axial strain. When we combined data from other researchers, it was found that the threshold shear strain increases from 0.1 % to 3.0 % with an increase in PI. The average line for threshold shear strain (γth) for postcyclic shear strength change was found to be almost parallel to that for cyclic pore water pressure in PI–logγth space.
Selection of Minimum Sample Size Tightened-Normal-Tightened Sampling Inspection Schemes
Authors: Vijayaraghavan R. , Loganathan A. , Rajalakshmi D.
Published: October 2013

Acceptance sampling schemes are frequently used when finished products or materials are supplied by the producer for making decisions about individual lots or group of lots by examining sample information of such products or material. A sampling scheme is a set of plans that are usually specified by certain parameters such as sample size(s) and acceptance number(s). The tightened-normal-tightened (TNT) sampling scheme is a scheme that incorporates two single sampling plans called normal and tightened sampling plans, having the same sample size, but with different acceptance numbers along with the rules for switching between the plans. The determination of parameters of a sampling scheme for specified requirements on its operating characteristic curve providing protection to the producer and consumer is termed as designing of the scheme. This paper presents an iterative procedure for designing TNT schemes for two specified points on the operating characteristic curve, namely, acceptable quality level and limiting quality level associated with the producer's risk and the consumer's risk, respectively. Tables providing the parameters of the schemes for various values of acceptable quality level and limiting quality level under the conditions of binomial and Poisson distributions are developed and presented. The efficiency of such schemes over the schemes developed by the unity value approach is demonstrated with illustrations.
Computer-Automated Triaxial Testing System for Assessing and Mitigating Sample Disturbance in a Natural Clay in the Laboratory
Authors: Karademir Tanay
Published: October 2013

A computer automation for a manual triaxial cell involved in designing new test instrumentation components and connections and in developing new controller software and supportive hardware for accurate functioning of the system during long test durations was undertaken to run high-quality, sophisticated triaxial tests for measuring the stress-strain properties of clays. For validation and further evaluation of the developed computer-automated triaxial testing system, a laboratory testing program was performed to investigate the effects of sample disturbance on laboratory-measured clay soil behavior and the mitigation of disturbance effects in the laboratory using two reconsolidation methods, the stress history and normalized soil properties (SHANSEP) method and the recompression method. Computer-automated triaxial tests were performed on specimens of Boston blue clay (BBC) from a test site (Newbury, MA) sampled using a Sherbrooke-type block sampler. The test results from the laboratory testing program are presented, including for (i) one-dimensionally consolidated undrained compression (CKoUC) tests on both normally consolidated (NC) and mechanically overconsolidated (OC) specimens using the SHANSEP method and (ii) anisotropically consolidated undrained compression (CAUC) tests using the recompression method. The CKoUC(NC) tests were performed to provide baseline SHANSEP data, and results were compared between CKoUC(OC) SHANSEP and CAUC recompression tests.
Improving Belleville Washer Spring Characteristics Using Elastomer Filling
Authors: Manđuka Abas , Gubeljak Nenad , Predan Jožef , Pinterić Marko
Published: October 2013

Belleville washer steel springs are characterized by a long fatigue life, better space utilization, low creep tendency, and high force bearing capacity with a small spring deflection. In the case of thicker springs, a greater force bearing and greater stiffness are obtained, but the deflection of the spring is reduced. In such a case, the fatigue life is reduced and there is a very high probability that a Belleville washer spring may fail in a brittle manner, causing additional damage to machinery. In order to prevent such a fracture of a Belleville washer, an elastomeric filling was used on both free surfaces of the spring. Experimental testing and numerical analyses show that enhanced loading characteristics were obtained when the elastomer filling was increasingly involved in the force bearing process. When the elastomer filling is compressed, the stresses in the Belleville washer steel are reduced, because the majority of the deflection stress is shared by the elastomer instead of the steel.
A Performance Evaluation Model Using FAHP/DEA and the Malmquist Productivity Index to Assess the Photovoltaics Industry in Taiwan
Authors: Lee Amy H. I. , Kang He-Yau , Lin Chun-Yu
Published: October 2013

With the depletion of fossil fuels and public consciousness of environmental degradation, the use of renewable energy resources has become a must in order to meet consistently increasing global energy demands. Solar energy is a promising renewable energy source that can be generated from the infinite sunlight resource with environmental sustainability and high safety standards. Nevertheless, the development of the photovoltaics (PV) industry still faces some obstacles, such as a versatile market cycle in response to economic conditions and high production costs with low conversion efficiency. Therefore, finding ways to strengthen their competitiveness is important in order for PV companies to survive and acquire decent profits in this new market. This research proposes a performance evaluation framework of firms in the PV industry. A fuzzy analytic hierarchy process (FAHP) is applied to set the assurance region of the factors, and then data envelopment analysis (DEA) is carried out to assess the business performance of the PV firms. Next, the Malmquist productivity index (MPI) is applied to evaluate the changes in efficiency of each firm over time. Based on the analysis, the firms can understand their current positions in the market and can gain a clear idea of how to improve their business.
Polyfluorenes as Organic Semiconductors for Polymeric Field Effect Transistors
Authors: Brennan David J. , Townsend Paul H. , Welsh Dean M. , Dibbs Mitchell G. , Shaw Jeff M. , Miklovich Jessica L. , Boeke Robyn B.
Published: October 2013

Polyfluorenes are a class of polyaromatic macromolecules that are characterized by an alternating backbone structure that consists of a 9,9-dialkylfluorene unit in combination with another aromatic group. The nature of this aromatic unit plays a key role in the electronic properties of the polymers. For example, polyfluorenes which combine chromophoric and charge transporting aromatic units have received a great deal of attention over the last several years as the emissive layer in polymeric light emitting diodes [LUMATION* Light-Emitting Polymers (LEPs)]. More recently, polyfluorenes have also been designed to perform as the organic semiconducting layer in polymeric field effect transistors (PFETs). This effort has led to a class of polymeric semiconductors with an excellent combination of charge mobility, environmental stability, and processability. One such polymer is the polyfluorene based on an alternating backbone of 9,9-dioctylfluorene and 2,2'-bithiophene units. This material has been shown to have charge mobilities as high as 0.02 cm2/V-s with current on/off ratios of up to 106. The poly(fluorene-bithiophene) is more resistant to doping by atmospheric oxygen than other polymeric semiconductors such as poly(3-hexylthiophene). Inks based on solutions of poly(fluorene-bithiophene) in xylene, mesitylene, and other solvents have also been prepared. The paper will focus on the recent advances in the synthesis, fabrication, and electrical characterization of poly(fluorene-bithiophene). *Trademark of The Dow Chemical Company
Non-Stick and Scratch Resistant Sol-Gel Coating for Aluminum
Authors: Y.L. Wu Linda , Nemeth Sandor
Published: October 2013

PTFE-based coatings have been widely used, for example, on aluminum molds for molding of polyolefin packaging materials for its non-stick property. However, these coatings do not meet the users' scratch resistance and durability requirements. This paper describes a preliminary study on the synthesis and characterization of a PTFE/sol-gel composite coating material which combines the required non-stick and low friction properties of PTFE filler with the high scratch resistance and durability of a silica-based sol-gel matrix. The non-stick and low friction properties were achieved by using both the PTFE filler and the lubricious compound resulting from the reaction of a solvent with siloxane. The high scratch resistance was attributed to the enhanced adhesion to the electro-chemically pre-treated surface and the optimized silica and alumina filler contents in the sol-gel material. FE-SEM/EDX, FTIR, contact angle goniometry, scratch testing and a pin-on-disc tribometry were used to evaluate the coating properties.