bluuebunny/crossref_metadata_2025 huggingface dataset:
Arab–American Muslims’ Home Interiors in the US: Meanings, Uses and Communication
Authors: Amor Cherif M.
Published: June 2008

The role of tradition and the attachment to homeland culture remain prerequisites that guide the development of the interior home environment of Arab–American Muslims in the United States. Space appropriation and the use of artifacts illustrate the rooted sensory need to reaffirm the attachment to the homeland's social and cultural values; additionally, these trends symbolize the enduring values of the group and render the home interior a place apart. This paper explores the role of tradition and its influence in shaping the home interior's physical environment, identifies the meanings associated with the resulting composition, and examines the consequences of adaptation to the host environment.

This qualitative investigation used a grounded theory of two Arab–American Muslim immigrant settlements in Chicago, Illinois and Dearborn, Michigan. The sample consisted of 20 household heads living in two–parent families. The heterogeneity of the Arab–Muslim immigrants necessitated the use of purposeful sampling. Focus groups, interviews, and participant observation constituted the different forms of data collection. Data were analyzed using open coding (Strauss & Corbin, 1990).

Findings indicated and confirmed that cultural forces remain a pivotal role in influencing the design of the home interior. More importantly, it was found that despite the attachment to traditional values, a growing indifference to homeland ideals can be sensed as the household undergoes generational, social, and cultural metamorphosis.
Bounded Choices: Somali Women Constructing Difference in Minnesota Housing
Authors: Hadjiyanni Tasoulla
Published: June 2008

Coming to Minnesota to escape a devastating war, Somali refugees found themselves living in rental units that had little resemblance to the dwellings they left behind. Interviews with eight Somali women in their Minnesota homes reveal the difficult choices they had to make in order to preserve Somali cultural traditions and practices amidst strong American influences. As a way to construct the Somali sense of difference, women appropriated their living environments by relying on all five senses and various forms of cultural expressions that range from burning unsi to adorning the walls with Somali handicrafts. Unwilling to let go of valued Somali institutions, many had to make bounded choices like cooking while veiled in open kitchens, limiting children's play to accommodate formal impromptu visits, and restraining their social gatherings to the bedrooms to continue the tradition of gender separation. By proposing design solutions to the housing problems revealed through the study, this paper hopes to alert those who work with refugees and other immigrant groups that, with a little extra care, a house can be transformed into a home that fosters a sense of belonging and eases the stresses of adjusting to new life circumstances.
Knowledge in Interior Design
Authors: Marshall–Baker Anna
Published: June 2008

Anna Marshall–Baker teaches in the Department of Interior Architecture at the University of North Carolina at Greensboro where she focuses on sustaining design and the reciprocal effects of environments and human development, particularly in the neonatal intensive care unit (NICU). With academic and practical experience in fine and commercial art, interior design, and psychology, she serves as a member of the Recommended Standards Consensus Committee for NICU Design, Interim Chair of the Sustaining Design Task Force for IDEC, Department Undergraduate Program Coordinator, Past–President of IDEC, and a reviewer for the Journal of Interior Design.
The American Master Bedroom: Its Changing Location and Significance to the Family
Authors: Vollmer John L. , Schulze Pamela A. , Chebra Janice M.
Published: June 2008

This article discusses the possible relationship between changes in the master bedroom and parenting values in middle class America. The authors review information from the US homebuilding industry, statistical data on housing trends, literature on the history of the bedroom from the Colonial period to the present, and literature on family sleep practices. The owner's bedroom, one domain among various domains in the home, is an individual–private domain that functions to ensure adult privacy and increase physical barriers between parents and children. The authors contend that changes in the location and function of the master bedroom in the American home over the past centuries reflect the upward social mobility afforded by rising incomes, expansive and undeveloped land, and shared concepts of prestige held by home builders and homeowners. These influences have helped develop a purely American sense of parenting among middle and upper–income families that reflects their individualism. Middle class parents have encouraged more physical distance between themselves and their offspring. Consistent with this trend, they have shown a preference for houses with large master suites that are sometimes located at a distance from other bedrooms in the house. Using a model by Chermayeff and Alexander (1965), the authors examine the relationship between parenting practices and private space, highlighting the implications of this trend for home planners and interior designers.
Technology as a Tool for Globalization: Cross–cultural Collaborative Design Studio Projects
Authors: Asojo Abimbola O.
Published: June 2008

This paper discusses how distance learning technology is utilized to breakdown geographical barriers and expose students to cross–cultural and global issues in the interior design studio. Two design studio collaborations—one of which was with Technikon, a South African institution of higher learning, and the second of which was with a British client of Nigerian descent—will be discussed here. The first project occurred between Spring 2001 and Spring 2002. Interior Design students at the University of Oklahoma were required to design affordable housing in response to issues identified in slums and squatter settlements in both South Africa and Nigeria. The students were able to accomplish this through the use of video conferencing technology while working in collaboration with the Technikon institution in South Africa. A second project occurred in fall 2005 in a lighting design studio. The students designed the lighting for a house in Nigeria via web conferencing with a British client of Nigerian origin. Through projects like these, design educators can help students learn about global design issues, develop competencies to allow them to view the world from multiple perspectives by studying design contributions from other cultures, and thus provide them with practical and intellectual skills to be actively engaged in an increasingly global society.
The History of Women in Interior Design: A Review of Literature
Authors: Turpin John
Published: June 2008

The purpose of this study is to analyze the development and current state of literature regarding the history of the interior design profession, particularly as it relates to the female decorators and interior designers of the 20th century. Currently, a masculine narrative of architects constitutes the identity of a field dominated by women in number, but by men in perceived significance. With the growth and development of the feminist movement over the past few decades, numerous scholars have re–examined the role of women within their individual disciplines. As a result, histories have been rewritten and professional identities have been redefined. However, the field of interior design–specifically the writing of its history—has not been affected by feminist scholarship to the same degree as many other fields. This has prevented a fully–developed history of the profession.

The following literature review identifies three types of publications: 1) general surveys of women in design, 2) critiques of the current state of the history of interior design, and 3) specific case studies/biographies. A comparative content analysis of the texts is conducted with the intent of identifying major themes and issues. The presentation of materials in chronological order sets up an opportunity to analyze evolving attitudes and theories.

The findings are twofold. First, a cyclical trend of survey–critique characterizes the last three decades of the 20th century with little advancement. Second, five major concepts dominate those poststructuralist case studies that demonstrate a 21st–century shift in methodological approaches regarding the evaluation of women and design. These concepts include: gender, taste, consumerism, identity, and modernism. The overall conclusion is encouraging. Scholarship has momentum in a positive direction, but there is still much to be done.
Diagramming Design Research
Authors: Wang David
Published: June 2008

This paper proposes a diagramming method to help conceptualize and structure design research. In addition, it shows how the method is useful in situating the design process into larger interdisciplinary bodies of knowledge. The paper begins by defining design and research with consideration of the difference between research and fact–finding. It then outlines common ways human beings come to know the world; these ways of knowing supply material to devise the proper research diagram for any particular topic. The paper then shows how research from the existing literature can be diagrammed, thus supplying students with a new analytical tool. Following this, several examples from student work in diagramming design research are outlined and analyzed. The conclusion considers how the diagramming method serves as a bridge to research nomenclature in other disciplines. Far from taking anything away from the design process, the use of the diagramming tool strengthens design itself as a form of inquiry. In short, the diagramming tool not only integrates design with research, it also promotes a more systematic interdisciplinary understanding of the design process.
Automated Creativity: Digital Morphology and the Design Process
Authors: Gibson Kathleen
Published: June 2008

Literature shows that traditional creative methods may reinforce repetitive and habitual behavior resulting in ineffective environmental design solutions (Lawson, 1980; Lang, 1987; Laseau, 1989). Two case studies explored the use of an automated system called cyber–ideation (Gibson, 2000b) as a method to stimulate idea generation. This procedure employed individual and team involvement, recursive and linear exploration, and manual and digital processes. Analysis compared students’ production using traditional ideation processes with that resulting from cyber–ideation. Results from this case study found that: 1) digital creation was more linear when evaluated against traditional ideation output, 2) cyber–ideation had a positive impact on team dynamics, and 3) automated output possessed greater surface delineation when compared with subjects’ manual sketching.
Motive, Mind, and Media: Digital Sketching in the Creative Culture of Design
Authors: Meneely Jason , Danko Sheila
Published: June 2008

As continuously evolving digital tools are incorporated into design education, educators and students must question the use of technology to ensure that creative processes are not diminished. This article presents a framework for questioning the relationships people form with new technology and explores the role of digital sketching in design education. The authors observed that conceptual drawing and ideational processes deteriorated in undergraduate work as design students placed greater reliance on computer aided design (CAD) techniques. Digital sketching was integrated into the existing coursework of four undergraduate interior design studios to improve conceptual drawing processes. Student reactions were collected and assessed using three key framework components: 1) Motive: What core philosophies and processes do design students value? 2) Mind: How do mindsets govern the use of technology in design education? 3) Media: How do tools empower design students to achieve their goals? Findings suggest that reflective thinking strategies should form the foundation of any technology–based design curriculum to ensure that motive, mind, and media are aligned.
Consistent preload calculations for jackup spudcan penetration in clays
Authors: Dean E. T.R.
Published: June 2008

Onshore bearing capacity methods have conventionally been used to predict the penetration of offshore jackup spudcans into the seabed. However, the Brinch Hansen depth factor has a step change in value at the point at which the lateral dimension of a footing equals its embedment. For soft clay seabeds, where penetrations can be greater than the spudcan diameter, the step produces a spurious, unrealistic prediction of punchthrough. A small modification is proposed to the depth factor to avoid this. Some consistent modifications are proposed for several related calculations.
Geotechnical properties of a municipal water treatment sludge incorporating a coagulant
Authors: O’Kelly Brendan C.
Published: June 2008

The geotechnical properties of a municipal water treatment sludge from an upland catchment are presented. The gelatinous sludge comprised flocs of mainly quartz, manganoan calcite, and clay-sized organic solids, and incorporated an alum coagulant and an anionic polyelectrolyte. Standard Proctor compaction yielded low bulk density values of 0.95–1.10 t/m3and dry density values of 0.12–0.36 t/m3(water content is 160%–780%) in line with the low specific gravity of solids value of 1.86. The undrained shear strength and the water content were inversely related on a semi-log plot. The effective stress shear strength parameter values were c' = 0 and ϕ' = 39°. The consolidation properties were studied using the oedometer, consolidometer, and triaxial apparatus. The material was highly compressible with primary compression index (Cc) values of 2.5–3.7, and primary compression ratio (C*c) values of 0.20–0.28. The majority of the strain response occurred due to primary consolidation although the material had a very low permeability (coefficient of permeability values decreasing from 2 × 10−9to 5 × 10−11m/s for an effective vertical stress of σ'v= 3–800 kPa). Secondary compression was minor, with a mean secondary compression index (Cαe) value of 0.15, and Cαe/Cc= 0.04–0.06.
Laterally loaded rigid piles in cohesionless soil
Authors: Guo Wei Dong
Published: June 2008

In this paper, limiting force profile for laterally loaded rigid piles in sand is differentiated from the on-pile force profile, from which elastic–plastic solutions are established and presented in explicit expressions. Nonlinear responses of the piles are characterized by slip depths mobilized from mudline and the pile-tip. At the states of tip-yield and rotation point yield, expressions for some critical depths are developed, which allow the on-pile force profiles to be constructed. The solutions and the expressions are developed concerning a constant subgrade modulus (k) and a linearly increasing modulus with depth (Gibson k), respectively. Capitalized on three measurable parameters, the solutions agree well with measured data and numerical predictions. Nondimensional responses are presented for various eccentricities at the tip-yield state and in some cases at the rotation point yield state. Nonlinear responses are obtained for typical eccentricities from elastic state right up to failure. Comments are made regarding displacement-based capacity. A case study is elaborated to illustrate (i) the use of the current solutions; (ii) the impact of the k distributions; (iii) the evaluation of stresses on pile surface; and (iv) the deduction of soil modulus. The current solutions are easily implemented and suitable for general design.
Vertical uplift capacity of horizontal anchors using upper bound limit analysis and finite elements
Authors: Kumar Jyant , Kouzer K. M.
Published: June 2008

The vertical uplift capacity of strip anchors embedded horizontally at shallow depths in sand is examined by using an upper bound limit analysis in conjunction with finite elements and linear programming. Velocity discontinuities were allowed along the interfaces of all the elements. The plastic strains within elements were incorporated by using an associated flow rule. The collapse load was expressed in terms of a nondimensional uplift factor Fγ, which was found to increase continuously with an increase in both embedment ratio (λ) and the friction angle (ϕ) of sand. Even though the analysis considers the development of plastic strain within all elements, however, at collapse, the soil mass just above the anchor was found to move as a single rigid block bounded by planar rupture surfaces making an angle ϕ with the vertical. The results were found to be almost the same as reported in the literature for those based upon a simple rigid wedge mechanism.
Significance and evaluation of Poisson's ratio in Rayleigh wave testing
Authors: Karray Mourad , Lefebvre Guy
Published: June 2008

Important progress has been made in the past 20 years in the use of surface-wave testing in soil characterization. However, the effect of Poisson's ratio on the construction of the theoretical dispersion relationships, associated with the inversion process, has not received enough attention and remains poorly documented. Five ideal profiles with different degrees of variation of shear-wave velocity with depth and three published case records are considered in this paper to study the effect of Poisson's ratio on Rayleigh wave phase velocities. The effect of the variation of Poisson's ratio on the evaluation of shear-wave velocity profiles (Vs) is also examined. Poisson's ratio is generally assumed in surface-wave testing, and therefore the paper also examines the possibility of evaluating its value using a multi-mode inversion process. The results of surface-wave testing obtained at two experimental sites are then used to illustrate the potential of surface-wave testing to evaluate the Poisson's ratio profile in addition to the Vsprofile. The impact of Poisson's ratio in Rayleigh wave testing is shown to be significantly more important than previously demonstrated. The error resulting from Poisson's ratio does not depend solely on the magnitude of the inaccuracy. A multi-mode inversion process is shown to be a useful tool to determine the Poisson's ratio profile, leading to a more accurate soil characterization.
Modeling trends in stem quality characteristics of loblolly pine trees in unthinned plantations
Authors: Choi Jungkee , Burkhart Harold E. , Amateis Ralph L.
Published: June 2008

Trends in stem quality characteristics of loblolly pine trees were investigated by using data from unthinned control plots established in plantations across 12 southern states in the United States and measured at 3 year intervals. At each measurement, the stem quality was classified into (i) single stem or forked, (ii) normal top or broken top, (iii) straight or sweep (bole sweep, butt sweep, short crook), and (iv) no disease or disease. Data through the first 15 years of observation showed that, on average, 4% of the trees were forked, 5% had broken tops, 41% had sweep, and 12% had disease or insect damage; 48% exhibited single stem, normal top, straight, and no disease or insect damage. Recovery rates out of forked, broken top, sweep, and disease classes were 37%, 83%, 30%, and 11%, respectively, over the 15 years. Multicategorical logit models were developed to predict stem quality characteristics from stand-and tree-level variables. Forked trees were related with tree diameter; broken tops were related with stand density, DBH, and relative height; sweep was related with stand age. Significant predictor variables for the incidence of disease or insect attack were not found. The occurrence of undamaged and disease-free trees can be predicted from DBH and relative height.
Product attributes affecting consumer preference for residential deck materials
Authors: Nyrud Anders Q. , Roos Anders , Rødbotten Marit
Published: June 2008

In many countries, restrictions on the use of traditional preservative treatments have resulted in efforts to develop wood products for outdoor use that are durable, environmentally friendly, and appealing to consumers. In the present study, consumers’ preferences for wooden deck materials were investigated using sensory analysis. The analysis included an analytical sensory profiling of five deck materials, conducted by a trained sensory panel, as well as a hedonic preference study conducted on Norwegian customers. Eighteen visual and tactile attributes were identified, and statistical analysis indicated that these attributes were sufficient to discriminate between the different deck materials. The results imply that consumers prefer deck materials with a homogeneous visual appearance and moderate color intensity. The study demonstrated a successful application of sensory research on wood products and implies that sensory analysis is an appropriate tool to study relationships between hedonic judgments and product characteristics. The study was carried out on wooden deck materials, but the results are probably also relevant for other wood products.
Generic biomass functions for Common beech (Fagus sylvatica) in Central Europe: predictions and components of uncertainty
Authors: Wutzler Thomas , Wirth Christian , Schumacher Jens
Published: June 2008

This study provides a comprehensive set of functions for predicting biomass for Common beech ( Fagus sylvatica L.) in Central Europe for all major tree compartments. The equations are based on data of stem, branch, timber, brushwood (wood with diameter below 5 or 7 cm), foliage, root, and total aboveground biomass of 443 trees from 13 studies. We used nonlinear mixed-effects models to assess the contribution of fixed effects (tree dimensions, site descriptors), random effects (grouping according to studies), and residual variance to the total variance and to obtain realistic estimates of uncertainty of biomass on an aggregated level. Candidate models differed in their basic form, the description of the variance, and inclusion of various combinations of additional fixed and random effects and were compared using the Akaike information criterion. Model performance increased most when accounting for between-study differences in the variability of biomass predictions. Further, performance increased with the inclusion of age, site index, and altitude as predictor variables. We show that neglecting variance partitioning and the fact that prediction errors of trees are not independent with respect to their predictor variables will lead to a significant underestimation of prediction variance.
Effect of precommercial thinning followed by a fertilization regime on branch diameter in coastal United States Douglas-fir plantations
Authors: Briggs David G. , Kantavichai Rapeepan , Turnblom Eric C.
Published: June 2008

The effect of precommercial thinning in 6- to 13-year-old Douglas-fir ( Pseudostuga menziesii (Mirb.) Franco var. menziesii ) plantations with and without fertilization with 224 kg·ha–1nitrogen (N) as urea on the mean diameter of the largest limb at breast height (DLLBH) was modeled. DLLBH is a simple, nondestructive field measurement related to log knot indices used to measure log quality in product recovery studies. Model [1] succeeded in predicting mean DLLBH (RMSE = 2.80 and radj2= 0.84) using only site, initial stocking, and treatment variables. Model [2], which used only mean tree variables, improved on model [1] and was simpler. However, model [3], which used a combination of both groups of variables, produced the best model. Model [4] successfully predicted mean DLLBH using variables that can be measured with light detection and ranging (LIDAR), a high-resolution remote sensing technology. Since the age when the live crown receded above breast height is an important variable in some of the models, model [5] was developed to predict when crown recession above breast height occurs. This study found that mean DLLBH of Douglas-fir plantations can be estimated using variables obtained from stand-level growth models or remote sensing, providing a quality indicator that can be easily measured and verified in the field.
Fire return intervals and tree species succession in the North Shore region of eastern Quebec
Authors: Bouchard Mathieu , Pothier David , Gauthier Sylvie
Published: June 2008

We evaluated geographic variations in mean fire return intervals and postfire forest succession within a 66 497 km2 land area located in the eastern Quebec boreal forest. Fire return intervals were calculated using a time since last fire map for 1800–2000, and forest dynamics were studied by superimposing 3204 forest inventory plots onto the fire map. Mean fire return interval proved significantly shorter in the western part of the study area, at 270 years, compared with the eastern part, where it was probably more than 500 years. The two main tree species in the study area were balsam fir ( Abies balsamea (L.) P. Mill.) and black spruce ( Picea mariana (Mill.) BSP). Balsam fir abundance increased progressively as a function of time since fire, whereas black spruce abundance increased during the first 90 years after fire and then declined. Balsam fir was significantly more abundant in the southeastern portion of the study area, which we attribute to the combined limitations imposed by temperature along the north–south axis and by fire along the east–west axis. Large forest patches (i.e., ≥200 km2) dominated by early successional tree species, within a matrix of irregular black spruce – balsam fir mixtures, are an important feature of preindustrial forest landscapes in this region.
Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization
Authors: Coyle David R. , Coleman Mark D. , Aubrey Doug P.
Published: June 2008

Increased forest productivity has been obtained by improving resource availability through water and nutrient amendments. However, more stress-tolerant species that have robust site requirements do not respond consistently to irrigation. An important factor contributing to robust site requirements may be the distribution of biomass belowground, yet available information is limited. We examined the accumulation and distribution of above- and below-ground biomass in sweetgum ( Liquidambar styraciflua L.) and loblolly pine ( Pinus taeda L.) stands receiving irrigation and fertilization. Mean annual aboveground production after 4 years ranged from 2.4 to 5.1 Mg·ha–1·year–1for sweetgum and from 5.0 to 6.9 Mg·ha–1·year–1for pine. Sweetgum responded positively to irrigation and fertilization with an additive response to irrigation + fertilization. Pine only responded to fertilization. Sweetgum root mass fraction (RMF) increased with fertilization at 2 years and decreased with fertilization at 4 years. There were no detectable treatment differences in loblolly pine RMF. Development explained from 67% to 98% of variation in shoot versus root allometry for ephemeral and perennial tissues, fertilization explained no more than 5% of the variation in for either species, and irrigation did not explain any. We conclude that shifts in allocation from roots to shoots do not explain nutrient-induced growth stimulations.
Heritability and phenotypic and genetic correlations of coastal Douglas-fir (Pseudotsuga menziesii) wood quality traits
Authors: Ukrainetz Nicholas K. , Kang Kyu-Young , Aitken Sally N. , Stoehr Michael , Mansfield Shawn D.
Published: June 2008

Genetic control and relationships among coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and wood quality traits were assessed by estimating heritability and phenotypic and genetic correlations using 600 trees representing 15 full-sib families sampled from four progeny test sites. Heritability estimates ranged from 0.23 to 0.30 for growth traits, 0.19 for fibre coarseness, from 0.21 to 0.54 for wood density, from 0.16 to 0.97 for cell wall carbohydrates, and 0.79 and 0.91 for lignin content at two sites, Squamish River and Gold River, respectively. Glucose content, indicative of cell wall cellulose composition, and lignin were shown to be under strong genetic control, whereas fibre coarseness was shown to be under weak genetic control. Phenotypic correlations revealed that larger trees generally have longer fibres with higher fibre coarseness, lower density, lower carbohydrate content, a greater proportion of cell wall lignin, and higher microfibril angle. Genetic correlations and correlated response to selection suggest that breeding for height growth would result in a reduction in wood quality, whereas breeding for improved earlywood density in Douglas-fir would result in negligible reductions in volume and appears to be an ideal target for selecting for improved wood quality (density) while maintaining growth in the sample population.
Understory plant responses to uneven-aged forestry alternatives in northern hardwood–conifer forests
Authors: Smith Kimberly J. , Keeton William S. , Twery Mark J. , Tobi Donald R.
Published: June 2008

The understory layer encompasses the majority of plant species diversity in forested ecosystems and may be sensitive to timber harvest disturbance. We hypothesize that (i) uneven-aged, low-intensity silvicultural systems can maintain understory plant diversity and support late-successional species following harvest disturbance; (ii) retaining and enhancing stand structural complexity can increase understory plant diversity in northern hardwood–conifer forests; and (iii) plant responses are influenced by interactions among canopy structure, soils, and climate processes. Experimental treatments include single-tree selection and group selection, both modified to increase structural retention, and a third technique designed to promote late-successional forest structure and function, structural complexity enhancement. Four replications of each treatment were applied to 2 ha units in Vermont and New York, USA. Understory vegetation was monitored 2 years pre- and 4 years post-treatment. Results show that over time, understory responses were strongly affected by overstory treatment and less influenced by soils and drought. All treatments succeeded at maintaining overall composition and diversity. However, late-successional diversity increased significantly in structural complexity enhancement units compared with group selection units. These results indicate that while conventional uneven-aged systems can maintain understory plant diversity, variations that retain or enhance structural complexity may be more effective at retaining late-successional species.
Natural durability of black locust (Robinia pseudoacaciaL.) wood grown in Wallonia, Belgium
Authors: Pollet Caroline , Jourez Benoit , Hébert Jacques
Published: June 2008

The decay resistance of black locust ( Robinia pseudoacacia L.) heartwood was evaluated on standardized test specimens taken from mature and juvenile wood in 25 trees distributed over five sites in Wallonia, Belgium. The percentage mass losses caused by the wood-destroying fungi Coriolus versicolor CTB 863 A and Coniophora puteana BAM Ebw.15 were evaluated according to Cen/ts 15083-1 (Cen/ts 15083-1. 2005. Durability of wood and wood-based products — determination of the natural durability of solid wood against wood-destroying fungi, test methods — Part 1: Basidiomycetes. European Comm. for Standardization, Brussels). Black locust is classified as a “very durable” wood (class 1), while the juvenile heartwood (located near the pith) is classified in classes 1 to 2. The statistical analysis does not reveal any significant differences among the sites, suggesting that the growth environment of the trees has no effect on their natural durability. However, statistical analysis shows very highly significant differences among trees and between the two radial positions in the tree, with mature wood being more resistant than juvenile wood. Using such a naturally very durable species could reduce reliance on preservative treatment and the use of tropical species generally recommended for outdoor woodwork.
Impacts of a regional drought on the productivity, dieback, and biomass of western Canadian aspen forests
Authors: Hogg E. H. (Ted) , Brandt J. P. , Michaelian M.
Published: June 2008

We examined the impacts of a severe, regional drought (2001–2002) on trembling aspen ( Populus tremuloides Michx.) forests in the western Canadian interior. A total of 150 plots were established in 25 study areas as part of a regional-scale study (CIPHA). Aspen health and mortality were assessed annually during 2000–2005, and changes in stem biomass were estimated using tree-ring analysis and plot-based measurements. Net mean increment in living biomass for all plots was 2.2 t·ha–1·year–1 during 2000–2002 but subsequently decreased to near zero. This collapse was driven by a more than two-fold increase in stem mortality and a 30% decrease in regional stem growth during and following the drought. The analysis showed that spatial variation in aspen productivity and biomass across the region was positively related to multiyear mean values of a climate moisture index and mineral soil silt content but was negatively related to levels of insect defoliation and wood-boring insects. In contrast, mortality and dieback was best correlated with minimum annual climate moisture index, which provided a measure of short-term drought severity. The results support previous studies showing that aspen forests are moisture limited in this region, which poses concerns for the future under a changing climate.
Response of trembling aspen to partial cutting and subsequent forest tent caterpillar defoliation in a boreal mixedwood stand in northeastern Ontario, Canada
Authors: Man Rongzhou , Kayahara Gordon J. , Rice James A. , MacDonald G. Blake
Published: June 2008

The growth response and mortality of trembling aspen ( Populus tremuloides Michx.) were monitored 1, 3, 5, and 11 years after partially harvesting an aspen-dominated mature mixedwood stand in northeastern Ontario. Both diameter and height of aspen trees responded positively to harvesting. However, 3 years after harvest, the growth rates of residual aspen were severely suppressed by 3 years of moderate to severe defoliation by forest tent caterpillar ( Malacosoma disstria Hbn.). The diameter growth of surviving trees almost recovered, but due to continuous crown dieback in the 6 years after defoliation ceased, height growth did not. Over the 11 years after harvest, 70% of residual aspen died, with 80% of that mortality occurring in the 6 years after defoliation. Trees in the lower canopy and in the partial cut had higher mortality rates than those in the upper canopy and in the uncut control. Increased mortality at the individual tree level was generally associated with greater foliage loss. Aspen growth and mortality were associated with defoliation levels, particularly for trees in partial cut treatments. Partial cutting and crown class strongly influenced the response of aspen trees to insect defoliation and should be considered when selecting residual trees during harvesting.
Transient physiological responses of planting frozen root plugs of Douglas-fir seedlings
Authors: Islam M. Anisul , Jacobs Douglass F. , Apostol Kent G. , Dumroese R. Kasten
Published: June 2008

Short-term physiological responses of planting frozen (FR) and rapidly thawed (TR) root plugs of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) seedlings were examined through time series (0 h, 6 h, 12 h, 1 day, 3 days, and 7 days) measurements in two separate experiments: 10 °C day : 6 °C night, RH 75% and 30 °C day : 20 °C night, RH 50%, respectively. Net photosynthesis, transpiration, shoot water potential, and root hydraulic conductance were lower in FR compared with TR seedlings under both growing conditions. Magnitude of difference in root hydraulic conductance was higher under warm-dry conditions. Chlorophyll fluorescence (Fv/Fm) values were higher for TR than FR seedlings at 0 h, but similar thereafter for both growing conditions. Needle electrolyte leakage and chlorophyll content did not differ between FR and TR seedlings under both environmental regimes. Higher root O2uptake was observed in FR seedlings in warm-dry conditions and in TR seedlings under cool-moist conditions. TR seedlings planted under warm-dry conditions had more flushed buds and new roots than FR seedlings, while no buds flushed for both FR and TR seedlings under cool-moist conditions. Comparatively higher photosynthesic rates in TR seedlings planted under warm-dry conditions likely contributed toward more new roots, which could be advantageous for survival and early growth.
Analysis of cellulose microfibril angle using a linear mixed model in Pinus taeda clones
Authors: Isik Fikret , Gumpertz Marcia , Li Bailian , Goldfarb Barry , Sun Xuan
Published: June 2008

Variation in microfibril angle (MFA) (degrees) among loblolly pine ( Pinus taeda L.) full-sib families and clones was investigated using 43 clones from nine full-sib crosses tested at two locations. When the experiments were 12 years old, a total of 316 trees were drilled and 12 mm thick wood increment cores were collected. MFA for each growth ring in the wood core was measured using the SilviScan-2 tool. A quadratic mixed model was fitted to evaluate the MFA variation over different rings. Among the error covariance structures tested in the model, autoregressive order 1 was the best model for producing MFA estimates with the smallest errors. Estimated MFA was about 33° in the pith (ring 1) of the trees and decreased to 18° in the outer wood (ring 11). Full-sib crosses and clones within crosses explained about 12.5% of the total phenotypic variation. Repeatability of full-sib family means (H2f = 0.46) was moderate but repeatability of clone means was high (H2c = 0.79). Although it is possible to improve (decrease) MFA with recurrent selection in tree improvement programs to improve lumber quality, cost efficient and rapid methods for measuring MFA are needed.
Quantitative-genetic variation in morphological and physiological traits within a quaking aspen (Populus tremuloides) population
Authors: Kanaga Megan K. , Ryel Ronald J. , Mock Karen E. , Pfrender Michael E.
Published: June 2008

Genetic diversity within populations is an important component of adaptive evolution, and recent research has demonstrated that genetic variation within plant populations can have important ecological effects. In this study, we investigate quantitative-genetic variation in several traits within a quaking aspen ( Populus tremuloides Michx.) population. A common garden experiment was planted with replicates of 13 aspen genotypes collected from wet and dry sites within a population in southern Utah, USA. Ten growth, leaf, physiological, and structural traits were measured. There were significant, heritable phenotypic differences among genotypes in every measured trait and differences in 4 of the 10 traits among genotypes originating from wet and dry collection sites. The data were compared with other published studies, showing that aspen heritability (H2) estimates and coefficients of genetic variation (CVG) were comparable or higher than other Populus species and hybrid F1 Populus genotypes, indicating a large amount of quantitative-genetic variation in aspen.
Long-term development of above- and below-ground carbon stocks following land-use change in subalpine ecosystems of the Swiss National Park
Authors: Risch Anita C. , Jurgensen Martin F. , Page-Dumroese Deborah S. , Wildi Otto , Schütz Martin
Published: June 2008

Vegetation changes following agricultural land abandonment at high elevation — which is frequent in Europe — could have a major impact on carbon (C) sequestration. However, most information on the effects of vegetation changes on ecosystem C stocks originates from low-elevation studies on reforestation or early successional forests, and little is known about how these stocks change during long-term secondary forest succession and at high elevation. We assessed aboveground, belowground, and ecosystem organic matter and C stocks in high-elevation ecosystems that represent the long-term development (centuries) following land abandonment: short- and tall-grass pastures, Swiss mountain pine (Pinus mugo Turra), mixed-conifer, and Swiss stone pine ( Pinus cembra L.) – European larch ( Larix decidua P. Mill.) forests. Aboveground C stocks were lowest in the short-grass pastures (0.1 Mg C·ha–1) and reached a maximum in the mixed-conifer and stone pine – larch forests (166 Mg C·ha–1). Belowground C stocks did not differ among the ecosystems studied. We only detected ecosystem C sequestration during reforestation; whereas no significant differences in ecosystem C stocks were found during long-term secondary forest development. Our calculations showed that only an additional 1733–3032 Mg C·year–1 would be sequestered owing to natural reforestation in high-elevation Switzerland, which likely can be considered negligible compared with total annual C sequestration calculated for Swiss forests in other studies.
Short-day treatment alters Douglas-fir seedling dehardening and transplant root proliferation at varying rhizosphere temperatures
Authors: Jacobs Douglass F. , Davis Anthony S. , Wilson Barrett C. , Dumroese R. Kasten , Goodman Rosa C. , Salifu K. Francis
Published: June 2008

We tested effects of shortened day length during nursery culture on Douglas-fir ( Pseudotsuga menziesii var. menziesii (Mirb.) Franco) seedling development at dormancy release. Seedlings from a 42°N source were grown either under ambient photoperiods (long-day (LD)) or with a 28 day period of 9 h light : 15 h dark photoperiods (short-day (SD)). Seedlings were periodically removed from freezer storage from January to May. Sensitivity of plant tissues to cold temperatures was investigated via electrolyte leakage at nine test temperatures ranging from 2 to –40 °C. New root growth was assessed with rhizosphere temperatures of 10, 15, 20, and 25 °C. From 2 to –13 °C, there was no difference between treatments in cold hardiness. However, at or below –18 °C, LD seedlings exhibited higher indices of damage than SD seedlings. The LT50(temperature at which 50% cell electrolyte leakage occurred) was consistently lower for SD than LD seedlings. Rhizosphere temperature differentially influenced new root proliferation: LD seedlings had greater new root production than SD seedlings at 20 °C, whereas the opposite response was detected at 10 °C. Our results confirm photoperiod sensitivity of Douglas-fir sources from relatively low (i.e., <45°N) latitudes. Increased spring cold hardiness and greater rooting at lower rhizosphere temperatures may improve field performance potential of SD-treated seedlings.
CORRECTION OF LATERAL INERTIA EFFECT IN SHPB
Authors: GANG CHEN , TAO JUNLIN , CHEN ZHONGFU , HUANG XICHENG , XU WEIFANG
Published: June 2008

A theoretical analysis of the stress state in specimen of the SHPB experiment was performed in consideration of lateral inertia effect. The nonuniformity of lateral stress in specimen and variety of deforming velocity in the loading process were taken into account in the analysis. A formula to correcting the lateral inertia effect was obtained. The force and deformation velocity of specimen-bar interfaces during the loading process got from a numerical simulation of SHPB were used to verify the theoretical analysis formula. It shows that the deviation of reconstructed curve from the inputted relationship can be brought down with the correction formula.
DEVELOPMENT OF A NEW RAIN EROSION TEST METHOD
Authors: CHUNG DONG-TEAK , KANG HYUNG , JIN DOO-HAN
Published: June 2008

The nose of a missile, flying through raining region with a supersonic speed, is subjected to the rain erosion because the nose is made of a brittle ceramic material. Various test methods are used to address such a phenomenon. However, most of the methods are expensive and/or require complicated facilities. The simple yet very effective rain erosion test method is developed. It consists of (1) a low pressure air gun, (2) a sabot assembly for launching single rain drop, (3) a stopper, and (4) a specimen holder block. The sabot assembly similar to the hypodermic syringe carries specific amount of water toward the stopper launched by the low pressure air gun. When the impact occurs against the stopper which stops the sabot, the water and the steel plunger (at the back of the sabot) continues pushing the sabot to generate a high pressure in the chamber filled with resilient silicon rubber. The pressurized silicon rubber then is squeezed through the small opening in front of the sabot, thus, accelerates the water droplet to a much higher velocity. The velocity of the droplet is measured by the make-screen method, where there are two aluminum foils with an insulating layer in between. The droplet velocity up to 800 m/s is successfully attained using a low pressure air compressor. The specimen made of a ceramic material is placed in front of the high speed water droplet and the rain erosion damage on the surface of the specimen is observed.
CHARACTERISTICS METHOD FOR VISCOELASTIC ANALYSIS IN A HOPKINSON TENSILE BAR
Authors: DONG X. L. , LEUNG MING YAN , YU T. X.
Published: June 2008

A mini-Split Hopkinson Tensile bar (mSHTB) system is developed. The system employs small diameter polymeric bars, which can achieve a closer impedance match with the specimens, thus it provides a lower noise-to-signal ratio and a longer duration of tensile pulse, which results in a higher maximum strain. With the three element viscoelastic model, a characteristic method for reconstruction of the profiles of strain, particle velocity, and stress in an arbitrary cross section of a viscoelastic bar on the basis of the strain signal measured in one section is developed. Experiments using the mSHTB enable us to appropriately characterize the dynamic behavior of small-sized, low-impedance material under a particular range of high strain rate.
NEW EXPERIMENTAL SAMPLE FOR SHEAR TESTING OF ADHESIVELY BONDED ASSEMBLIES
Authors: CHALLITA GEORGES , OTHMAN RAMZI , GUEGAN PIERRICK , KHALIL KHALID , POITOU ARNAUD
Published: June 2008

In this paper, Split Hopkinson Bar technique was used to investigate the shear behaviour of adhesively bonded assemblies at high rates of loading. New sample geometry was adopted so that the compressive wave is transformed in a shear loading in the sample. Samples are conditioned at 20°C and 50% of hygrometry to eliminate any interference with temperature and humidity effects. The new technique is applied to an assembly built with a cyanoacrylate based adhesive and a metallic (Steel) adherent. They are found to be highly rate sensitive.
EMPLOYING IMPACT TO INDUCE ULTRA-FINE GRAINS IN OXYGEN-FREE PURE COPPER
Authors: GONG M. , SHIM V. P. W. , YANG L. M. , CHEN F.
Published: June 2008

An experimental investigation is undertaken to examine the possibility of producing ultra-fine grained bulk material through high-speed impact compression followed by annealing. A gas gun was employed to impose high-rate deformation on oxygen-free high-conductivity copper specimens to 90% strain. Samples were also quasi-statically compressed to identical final strains and similar heat treatment. Results show that after impact compression, grain boundaries widen and become less sharply defined, and many narrow twins are formed. For dynamic loading, grain boundary slip appears to accompany dislocation movement. Two dislocation characteristics were identified and the dislocation density was lower than that in samples compressed quasi-statically. Small dislocation loops were also observed. Portions of grains in specimens subjected to impact were mechanically broken into sizes less than 1 μm before annealing. The microhardness of impacted and statically compressed samples increased respectively by HV50 and HV60. After annealing at 190°C for 1 hour, ultra-fine grains with grain sizes ranging from 40∼200 nanometers were observed in impacted samples. This study highlights the potential of utilizing impact compression to produce bulk material with ultra-fine grains.