September 2016, Vol.88:24–29, doi:10.1016/j.micron.2016.05.007
Title
Microscopic characterization of tension wood cell walls of Japanese beech (Fagus crenata) treated with ionic liquids
Author
Toru Kanbayashi a,b
Hisashi Miyafuji b,,
aDepartment of Wood Improvement, Forestry and Forest Products Research Institute, Tsukuba, Japan
bGraduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
Received 15 March 2016. Revised 16 May 2016. Accepted 22 May 2016. Available online 24 May 2016.
Highlights
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Morphological and chemical features of tension wood treated with ionic liquids were described.
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Cell walls in tension wood were swollen by ionic liquid treatment.
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Changes in tissue structure were different for normal wood and tension wood.
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Chemical changes in gelatinous layers were different for the types of ionic liquids.
Abstract
Tension wood that is an abnormal part formed in angiosperms has been barely used for wood industry. In this study, to utilize the tension wood effectively by means of liquefaction using ionic liquid, we performed morphological and topochemical determination of the changes in tension wood of Japanese beech (Fagus crenata) during ionic liquid treatment at the cellular level using light microscopy, scanning electron microscopy and confocal Raman microscopy. Ionic liquid treatment induced cell wall swelling in tension wood. Changes in the tissue morphology treated with ionic liquids were different between normal wood and tension wood, moreover the types of ionic liquids. The ionic liquid 1-ethyl-3-methylimidazolium chloride liquefied gelatinous layers rapidly, whereas 1-ethylpyridinium bromide liquefied slowly but delignified selectively. These novel insights into the deconstruction behavior of tension wood cell walls during ionic liquid treatment provide better understanding of the liquefaction mechanism. The obtained knowledge will contribute to development of an effective chemical processing of tension wood using ionic liquids and lead to efficient use of wood resources.
Corresponding author at: Division of Environmental Sciences, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Hangi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
Published Date March 2009, Vol.63(2):130–134,doi:10.1016/j.ibiod.2008.08.002
Title
Fungal decay resistance and durability of organosilicon-treated wood
Author
Liesbeth De Vetter,
Marc Stevens
Joris Van Acker
Ghent University, Faculty of Bioscience Engineering, Laboratory of Wood Technology, Coupure Links 653, B-9000 Gent, Belgium
Received 15 May 2008. Accepted 1 August 2008. Available online 21 September 2008.
Abstract The potential use of organosilicons as protective agents against basidiomycetes attack of wood used in outdoor applications was investigated using Scots pine sapwood and beech specimens. Both mini-blocks and EN 113 specimens were subjected to brown-rot and white-rot fungi. A dose–response could be observed showing that with higher weight percentage gain of the organosilicon, the resistance (i.e., efficacy) against fungi increased. At relatively low weight percentage gains, which are assumed to be economically feasible, Scots pine could be partly protected against decay byPostia placentaandConiophora puteanaand beech could be partly protected against decay byC. puteanaandTrametes versicolor. Full protection was achieved by some silicons for Scots pine sapwood againstC. puteanaand for beech againstT. versicolor. The most promising products were a solvent-based mixture of the alkoxysilanes methyltrimethoxysilane (MTM) and octyltriethoxysilane (OTES) and a water-based micro-emulsion of polydimethylsiloxane (PDMS) and triethoxysilane (TES) when applied above 20 and 30% weight gain for Scots pine and above 30 and 40% weight gain for beech. A water-based mixture of dimethylmethylhydrogen siloxane (DMS) andN-octyltriethoxysilane (n-OTES) was able to protect beech at weight gains above 30%. Keywords
Warming and drought will occur with increased frequency and intensity at high latitudes in the future. How heat and water stress can influence tree mortality is incompletely understood. The aim of this study was to evaluate how carbon resources, stem hydraulics, and wood anatomy and density determine the ability of black spruce saplings to survive daytime or night-time warming (+ 6 °C in comparison with control) in combination with a drought period. Plant water relations, the dynamics of non-structural carbohydrates and starch, mortality rate, and wood anatomy and density of saplings were monitored. Warming, in conjunction with 25 d of water deficit, increased sapling mortality (10% and 20% in night-time and daytime warming, respectively) compared with the control conditions (0.8%). Drought substantially decreased gas exchange, and also pre-dawn and mid-day leaf water potential to values close to –3MPa which probably induced xylem embolism (xylem air entry point, P12, being on average around –3MPa for this species). In addition, the recovery of gas exchange never reached the initial pre-stress levels, suggesting a possible loss of xylem hydraulic conductivity associated with cavitation. Consequently, mortality may be due to xylem hydraulic failure. Warmer temperatures limited the replenishment of starch reserves after their seasonal minimum. Lighter wood was formed during the drought period, reflecting a lower carbon allocation to cell wall formation, preventing the adaptation of the hydraulic system to drought. Saplings of black spruce experienced difficulty in adapting under climate change conditions, which might compromise their survival in the future.
Michael A. Kilgore Journal of Forest Economics, 2014, vol. 20, issue 2, pages 161-173 Abstract: Studies have repeatedly documented high property taxes as being a major determinant of a landowner's decision to divest of its forest land. To empirically investigate the relationship between property tax burden and forest land sale activity, property tax data and over 5300 Minnesota forest land sale records from 2000 to 2008 were assembled. Analyses were carried out to identify statistically significant relationships between several measures of private forest land sale activity and forest land property tax burden. The analyses failed to find a statistically positive relationship between the two. Statistically significant negative associations were found between some measures of forest property tax burden and forest land sale frequency, indicating forest land sales activity actually decreased with increasing property tax burden. While high property taxes, no doubt, influence forest land sale decisions, the findings from this study suggest its influence may not be as pervasive as once thought. Keywords:Property taxes; Forest land sale; Turnover; Tenure (search for similar items in EconPapers) JEL-codes:Q23Q24H20 (search for similar items in EconPapers) Date: 2014 References:Add references at CitEc CitationsTrack citations by RSS feed Downloads: (external link) http://www.sciencedirect.com/science/article/pii/S1104689914000166 Full text for ScienceDirect subscribers only Related works: This item may be available elsewhere in EconPapers: Search for items with the same title. Export reference:BibTeXRIS (EndNote, ProCite, RefMan) HTML/Text Persistent link:http://EconPapers.repec.org/RePEc:eee:foreco:v:20:y:2014:i:2:p:161-173 Ordering information: This journal article can be ordered from http://www.elsevier.com/wps/find/journaldescription.cws_home/701775/bibliographic http://www.elsevier. ... 701775/bibliographic Access Statistics for this article Journal of Forest Economics is currently edited by P. Gong and R. Brännlund More articles in Journal of Forest Economics from Elsevier Series data maintained by Zhang, Lei (repec@elsevier.com).
Published Date
Author Lixia He, Burton English, Daniel G. De La Torre Ugarte and Donald G. Hodges Journal of Forest Economics, 2014, vol. 20, issue 2, pages 174-191 Abstract: The production reliability and relatively low costs of sustainably harvested woody biomass such as logging residue and low value roundwood could make it a significant component of the Renewable Fuel Standards portfolio. This research explored a set of woody biomass harvesting combinations of different sources and wood types using a cost minimizing linear programming model populated with disaggregated regional inventory, yield, and cost data, and projected future conventional wood demand of the United States. The model pre-satisfied conventional wood demand before harvesting roundwood as woody biomass. Findings suggest that collecting forest residue and non-merchantable (small sized) timber may provide the largest initial contribution in woody biomass supply. Regional estimations imply that not all regions have the capacity to develop bioenergy plants without using merchantable (medium sized) wood. Within a reasonable range of harvesting costs, demand for roundwood is expected to increase with higher energy production targets. Harvesting merchantable natural softwood as woody biomass has a relatively small impact on marginal supply costs. This will result in little or no disturbance to merchantable natural softwood timber management and operations if demand for woody biomass increased. Keywords:Residue; Round wood; Bioenergy; Supply curve; Natural and planted softwood; Hardwood (search for similar items in EconPapers) JEL-codes:C02Q16Q23Q42 (search for similar items in EconPapers) Date: 2014 References:Add references at CitEc CitationsTrack citations by RSS feed Downloads: (external link) http://www.sciencedirect.com/science/article/pii/S1104689914000178 Full text for ScienceDirect subscribers only Related works: This item may be available elsewhere in EconPapers: Search for items with the same title. Export reference:BibTeXRIS (EndNote, ProCite, RefMan) HTML/Text Persistent link:http://EconPapers.repec.org/RePEc:eee:foreco:v:20:y:2014:i:2:p:174-191 Ordering information: This journal article can be ordered from http://www.elsevier.com/wps/find/journaldescription.cws_home/701775/bibliographic http://www.elsevier. ... 701775/bibliographic Access Statistics for this article Journal of Forest Economics is currently edited by P. Gong and R. Brännlund More articles in Journal of Forest Economics from Elsevier Series data maintained by Zhang, Lei (repec@elsevier.com).
by ERIKA HENRITZKnowing your maximum heart rate can help you train when using a treadmill.Photo Credit Jupiterimages/Comstock/Getty Images
Medical experts and exercise professionals use a universal calculation to determine an individual's maximum heart rate. This formula is based on your age, and using it to determine your maximum heart rate for any type of cardiovascular exercise, such as walking or running on a treadmill, riding a bicycle or training on an elliptical machine, can help you keep track of how hard your heart is working during your workouts.
The Maximum Heart Rate Calculation
To keep tabs on your heart rate during aerobic exercise so that you can pace yourself at an appropriate level, you will first need to know your maximum heart rate -- or MHR. Your MHR is an approximation of your heart's maximum exertion level, the number of times in 1 minute your heart can beat while still performing its duty of moving blood throughout your body efficiently. The universal MHR calculation is simple, requiring only that you subtract your age in years from the number 220. Therefore, a 70-year old man has a MHR of 150 beats per minute.
MHR: What It Means
MHR represents the maximum times your heart should beat per minute in any scenario, during exercise or otherwise. At 70 years of age, allowing your heart to beat faster than 150 beats per minute -- particularly over extended periods of time -- may potentially put your health at risk. Your predicted recommended maximum heart rate will continue to decline as you age, and this is because your cardiovascular risks increase as you age. At 70 years old, you may notice that it takes longer for your heart rate to rise during exercise and return to baseline at the end of your workout than it did 10 years ago.
Using MHR
Your MHR is only one piece of the puzzle when it comes to exercising at a healthy target heart rate for your age. To ensure that you are not overtaxing your heart during your workouts, you must use your MHR to determine your target heart rate -- or THR--zone. This THR zone describes a range within which your exercise pulse should fall so that you may reap maximum rewards from your exercise regime. Your THR range is 50 to 85 percent of your MHR. Therefore, because you are 70 years old, you will gain maximum rewards from cardiovascular exercise on a treadmill and minimize your risk of exercise injury by exercising within a heart rate range of 75 to 128 beats per minute.
To Put It All Together
At 70 years old, exercise is an important component of your overall health. Aerobic exercise can help to keep your heart strong and ward off complications, such as heart disease. Exercise can also help you manage age-related illness, such as diabetes and hypertension, that can also increase cardiovascular risks. Whatever your personal reason to exercise on a treadmill or in any other way, using your MHR and THR rate calculations empowers you to do so safely, and in a manner that rewards you with the most benefit for your effort.
by AMY SUTTONParents hiking with child in jogging stroller.Photo Credit Jupiterimages/Stockbyte/Getty Images
Hiking is a fantastic way to get outside with your child, get some fresh air and enjoy being out in nature. If you're planning to do some hiking with a baby or young child, it's a good idea to bring along a stroller for when he gets tired of walking or you get tired of carrying him. Before purchasing a stroller to use for hiking, consider what features you'll need most.
What to Look for
When you start looking for a hiking stroller, it can be intimidating, since there are so many types to choose from. Usually a jogging stroller or all-terrain-style stroller is recommend for hiking. Both generally have larger, inflatable, rugged wheels that can handle various types of terrain. If the front wheels swivel, they should have a wheel lock that can be engaged during a hike to prevent the stroller from tipping over. Look for a stroller that has a parking brake. Some even have hand brakes installed, to make them safer for use on steep trails. If you're planning to hike on bumpy terrain, find a stroller with good wheel suspension.
Stroller Safety
Ensure that the stroller you choose is designed for your child's height, weight and age. Keep in mind that newborns don't have much head control and need to lie almost flat in the stroller you select. Your hiking stroller should have a five-point harness to keep your child safe and secure. Babies younger than 1 year old shouldn't be brought along on the hike if you're planning to take the stroller on rough terrain, since it can cause too much jarring, warns ConsumerReports.org.
by ELIZABETH GRAYJogging with your baby can help keep you in shape.Photo Credit Comstock/Stockbyte/Getty Images
Jogging with your child can be difficult without a good stroller, but with the right jogging stroller, the benefits of jogging increase. The added weight of your child or children gives you added resistance to your run, increasing your heart rate and aiding in your fitness goals. As your child gets bigger, you may need to upgrade to a stroller with a larger weight capacity. A few options include Navigator, Baby Jogger, B.O.B. and Graco.
Navigator
Navigator makes a double stroller with a capacity of 50 pounds per child. It has a 5-point safety harness and two front-locking wheels for optimum child safety. It has a large storage basket, reclining seats and canopies so the children are out of the sun. It also features an mp3 speaker system that is compatible with most Apple products and two cup-holders for the jogger. It also folds into a compact space. Navigator's products are durable and well-reviewed by customers.
Baby Jogger
Baby Jogger makes an entire line of jogging strollers, a few with 100-pound capacity. Their strollers feature large wheels to run over many different kinds of terrain, in case you are planning on running on dirt or gravel. They also offer pod-style models so children can sit inside a tent-like area. The jogging stroller folds in one easy step and holds one or two children. Baby Jogger's strollers have a 5-point harness system to ensure the safety of your children, as well as canopies to protect from the sun.
B.O.B.
B.O.B. also makes a double stroller for twins or two children similar in age. It has extra padding, reclining seats and canopies to keep children comfortable, as well as a padded 5-point harness to keep them safe. It folds into a compact shape in two steps and has a large storage basket and windows in the canopy so you can watch your children. The stroller also has a car-seat adapter and snack tray that you can buy. B.O.B. has also designed a suspension system to keep their strollers running smoothly over rough terrain.
Graco
Graco also offers a line of jogging strollers for one or two children. Their strollers are also equipped with 5-point harnesses and canopies for child safety. Depending on the model, they come with such features as snack trays, large baskets and adjustable handles. Graco strollers' wheels are designed for optimum speed and quick turning.
