Study of the properties larch and larch wood construction materials

2016 ◽  
Author(s):  
М.А. Чубинский ◽  
К.В. Чаузов
Keyword(s):  
Weight Loss ◽  
Urea Formaldehyde ◽  
Construction Materials ◽  
Siberian Larch ◽  
Larix Sibirica ◽  
Average Weight ◽  
Biological Stability ◽  
Laminated Beam ◽  
Coniophora Puteana ◽  
Larch Wood

Несмотря на огромные запасы, древесина лиственницы до сего времени в незначительных объемах используется в строительной индустрии, других отраслях экономики, что связано как с технологическими сложностями ее переработки, так и недостаточной изученностью ее свойств. Одним из уникальных свойств древесины лиственницы сибирской (Larix sibirica) является ее повышенная естественная биостойкость, наряду с максимально высокой среди отечественных хвойных пород прочностью. Стойкость древесины лиственницы (Larix sibirica) к воздействию дереворазрушающих грибов Coniofora puteana значительно превышает стойкость сосны. В среднем потеря массы ядровой древесины лиственницы сибирской под воздействием дереворазрушающего гриба Coniophora puteana составляет 14,84%, снижаясь с увеличением возраста дерева, а контрольные образцы из ядровой древесины сосны в возрасте 90 лет имели потерю массы 57,8%. Возраст дерева является одним из наиболее значимых факторов, влияющих на степень биостойкости древесины. По мере его увеличения значительно повышается устойчивость деструктивному воздействию дереворазрушающих грибов Coniophora puteana. Положение образцов также влияет на степень биостойкости древесины, однако эта зависимость слабо выражена по сравнению с влиянием возраста и плотности древесины. Исследования кинетики разложения древесины лиственницы сибирской и роли экстрактивных веществ в развитии дереворазрушающих грибов позволяют утверждать наличие связи биостойкости и содержания в древесине экстрактивных веществ. Для изготовления клееного бруса из древесины лиственницы предложена клеевая композиция, включающая карбамидомеламиноформальдегидный клей и карбамидоформальдегидную смолу, модифицированную шунгитами. Ее применение позволяет получать клеевые соединения, не уступающие по прочности при скалывании массивной древесине, как по сухому образцу, так и после его вымачивания. Таким образом, клееный брус из древесины лиственницы сибирской характеризуется высокими показателями биостойкости, прочности и водостойкости. Despite vast reserves, larch wood so far in small volumes used in the construction industry and other sectors of the economy, which is connected as the technological difficulties of its treatment, as well as insufficient knowledge of its properties. One of the unique properties of the wood of Siberian larch (Larix sibirica) is its increased natural biological stability (decay resistant), along with the highest among the domestic softwood strength. Resistance Larch (Larix sibirica) to the effects of wood-destroying fungi Coniofora puteana is much higher than pine. The average weight loss of Siberian larch heartwood exposed wood-destroying fungi Coniophora puteana is 14.84%, decreasing with increasing age of the tree, and control samples of heartwood pine at age 90 had a weight loss of 57.8%. Age of a tree is one of the most significant factors affecting the degree of biological stability of wood. With the increase it significantly increases the stability of the destructive effects of wood-destroying fungi and Coniophora puteana. The position of the sample in tree also affects the degree of biological stability of wood, but this dependence is poorly developed in comparison with the influence of age and wood density. Studies of the kinetics of decomposition of Siberian larch wood and the role of extractives in the development of wood-destroying fungi suggest a link, and the decay resistant of the content in the wood extractives. For the manufacture of larch glued laminated beam proposed adhesive composition comprising urea and melamine-formaldehyde glue and urea-formaldehyde resins, modified shungites. Its use allows to obtain the bonds are not inferior in strength at shearing solid wood as dry sample, and after soaking. Thus, glued laminated beam from Siberian larch wood is characterized by high decay resistant, strength and water resistance.

A Simple Empirical Model for Predicting Weight Loss of Mild Steel due to Corrosion in NaCl Solution

2020 ◽  
Vol 17 (1) ◽  
pp. 7784-7791
Author(s):  
Nurdin Ali ◽  
T. E. Putra ◽  
V. Z. Iskandar ◽  
M. Ramli
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Empirical Model ◽  
Degradation Rate ◽  
Construction Materials ◽  
Average Weight ◽  
Nacl Solution ◽  
Nacl Concentration ◽  
Materials Used

Validating the degradation rate of construction materials used in public facilities is important for reliability and safety reasons. This is determined through direct measurements using weight loss or electrochemical methods. Both methods, however, are time-consuming and expensive. Therefore the development of a corrosion model for estimating the degradation rate based on weight loss is needed. For this purpose, 25 samples of 80×24×3 mm sized coupons were prepared. The measurements of the weight loss were carried out on the specimens for 10, 20, 30, 40, 50, 60, and 70 days, respectively by total immersion of the samples in NaCl solution of 2, 3, 4, and 5 wt.% with one treated in distilled water. The results show that NaCl concentration significantly influenced the corrosion rate for all variations with an average weight loss value of 1.38 mg/cm2 and corrosion rate value of 25×10-5 mm/year. The proposed empirical model was WL=0.001*1.34α* t0.87. In conclusion, the proposed model was successfully established based on the experimental data for predicting the weight loss of mild steel in the NaCl solution.

Estimate of annual carbon balance of a young Siberian larch (Larix sibirica) plantation in Iceland

Tellus B ◽  
2007 ◽  
Vol 59 (5) ◽  
Author(s):  
Brynhildur Bjarnadottir ◽  
Bjarni D. Sigurdsson ◽  
Anders Lindroth
Keyword(s):  
Carbon Balance ◽  
Siberian Larch ◽  
Larix Sibirica ◽  
Annual Carbon ◽  
Annual Carbon Balance

Isolation and sulfation of galactoglucomannan from larch wood (Larix sibirica)

2021 ◽  
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Natalya Yu. Vasilyeva ◽  
Olga Yu. Fetisova ◽  
Anna I. Chudina ◽  
...  
Keyword(s):  
Larix Sibirica ◽  
Larch Wood

scholarly journals Incidence and Outcomes of Home Parenteral Nutrition in Patients With Crohn Disease in Olmsted County, Minnesota

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Zeinab Bakhshi ◽  
Siddhant Yadav ◽  
Bradley R Salonen ◽  
Sara L Bonnes ◽  
Jithinraj Edakkanambeth Varayil ◽  
...  
Keyword(s):  
Weight Loss ◽  
Parenteral Nutrition ◽  
Short Bowel Syndrome ◽  
Crohn Disease ◽  
Severe Disease ◽  
Bloodstream Infections ◽  
Home Parenteral Nutrition ◽  
Average Weight ◽  
Olmsted County ◽  
Short Bowel

Abstract Background We sought to estimate the incidence of home parenteral nutrition (HPN) use in a population-based cohort of patients with Crohn disease (CD), and to assess clinical outcomes and complications associated with HPN. Methods We used the Rochester Epidemiology Project (REP) to identify residents of Olmsted County, who were diagnosed with CD between 1970 and 2011, and required HPN. Results Fourteen out of 429 patients (3.3%) with CD received HPN (86% female). Eleven patients (79%) had moderate–severe CD and 12 patients (86%) had fistulizing disease. Thirteen patients (93%) underwent surgery, primarily due to obstruction. Among CD incidence cases, the cumulative incidence of HPN from the date of CD diagnosis was 0% at 1 year, 0.5% at 5 years, 0.8% at 10 years, and 2.4% at 20 years. Indications for HPN included short bowel syndrome in 64%, malnutrition in 29%, and bowel rest in 21%. The median duration of HPN was 2.5 years. There was an average weight gain of 1.2 kg at 6 months, an average weight loss of 1.4 kg at 1 year, and a further weight loss of 2.2 kg at 2 years from the start of HPN. Patients were hospitalized a mean of 5 times after the start of HPN, mainly due to catheter-related bloodstream infections and thrombosis. Conclusions Less than 4% of patients with CD need HPN. Most have moderate to severe disease with short bowel syndrome or malnutrition. Possible reasons for the patients’ weight loss could be noncompliance, and increased metabolic needs because of active disease.

scholarly journals Bending properties of dimension lumber produced from Siberian larch (Larix sibirica) in Mongolia

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Bayasaa Tumenjargal ◽  
Futoshi Ishiguri ◽  
Yusuke Takahashi ◽  
Ikumi Nezu ◽  
Bayartsetseg Baasan ◽  
...  
Keyword(s):  
Siberian Larch ◽  
Larix Sibirica ◽  
Bending Properties ◽  
Dimension Lumber

scholarly journals Patterns of Weight Change in Aging and Dying

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 491-491
Author(s):  
Stephen Thielke
Keyword(s):  
Older Adults ◽  
Weight Loss ◽  
Risk Factor ◽  
Weight Change ◽  
Population Level ◽  
Chronological Age ◽  
Average Weight ◽  
Remaining Life ◽  
Entire Cohort ◽  
History Of

Abstract Little research has characterized the natural history of weight change in older adults. Different changes may occur during aging and dying. We analyzed 18 years of weight measures from a cohort of 736,361 Veterans, all of whom had died at age 70 or older. We produced summary measures that accounted for both chronological age and number of years before death. Several clear population-level trends appeared. (1) The average weight of the sample declined across all ages at a rate of about 0.18 BMI points per year. (2) Starting about seven years before death, the amount of loss began to accelerate, reaching a decline of 0.75 BMI points in the year before death. (3) Changes in weight relative to years of remaining life were independent of chronologic age. People who died at age 70 experienced, on average, the same type and duration of terminal decline as did those who died at age 95. (4) The dying process involved a cumulative loss of about 1.3 BMI points. (5) The distribution of weights during advancing age both declined and narrowed. (6) Disproportionate deaths occurred at the lower BMI ranges (below a BMI of 24), and especially below 18, regardless of age. (7) The finding in #5 is explained by the entire cohort losing weight, with death of the thinnest members. These findings argue for examining survival time in studies of weight change. They indicate that weight loss may be a natural part of dying, rather than a risk factor for it.

Complexation of carboxyarabinogalactan of Siberian larch (Larix Sibirica L.) with Kanamycin

2010 ◽  
Vol 83 (3) ◽  
pp. 497-500 ◽  
Author(s):  
R. Kh. Mudarisova ◽  
L. A. Badykova ◽  
E. I. Koptyaeva ◽  
A. A. Fatykhov ◽  
Yu. B. Monakov
Keyword(s):  
Siberian Larch ◽  
Larix Sibirica

Weight loss trajectories and related factors in a 16-week mobile obesity intervention: A retrospective observational study (Preprint)

2021 ◽  
Author(s):  
Ho Heon Kim ◽  
Young In Kim ◽  
Andreas Michaelides ◽  
Yu Rang Park
Keyword(s):  
Machine Learning ◽  
Weight Loss ◽  
Effect Size ◽  
Weight Change ◽  
Average Weight ◽  
Learning Approach ◽  
Obesity Management ◽  
Significant Difference ◽  
Machine Learning Approach ◽  
Cluster 2

BACKGROUND In obesity management, whether patients lose 5% or more of their initial weight is a critical factor in their clinical outcome. However, evaluations that only take this approach cannot identify and distinguish between individuals whose weight change varies and those who steadily lose weight. Evaluation of weight loss considering the volatility of weight change through a mobile-based intervention for obesity can facilitate the understanding of individuals’ behavior and weight changes from a longitudinal perspective. OBJECTIVE With machine learning approach, we examined weight loss trajectories and explored the factors related to behavioral and app usage characteristics that induce weight loss. METHODS We used the lifelog data of 19,784 individuals who enrolled in a 16-week obesity management program on the healthcare app Noom in the US during August 8, 2013 to August 8, 2019. We performed K-means clustering with dynamic time warping to cluster the weight loss time series and inspected the quality of clusters with the total sum of distance within the clusters. To identify the usage factors to determine clustering assignment, we longitudinally compared weekly usage statistics with effect size on a weekly basis. RESULTS Initial Body Mass Index (BMI) of participants was 33.9±5.9 kg/m2, and ultimately reached an average BMI of 32.0±5.7 kg/m2. In their weight log, 5 Clusters were identified: Cluster 1 (sharp decrease) showed a high proportion of weight reduction class between 10% and 15%—the highest among the five clusters (n=2,364/12,796, 18.9%)—followed by Cluster 2 (moderate decrease), Cluster 3 (increase), Cluster 4 (yoyo), Cluster 5 (other). In comparison between cluster 2 and cluster 4, although the effect size of difference in the average meal input adherence and average weight input adherence did not show a significant difference in the first week, it increased continuously for 7 weeks (Cohen’s d=0.408; 0.38). CONCLUSIONS With machine learning approach clustering shape-based timeseries similarity, this study identified 5 weight loss trajectories in mobile weight management app. Overall adherence and early adherence related to self-monitoring emerged as a potential predictor of these trajectories.

scholarly journals Long-Term Effect of Interactive Online Dietician Weight Loss Advice in General Practice (LIVA) Protocol for a Randomized Controlled Trial

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Carl J. Brandt ◽  
Vibeke Brandt ◽  
Mathilde Pedersen ◽  
Dorte Glintborg ◽  
Søren Toubro ◽  
...  
Keyword(s):  
Weight Loss ◽  
General Practice ◽  
Large Scale ◽  
Controlled Trial ◽  
Complex Interventions ◽  
Control Group ◽  
Average Weight ◽  
Practice Setting ◽  
Management Support ◽  
General Practice Setting

Background. Internet-based complex interventions aiming to promote weight loss and optimize healthy behaviors have attracted much attention. However, evidence for effect is lacking. Obesity is a growing problem, resulting in an increasing demand for cost efficient weight loss programs suitable for use on a large scale, for example, as part of standard primary care. In a previous pilot project by Brandt et al. (2011) without a control group, we examined the effects of online dietician counseling and found an average weight loss of 7.0 kg (95% CI: 4.6 to 9.3 kg) after 20 months. Aims and Methods. To analyze the effects of a complex intervention using trained dieticians in a general practice setting combined with internet-based interactive and personalized weight management support compared with conventional advice with a noninteractive internet support as placebo treatment in 340 overweight patients during a 2-year period. Primary endpoints are weight loss and lowering of cholesterol (LDL). We will also explore patients’ sociodemographics and use of the intervention as well as the health professionals’ views and perceptions of the intervention (their role and the advice and support that they provide). Perspective. The project will generate knowledge on the cost-effectiveness of a complex internet-based intervention in a general practice setting and on barriers and acceptability among professionals and patients.

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