The Role of Water in the Hygro-Thermo-Mechanical Behavior of Wood

Author(s):  
Dominique Derome ◽  
Alessandra Patera ◽  
Ahmad Rafsanjani ◽  
Saeed Abbasion ◽  
Jan Carmeliet

Wood, due to its biological origin, has the capacity to interact with water. Sorption/desorption of moisture is accompanied with swelling/shrinkage and softening/hardening of its stiffness. The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygric, thermal and mechanical (HTM) behavior of wood are considered in a coupled manner. In addition, we propose a comprehensive framework using a fully coupled poromechanical approach, where its multiscale implementation provides the capacity to take into account, directly, the exact geometry of wood cellular structure, using computational homogenization. A hierarchical model is used to take into account the subcellular composite-like organization of the material. Such advanced modeling requires high resolution experimental data for the appropriate determination of inputs and for its validation.

Holzforschung ◽  
2015 ◽  
Vol 69 (7) ◽  
pp. 825-837 ◽  
Author(s):  
Saeed Abbasion ◽  
Jan Carmeliet ◽  
Marjan Sedighi Gilani ◽  
Peter Vontobel ◽  
Dominique Derome

Abstract The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygrothermal and mechanical (HTM) behavior of wood is considered in a coupled manner. A fully coupled poromechanical approach is proposed and validated with neutron imaging measurements of moist wood specimens exposed to high temperature. This paper demonstrates that a coupled HTM approach adequately captures the variations of temperature, moisture content, and dimensions that result in a moist wood sample exposed to one-side heating.


Holzforschung ◽  
2015 ◽  
Vol 69 (7) ◽  
pp. 839-849 ◽  
Author(s):  
Saeed Abbasion ◽  
Peter Moonen ◽  
Jan Carmeliet ◽  
Dominique Derome

Abstract The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygric, thermal and mechanical (HTM) behavior of wood are considered in a coupled manner. A fully coupled poromechanical approach has been used to perform a parametric study on wood HTM behavior, and the results have been validated with neutron imaging measurements on a moist wood specimen exposed to high temperature. Further, HTM behavior of wood during welding has been simulated by the model. For such a simulation, proper material properties are needed, as some of them, for example thermal conductivity, have a significant influence on the local and temporal behavior of the material.


2017 ◽  
Vol 54 (2) ◽  
pp. 316-320
Author(s):  
Mihaela Gabriela Dumitru ◽  
Anca Ganescu

The objective of this study was to analyse the role of package obtained from a natural biopolymer of Quercurs robur L incorporating natural antioxidant compounds found in roasted seeds of grapes to lipid oxidation of butter during storage. Also were determined the properties of film: solubility in water, determination of antioxidant activity and water sorption activity. Were formed two sets of butter samples packed in paper respectively in a biopolymer mixed with antioxidant. Samples were stored at a temperature of +6�C for a period of fourty days. Frequently was determined the peroxide index. The values of peroxide index show the role of package obtained from starch and polyphenolics extract of roasted seeds of Vitis vinifera grapes on lipid found in butter.


Twin Research ◽  
2001 ◽  
Vol 4 (4) ◽  
pp. 223-226 ◽  
Author(s):  
Roland G.L. Devlieger ◽  
Thomas Demeyere ◽  
Jan A. Deprest ◽  
Dominique Van Schoubroeck ◽  
Ingrid Witters ◽  
...  

AbstractTo evaluate the accuracy of ultrasound in early detection of chorionicity and amnionicity in twin pregnancies and evaluate the role of operator-experience, a prospective follow up of 87 consecutive twin pregnancies was performed. Chorionicity and amnionicity were determined by 17 different observers, divided in 2 groups on the basis of their experience, using a composite of US markers at the first US examination confirming a viable intrauterine twin pregnancy. Accuracy of prediction was determined for both groups by comparison with postnatal pathology. From the 87 pregnancies examined at 10.1 (minimum 5.5 weeks, maximum 26.0) weeks of gestation, pathology was available in 82 cases and a correct prediction of chorionicity was made in all but two cases, both being diagnosed as monochorionic while dichorionic by observers belonging the more experienced group. No monochorionic pregnancy was missed and amnionicity was correctly diagnosed in all cases, including two monoamniotic twins. We conclude that use of a composite of ultrasound markers for early detection of chorionicity and amnionicity is reliable in a clinical setting where physicians with a variable degree of experience perform ultrasound examination.


1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.


1981 ◽  
Author(s):  
M Yamamoto ◽  
K Watanabe ◽  
Y Ando ◽  
H Iri ◽  
N Fujiyama ◽  
...  

It has been suggested that heparin caused potentiation of aggregation induced by ADP or epinephrine. The exact mechanism of heparin-induced platelet activation, however, remained unknown. In this paper, we have investigated the role of anti-thrombin III ( AT ) in heparin-induced platelet activation using purified AT and AT depleted plasma. When ADP or epinephrine was added to citrated PRP one minute after addition of heparin ( 1 u/ml, porcine intestinal mucosal heparin, Sigma Co. USA ), marked enhancement of platelet aggregation was observed, compared with the degree of aggregation in the absence of heparin. However, in platelet suspensions prepared in modified Tyrode’s solution, heparin exhibited no potentiating effect on platelet aggregation induced by epinephrine or ADP. Potentiation of epinephrine- or ADP-induced platelet aggregation by heparin was demonstrated when purified AT was added to platelet suspensions at a concentration of 20 μg/ml. AT depleted plasma, which was prepared by immunosorption using matrix-bound antibodies to AT, retained no AT, while determination of α1-antitrypsinα2- macroglobulin and fibrinogen in AT depleted plasma produced values which corresponded to those of the original plasma when dilution factor was taken into account. The activities of coagulation factors were also comparable to those of the original plasma. Heparin exhibited potentiating effect on ADP- or epinephrine-induced aggregation of platelets in original plasma, but no effect in AT depleted plasma. When purified AT was added back to AT depleted plasma at a concentration of 20 μg/ml, potentiation of platelet aggregation by heparin was clearly demonstrated.Our results suggest that effect of heparin on platelet aggregation is also mediated by anti-thrombin III.


Author(s):  
C. Claire Thomson

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.


1970 ◽  
Vol 8 (1) ◽  
pp. 22-30
Author(s):  
Анжеліка Шамне

У статті розглянуто сучасні підходи до інтерпретації категорії розвитку, розкрито теоретичні  та методологічні підходи до вивчення категорії розвитку у сучасній психології, визначено її психологічний  зміст,   моделі,   структуру   та   динаміку.   Категорія   розвитку   розглядається   як   епіцентр   наукової  проблематики у психології та як поняття інтегративного типу. Розвиток проаналізовано як категорію,  явище і проблему психології розвитку в різних аспектах аналізу. Розглянуто місце розвитку в системі  споріднених психологічних понять. У статті також аналізуються психологічні аспекти теоретичних та  методологічних  постнекласичних  тенденцій  вивчення  природи,  характеру  та  визначення  психічного  розвитку. Постнекласична парадигма та плюралістична методологія пізнання визначають розмитість  дисциплінарної мови  та  врахування  ролі  соціокультурного  контексту  при  вивченні  психологічних явищ.  Важливими тенденціями сучасного теоретико-методологічного стану психологічних досліджень розвитку  також є визнання неефективності моністичного підходу до його вивчення, взаємозв'язок теоретичних ідей  та   спроби   створення   метатеоретичних   схем,   постнекласичне   розуміння   розвитку   як   принципово  незавершеного   процесу   саморуху,   актуалізація   антропологічного   діапазону   проблем   та   посилення  спрямованості на роль культурного контексту в дослідженні розвитку людини.  The article deals with the modern approaches to the interpretation of the category of development, reveals  the theoretical and methodological approaches to study of development in modern psychology, its psychological  content, patterns, structure and dynamics. Category of development is viewed as an epicenter of scientific issues in  modern  psychology  and  the  concept  of  the  integrative  type.  Category  of  development  is  considered  as  the  phenomenon  and  the  problem  of  developmental  psychology  in  various  aspects  of  the  analysis.  Analyzed  the  development site in the related psychological concepts. The article analyzes the psychological aspects of theoretical  and methodological postnonclassical contemporary trends in the study of nature, character, and determination of  mental  development.  Postnonclassical  paradigm  and  pluralistic  methodology  of  knowledge  determine  the  disciplinary blurring and increase of the role of the analysis of socio-cultural context in the study of psychological  phenomenon. The important tendencies of modern theoretical and methodological state of psychological researches  of development are facts of inefficiency of the monistic approach to its study, interconnection of theoretical ideas  and   attempts   of  creating   metatheoretical   schemes,   postnonclassical   understanding   of   development   as   a  fundamentally  uncompleted  process  of  self-motion,  actualization  of  anthropological  range  of  problems  and  strengthening of focus on the role of cultural context in research of human development.   


2016 ◽  
pp. 64-66
Author(s):  
S.Yu. Vdovichenko ◽  

The objective: to show a role of the family focused technologies in depression of frequency of pathology of pregnancy at women of high obstetric risk. Patients and methods. For determination of efficiency of prophylaxis of pathology of pregnancy on the basis of use of the family focused technologies complex clinical-psychological and laboratory and tool examination of 300 women with factors of obstetric risk which were divided into two groups was conducted. In the main group – 182 women with motivation on partner labors to which provided training on system of individual preparation of married couple to labors. The comparison group consisted of 118 women who were not in prenatal training and had individual support in childbirth, with the traditional approach to pain management. Results. Use of the family focused technologies during pregnancy allows to reduce significantly the frequency of the main complications of pregnancy, especially not incubation and premature births. Conclusion. In our opinion, the technique is simple, available and can widely be used in practical health care at women with high obstetric risk. Key words: obstetric risk, the family focused technologies, prophylaxis.


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