Stress-Strain Response of Wood Under Radial Compression. Part I. Test Method and Influences of Cellular Properties

A new test system was developed for real-time microscopic observation of wood cell-wall deformation and stress-strain relationship under transverse compression. The system consists of a small compression device, a stereo-microscope, a video microscaler, a videocassette recorder and a computer-based data logger. The significance of this system is that it allows the influence of cellular structure of wood on its stress-strain behavior and the cell-wall collapse mechanism to be studied. This test system was used in a research program aimed at generating some basic understanding of microstructural behavior of wood under transverse compression. Tests were conducted on white spruce specimens to evaluate the proposed test procedure and system, and the influences of some microscopic and macroscopic features such as wood density, cell-wall thickness, and earlywood/latewood ratio. End-matched specimens were tested using the test system at three levels of magnification. Gross and individual ring behaviors were observed and measured by testing at a low magnification (12X). Earlywood and latewood behaviors were measured separately using a medium level of magnification (32X). Finally the mechanism of cell-wall collapse was observed using the highest magnification (160X). Test results show that earlywood and latewood have varying degrees of influence on the various segments of the gross stress-strain curve in radial compression. First collapse of cellular structure occurs at a location with minimum cell-wall thickness and density. Initiation of cell-wall collapse and its gradual progression are clearly visible using the apparatus, thereby verifying the capability of the proposed method

Characterizing Microscopic Behavior of Wood Under Transverse Compression. Part II. Effect of Species and Loading Direction

Specimens of four species with different cellular structures (white spruce, jack pine, white ash, and aspen) were tested in radial compression. Deformation characteristics were observed and measured using a microscope at different magnifications. The magnified images were recorded with a video recorder, which were then played back for deformation measurements. Stress-strain responses of these specimens were determined from the measured load and deformation. As expected, the softwood and hardwood responses to radial compression were influenced by the anatomical features. Tangential compression tests were also conducted on white spruce and jack pine specimens. It was found that the mechanisms of deformation in radial and in tangential compression were distinctly different for these softwood species. In radial compression, cell-wall deformation dominated elastic behavior, and collapse of the weakest cells in earlywood coincided with the onset of yielding observed in the stress-strain curve. Cell collapse developed only in earlywood, while latewood cells mainly underwent elastic deformation. In tangential compression, elastic deformation was dominated by the bending of the latewood layers. For the two hardwood species, the measured elastic strain under radial compression was dominated by deformations in the vessels. Yield point on stress-strain curves was related to the collapse of these vessels

Utilization of bio-waste cotton (Gossypium hirsutum L.) stalks and underutilized paulownia (paulownia fortunie) in wood-based composite particleboard

The objective of this study was to investigate some mechanical (modulus of rupture, modulus of elasticity and internal bond) and physical (thickness swelling and water absorption) properties of wood-based three-layer particleboard containing different cotton (Gossypium hirsutum L.) stalks and underutilized paulownia (paulownia fortunie) wood particle ratios (30, 50 and 70%) using urea formaldehyde resin. Addition of cotton stalk and paulownia wood in particleboard improved mechanical properties of resulting composites boards significantly. However, the water resistance decreased with increasing cotton stalk and paulownia wood particle contents. The highest mechanical properties were obtained at cotton stalk and paulownia wood particle loading of 50 and 70%, respectively. Conclusively, valuable underutilized natural resources, cotton stalk and paulownia wood can be used with the mixture of industrial wood particles in the production of particleboards with high mechanical properties.Keywords: Wood, resin, urea-formaldehyde, mechanical properties, physical propertie

Fish Protein Hydrolysate from Sulfated Polysaccharides Extraction Residue of Tuna Processing By-Products with Bioactive and Functional Properties

The ethanol-induced precipitation after enzymatic hydrolysis commonly used for sulfated polysaccharide extraction from marine resources wastes a large amount of proteins. Here, possible extraction of fish protein hydrolysates (FPH) from the ethanol residue of sulfated polysaccharide precipitation from head, bone, and skin of skipjack tuna is investigated. Antioxidant, antibacterial, angiotensin I-converting enzyme (ACE) inhibitory activities and functional properties of the recovered FPHs are also evaluated. A degree of hydrolysis of 40.93, 38.13, and 37.23 is achieved for FPH from head, bone, and skin, respectively. FPH from the head presents the highest antioxidant and ACE inhibitory activity as well as foam/emulsion capacity among all the FPHs. The FPHs are all able to inhibit three Gram-positive bacteria and three Gram-negative bacteria to varying degrees and have a water solubility >65%. Altogether, the results\ua0demonstrate great potential for recovery of bioactive/functional peptides from the residue of sulfated polysaccharide extraction process enabling efficient biorefining of aquatic resources

Considering Effective Factors on Electronic Learning System Acceptance (ELS) According to Technology Acceptance Model (TAM)

Electronic learning shows in general refer to methods that use electronic educational content This research have been done among university faculty of Lorestan Province which has familiarity with learning systems.. According to statistical society (unlimited) the size of the sample determines 150 people and with %5 significance level. Instrument used in this research was closed questionnaire and for determining the relations between variables, data by path analysis technique and correlation matrix has been used effects directly on usefulness of understanding with a coefficient of .28. Understanding of extended network and self-success of computer with effect on ease of understanding indirectly effect with a coefficient of .20 on electronic learning system acceptance.  Also Learners by greater confidence in using computers believe their ability to use e-learning system for education and perceptual the usefulness of system in E-learning and use it. As a result, they consider  system as a useful tool in learning

The Impact of Work - Life Balance on Psychological Safety of Staff with the Mediating Role of Organizational Optimism

The present study was conducted to investigate the effect of work- life balance on psychological safety of staff with the mediating role of organizational optimism. The study in terms of purpose is practical and in terms of methods of data collection is survey from group of descriptive researches. The statistical population is female faculty members in the faculties and research institutes of Shahid Beheshti University 163 persons, The number of statistical samples obtained is 65 people. The tool of data collection is questionnaire of work – life balance provided by Agha et al. (2017) and questionnaire of optimism provided by Carver et al. (2010) and questionnaire of psychological safety of staff provided by Maslow (2004). Data analysis was performed with Structural Equation Modeling approach (SEM) with partial least squares method through Smart-PLS 3 software. The findings of this study showed that proposed research model is validated and based on it; Work- life balance has led to organizational optimism and this has an impact on psychological safety of staff. Also, organizational optimism variable plays an intermediary role in the relationship between work – life balance and psychological safety of staff

Practical Approaches Toward Sustainable Development in Iranian Green Construction

Developed nations acknowledge sustainable development as a legal right for current and future generations. Although instances of domestic and international efforts are prevalent, there is a long way to go before accomplishing developmental ideals. A practical approach for realizing the vital goals of sustainable development is of the utmost importance. In effect, the construction sector requires extensive forward-looking studies for strategizing, building and granting a sustainable future. The inconsistency between the goals and activities of different sectors is a main impediment upon undertaking sustainable development’s goals; decision and lawmakers must consider the purpose and interests of the building industry on a micro and macro level. This paper is a brief review for understanding the concept of sustainable development and illustrates some of the international efforts, and highlights them for decision makers.  Using the ‘PESTLE’ analysis technique, external and internal factors influencing sustainability in the Iranian construction sector were identified. Interviews were conducted with experts using the ‘Snowball’ research method due to the lack of knowledgeable respondents in the subject area. 11 Practical steps needed in Iran were recommended and sorted by their importance to make this vision a reality. The results can be generalized to other disciplines as well

Designing a model of resilience in government organizations of Kermanshah province

The purpose of the research is to design a model of resilience in government organizations of Kermanshah province. The research method is qualitative-quantitative. This research is developmental-applicative in terms of purpose, and descriptive-survey in terms of data collection. The statistical population of the research includes government managers who have at least 10 years of experience. In order to sample; purposeful sampling method in the qualitative part was used, and in the quantitative part based on the number of extracted components, the number of samples was determined to be 396 people and the cluster method was used for sampling. In order to analyze the data, the coding method was used in the qualitative part and the structural equation model method was used in the quantitative part by PLS software. The results indicate that the causal factors include; individual, group and organizational factors. Also, the environmental platform includes; the role of the government, political and economic factors, and electronic platforms. The consequences also indicate the continuity and progress of the organization. The results of the structural equations also showed that the resilience model has a favorable fit in government organizations. Extended abstract Introduction Organizational resilience is a subcategory of positive organization and today, despite the attention to the term resilience and its vastly uses in various fields, there is a limited theoretical and practical understanding of this concept in its evaluation and measurement in relation to organizational resilience (Rafiyan et al, 2011). Resilience has been studied in many different fields, including management, security, ecology, psychology, disaster management, organization management, engineering, etc., but there is no definition acceptable in any field (Bergström et al., 2015). Resilience in the organizational field is not an exception to this rule. Researchers such as Alblas & Jayaram (2015), Alblas & Jayaram (2015), Chand & Loosemore (2016), and Hu et al, (2018) have considered organizational resilience as the ability to deal with changes, internal and external risks and impulses, and some such as Linnenluecke & Griffiths (2010), Alexiou (2014), and Ortiz & Bansal (2015) have defined resilience as a capacity to deal with changes, risk and impulses, and some others have considered it as an essential asset for the organization when it faces a risk (Ruiz-Martin et al, 2018). Rai et al, (2021) have considered organizational resilience as a way to deal with successive environmental crises. Organizations try to prepare themselves for all kinds of crises in advance and without fear by planning and making necessary preparations against all kinds of crises. Resilience means developing new competencies and broad capabilities to sustain momentum by creating new opportunities. Also, in this definition, resilience is considered as success due to the ability to invest in challenges and unexpected changes. According to another definition, resilience is the ability of a person or organization to quickly design and implement positive adaptive movements coordinated with an emergency situation, in such a way as to bear little pressure. Others define it as an essential asset for the organization when it faces a risk (Ruiz-Martin et al, 2018). Therefore, the concept of organizational resilience includes resistance, compromise and adaptation as the main assets and refers to shock absorption, reorganization and learning, etc. as the main capacities. Resilient organizations are also organizations that are able to deal with unforeseen shocks such as financial crises and globalization of competition, etc., and in some cases, it makes the organization prosper. In fact, resilience can be considered a necessity in recent centuries. Today's societies are increasingly facing emergency and crisis situations that challenge social and economic stability, and they rely on the services and employment provided by organizations to achieve resilience, because organizational resilience and societies' resilience are two sides of the same coin, and this means that if organizations are not ready to respond to emergencies and crises, then societies will not be ready either (Stephenson, 2010). Resilient organizations are organizations that can overcome crises with low costs due to their preparation and planning and high flexibility. All organizations should consider resilience against threats and environmental changes as one of their important and strategic goals and consider achieving this important goal. Therefore, the present research, with regard to the earthquake that happened in some cities of Kermanshah province in 2016 and caused a lot of money and lives (about 2,000 dead and 10,000 injured), seeks to, by designing a model of resilience in the government organizations of this province, help to increase their strength and readiness, which will reduce the amount of damages to the lowest possible level in the repetition of such events. The main question of the current research is: what are the characteristics of the model of resilience in government organizations of Kermanshah province? Theoretical framework The word resilience was presented for the first time by Holling in 1973 in a study titled resilience and stability of ecological systems. Then this term has been used for various other forms of resilience such as individual, organizational, supply chain, etc. If we consider people as a part of societies, resilience depends on societies and is not limited to social relations and social structure. One way to create resilience is to support people to create favorable social relations through technical resilience interventions. These interventions can include the development of services, the use of resources in communities, and the creation of new social and operational values for them. The origins and meaning of resilience as a scientific concept is ambiguous (Friend & Moench, 2013). The concept of resilience is used everywhere in both physical and social sciences. However, it has different meanings at different times. In recent years, resilience has become more common in both scientific and political discourses (Meerow & Newell, 2015). In fact, there are many meanings and concepts for resilience, there are wide definitions and interpretations of resilience, many of which are taken from the academic community of ecological systems. Originally, resilience is related to hazard studies, materials science and environmental studies, and also is a concept that has been used freely and enthusiastically by a wide range of policy makers, practitioners and academic researchers in the last decade. Although the actual meaning associated with this term varies accordingly, there are actually a large number of conceptual frameworks for resilience that are increasing day by day, reflecting its complex and multidimensional nature (Breetzke & Pearson, 2017). In relation to organizational resilience, it can be acknowledged that this category is a subcategory of positive organization, but today, even with attention to the term resilience and its many uses in various fields, especially in relation to organizational resilience, there is a limited theoretical and practical understanding of this concept in its evaluation, measurement or creation (Rafiyan, 2011). In general, two views have been mentioned in relation to organizational resilience, one of which defines resilience as the ability to return to the normal situation in the face of adversity, conflict, failure or positive events, and the other includes the development of new capabilities and the ability to expand simultaneously or even create new opportunities. Vogest also acknowledges that a resilient organization is considered to be able to maintain positive settings under challenging conditions (Hillmann & Guenther, 2021). Therefore, resilience is a necessity to respond to threats and also to adapt positively in the face of challenging conditions, accept opportunities, and provide sustainable performance (Duchek, 2020). Methodology The current research is developmental-applicative in terms of its purpose, and descriptive-survey in terms of data collection according to the nature of the research. In order to collect data in the qualitative part, in-depth semi-structured interviews were used, which were selected through purposeful and snowball sampling. The statistical population of the research included managers who are in government organizations of Kermanshah province and had at least 10 years of experience. The statistical population of quantitative section is a small part of the employees of the government organizations of Kermanshah province, whose number is 5641 people. Sampling in the quantitative section is 5 to 15 times the number of observed or apparent components (Homan, 2017). Considering that 33 primary components have been extracted, at least 190 questionnaires should have been distributed. The sampling method in this research was cluster. As a result, 400 questionnaires were distributed, of which 396 were usable. Discussion and Results The researcher analyzes the data in depth and presents them in the form of Strauss & Corbin theory (2008), and the main purpose of the research is to understand the situation. In this research process, after determining the core category, other categories are drawn in the form of a paradigmatic pattern around the core category. By using selective coding, the relationship between the categories has been identified and the conceptual model has been presented in an integrated manner. After making sure that there is a reasonable correlation and relationship between the observations and the related local variables, it is time for another important analysis, through which the statistical hypotheses of the current research will be investigated. In this part, the overview of the research model was examined first, and then each hypothesis was investigated separately. As it is clear in the previous figures, the value of t among the causal conditions, the central phenomenon, the consequences and the environmental background is higher than 1.96, which indicates the significance of the relationships between them. This shows that the model extracted in government organizations of Kermanshah is a suitable model. Also, the coefficients between the mentioned factors are all positive. Therefore, it is positive and direct between them. Also, in Table 13, the estimated coefficients and explained variance of the research variables are reported.   Conclusion The purpose of this research is to study resilience in government organizations of Kermanshah province. Therefore, while examining the concept of resilience; antecedents, environmental background and consequences of organizational resilience have been identified and a model of resilience has been presented in government organizations of Kermanshah province. After designing the research model, a number of interviewees were asked to express their opinions regarding the presented model so that required corrections can be made if necessary. The findings of the research were evaluated and reviewed by five university professors and three PhD. students, and necessary corrections were made while receiving opinions. In the following, explanations are given about each of the factors of the model. Based on the research model, "organizational resilience" as a central category based on the causal conditions of "individual, group and organizational factors" and taking into account the role of the government, economic and political factors and electronic platforms as a pattern is realized and leads to the creation of continuity in the organization and the progress of the organization. The research findings are in line with the results of Ruiz-Martin et al, (2018) and Lengnick-Hall et al, (2011)

Chestnut wood in compression perpendicular to the grain : non-destructive correlations for test results in new and old wood

This paper addresses the evaluation of the compressive properties of chestnut wood under compression perpendicular to the grain, using destructive and non-destructive methods. Three non-destructive methods (ultrasonic testing, Resistograph and Pilodyn) are proposed and the possibility of their application is discussed based on the application of simple linear regression models. Timber specimens were tested up to failure, divided in two different groups for assessing a possible load history related degradation, namely New Chestnut Wood (NCW), never been used structurally, and Old Chestnut Wood (OCW), obtained from structural elements belonging to ancient buildings. The specimens were also divided into four groups according to the orientation of annual growth rings towards load and wave propagation direction. The results show, in general, good correlations between compression strength and stiffness with non-destructive techniques via ultrasonic testing, Resistograph and Pilodyn. However, the orientation of the loading direction with respect to the annual growth rings must be taken into account. This conclusion, and the observation that NCW and OCW shows correlations and regression models usually different, add additional complexity to the quantitative use of non-destructive evaluation techniques for the assessment of the mechanical behaviour of timber elements.Fundação para a Ciência e Tecnologia (FCT) - SFRH/BD/ 5002/200