A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel

Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement

A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel

Peer reviewedPublisher PD

A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel

Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement

Pengelolaan Objek Wisata Sejarah Kerajaan Siak di Kabupaten Siak

Siak as a growing area, and has always been in the campaigning slogan by Siak Regent Drs. H. Syamsuar, M.Si namely "Siak The Truly Malay" or Siak indeed wither area. Siak has a myriad of attractions that can be enjoyed by the community, both domestically and abroad, namely historical tourism, cultural tourism, culinary tourism, nature tourism and agrotourism. In realizing the slogan "Siak The Truly Malay" Siak Regency presents various panoramic underlying siak district as an area known as the Malay region. One of them is the number of heritage - historical remains a silent witness and proof that the district is indeed melayu area.Under these conditions, formulated the problem of how the Object Management History Siak Kingdom as well as the factors that meghambat in the management of historical attractions in Siak. This study uses the theory of Natural Luther Gulick in 2004 to find out how the planning, organization, coordination, budgeting, and oversight in the management of attraction Siak royal history. Qualitative research with descriptive method. Researchers are trying to reveal the facts in accordance with the reality. This study did not look for or explain the relationship, not test hypotheses or make predictions. Data will be explained by what so we get an understanding.Based on the results of research and discussion, it can be concluded that the management of historical attractions in the category Kingdom of Siak still not optimal. Lack of good planning, organization, coordination, budgeting and supervision make the management has not run optimally. The lack of knowledge and curiosity of employees regarding the management of historical attractions and other aspects related to the management of historical attractions making them incapable in preparing and planning for management of historical attractions. Lack of supervision and evaluation conducted by the Office of the performance and duties of the employees that make the employees do not feel responsible for the management of historical attractions.Keyword: Management, Histor

Strategi Pengembangan Ekowisata Mangrove di Kecamatan Sungai Apit Kabupaten Siak

Tourism industry plays an important role in the country's development. In addition, tourism also has an influence on the revenue for local government. Siak is one of the areas in Riau Province which has variety tourist attractions. One of tourist attractions is Mangrove Ecotourism in the District of Sungai Apit. Mangrove Ecotourism has enormous potential to develop. Therefore, a developmental strategy is needed in order to develop and increase the interest of tourists to visit Mangrove Ecotourism.Theory are used in this research is management strategy of Elitan and Anatan and analysis are used is SWOT analysis. The method used in this research is descriptive qualitative. The data were collected through interviews, observations and documentations. The technique of data analysis which used in this research was qualitative method and descriptive approachment.From the results, it can be seen that the develop Mangrove Ecotourism in the District Sungai Apit done the using technology strategy, innovation strategy and operating strategy. SWOT analysis is then performed to determine what strategies are suitable for the developmet of Ecotourism Mangrove in the District Sungai Apit

Pengawasan Pada Objek Wisata Danau Raja Di Kecamatan Rengat Kabupaten Indragiri Hulu Provinsi Riau

Supervision is all efforts and activities to identify and assess the actual reality on the implementation of tasks or activities are in accordance with rules or not. Supervision towards tourist attraction of Danau Raja is done directly by government, youth section, sports section and tourism section. In addition, supervisor coordinated with the Organization of Pancasila Youth through the MOU (Memorandum Of Understanding). However, until now there are some extortions in tourist areas by use government name. The purpose of this study is to de determine the extent of supervision in Danau Raja and to identify the obstacle factor towards overseeing Danau Raja tourism in Rengat, Indragiri Hulu, Riau Province.Based on the theory of Manullang, supervisory process of every objects are consists of phases, setting standards, conducting assessment and conduct corrective action the method of this study is descriptive qualitative with snowball sampling technique. The informants of this study are the Head of Tourism, Head of Development Section in tourist attraction and Head of tourist attraction charm, Pancasila Youth section, merchants and visitors.The result of the data analysis by descriptive qualitative, supervisory standards of Danau Raja carried out by the department based on the main objectives and functions that has been set, the action assessment made officially through the two officers who works to maintain the cleanliness of the tourism are of Danau Raja and it coordinates with the Organization of Pancasila Youth by used MOU authority to manages the entire facility of tourist attraction of Danau Raja along fee collection agency, then the government and The Organization of Pancasila Youth held a corrective action by conducting socialization and appeal to visitors or merchants in Danau Raja to maintain the environtment. There are several factors inhibiting the supervision of Danau Raja that are government regulations about tourism until now has not implemented, the lack of funds allocated for insfrastructure improvements, the lack of human resources professionals especially in the field of supervision as well as people who are less concerned to maintain the environment of danau Raja

Mobilitas Migran Pedagang Kaki Lima Sumatera Barat di Pasar Mandau Duri Provinsi Riau

A Migration is a population movement aimed to maintain from one place to another place exceed the limits of politics/country or part of administrative limits one of the countries. A Migration defines as a permanent movement from one area to another area. People who do migration called Migrant. This study is about “The Migrants mobility of west Sumatera retailers at Mandau Duri market in Riau Province”. The purpose of this study is to find out the push and pull factor of west Sumatera retailers at Mndau Duri market and also to find out a socio-economic situation of the migrants at Mandau Duri market. The method that used in this research is a qualitative research. A qualitative research is a research which revals the facts, situation and focused on social phenomena. The data collection technique used observation, questionnaire, interview and documentation techniquese based on the result, the number of the migrants of west sumatera retailers at Mandau Duri market was 300 vendors. From the interview result a researcher found the fact about the migrants incneased on income in the destination area rather than in the origin area. The migrant push factors is the family and williners aimed to change the life to be better

Looking downstream: the role of cyclic AMP-regulated genes in axonal regeneration

Elevation of intracellular cyclic AMP (cAMP) levels has proven to be one of the most effective means of overcoming inhibition of axonal regeneration by myelin-associated inhibitors such as myelin-associated glycoprotein, Nogo, and oligodendrocyte myelin glycoprotein. Pharmacological manipulation of cAMP through the administration of dibutyryl cAMP or rolipram leads to enhanced axonal growth both in vivo and in vitro, and importantly, upregulation of cAMP within dorsal root ganglion neurons is responsible for the conditioning lesion effect, which indicates that cAMP plays a significant role in the endogenous mechanisms that promote axonal regeneration. The effects of cAMP are transcription-dependent and are mediated through the activation of protein kinase A and the transcription factor CREB. This leads to the induction of a variety of genes, several of which have been shown to overcome myelin-mediated inhibition in their own right. In this review, we will highlight the pro-regenerative effects of arginase I, interleukin-6, secretory leukocyte protease inhibitor, and metallothionein-I/II, and discuss their potential for therapeutic use in spinal cord injury