Structural performance of timber frame joints - Full scale tests and numerical validation

S.A. Aejaz,A.R. Dar,J.A. Bhat 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.4

The force resisting ability of a connection has direct implications on the overall response of a timber framed structure to various actions, thereby governing the integrity and safety of such constructions. The behavior of timber framed structures has been studied by many researchers by testing full-scale-connections in timber frames so as to establish consistent design provisions on the same. However, much emphasis in this approach has been unidirectional, that has focused on a particular connection configuration, with no research output stressing on the refinement of the existing connection details in order to optimize their performance. In this regard, addition of adhesive to dowelled timber connections is an economically effective technique that has a potential to improve their performance. Therefore, a comparative study to evaluate the performance of various full-scale timber frame Nailed connections (Bridled Tenon, Cross Halved, Dovetail Halved and Mortise Tenon) supplemented by adhesive with respect to Nailed-Only counterparts under tensile loading has been investigated in this paper. The load-deformation values measured have been used to calculate stiffness, load capacity and ductility in both the connection forms (with and without adhesion) which in turn have been compared to other configurations along with the observed failure modes. The observed load capacity of the tested models has also been compared to the design strengths predicted by National Design Specifications (NDS-2018) for timber construction. Additionally, the experimental behavior was validated by developing non-linear finite element models in ABAQUS. All the results showed incorporation of adhesive to be an efficient and an economical technique in significantly enhancing the performance of various timber nailed connections under tensile action. Thus, this research is novel in a sense that it not only explores the tensile behavior of different nailed joint configurations common in timber construction but also stresses on improvising the same in a logical manner hence making it distinctive in its approach.

Breakdown Strength Estimation of Non-Cellulosic Insulating Materials Used in Electrical Power Equipment

Singh, Sakshi,Mohsin, Mirza Mohd.,Masood, Aejaz The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.6

Breakdown of solid insulating materials in power equipment could result in undesired outages and replacements, and may be due to an increase in electric stress on the material. Therefore, it is necessary to conduct a proper diagnosis of materials before their practical use. In this work, a few inherent properties of different non-cellulosic insulating materials, such as Nomex, Teflon, laminated Nomex, glass bonded mica, epoxy resin bonded mica paper, and epoxy resin bonded fiberglass, have been evaluated by performing non-destructive dielectric diagnostic measurements, and an attempt has been made to correlate these basic parameters to evaluate the breakdown strength (BDS). An equation has been proposed using a basic theory which defines the correlation between the BDS, dielectric constant, dissipation factor, sample thickness, and volume resistivity. The results obtained from the equation are also compared with the experimental values. The suggested equation will be helpful to predict the BDS of any non-cellulosic material without experimentation in the laboratory.

Breakdown Strength Estimation of Non-Cellulosic Insulating Materials Used in Electrical Power Equipment

Sakshi Singh,Mirza Mohd. Mohsin,Aejaz Masood 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.6

Breakdown of solid insulating materials in power equipment could result in undesired outages and replacements, and maybe due to an increase in electric stress on the material. Therefore, it is necessary to conduct a proper diagnosis of materialsbefore their practical use. In this work, a few inherent properties of different non-cellulosic insulating materials, such asNomex, Teflon, laminated Nomex, glass bonded mica, epoxy resin bonded mica paper, and epoxy resin bonded fiberglass,have been evaluated by performing non-destructive dielectric diagnostic measurements, and an attempt has been made tocorrelate these basic parameters to evaluate the breakdown strength (BDS). An equation has been proposed using a basictheory which defines the correlation between the BDS, dielectric constant, dissipation factor, sample thickness, and volumeresistivity. The results obtained from the equation are also compared with the experimental values. The suggested equationwill be helpful to predict the BDS of any non-cellulosic material without experimentation in the laboratory.

Loss of Expression and Aberrant Methylation of the CDH1 (E-cadherin) Gene in Breast Cancer Patients from Kashmir

Asiaf, Asia,Ahmad, Shiekh Tanveer,Aziz, Sheikh Aejaz,Malik, Ajaz Ahmad,Rasool, Zubaida,Masood, Akbar,Zargar, Mohammad Afzal Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Aberrant promoter hypermethylation has been recognized in human breast carcinogenesis as a frequent molecular alteration associated with the loss of expression of a number of key regulatory genes and may serve as a biomarker. The E-cadherin gene (CDH1), mapping at chromosome 16q22, is an intercellular adhesion molecule in epithelial cells, which plays an important role in establishing and maintaining intercellular connections. The aim of our study was to assess the methylation pattern of CDH1 and to correlate it with the expression of E-cadherin, clinicopathological parameters and hormone receptor status in breast cancer patients of Kashmir. Materials and Methods: Methylation specific PCR (MSP) was used to determine the methylation status of CDH1 in 128 invasive ductal carcinomas (IDCs) paired with the corresponding normal tissue samples. Immunohistochemistry was used to study the expression of E-cadherin, ER and PR. Results: CDH1 hypermethylation was detected in 57.8% of cases and 14.8% of normal adjacent controls. Reduced levels of E-cadherin protein were observed in 71.9% of our samples. Loss of E-cadherin expression was significantly associated with the CDH1 promoter region methylation (p<0.05, OR=3.48, CI: 1.55-7.79). Hypermethylation of CDH1 was significantly associated with age at diagnosis (p=0.030), tumor size (p=0.008), tumor grade (p=0.024) and rate of node positivity or metastasis (p=0.043). Conclusions: Our preliminary findings suggest that abnormal CDH1 methylation occurs in high frequencies in infiltrating breast cancers associated with a decrease in E-cadherin expression. We found significant differences in tumor-related CDH1 gene methylation patterns relevant to tumor grade, tumor size, nodal involvement and age at diagnosis of breast tumors, which could be extended in future to provide diagnostic and prognostic information.

Lack of Association of a Common Polymorphism in the 3'-UTR of Interleukin 8 with Non Small Cell Lung Cancer in Kashmir

Bhat, Imtiyaz Ahmad,Pandith, Arshid A.,Bhat, Bashir A.,Naykoo, Niyaz A.,Qasim, Iqbal,Rasool, Roohi,Aziz, Sheik Aejaz,Shah, Zafar Amin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Background: Chronic inflammation is considered as an important factor in the pathogenesis of lung cancer. The presence of inflammatory cells and higher levels of pro-inflammatory cytokines in the tumor microenvironment and their surrounding tissues is gaining much importance in research. Materials and Methods: One hundred ninety NSCLC cases and 200 age, smoking and sex matched controls were evaluated for association of IL-8 -251 (rs4073) and IL-8 -845 (rs2227532) in our population. Restriction fragment length polymorphism (RFLP) was used followed by direct sequencing for the detection of SNPs. Results: The IL-8 -845 polymorphism was not found in our population. No significant association was observed between the IL-8 -251 AT genotypes and IL-8 -25 AA genotypes and NSCLC (p=0.05) in our population. The IL-8 -251 A allele was also non-significant (p=0.05) in NSCLC patients. Conclusions: In conclusion, this report reveals lack of association between IL-8 - 251 A/T polymorphism and NSCLC in our Kashmir Valley population.

Association Between p16, hMLH1 and E-cadherin Promoter Hypermethylation and Intake of Local Hot Salted Tea and Sun-dried Foods in Kashmiris with Gastric Tumors

Mir, Manzoor R.,Shabir, Nadeem,Wani, Khursheed A.,Shaffi, Sheikh,Hussain, Ishraq,Banday, Manzoor A.,Chikan, Naveed A.,Bilal, S.,Aejaz, Sheikh Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

The aim of this study was to evaluate the methylation status of three important cancer related genes viz. p16, E-cadherin and hMLH1 promoters and to associate the findings with specific dietary habits in Kashmiris, a culturally distinct population in India, with gastric cancer. The study subjects were divided into three age groups viz. 0-30yrs ($1^{st}$), 31-60yrs ($2^{nd}$) and 61-90yrs ($3^{rd}$). A highly significant association between the intake of local hot salted tea in $2^{nd}$ (p=0.001) and $3^{rd}$ (p=0.009) age groups was observed with the promoter hypermethylation of E cadherin. Again a highly significant association between the aberrant methylation of hMLH1 (p=0.000) and p16 (p=0.000) promoters and the intake of local hot salted tea was observed in the $2^{nd}$ age group of gastric cancer patients. The intake of sun-dried food was also significantly associated with the promoter hypermethylation of E cadherin (p=0.003) and p16 (p=0.015) genes in $3^{rd}$ age group. The results of the present study suggest a close association between the aberrant methylation of p16, E-cadherin and hMLH1 promoters and the intake of local hot salted tea and sun-dried foods in Kashmiri population.