Behaviour of undercut anchors subjected to high strain rate loading

The increase in global terrorism has culminated in the protection of high profile buildings and monuments against the effects of blast loading - a high strain rate loading event. Depending on the design basis threat, the level of protection can range from façade and fenestration upgrade to retrofit of the structural systems. Post-event surveys after the Oklahoma City Bombing and other similar events indicated widespread window glass damage. Most of the injuries reported were attributed to the glass shards, especially in buildings proximate to the target building. Thus, the least protection recommended for buildings is to retrofit window glass against glass shard injury. When the window retrofit consists of anti-shattered film anchored to the window frames, blast loads are transferred to the window frames and ultimately to the structure of the façade through discrete window retention steel anchors. A lot of research has been conducted to investigate the response of upgraded windows however little research is available on the load transfer from the window frames to the façade structure through the window retention anchors. This paper presents results from a finite element analysis program to investigate the tensile behaviour of post-installed undercut anchors under high strain rates. Strain rates varying from 10-5 to 103 s-1 were applied to single undercut steel anchors embedded in concrete blocks. Anchor diameters of 12 mm, 16 mm and 20 mm with various embedment depths were selected for the analyses. The analyses results show increased tensile capacity of undercut anchors with increase in strain rate. The maximum dynamic increase factor for tension of undercut anchors at strain rate of 103 s-1 was about 1.60 for the anchors investigated

GAMBARAN PATOLOGI ANATOMI PADA BABI LANDRACE SUSPECT AFRICAN SWINE FEVER (ASF) DI KABUPATEN KUPANG

African Swine Fever (ASF) is a viral disease that attacks pigs and to date has caused many pig deaths in Kupang Regency. ASF is caused by a double-stranded DNA virus from the Asfivirus genus and the Asfarviridae family. This research aims to determine the anatomical pathology of the swine landrace suspect ASF. Organ samples were collected from two male landrace pigs and two female landrace pigs, aged 7 months, from Oeltuah Village, Taebenu District and Tarus Village, Central Kupang District, Kupang Regency, NTT. Clinical examinations were carried out on sick animals that were found during the investigation, then necropsied on the dead animals were carried out and continued with anatomical pathology examinations at the Pathology Laboratory, Faculty of Veterinary Medicine, Nusa Cendana University. Anatomical pathology examinations are carried out by observing changes in the structure and appearance of the organs. The necropsy results showed sub-cutaneous ecchymosis hemorrhage in the abdomen, limbs and ears, gastric, intestinal and hepatic hemorrhage, hemorrhagic lymphadenitis in mesenteric lymph nodes, hyperemic splenomegaly, pteckie hemorrhage in the renal capsule,, multifocal hemorrhage in the renal medulla and pulmonary lobe. Based on the observation of clinical symptoms and changes in anatomical pathology, it can be concluded that the death of pigs was suspected to be caused by the suspect ASF

Intestinal Microbiota Composition of Interleukin-10 Deficient C57BL/6J Mice and Susceptibility to Helicobacter hepaticus-Induced Colitis

The mouse pathobiont Helicobacter hepaticus can induce typhlocolitis in interleukin-10-deficient mice, and H. hepaticus infection of immunodeficient mice is widely used as a model to study the role of pathogens and commensal bacteria in the pathogenesis of inflammatory bowel disease. C57BL/6J Il10[superscript −/−] mice kept under specific pathogen-free conditions in two different facilities (MHH and MIT), displayed strong differences with respect to their susceptibilities to H. hepaticus-induced intestinal pathology. Mice at MIT developed robust typhlocolitis after infection with H. hepaticus, while mice at MHH developed no significant pathology after infection with the same H. hepaticus strain. We hypothesized that the intestinal microbiota might be responsible for these differences and therefore performed high resolution analysis of the intestinal microbiota composition in uninfected mice from the two facilities by deep sequencing of partial 16S rRNA amplicons. The microbiota composition differed markedly between mice from both facilities. Significant differences were also detected between two groups of MHH mice born in different years. Of the 119 operational taxonomic units (OTUs) that occurred in at least half the cecum or colon samples of at least one mouse group, 24 were only found in MIT mice, and another 13 OTUs could only be found in MHH samples. While most of the MHH-specific OTUs could only be identified to class or family level, the MIT-specific set contained OTUs identified to genus or species level, including the opportunistic pathogen, Bilophila wadsworthia. The susceptibility to H. hepaticus-induced colitis differed considerably between Il10[superscript −/−] mice originating from the two institutions. This was associated with significant differences in microbiota composition, highlighting the importance of characterizing the intestinal microbiome when studying murine models of IBD.National Institutes of Health (U.S.) (Grant NIH P01-CA26731)National Institutes of Health (U.S.) (Grant NIH P30ES0026731)National Institutes of Health (U.S.) (Grant NIH R01-OD011141

Tensile behaviour of adhesive anchors under different strain rates

The use of post-installed anchors in connecting window frames to concrete elements has seen a dramatic increase in the post September-11 era. However, the behaviour of post-installed anchors under high strain rates of loading corresponding to blast loading transferred from retrofitted windows has not been extensively investigated. This paper presents the results of a finite element analysis to investigate the tensile behaviour of adhesive anchor embedded into concrete at strain rates ranging from 10 −5 s −1 to 10 3 s −1 . The adhesive anchor to concrete numerical models were validated with results from a drop-mass experimental test and then used to investigate the tensile capacity and the corresponding dynamic increase factor (DIF)at the different strain rates (ε̇)and for different anchor diameters (d)and embedment depths (h ef ). Failure modes and ultimate capacity under different rates of loading of the adhesive anchor were examined. The results show that the increase in the strain rate increased the tensile capacity and the DIF. The adhesive anchors exhibited maximum DIF of 3.77 under tensile load for the 19.1-mm anchor diameter with 76.2 mm embedment depth at the high strain rate of 10 3 s −1 . The strain rate affects the failure mode for the adhesive anchor; the failure mode transitions from concrete cone failure to combined cone-bond failure and then to steel failure as the strain rate increased