CHARACTERIZING LIQUEFACTION RESISTANCE OF AGED SAND DEPOSITS

Presented in this dissertation are the results of various studies conducted to characterize the liquefaction resistance of aged natural deposits. The data considered include laboratory and field test results from sites in five countries with particular focus on multiple locations in the South Carolina Coastal Plain. A new liquefaction potential map of the peninsula of Charleston, South Carolina, is presented. Liquefaction potential is expressed in terms of the liquefaction potential index (LPI) developed by Iwasaki et al. and calculated using 44 cone penetration test (CPT) profiles. The CPT profiles are supplemented with information from the 1:24,000 scale geologic map by Weems and Lemon, several first-hand accounts of liquefaction and ground deformation that occurred during the 1886 Charleston earthquake, and liquefaction probabilities determined by Elton and Hadj-Hamou based on standard penetration tests. Nearly all of the cases of liquefaction and ground deformation occurred in the Holocene to late Pleistocene beach deposits that flank the higher-ground sediments of the Wando Formation. To match the observed field behavior, a deposit resistance correction factor of 1.8 is applied to the cyclic resistance ratios calculated for the 100,000-year-old Wando Formation. The liquefaction susceptibility of four clayey soils in the Charleston is examined using primarily CPT measurements. The liquefaction susceptibility criteria by Robertson and Wride appear to be adequate for the three younger clayey soils, which are Holocene and Pleistocene estuarine deposits. On the other hand, as noted previously by Li et al., the Robertson and Wride criteria incorrectly predict susceptible for the Tertiary-age clayey soil, called the Cooper Marl. A new CPT-based liquefaction susceptibility chart that better predicts susceptibility of clayey soils is presented. Data from over 30 sites in 5 countries are analyzed to develop updated factors for correcting liquefaction resistance of aged sand deposits. Results of cyclic laboratory tests on relatively undisturbed and reconstituted specimens suggest an increase in liquefaction resistance of 12% per log cycle of time and a reference age of about 2 days. Laboratory and field test results combined with cyclic resistance ratio (CRR) charts suggest an increase in liquefaction resistance of 13% per log cycle of time and a reference age of 23 years. A reference age of 23 years seems reasonable for the commonly used CRR charts derived from field case history data. Because age of natural deposits is often difficult to accurately determine, a relationship between measured to estimated shear-wave velocity ratio (MEVR) and liquefaction resistance correction factor is also derived directly from the compiled data. Also presented are the results of seismic crosshole tests conducted at the Clemson Research and Education Center (CREC) site, underlain by a beach sand deposit with age of about 100,000 years old. The crosshole shear-wave velocity measurements agree well with values obtained by seismic downhole CPT tests. Measured to estimated shear-wave velocity ratios (MEVR) are used to further characterize the CREC site. A procedure for back-calculating deposit resistance factor (KDR) based on field performance data is proposed. In the procedure, the percent of liquefied area is estimated from field performance data and/or from MEVR data. The KDR back-calculation procedure is applied to the CREC site and the Charleston peninsula. The back-calculated KDR values for the Wando Formation on the Charleston peninsula and at the CREC site are 1.7 and 1.9, respectively. The results provide strong support for the proposed procedure

A genre analysis of reprint request emails written by EFL and physics professionals

The present study aimed to analyze reprint request e-mail messages written by postgraduates (MA students) of two fields of study, namely Physics and EFL, to realize the differences and similarities between the two email types. The results showed that the two corpora were much alike at the level of move schemata while there were some differences concerning strategies and microstructural features. The results showed that the two corpora were much alike at the level of move schemata while there were some differences concerning strategies and microstructural features. The email writers within each discipline were affected by their previously learned texts and the physics group was affected by the conventions of Persian letter writing. The email writers within each discipline were affected by their previously learned texts and the physics group was affected by the conventions of Persian letter writing<br /

(Dis)agreements in Iranians’ internet relay chats

The present study on politeness is an attempt to examine (dis)agreeing strategies utilized by EFL learners while chatting on the internet. Subjects of the study were forty male and thirty-three female Iranian natives whose internet relay chat (IRC) interactions, composed of 400 excerpts, were collected between December 2007 and September 2008. Data analysis was based on the general taxonomy of politeness strategies suggested by Brown and Levinson (1987) which is the baseline of many politeness studies today. The results indicate that IRC is a mode of communication whose characteristics are typically different from face-to-face and real-life conversational settings. Some common face threatening acts (FTAs) like &lsquo;direct disagreements&rsquo; are performed widely in chat channels. Furthermore, gender-oriented differences were found not to be statistically significant on the internet

Randomized controlled trial on drowning prevention for parents with children aged below five years in Bangladesh: a study protocol

Background: Drowning is the third leading cause of death for children aged 0–4 years in many Asian countries, and is a serious but neglected health problem in low and middle-income countries like Bangladesh. The aim of the study is to outline the study protocol of a trial to test the efficacy of a mobile coach based intervention for the prevention of childhood drowning. Method/design: A two-arm cluster randomized community trial will be conducted to test the efficacy of the mobile coach intervention for childhood drowning on parents with children below five years of age and compared to an assessment only control group. A total of 1680 parents in the villages with children aged below five years of age will participate. The village will be used as a randomized unit, randomly assigned to an intervention group (N = 840) receiving the mobile coach based intervention or an assessment only control group (N = 840). An individualized mobile coach intervention based on the demographic data and the individual will be developed, and SMSs, audio messages, videos and images about childhood drowning will be sent to the participants of the intervention group over a period of six months. The participants will receive per week one text message (SMS) and image and one video and audio text per month. The primary outcome measure will be increased knowledge and safety awareness, and behaviour practice about childhood drowning assessed at the six-month follow-up, and the secondary outcome measure will be the reduced incidence of childhood drowning in Bangladesh. The study assistants conducting the baseline and the follow-up assessments will be blinded regarding the group assignment. Discussion: This is the first study testing a fully mobile coach intervention for childhood drowning prevention in Bangladesh. It is hoped that the programme will offer an effective and inexpensive way to prevent childhood drowning among children aged below five years and also increase the awareness of parents concerning the risks to their children from drowning

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Security Incident Handling and Organisational Models

This master thesis focuses on calculating the efficiency in handling security incidents and is of main interest for personnel dealing with security organisation, security management and security policies. The results achieved by this thesis can be used to get a better insight into the efficiency in handling security incidents in a hierarchical and matrix organisational model. One can also use the software prototype, developed during this thesis, to calculate the efficiency of other organisational models. Any changes like merging or dividing companies or department will create a new state in the organisation. By mapping the current organisations chart, at any time, our prorotype can calculate/compute the efficiency of the organisation in the most efficient way within few seconds

Security Incident Handling and Organisational Models

This master thesis focuses on calculating the efficiency in handling security incidents and is of main interest for personnel dealing with security organisation, security management and security policies. The results achieved by this thesis can be used to get a better insight into the efficiency in handling security incidents in a hierarchical and matrix organisational model. One can also use the software prototype, developed during this thesis, to calculate the efficiency of other organisational models. Any changes like merging or dividing companies or department will create a new state in the organisation. By mapping the current organisations chart, at any time, our prorotype can calculate/compute the efficiency of the organisation in the most efficient way within few seconds