Crack Evolution from Ballistic Threats in Laminated Glass

2014 ◽  
Vol 608 ◽  
pp. 316-321
Author(s):  
Chidchanok Chaichuenchob ◽  
Pavadee Aungkavattana ◽  
Sujarinee Kochawattana
Keyword(s):  
Laminated Glass ◽  
Crack Evolution ◽  
Ballistic Performance ◽  
Cross Sectional ◽  
Typical Structure ◽  
Transparent Armor ◽  
Water Jet Cutting ◽  
Level 3 ◽  
Radial Cracks ◽  
Armor System

Laminated glass is widely used as safety material and transparent armor. Its typical structure is sandwich layers of glass sheets and Poly Vinyl Butyral (PVB) film. It is known that the ballistic performance of the laminated glass is highly influenced by its configuration. In this study, the damages from ballistic threats at level 3 according to NIJ standard in laminated glass were investigated. Laminated glass with various configurations was fabricated using rolling and vacuum techniques. The ballistic tests were performed and the resulting radial cracks, which intercept several circumferences on each sheet of glass, were quantified. It was found that the number of crack bifurcation and the configurations of laminated glass were significantly correlated. The tested specimens were also cross-sectional observed using water jet cutting machine so that, their ballistic penetration could be determined. The analysis results provide better understanding of crack evolution, leading to improved new transparent armor system.

scholarly journals Discharge against medical advice from the emergency department in a university hospital

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Feras H. Abuzeyad ◽  
Moonis Farooq ◽  
Salah Farhat Alam ◽  
Mudhaffar Ismael Ibrahim ◽  
Luma Bashmi ◽  
...  
Keyword(s):  
Emergency Department ◽  
Cross Sectional Study ◽  
Small Sample ◽  
Medical Advice ◽  
University Hospital ◽  
High Risk Population ◽  
Cross Sectional ◽  
Against Medical Advice ◽  
Level 3 ◽  
Collection Form

Abstract Background Patients discharged against medical advice (DAMA) act as a high-risk population for the Emergency Department (ED), regardless of their presentations, and can pose a serious burden for the hospital. This study examines the prevalence, demographic and clinical characteristics, reasons, and clinical outcomes of a small sample of DAMA patients in a teaching university hospital, including readmission, morbidity, and mortality. Methods A prospective, descriptive cross-sectional study was conducted in the ED of King Hamad University Hospital (KHUH) with 98,992 patient visits during a 1-year period from June 2018 to June 2019. Consenting DAMA patients were asked to complete a data collection form. Results Patients (n = 413) had a mean age of 44.1 years with a female majority (57.1%). The majority were categorized as triage level-3 (87.7%). The main reasons for DAMA included refusal of the procedure/operation (23.2%), long ED waiting time (22.2%), subjective improvement with treatment (17.7%), and children at home (14.8%), whereas the least selected reason was dissatisfaction with medical care (1.2%). Follow-up of DAMA patients revealed that 86 cases (20.8%) were readmitted to the ED within 72 h of which 41 (47.7%) cases were morbidity and 2 (2.3%) were mortality. Marital status was a predictor of DAMA patients who revisit the ED within 72 h. Conclusion The results act as a pilot study to examine a small sample of DAMA patients’ characteristics, diagnosis, and ED revisits. Hospitals should investigate further the DAMA population on a larger scale, reasons for refusing procedures, and utilize this knowledge to improve the healthcare process.

scholarly journals A Study on Knowledge Towards Brain Death among Residents in Indonesia

2020 ◽  
Vol 56 (2) ◽  
pp. 140
Author(s):  
Asra Al Fauzi ◽  
Christrijogo Sumartono Waloejo ◽  
Abdulloh Machin ◽  
Muhammad Ja'far Shodiq
Keyword(s):  
Brain Death ◽  
Medical Center ◽  
Academic Medical Center ◽  
Cross Sectional Study ◽  
Research Subjects ◽  
Cross Sectional ◽  
Academic Medical ◽  
Center Hospital ◽  
Level 3 ◽  
Level 2

This research was conducted to evaluate the knowledge and diagnosis of brain death among resident in Indonesia. This study used an observational analytic study with a cross-sectional study design using a questionnaire. The research subjects consisted of 132 level 2 (after 2 years of residency) and level 3 (after 4 years of residency) residents, the total sampling for which was taken from the departments of Neurosurgery, Anesthesiology, and Neurology at Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia. Data were taken from November 2018 to January 2019. A total of 132 residents of Neurosurgery, Neurology, and Anesthesiology participated in this study. From the series of studies, residents’ knowledge of the concept of brain death was in the sufficient category (41.7%), residents’ knowledge of the technical diagnosis of brain death was in the good category (40.2%), residents’ knowledge of brain death examination was in the less category (43.2%), and finally, it was found that the resident's knowledge of brain death was in a good category (35.6%). There were also significant differences in knowledge of brain death between Neurosurgery, Neurology, and Anesthesiologist Resident (P <0.001) and knowledge of brain death between level 2 and level 3 residents (P=0.032). In general, the Indonesian resident doctors’ knowledge of brain death is adequate, but knowledge of the clinical examination of brain death is still lacking. Further research must be carried out to promote knowledge of brain death in residents as well as professional doctors/specialists, so that the number of organ transplants, especially in Indonesia, will increase.

scholarly journals The role of knowledge, attitudes, and health workers’ behavior in COVID19 pandemic preparedness at Aceh Pidie Jaya District, Indonesia

2021 ◽  
pp. 205343452110616
Author(s):  
Budi Yanti ◽  
Nurdarlila Armita ◽  
Iskandar Zakaria
Keyword(s):  
Health Workers ◽  
Cross Sectional Study ◽  
Good Knowledge ◽  
District Health ◽  
Chi Square ◽  
Cross Sectional ◽  
Positive Attitudes ◽  
Chi Square Test ◽  
Level 3

Introduction Health workers are at high risk of contracting the disease because they are at the forefront of assisting COVID19 patients. Globally, Indonesia has the worst death toll of health workers. Many previous studies have shown the differences in knowledge, attitudes, and behavior of health workers in handling with the COVID19 pandemic. This study aims to asses the role of knowledge, attitudes, and health workers' preparedness during the COVID-19 pandemic in Aceh Pidie Jaya District. Methods A cross-sectional study and the data were collected by distributing online questionnaires about knowledge, attitudes, behavior, and preparedness related to the COVID-19 at 12 Pidie Jaya District health centers. The knowledge, behavior, and preparedness parameters used Guttman and Likert scales to measure the workers' attitudes. Chi-square test was used to evaluate the relationship between knowledge, attitudes, behavior, and preparedness. Results In this study, 377 health workers were selected, the majority of respondents' education level was diploma, level 3 (257, 76.3%), and one-third of the respondents did not attend training. There are 197 (58.5%) respondents who had good knowledge, 177 (52.5%) positive attitudes, 283 (84%) good behavior, and 173 (51, 3%) well prepared. Furthermore, good knowledge, positive attitude, and good behavior had a significant correlation statistically with well prepared during the pandemic (p < 0.05). Discussion Most of the health workers in Aceh Pidie Jaya have good knowledge, positive attitudes, and good behavior that create adequate preparedness. Even though training is still very limited, educational attainment would remain the cornerstone for preparedness to encounter COVID-19.

Hospital medication errors: a cross-sectional study

2020 ◽  
Author(s):  
Anton N ISAACS ◽  
Kenneth CH’NG ◽  
Naaz DELHIWALE ◽  
Kieran TAYLOR ◽  
Bethany KENT ◽  
...  
Keyword(s):  
Medication Errors ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Workload Management ◽  
Severity Rating ◽  
Junior Staff ◽  
Nurse Workload ◽  
Level 3 ◽  
Day Of The Week

Abstract Background Medication errors (MEs) are among the most common types of incidents reported in Australian and international hospitals. There is no uniform method of reporting and reducing these errors. This study aims to identify the incidence, time trends, types and factors associated with MEs in a large regional hospital in Australia. Methods A 5-year cross-sectional study. Results The incidence of MEs was 1.05 per 100 admitted patients. The highest frequency of errors was observed during the colder months of May–August. When distributed by day of the week, Mondays and Tuesdays had the highest frequency of errors. When distributed by hour of the day, time intervals from 7 am to 8 am and from 7 pm to 8 pm showed a sharp increase in the frequency of errors. One thousand and eighty-eight (57.8%) MEs belonged to incidence severity rating (ISR) level 4 and 787 (41.8%) belonged to ISR level 3. There were six incidents of ISR level 2 and only one incident of ISR level 1 reported during the five-year period 2014-2018. Administration-only errors were the most common accounting for 1070 (56.8%) followed by prescribing-only errors (433, 23%). High-risk medications were associated with half the number of errors, the most common of which were narcotics (17.9%) and antimicrobials (13.2%). Conclusions MEs continue to be a problem faced by international hospitals. Inexperience of health professionals and nurse–patient ratios might be the fundamental challenges to overcome. Specific training of junior staff in prescribing and administering medication and nurse workload management could be possible solutions to reducing MEs in hospitals.

scholarly journals A Coupled Gas Flow-Mechanical Damage Model and Its Numerical Simulations on High Energy Gas Fracturing

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yu Bai ◽  
Li Sun ◽  
Chenhui Wei
Keyword(s):  
Numerical Simulations ◽  
Stress Wave ◽  
Gas Flow ◽  
High Energy ◽  
Stress Wave Propagation ◽  
Crack Evolution ◽  
Element Analysis ◽  
Unconventional Gas ◽  
Radial Cracks ◽  
The Impact

High-energy gas fracturing (HEGF) and gas fracturing (GF) are considered to be efficient to enhance the permeability of unconventional gas reservoir. The existing models for HEGF mainly focus on the dynamic loading of stress wave or static loading of gas pressurization, rather than on the combined actions of them. Studies on the combination of HEGF and GF (HEGF+GF) are also few. In this paper, a damage-based stress wave propagation-static mechanical equilibrium-gas flow coupling model is established. Numerical model and determination of mesomechanical parameters in finite element analysis are described in detail. Numerical simulations on crack evolution under HEGF, GF, and HEGF+GF are carried out, and the impact of in situ stress conditions on crack evolution is discussed further. A total of 11 cracks with length of 2.3-4 m in HEGF, 4 main cracks with length of 6.5–8 m in GF, and 11 radial cracks with length of 2–11.5 m in HEGF+GF are produced. Many radial cracks around the borehole are formed in HEGF and extended further in GF. The crustal stress difference is disadvantageous for crack complexity. This study can provide a reference for the application of HEGF+GF in unconventional gas reservoirs.

Ballistic Performance of Commercially Available Saint-Gobain Sapphire Transparent Armor Composites

2009 ◽  
pp. 113-124 ◽  
Author(s):  
Christopher D. Jones ◽  
Jeffrey B. Rioux ◽  
John W. Locher ◽  
Vincent Pluen ◽  
Mattias Mandelartz
Keyword(s):  
Ballistic Performance ◽  
Transparent Armor

scholarly journals Vertical and Horizontal Hop Performance: Contributions of the Hip, Knee, and Ankle

2021 ◽  
Vol 13 (2) ◽  
pp. 128-135
Author(s):  
Argyro Kotsifaki ◽  
Vasileios Korakakis ◽  
Philip Graham-Smith ◽  
Vasileios Sideris ◽  
Rod Whiteley
Keyword(s):  
Peak Power ◽  
Performance Testing ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Physically Active ◽  
Jump Distance ◽  
Ankle Joints ◽  
Level 3 ◽  
Ankle Function ◽  
Work Done

Background: Single-leg vertical and horizontal hop tests are commonly used to assess performance of healthy athletes and as a measure of progress during rehabilitation from knee injury. It is unclear if they measure similar aspects of leg function, as the relative joint contributions of the hip, knee, and ankle joints during propulsion and landing are unknown. Hypothesis: The proportion of work done by the hip, knee, and ankle will not be the same for these 2 jump types and will vary for propulsive and landing phases. Study Design: Cross-sectional cohort study. Level of Evidence: Level 3. Methods: Twenty physically active participants completed instrumented single-leg hop analysis in both vertical and horizontal directions. Joint peak power, work generated or absorbed, and percentage contribution of each joint during propulsive and landing phases were compared between tasks using paired t tests. Results: Vertical hop was performed with roughly similar contributions of the hip, knee, and ankle for both propulsion (31%, 34%, 35%, respectively) and landing (29%, 34%, 37%, respectively). Horizontal hop distance was mostly (87%) determined by the hip and ankle (44% and 43%), but landing was mostly (65%) performed by the knee with lesser contribution from the hip and ankle (24% and 11%). Propulsive phase showed a proximal-to-distal temporal sequence for both hop types, but landing was more complex. Conclusion: Performance during vertical and horizontal hops (jump height and jump distance, respectively) measures different aspects of hip, knee, and ankle function during the propulsive and landing phases. Clinical Relevance: Assessment of knee joint function during rehabilitation should not be done using a horizontal hop. The knee contributes about a third to vertical hop height, but only about an eighth to horizontal hop distance. Practitioners carrying out performance testing using either vertical or horizontal hops should be mindful of the relative contributions for meaningful training inferences to be derived.

Contact Damage in Brittle Curved Coatings: The Influence of Indenter/Coating Modulus Mismatches

2006 ◽  
Vol 312 ◽  
pp. 369-374 ◽  
Author(s):  
Tarek Qasim ◽  
Chris Ford ◽  
Mark Bush ◽  
Xiao Zhi Hu
Keyword(s):  
Crack Initiation ◽  
Damage Evolution ◽  
Radial Crack ◽  
Crack Evolution ◽  
Contact Damage ◽  
Brittle Coating ◽  
Axis Of Symmetry ◽  
Coating Layers ◽  
Polymeric Underlayers ◽  
Radial Cracks

The effects of indenter/coating modulus mismatch on contact damage in bilayer systems composed of brittle coating layers on compliant polymeric underlayers is investigated. Convex specimens having curvature of 12 mm inner coating diameter are produced, and loaded using flat indenters of four different moduli. Glass plates of d = 1 mm thick are used as representative of the brittle coating, and soft epoxy filler is used as an underlayer. Specimens are loaded along the convex axis of symmetry. In this fashion the influence of indenter modulus on radial crack initiation and damage evolution is examined. Previous studies utilised hard spherical indenters of various sizes, and did not consider the effect of a compliant indenter on radial crack evolution and subsequent damage patterns. It is demonstrated that critical loads for initiation of radial cracks and subsequent damage patterns especially at specimen margins are sensitive to indenter modulus (indenter/coating modulus mismatch).

scholarly journals Ballistic Performance of a Composite Metal Foam-ceramic Armor System

2014 ◽  
Vol 4 ◽  
pp. 151-156 ◽  
Author(s):  
Matias Garcia-Avila ◽  
Marc Portanova ◽  
Afsaneh Rabiei
Keyword(s):  
Metal Foam ◽  
Ballistic Performance ◽  
Foam Ceramic ◽  
Armor System
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