scholarly journals Miniaturised Rod-Shaped Polymer Structures with Wire or Fibre Reinforcement—Manufacturing and Testing

2020 ◽  
Vol 4 (3) ◽  
pp. 84
Author(s):  
Michael Kucher ◽  
Martin Dannemann ◽  
Ansgar Heide ◽  
Anja Winkler ◽  
Niels Modler
Keyword(s):  
Composite Structures ◽  
Low Cost ◽  
Fibre Reinforcement ◽  
Continuous Manufacturing ◽  
Consolidation Process ◽  
Cross Sectional ◽  
Pultrusion Process ◽  
Adequate Knowledge ◽  
Wide Range ◽  
Manufacturing Methods

Rod-shaped polymer-based composite structures are applied to a wide range of applications in the process engineering, automotive, aviation, aerospace and marine industries. Therefore, the adequate knowledge of manufacturing methods is essential, covering the fabrication of small amounts of specimens as well as the low-cost manufacturing of high quantities of solid rods using continuous manufacturing processes. To assess the different manufacturing methods and compare the resulting quality of the semi-finished products, the cross-sectional and bending properties of rod-shaped structures obtained from a thermoplastic micro-pultrusion process, conventional fibre reinforced epoxy resin-based solid rods and fibre reinforced thermoplastic polymers manufactured by means of an implemented shrink tube consolidation process, were statistically analysed. Using the statistical method one-way analysis of variance (ANOVA), the differences between groups were calculated. The statistical results show that the flexural moduli of carbon fibre reinforced polymers were statistically significantly higher than the modulus of all other investigated specimens (probability value ). The discontinuous shrink tube consolidation process resulted in specimens with a smooth outer contour and a high level of roundness. However, this process was recommended for the manufacturing of small amounts of specimens. In contrast, the pultrusion process allowed the manufacturing of high amounts of semi-finished products; however, it requires a more extensive process controlling and manufacturing equipment.

scholarly journals Fabrication Technique for Bio-Composite Patch Repair on Laminated Structures of CFRP Plate

2014 ◽  
Vol 564 ◽  
pp. 366-371 ◽  
Author(s):  
M.K.H. Muda ◽  
Faizal Mustapha ◽  
K.D. Mohd Aris ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Mechanical Properties ◽  
Composite Structures ◽  
Mechanical Performance ◽  
Low Cost ◽  
Natural Fibre ◽  
Patch Repair ◽  
Fabrication Technique ◽  
Composite Surface ◽  
Wide Range ◽  
Laminated Structures

Laminated structures are assembled so that the fibre orientation provides most of desired mechanical properties and the matrix largely determines the environmental performance. Composites laminate structures are used in a wide range of applications in aerospace, marine, automotive, surface transport and sports equipment markets. Damage to composite components is not always visible to the naked eye and the extent of damage is best determined for structural components by suitable Non Destructive Test (NDT) methods. Alternatively the damaged areas can be located by simply tapping the composite surface and listening to the sound. The damaged areas give a dull response to the tapping, and the boundary between the good and damaged composite can easily be mapped to identify the area for repair. Awareness of and inspection for composite damage should be included in the regular maintenance schedules for composite structures. Particular attention would be made to areas which are more prone to damage. The repair can be done by using composite itself or bio-composite. Bio-composite is a reinforcement of natural fibre such as plant and a material that formed by matrix or resin. Then repairs to aircraft structures are controlled and should be carried out according to the Aircraft Structural Repair Manual (SRM). For other applications the repaired components would normally be expected to meet the original specifications and mechanical performance requirements. This paper presents the fabrication technique including patch repair by using bio-composite which is kenaf and its aim to give a general approach to composite fabrication on patch repair in all applications. Through the described approach, the life of the structure is expanded and met the properties requirements such as low cost, fairly good mechanical properties, high specific strength, non-abrasive, eco-friendly and bio-degradability characteristics.

scholarly journals Knowledge, attitude and perception of Pakistanis towards COVID-19; a large cross-sectional survey

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zoya Fatima Rizwan Ladiwala ◽  
Rubaid Azhar Dhillon ◽  
Ibrahim Zahid ◽  
Omar Irfan ◽  
Muhammad Sharjeel Khan ◽  
...  
Keyword(s):  
Age Groups ◽  
Female Gender ◽  
Educational Status ◽  
Educational Interventions ◽  
Public Understanding ◽  
Cross Sectional Survey ◽  
Online Questionnaire ◽  
Cross Sectional ◽  
Adequate Knowledge ◽  
Wide Range

Abstract Background The Novel Coronavirus Disease (COVID-19) has created havoc globally as countries worldwide struggle to combat this pandemic. Since prevention and social isolation are known to be the only ways to prevent the spread of COVID-19, this has created challenges among the lower-middle income countries (LMIC) including Pakistan, as it battles between an under-resourced healthcare, an economic shutdown, and widespread myths and misconceptions. Therefore, a study was conducted to evaluate the knowledge, attitude and perceptions regarding COVID-19 as public understanding is vital to help facilitate the control of this outbreak. Methods A pre-validated online questionnaire was distributed among the general population of Pakistan from 1st to 12th June 2020. Descriptive statistics were analyzed using SPSS v25. Adequate knowledge was assigned as a score of > 4 (range: 0–8) and good perception as a score of > 3 (range: 0–5). Chi-square test was used to determine the significance of difference in knowledge and perception of COVID-19 with socio-demographic characteristics. Logistic regression analysis was run to identify factors associated with adequate knowledge and perception. P < 0.05 was considered as significant. Results A total of 1200 respondents participated in this study with a wide range of age groups and education. Majority of the respondents had adequate knowledge (93.3%) with a mean score of 6.59 ± 1.35, and good perception (85.6%) with a mean score of 4.29 ± 0.82. Significant differences in knowledge and perception were observed among genders, age groups, education and between students and employees in the healthcare and non-healthcare department. A multivariate analysis revealed a higher educational status and female gender to be significant predictors of adequate knowledge and perception. Conclusions Albeit the surge of COVID-19 cases in Pakistan, the participants demonstrated an overall adequate knowledge and good perception towards COVID-19. There is a need to follow the preventive protocols and dissemination of correct information through conducting educational interventions that target safe health practices and provide appropriate information on this infection.

Doppelphotonen-Absorptiometrie: Eine neue Methode zur Bestimmung des Knochenmineralgehaltes. I. Grundlagen

1988 ◽  
Vol 27 (01) ◽  
pp. 12-18 ◽  
Author(s):  
J. Eiber ◽  
J. Hennig ◽  
H W. Pabst ◽  
G. Buttermann
Keyword(s):  
Fracture Risk ◽  
Early Stage ◽  
Low Cost ◽  
Premenopausal Women ◽  
Bone Diseases ◽  
Dual Photon Absorptiometry ◽  
Neck Of Femur ◽  
Cross Sectional ◽  
Wide Range ◽  
The Individual

Today dual-photon absorptiometry (DPA) is recommended as the best procedure for diagnosing osteoporosis at an early stage considering its low cost, low radiation exposure and reasonable reliability. Cortical (neck of femur) and trabecular (L 2-4) bone mass has been determined repeatedly with DPA using 153Gd (NOVO Lab 22 a) in 545 females and 112 males with no evidence of bone diseases. Measured “normal” (age-and sex-related average) values for bone mineral content (BMC) differed significantly (p <0.01) from those of US inhabitants determined by the same equipment, i. e., they were on average about 30% lower, but matched well with corresponding results from Belgium. BMC-area was found the most suitable parameter both for cross-sectional and longitudinal studies, since it is independent of height and weight. But there is still need to reduce the overlap and improve accuracy and reproducibility for making decisions after shorter intervals. - Assessment of the individual mineral loss and fracture risk by comparison with average values remains problematical due to the wide range of “normal” BMC values, and in women additionally due to the variable onset of menopause. For estimations of the individual fracture risk of elderly patients BMC should not be normalized on age, because at the age of 65 half of the women had “pathologic” values, i.e. were below the so-called “osteoporosis threshold”. Comparison of the individually measured postmenopausal BMC with average values of premenopausal women and with BMC values normalized to their menopausal age may be helpful approaches to overcoming these difficulties. Because of the lack of earlier individual data in most cases repeated BMC measurements are still required for assessment of demineralization speed.

Ultrasonic Assembly of Biologically Inspired Anisotropic Short Fibre Reinforced Composites

2014 ◽  
Author(s):  
Richard S. Trask
Keyword(s):  
Self Assembly ◽  
Composite Structures ◽  
High Performance ◽  
Mechanical Performance ◽  
Low Cost ◽  
Building Blocks ◽  
Functionally Graded ◽  
Fibre Reinforcement ◽  
Fibre Direction ◽  
Volume Percentage

In nature, both material and structure are formed according to the principles of biologically controlled self-assembly, a process defined as the spontaneous and reversible ordering of small molecular building blocks under the influence of non-covalent, static interactions. The orientation and distribution of reinforcing entities in engineering composites is key to enabling structural efficiency, yet the architecture remains simplistic when compared to the distinctive and unique hierarchies found in Nature. These biological ‘composite’ materials achieve such configurations by accurately controlling the orientation of anisotropic nano- and micro-sized ‘building blocks’, thereby reinforcing the material in specific directions to carry the multidirectional external loads at different length scales. Capturing the design principles underlying the exquisite architecture of such biological materials will overcome many of the mechanical limitations of current engineering composites. The scientific vision for this study is the development of a novel and highly ordered complex architecture fibrous material for additive layer manufacturing. Using novel chemistry and controlled field-effect assembly, functionally graded, stiffness modulated architectures, analogous to those found in nature, are synthesised to realise enhanced mechanical performance, multi-dimensional composite structures. To achieve this, both hierarchical discontinuous fibres (glass fibres with ZnO nanrods) and a new type of ultrasonic device has been developed. The two studies reported here have been successfully employed to manufacture and mechanically characterise the fibres and aligned discontinuous fibres. A 43 % improvement in strength was observed for samples tested parallel to the direction of the fibre reinforcement over those strained normal to the fibre direction, despite the relatively low volume percentage of the reinforcement phase. This technique shows great potential for the low cost instantaneous alignment of structural reinforcement to generate the light-weight high performance structures required for the future.

scholarly journals Knowledge, Attitude and Practice on Dental Amalgam Restoration among Dental Students

2020 ◽  
pp. 39-48
Author(s):  
Kalaivani Natarajan ◽  
Manish Ranjan
Keyword(s):  
Online Survey ◽  
Low Cost ◽  
Dental Amalgam ◽  
Dental Students ◽  
Chi Square ◽  
Cross Sectional ◽  
Adequate Knowledge ◽  
Chi Square Test ◽  
Strength And Durability ◽  
Amalgam Restorations

Amalgam has been used in Dentistry for about 150 to 200 years and is still under use due to its low cost, ease of application, strength and durability. It is an alloy of mercury, is an excellent and versatile restorative material. The development of various tooth coloured cements and resins serves as an alternative and have reduced the use of amalgam. Yet, amalgam stands as one of the excellent restorative materials. The aim of the study was to assess the knowledge, awareness and practice of dental amalgam among dental students in a private dental school. Study was conducted as a cross sectional questionnaire based study among the dental students. The study was conducted as an online survey as it is timesaving and a majority of the population can be covered. There were one hundred participants involved in this online survey from second year, third years, final years and internship. The questionnaire consisting of ten questions were posted for an online survey using google forms. The validity of the questionnaire was cross verified by experts. The data were extracted and tabulated in MS Excel sheets with respect to each question and their response. The data obtained were subjected to statistical analysis using SPSS software v20. Chi square test was done to assess the association between the variables. The descriptive data obtained were plotted in bar graphs. It was evident that interns had adequate knowledge about amalgam restorations than other participants.

scholarly journals Increasing cell–device adherence using cultured insect cells for receptor-based biosensors

2018 ◽  
Vol 5 (3) ◽  
pp. 172366 ◽  
Author(s):  
Daigo Terutsuki ◽  
Hidefumi Mitsuno ◽  
Takeshi Sakurai ◽  
Yuki Okamoto ◽  
Agnès Tixier-Mita ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Low Cost ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Odorant Receptors ◽  
Cross Sectional ◽  
Wide Range ◽  
Sensitivity And Selectivity ◽  
Cost Measurement ◽  
Materials Used

Field-effect transistor (FET)-based biosensors have a wide range of applications, and a bio-FET odorant sensor, based on insect (Sf21) cells expressing insect odorant receptors (ORs) with sensitivity and selectivity, has emerged. To fully realize the practical application of bio-FET odorant sensors, knowledge of the cell–device interface for efficient signal transfer, and a reliable and low-cost measurement system using the commercial complementary metal-oxide semiconductor (CMOS) foundry process, will be indispensable. However, the interfaces between Sf21 cells and sensor devices are largely unknown, and electrode materials used in the commercial CMOS foundry process are generally limited to aluminium, which is reportedly toxic to cells. In this study, we investigated Sf21 cell–device interfaces by developing cross-sectional specimens. Calcium imaging of Sf21 cells expressing insect ORs was used to verify the functions of Sf21 cells as odorant sensor elements on the electrode materials. We found that the cell–device interface was approximately 10 nm wide on average, suggesting that the adhesion mechanism of Sf21 cells may differ from that of other cells. These results will help to construct accurate signal detection from expressed insect ORs using FETs.

3D Printing for Complex Cranial Surgery Education: Technical Overview and Preliminary Validation Study

2021 ◽  
Author(s):  
Christopher S Graffeo ◽  
Avital Perry ◽  
Lucas P Carlstrom ◽  
Maria Peris-Celda ◽  
Amy Alexander ◽  
...  
Keyword(s):  
3D Printing ◽  
Skull Base ◽  
Low Cost ◽  
Patient Specific ◽  
Cross Sectional ◽  
Case Examples ◽  
Cranial Surgery ◽  
Selection Accuracy ◽  
Wide Range ◽  
3D Printed

Abstract Background: 3D printing—also known as additive manufacturing—has a wide range of applications. Reproduction of low-cost, high-fidelity, disease- or patient-specific models presents a key developmental area in simulation and education research for complex cranial surgery. Methods: Using cadaveric dissections as source materials, skull base models were created, printed, and tested for educational value in teaching complex cranial approaches. In this pilot study, assessments were made on the value of 3D printed models demonstrating the retrosigmoid and posterior petrosectomy approaches. Models were assessed and tested in a small cohort of neurosurgery resident subjects (n = 3) using a series of 10 radiographic and 2 printed case examples, with efficacy determined via agreement survey and approach selection accuracy. Results: All subjects indicated agreement or strong agreement for all study endpoints that 3D printed models provided significant improvements in understanding of neuroanatomic relationships and principles of approach selection, as compared to 2D dissections or patient cross-sectional imaging alone. Models were not superior to in-person hands-on teaching. Mean approach selection accuracy was 90% ( ±  13%) for 10 imaging-based cases, or 92% ( ±  7%) overall. Trainees strongly agreed that approach decision-making was enhanced by adjunctive use of 3D models for both radiographic and printed cases. Conclusion: 3D printed models incorporating skull base approaches and/or pathologies provide a compelling addition to the complex cranial education armamentarium. Based on our preliminary analysis, 3D printed models offer substantial potential for pedagogical value as dissection guides, adjuncts to preoperative study and case preparation, or tools for approach selection training and evaluation.

Nurse’s knowledge and Awareness Regarding Cervical Cancer and its Prevention in Different Hospitals of Quetta, Pakistan

2017 ◽  
Vol 4 (1) ◽  
pp. 436-441
Author(s):  
Saba Haider ◽  
Noman Ul Haq ◽  
Sohail Riaz ◽  
Aqeel Nasim ◽  
Muhammad Saood ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Family History ◽  
Sampling Technique ◽  
Knowledge Score ◽  
Validity And Reliability ◽  
Contributing Factors ◽  
Cross Sectional ◽  
Adequate Knowledge ◽  
Current Area ◽  
One Year

Objective: This study aimed to assess the knowledge and awareness regarding cervical cancer and its prevention among nurses working in different hospitals of Quetta, Pakistan. Methodology: The cross sectional, descriptive study was conducted by using structured questionnaire in different hospitals of Quetta from January to September 2016. Convenient sampling technique was applied by targeting all the nurses working in different hospitals of Quetta city. Study questionnaire was developed and tested for validity and reliability. Descriptive and inferential statistics (Mann Whitney U test and Kruskal Wallis tests, p<0.05) were used to assess the significance among study variables and were performed by using IBM SPSS v.20. Results: Out of 415 distributed questionnaires 324 were returned (response rate of 78%). The mean Age of respondents was 28.18 ±9.5 years. Majority (n=127, 43.3%) of participants were interns and had no or less than one year of experience (n=128, 43.7%) with negative family history of any cancer (n=275, 93.9%). Mean knowledge score was 18.52±4.84with majority (n=258, 88.1%) had adequate knowledge regarding cervical cancer. Respondent sage, current area of practice, qualification, Institute of degree and past family history were contributing factors (p > 0.05) in adequate knowledge in this study. The results also reviled that not only 68.3% (n=200) and 65.5% (n=192) respondents knew that cervical cancer is vaccine preventable and availability of the vaccine for it. Conclusions: Nurses working in different hospitals of Quetta city had better understanding of the disease cervical cancer and its prevention. Yet many of the respondent are not aware of it vaccine and its availability.

A Cross Sectional Survey of Chicken Astroviruses Antibody in Broiler and Sonali (Cross-Bred) Chickens in Selected Areas in Bangladesh

2020 ◽  
Vol 43 (1) ◽  
pp. 75-80
Author(s):  
Md Zulfekar Ali ◽  
Mohammad Moktader Moula ◽  
Zafar Ahmed Bhuiyan ◽  
Muhammad Tariq Javed
Keyword(s):  
Age Groups ◽  
Winter Season ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Blood Samples ◽  
Elisa Kit ◽  
Published Report ◽  
Poultry Birds ◽  
Wide Range ◽  
Group B

AbstractChicken astroviruses (CAstV) are enteric viruses of poultry causing gastroenteritis, malabsorption, gout and white chick disease commonly known as runting-stunting syndrome (RSS). It can affect the wide range of poultry birds, especially chicken, turkey and duck worldwide. To our best knowledge there is no published report on presence of antibodies against CAstV in Bangladesh. Therefore, the study aimed to detect the presence of CAstV antibodies in broilers and sonali chickens (a cross-bread) in Bangladesh through a cross-sectional survey. A total of 454 blood samples from 66 flocks of broiler (n=343) and sonali chickens (n=111) of different ages were obtained during 2017 from four districts. The birds were healthy but were not vaccinated against CAstV. The samples were tested for specific antibodies against CAstV Group B by using commercially available ELISA kit. Overall, 16.74% (76/454) samples and 34.84% (23/66) flocks were positive for CAstV antibodies. The seroprevalence of CAstV was significantly (p=0.001) higher in sonali chickens (36.96%) than broiler (10.20%), while it was significantly higher (p=0.001) in birds of Bogura district (36.94%) than the other three districts. Regarding the age groups, seroprevalence was insignificantly (p=0.192) higher in sonali chicken before laying age (45%) than during laying age (27.45%). Regarding the seasons, CAstV infection was prevalent significantly (p=0.001) higher in winter season. Thus, the present study indicated the presence of CAstV in poultry in Bangladesh, so further studies are required to find out the magnitude of the problem in the country.

Assessment of knowledge about oral cancer: study with students of public education

RSBO ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 41 ◽  
Author(s):  
Elisabete Rabaldo Bottan ◽  
Iara Fiorentin Comunello ◽  
Constanza Marín ◽  
Eduardo Mazzetti Subtil
Keyword(s):  
Public Schools ◽  
Oral Cancer ◽  
Target Population ◽  
Cross Sectional Study ◽  
Primary Data ◽  
First Year ◽  
Research Subjects ◽  
Cross Sectional ◽  
Adequate Knowledge ◽  
Level Of Knowledge

Introduction and Objective: To evaluate the level of knowledge about oral cancer of students attending public school in one city of Santa Catarina (Brasil). Material and methods: A descriptive cross-sectional study, using primary data collection. Students of last year of elementary school and first year of high school, enrolled in public schools in the city of Itajaí (SC), in 2012, were the target population. The non-probability sample was obtained by convenience. Data were collected through a self-administered questionnaire structured with 13 questions divided into three fields. The level of knowledge was made based on pre-established scores. Results: 1149 instruments were analyzed (80.8% of the target population). The average age of the group was 15.5 years and 54.5% were female. The majority (78%) never had received information about oral cancer. Only 27.9% had cognizance about self-examination of the oral cavity. With regard to knowledge, 87.5% classified as unsatisfactory. For most issues the cognitive field did not identify a significant correlation between knowledge and the variables gender and education. When asked if they would like to participate in educational and preventive activitiesabout oral cancer and other issues related to health, 72.6% expressed interest. Conclusion: The group did not have adequate knowledge on the subject of oral cancer. Facing this reality, and the positive attitude of respondents, the researchers designed and offered an educational program to the research subjects.

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