Search results for: long persistent luminescent materials

Authors: Faris Alkhalil, Rana Bitar, Amer Azaz, Hisham Natour, Noora Almeraikhi, Mohamad Miqdady

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Background: Children with liver transplantation are achieving very good survival and so there is now a need to concentrate on achieving good health in these patients and preventing disease. Immunosuppressive medications have side effects that need to be monitored and if possible avoided. Glucocorticoids and calcineurin inhibitors are detrimental to bone and mineral homeostasis in addition steroids can also affect linear growth. Steroid sparing regimes in renal transplant children has shown to improve children’s height. Aim: We aim to review the growth and bone health of children post liver transplant by measuring bone mineral density (BMD) using dual energy X-ray absorptiometry (DEXA) scan and assessing if there is a clear link between poor growth and impaired bone health and use of long term steroids. Subjects and Methods: This is a single centre retrospective Cohort study, we reviewed the medical notes of children (0-16 years) who underwent a liver transplantation between November 2000 to November 2016 and currently being followed at our centre. Results: 39 patients were identified (25 males and 14 females), the median transplant age was 2 years (range 9 months - 16 years), and the median follow up was 6 years. Four patients received a combined transplant, 2 kidney and liver transplant and 2 received a liver and small bowel transplant. The indications for transplant included, Biliary Atresia (31%), Acute Liver failure (18%), Progressive Familial Intrahepatic Cholestasis (15%), transplantable metabolic disease (10%), TPN related liver disease (8%), Primary Hyperoxaluria (5%), Hepatocellular carcinoma (3%) and other causes (10%). 36 patients (95%) were on a calcineurin inhibitor (34 patients were on Tacrolimus and 2 on Cyclosporin). The other three patients were on Sirolimus. Low dose long-term steroids was used in 21% of the patients. A considerable proportion of the patients had poor growth. 15% were below the 3rd centile for weight for age and 21% were below the 3rd centile for height for age. Most of our patients with poor growth were not on long term steroids. 49% of patients had a DEXA scan post transplantation. 21% of these children had low bone mineral density, one patient had met osteoporosis criteria with a vertebral fracture. Most of our patients with impaired bone health were not on long term steroids. 20% of the patients who did not undergo a DEXA scan developed long bone fractures and 50% of them were on long term steroid use which may suggest impaired bone health in these patients. Summary and Conclusion: The incidence of impaired bone health, although studied in limited number of patients; was high. Early recognition and treatment should be instituted to avoid fractures and improve bone health. Many of the patients were below the 3rd centile for weight and height however there was no clear relationship between steroid use and impaired bone health, reduced weight and reduced linear height.

Keywords: bone, growth, pediatric, liver, transplantation

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Authors: Peter Mayeso Jiyajiya

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This paper discusses how the teaching of English as a foreign language in Malawi can enhance intercultural communication competence in a multicultural society. It argues that incorporation of intercultural communication in the teaching of English as a foreign language would improve cultural awareness in communication in the multicultural Malawi. The teaching of English in Malawi is geared towards producing students who would communicate in the global world. This entails the use of proper pedagogical approaches and instructional materials that prepare the students toward intercultural awareness. In view of this, the language teachers were interviewed in order to determine their instructional approaches to intercultural communication. Instructional materials were further evaluated to assess how interculturality is incorporated. The study found out that teachers face perceptual and technical challenges that hinder them from exercising creativity to incorporate interculturality in their lessons. This is also compounded by lack of clear direction in the teaching materials on cultural elements. The paper, therefore, suggests a holistic approach to the teaching of English language in Malawian school in which the diversity of culture in classrooms must be considered an opportunity for addressing students’ cultural needs that may be lacking in the instructional materials.

Keywords: cultural awareness, grammar, foreign language, intercultural communication, language teaching

Procedia PDF Downloads 335

Authors: Vishaal Subramanian, Annuatha Vinod Kumar, Santosh Kumar Budankayala, M. Senthil Kumar

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This paper discusses the aerodynamic and structural design, simulation and optimization of a mini-High Altitude Long Endurance (HALE) UAV. The applications of this mini HALE UAV vary from aerial topological surveys, quick first aid supply, emergency medical blood transport, search and relief activates to border patrol, surveillance and estimation of forest fire progression. Although classified as a mini UAV according to UVS International, our design is an amalgamation of the features of ‘mini’ and ‘HALE’ categories, combining the light weight of the ‘mini’ and the high altitude ceiling and endurance of the HALE. Designed with the idea of implementation in India, it is in strict compliance with the UAS rules proposed by the office of the Director General of Civil Aviation. The plane can be completely automated or have partial override control and is equipped with an Infra-Red camera and a multi coloured camera with on-board storage or live telemetry, GPS system with Geo Fencing and fail safe measures. An additional of 1.5 kg payload can be attached to three major hard points on the aircraft and can comprise of delicate equipment or releasable payloads. The paper details the design, optimization process and the simulations performed using various software such as Design Foil, XFLR5, Solidworks and Ansys.

Keywords: aircraft, endurance, HALE, high altitude, long range, UAV, unmanned aerial vehicle

Procedia PDF Downloads 392

Authors: Katielly Vianna Polkowski, Rodrigo Denizarte de Oliveira Polkowski, Cristiano Grings Herbert

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The use of nanomaterials in the formulation of polymeric materials modifies their molecular structure, offering an infinite range of possibilities for the development of smart products, being of great importance for science and contemporary industry. Shape memory polymers are generally lightweight, have high shape recovery capabilities, they are easy to process and have properties that can be adapted for a variety of applications. Shape memory materials are active materials that have attracted attention due to their superior damping properties when compared to conventional structural materials. The development of methodologies capable of preparing new materials, which use graphene in their structure, represents technological innovation that transforms low-cost products into advanced materials with high added value. To obtain an improvement in the shape memory effect (SME) of polymeric materials, it is possible to use graphene in its composition containing low concentration by mass of graphene nanoplatelets (GNP), graphene oxide (GO) or other functionalized graphene, via different mixture process. As a result, there was an improvement in the SME, regarding the increase in the values of maximum strain. In addition, the use of graphene contributes to obtaining nanocomposites with superior electrical properties, greater crystallinity, as well as resistance to material degradation. The methodology used in the research is Systematic Review, scientific investigation, gathering relevant studies on influence of nanomaterials on the properties of shape memory polymeric, using the literature database as a source and study methods. In the present study, a systematic reviewwas performed of all papers published from 2014 to 2022 regarding graphene and shape memory polymeric througha search of three databases. This study allows for easy identification of themost relevant fields of study with respect to graphene and shape memory polymeric, as well as the main gaps to beexplored in the literature. The addition of graphene showed improvements in obtaining higher values of maximum deformation of the material, attributed to a possible slip between stacked or agglomerated nanostructures, as well as an increase in stiffness due to the increase in the degree of phase separation that results in a greater amount physical cross-links, referring to the formation of shortrange rigid domains.

Keywords: graphene, shape memory, smart materials, polymers, nanomaterials

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Authors: G. B. M. Carvalho, V. A. C. Vale, E. T. L. Cöuras Ford

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A heated pool makes it possible to use it during all hours of the day and in the seasons, especially in physiotherapies and sports centers. However, the cost of installation, operation and maintenance often makes it difficult to deploy. In addition, the current global policy for the use of natural resources from energy sources contradicts the most common means of heating swimming pools, such as the use of gas (Natural Gas and Liquefied Petroleum Gas), the use of firewood or oil and the use of electricity (heat pumps and electrical resistances). In this sense, this work focuses on the use of solar water heaters to be used in swimming pools of physiotherapy centers, in order to analyze their viability for this purpose in view of the costs linked to the medium and/or long term heating. For this, materials of low cost, low weight, easy commercial acquisition were used besides easy manufacture. Parameters such as flow, temperature distribution, efficiency and technical-economic feasibility were evaluated.

Keywords: heating, water, pool, solar energy, solar collectors, temperature, efficiency

Procedia PDF Downloads 162

Authors: Umar Rehman, Holly Roy, K. T. Tsang, D. S. Jeyaretna, W Singleton, B. Fisher, P. A. Glew, J. Greig, Peter C. Whitfield

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Introduction: A brain abscess is a life-threatening condition, carrying significant mortality. It requires rapid identification and treatment. Management involves a combination of antibiotics and surgery. The aim of the current study was to identify common bacteria responsible for cerebral abscesses as well as the long term functional and neurological outcomes of patients following treatment in a retrospective series at a single UK neurosurgical centre. Methodology: We analysed patients that had received a diagnosis of 'cerebral abscess' or 'subdural empyema' between June 2002 and June 2018. This was done in the form of a retrospective review. The search resulted in a total of 180 patients; with 37 patients being excluded (spinal abscess, below 18 or non-abscess related admissions). Data were collected from medical case notes including information about demographics, comorbidities, immunosuppression, presentation, size/location of lesions, pathogens, treatment, and outcomes. Results: In total, we analysed 143 patients between the ages of 18-90. Focal neurological deficit and headaches were seen in 84% and 68% of patients respectively. 108 positive brain cultures were seen; with the largest proportion, 59.2% being gram-positive cocci, with strep intermedius being the most common pathogen identified in 13.9% of patients. Of the patients with positive blood cultures (n=11), 72.7% showed the same organism both in the blood and on the brain cultures. Long term outcomes (n=72) revealed that 48% of patients seizure-free without requiring anti-epileptics, 51.3% of patients had full recovery of their neurological symptoms. There was a mortality rate of 13.9% in the series. Conclusion: In conclusion, the largest bacterial cause of abscess within our population was due to gram-positive cocci. The majority of the patient demonstrated full neurological recovery with close to half of patients not requiring anti-epileptics following discharge.

Keywords: bacteria, cerebral abscess, long term outcome, neurological deficit

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Authors: Hirseland Andreas, Kerschbaumer Lukas

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In the case of Germany, there are about one million long-term unemployed – a figure that did not vary much during the past years. These long-term unemployed did not benefit from the prospering labor market while most short-term unemployed did. Instead, they are continuously dependent on welfare and sometimes precarious short-term employment, experiencing work poverty. Long-term unemployment thus turns into a main obstacle to become employed again, especially if it is accompanied by other impediments such as low-level education (school/vocational), poor health (especially chronical illness), advanced age (older than fifty), immigrant status, motherhood or engagement in care for other relatives. As can be shown by this current research project, in these cases the chance to regain employment decreases to near nil. Almost two-thirds of all welfare recipients have multiple impediments which hinder a successful transition from welfare back to sustainable and sufficient employment. Prospective employers are unlikely to hire long-term unemployed with additional impediments because they evaluate potential employees on their negative signaling (e.g. low-level education) and the implicit assumption of unproductiveness (e.g. poor health, age). Some findings of the panel survey “Labor market and social security” (PASS) carried out by the Institute of Employment Research (the research institute of the German Federal Labor Agency) spread a ray of hope, showing that unlikely does not necessarily mean impossible. The presentation reports on current research on these very scarce “success stories” of unlikely transitions from long-term unemployment to work and how these cases were able to perform this switch against all odds. The study is based on a mixed-method design. Within the panel survey (~15,000 respondents in ~10,000 households), only 66 cases of such unlikely transitions were observed. These cases have been explored by qualitative inquiry – in depth-interviews and qualitative network techniques. There is strong evidence that sustainable transitions are influenced by certain biographical resources like habits of network use, a set of informal skills and particularly a resilient way of dealing with obstacles, combined with contextual factors rather than by job-placement procedures promoted by Job-Centers according to activation rules or by following formal paths of application. On the employer’s side small and medium-sized enterprises are often found to give job opportunities to a wider variety of applicants, often based on a slow but steadily increasing relationship leading to employment. According to these results it is possible to show and discuss some limitations of (German) activation policies targeting the labor market and their impact on welfare dependency and long-term unemployment. Based on these findings, indications for more supportive small-scale measures in the field of labor-market policies are suggested to help long-term unemployed with multiple impediments to overcome their situation (e.g. organizing small-scale-structures and low-threshold services to encounter possible employers on a more informal basis like “meet and greet”).

Keywords: against-all-odds, mixed-methods, Welfare State, long-term unemployment

Procedia PDF Downloads 356

Authors: Svetlana V. Topolyanskaya, Tatyana A. Eliseeva, Olga N. Vakulenko, Leonid I. Dvoretski

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Introduction: Limited data are available on osteoporosis in centenarians. Therefore, we evaluated bone mineral density in long-living patients with coronary artery disease (CAD). Methods: 202 patients hospitalized with CAD were enrolled in this cross-sectional study. The patients' age ranged from 90 to 101 years. The majority of study participants (64.4%) were women. The main exclusion criteria were any disease or medication that can lead to secondary osteoporosis. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Results: Normal lumbar spine BMD was observed in 40.9%, osteoporosis – in 26.9%, osteopenia – in 32.2% of patients. Normal proximal femur BMD values were observed in 21.3%, osteoporosis – in 39.9%, and osteopenia – in 38.8% of patients. Normal femoral neck BMD was registered only in 10.4% of patients, osteoporosis was observed in 60.4%, osteopenia in 29.2%. Significant positive correlation was found between all BMD values and body mass index of patients (p < 0.001). Positive correlation was registered between BMD values and serum uric acid (p=0.0005). The likelihood of normal BMD values with hyperuricemia increased 3.8 times, compared to patients with normal uric acid, who often have osteoporosis (Odds Ratio=3.84; p = 0.009). Positive correlation was registered between all BMD values and body mass index (p < 0.001). Positive correlation between triglycerides levels and T-score (p=0.02), but negative correlation between BMD and HDL-cholesterol (p=0.02) were revealed. Negative correlation between frailty severity and BMD values (p=0.01) was found. Positive correlation between BMD values and functional abilities of patients assessed using Barthel index (r=0,44; p=0,000002) and IADL scale (r=0,36; p=0,00008) was registered. Fractures in history were observed in 27.6% of patients. Conclusions: The study results indicate some features of BMD in long-livers. In the study group, significant relationships were found between bone mineral density on the one hand, and patients' functional abilities on the other. It is advisable to further study the state of bone tissue in long-livers involving a large sample of patients.

Keywords: osteoporosis, bone mineral density, centenarians, coronary artery disease

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Authors: Sara Fallahi

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This paper reviews the importance of content familiarity of receptive skills and offers solutions to the issue of content unfamiliarity in language learning materials. Presently, language learning materials are mainly comprised of global issues and target language speakers’ culture(s) in receptive skills. This might leadlearners to focus on content rather than the language. As a solution, materials on receptive skills can be developed with a focus on learners’culture and social concerns, especially in the beginner levels of learning. Language learners often learn their target language through the receptive skills of listening and reading before language production ensues through speaking and writing. Students’ journey from receptive skills to productive skills is mainly concentrated on by teachers. There are barriers to language learning, such as time and energy, that can hinder learners’ understanding and ability to build the required background knowledge of the content. This is generated due to learners’ unfamiliarity with the skill’s content. Therefore, materials that improve content familiarity will help learners improve their language comprehension, learning, and usage. This presentation will conclude with practical solutions to help teachers and learners more authentically integrate language and culture to elevate language learning.

Keywords: language learning, listening content, reading content, content familiarity, ESL books, language learning books, cultural familiarity

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Authors: Ani Kojoyan

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Linguistic studies have been investigating a connection between gender and linguistic development since 1970s. Scholars claim that gender differences in first and second language learning are socially constructed. Recent studies to language learning and gender reveal that second language acquisition is also a social phenomenon directly influencing one’s gender identity. Those responsible for designing language learning-teaching materials should be encouraged to understand the importance of and address the gender sensitivity accurately in textbooks. Writing or compiling a textbook is not an easy task; it requires strong academic abilities, patience, and experience. For a long period of time Armenia has been involved in the compilation process of a number of foreign language textbooks. However, there have been very few discussions or evaluations of those textbooks which will allow specialists to theorize that practice. The present paper focuses on the analysis of gender sensitivity issues and policy aspects involved in an EFL textbook. For the research the following material has been considered – “A Basic English Grammar: Morphology”, first printed in 2011. The selection of the material is not accidental. First, the mentioned textbook has been widely used in university teaching over years. Secondly, in Armenia “A Basic English Grammar: Morphology” has considered one of the most successful English grammar textbooks in a university teaching environment and served a source-book for other authors to compile and design their textbooks. The present paper aims to find out whether an EFL textbook is gendered in the Armenian teaching environment, and whether the textbook compilers are aware of gendered messages while compiling educational materials. It also aims at investigating students’ attitude toward the gendered messages in those materials. And finally, it also aims at increasing the gender sensitivity among book compilers and educators in various educational settings. For this study qualitative and quantitative research methods of analyses have been applied, the quantitative – in terms of carrying out surveys among students (45 university students, 18-25 age group), and the qualitative one – by discourse analysis of the material and conducting in-depth and semi-structured interviews with the Armenian compilers of the textbook (interviews with 3 authors). The study is based on passive and active observations and teaching experience done in a university classroom environment in 2014-2015, 2015-2016. The findings suggest that the discussed and analyzed teaching materials (145 extracts and examples) include traditional examples of intensive use of language and role-modelling, particularly, men are mostly portrayed as active, progressive, aggressive, whereas women are often depicted as passive and weak. These modeled often serve as a ‘reliable basis’ for reinforcing the traditional roles that have been projected on female and male students. The survey results also show that such materials contribute directly to shaping learners’ social attitudes and expectations around issues of gender. The applied techniques and discussed issues can be generalized and applied to other foreign language textbook compilation processes, since those principles, regardless of a language, are mostly the same.

Keywords: EFL textbooks, gender policy, gender sensitivity, qualitative and quantitative research methods

Procedia PDF Downloads 191

Authors: F. Stake

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This work is a parametric study combining simple and well known optical theories. These simple theories are arranged to form part of one answer to the question: “Can a semi-transparent Thermo-Photo-Voltaic (TPV) emitter have an optical extinction spectrum so much greater than its optical absorption spectrum that it becomes its own band-pass pre-filter, and if so, how well might it be expected to suppress light of undesired wavelengths?” In the report, hypothetical materials and operating temperatures will be used for comparative analyses only. Thermal emission properties of these hypothetical materials were created using two openly available FORTRAN programs. Results indicate that if using highly transparent materials it may be possible to create a thermal emitter that is its own band-pass pre-filter.

Keywords: Christensen effect, DISORT, index of refraction, scattering

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Authors: O. D. Arbeláez-Echeverri, E. Restrepo-Parra, J. C. Riano-Rojas

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A two dimensional geometric model of Bit Patterned Media is proposed, the model is based on the crystal structure of the materials commonly used to produce the nano islands in bit patterned materials and the possible defects that may arise from the interaction between the nano islands and the matrix material. The dynamic magnetic properties of the material are then computed using time aware integration methods for the multi spin Hamiltonian. The Hamiltonian takes into account both the spatial and topological disorder of the sample as well as the high perpendicular anisotropy that is pursued when building bit patterned media. The main finding of the research was the possibility of replicating the results of previous experiments on similar materials and the ability of computing the switching field distribution given the geometry of the material and the parameters required by the model.

Keywords: nanostructures, Monte Carlo, pattern media, magnetic properties

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Authors: Hakimullah Hakim, Chiharu Toyofuku, Mari Ota, Mayuko Suzuki, Miyuki Komura, Masashi Yamada, Md. Shahin Alam, Natthanan Sangsriratanakul, Dany Shoham, Kazuaki Takehara

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Disinfectants and their application are essential part of infection control strategies and enhancement of biosecurity at farms, worldwide. Alkaline agents are well known for their strong and long term antimicrobial capacities and most frequently are applied at farms for control and prevention of biological hazards. However, inadequate information regarding such materials’ capacities to inactivate pathogens and their improper applications fail farmers to achieve the mentioned goal. Thus, this requires attention to further evaluate their efficacies, under different conditions and in different ways. Here in this study we evaluated bactericidal efficacies of food additive grade of calcium hydroxide (FdCa(OH)2) powder derived from natural calcium carbonates obtained from limestone (Fine Co., Ltd., Tokyo, Japan), and bioceramic powder (BCX) derived from chicken feces at pH 13 (NMG environmental development Co., Ltd., Tokyo, Japan), for their efficacies to inactivate bacteria in feces. [Materials & Methods] Chicken feces were inoculated by 100 µl Escherichia coli and Salmonella Infantis in falcon tubes, individually, then FdCa(OH)2 or BCX powders were individually added to make final concentration of 0, 5, 10, 20 and 30% (w/w) in total weight of 0.5g, followed by properly mixing and incubating at room temperature for certain periods of time, in a dark place. Afterwards, 10 ml 1M Tris-HCl (pH 7.2) was added onto them to reduce their pH, in order to stop powders’ activities and to harvest the remained viable bacteria, whereas using normal medium or dW2 to recover bacteria increases the mixture pH, and as a result bacteria would be inactivated soon; therefore, the latter practice brings about incorrect and misleading results. Samples were then inoculated on DHL agar plates in order to calculate colony forming units (CFU)/ml of viable bacteria. [Results and Discussion] FdCa(OH)2 powder at 10% and 5% required 3 hr and 6 hr exposure times, respectively, while BCX powder at 20% concentrations required 6 hr exposure time to kill the mentioned bacteria in feces down to lower than detectable level (≤ 3.6 log10 CFU/ml). This study confirmed capacities of FdCa(OH)2 and BCX powders to inactivate bacteria in feces, and both materials are environment friendly materials, with no risk to human or animal’s health. This finding helps farmers to properly apply alkaline agents in appropriate concentrations and exposure times in their farms, in order to prevent and control infectious diseases outbreaks and to enhance biosecurity. Finally, this finding may help farmers to implement better strategies for infections control in their livestock farms.

Keywords: bacterial inactivation, bioceramic, biosecurity at livestock farms, chicken feces

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Authors: C. W. Kan, H. F. Cheung, Y. S. Lee

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This study examines the results of colour fading of cotton fabric by plasma-induced ozone treatment, with an aim to provide learning materials for fashion designers when designing colour fading effects in fashion products. Cotton knitted fabrics were dyed with red reactive dye with a colour depth of 1.5% and were subjected to ozone generated by a commercially available plasma machine for colour fading. The plasma-induced ozone treatment was conducted with different parameters: (i) air concentration = 10%, 30%, 50% and 70%; (ii) water content in fabric = 35% and 45%, and (iii) treatment time = 10 minutes, 20 minutes and 30 minutes. Finally, the colour properties of the plasma–induced ozone treated fabric were measured by spectrophotometer under illuminant D₆₅ to obtain the CIE L*, CIE a* and CIE b* values.

Keywords: learning materials, colour fading, colour properties, fashion products

Procedia PDF Downloads 275

Authors: Eun Jae Ko, In Young Sung, Eui Soo Joeng

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Oropharyngeal dysphagia is prevalent in children with cerebral palsy (CP). There are many studies concerning this problem, however, studies examining long term outcomes of dysphagia using videofluoroscopic study (VFSS) are very rare. The Aim of this study is to investigate long-term outcomes of dysphagia in children with severe CP using initial VFSS. It was a retrospective study and chart review was done from January 2000 to December 2013. Thirty one patients under 18 years who have been diagnosed as CP in outpatient clinic of Rehabilitation Medicine, and who did VFSS were included. Long-term outcomes such as feeding method, height percentile, weight percentile, and body mass index (BMI) were tracked up for at least 3 years by medical records. Significant differences between initial and follow-up datas were investigated. The patients consisted of 18 males and 13 females, and the mean age was 31.0±18.0 months old. 64.5% of patients were doing oral diet, and 25.8% of patients were doing non-oral diet. When comparing VFSS findings among oral feeding patients, oral and non-oral feeding patients, and non-oral feeding patients at initial period, dysphagia severity, supraglottic penetration, and subglottic aspiration showed significant differences. Most of the patients who could feed orally at initial period were found to have the same feeding method at follow-up. But among eight patients who required non-oral feeding initially, three patients became possible to feed orally, and one patient was doing oral and non-oral feeding method together at follow-up. Follow up feeding method showed correlation with dysphagia severity by initial VFSS. Weight percentile was decreased in patients with GMFCS level V at follow up, which may represent poor nutritional status due to severe dysphagia compared to other patients. Initial VFSS severity would play a significant role in making an assumption about future diet in children with severe CP. Patients with GMFCS level V seem to have serious dysphagia at follow up and have nutritional deficiency over time, therefore, more careful nutritional support is needed in children with severe CP are suggested.

Keywords: cerebral palsy, child, dysphagia, videofluoroscopic study

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Authors: Hyun-Koo Kim, Yonghun Kim, Yong-Hoon Kim, Ju Hee Lee, Myungho Song

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In this paper, we have described an efficient stereo matching method and pedestrian detection method using stereo types LWIR camera. We compared with three types stereo camera algorithm as block matching, ELAS, and SGM. For pedestrian detection using stereo LWIR camera, we used that SGM stereo matching method, free space detection method using u/v-disparity, and HOG feature based pedestrian detection. According to testing result, SGM method has better performance than block matching and ELAS algorithm. Combination of SGM, free space detection, and pedestrian detection using HOG features and SVM classification can detect pedestrian of 30m distance and has a distance error about 30 cm.

Keywords: advanced driver assistance system, pedestrian detection, stereo matching method, stereo long-wave IR camera

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Authors: Prashant Dhiman, Viranshu Kumar, Pradeep Joshi

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Lot of research is going on to study the effect of cryogenic treatment on materials. Cryogenic treatment is a heat treatment process which is used widely to enhance the mechanical and metallurgical properties of various materials whether the material is ferrous or non ferrous. In almost all ferrous metals, it is found that retained austenite is converted into martensite. Generally deep cryogenic treatment is done using liquid nitrogen having temperature of -195 ℃. The austenite is unstable at this stage and converts into martensite. In non ferrous materials there presents a microcavity and under the action of stress it becomes crack. When this crack propagates, fracture takes place. As the metal contract under low temperature, by doing cryogenic treatment these microcavities will be filled hence increases the soundness of the material. Properties which are enhanced by cryogenic treatment of both ferrous and non ferrous materials are hardness, tensile strength, wear rate, electrical and thermal conductivity, and others. Also there is decrease in residual stress. A large number of manufacturing process (EDM, CNC etc.) are using cryogenic treatment on different tools or workpiece to reduce their wear. In this Review paper the use of cryogenic heat treatment in different manufacturing has been shown along with their advantages.

Keywords: cyrogenic treatment, EDM (Electrical Discharge Machining), CNC (Computer Numeric Control), Mechanical and Metallurgical Properties

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Authors: Irena Basaric Ikodinovic, Dragoslav Rakic, Mirjana Vukicevic, Sanja Jockovic, Jovana Jankovic Pantic

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Large long-term settlement occurs at the municipal solid waste landfills over an extended period of time which may lead to breakage of the geomembrane, damage of the cover systems, other protective systems or facilities constructed on top of a landfill. Also, municipal solid waste is an extremely heterogeneous material and its properties vary over location and time within a landfill. These material characteristics require the formulation of a new constitutive model to predict the long-term settlement of municipal solid waste. The paper presents a new constitutive model which is formulated to describe the mechanical behavior of municipal solid waste. Model is based on Modified Cam Clay model and the critical state soil mechanics framework incorporating time-dependent components: mechanical creep and biodegradation of municipal solid waste. The formulated constitutive model is optimized and defined with eight input parameters: five Modified Cam Clay parameters, one parameter for mechanical creep and two parameters for biodegradation of municipal solid waste. Thereafter, the constitutive model is implemented in the software suite for finite element analysis (ABAQUS) and numerical analysis of the experimental landfill settlement is performed. The proposed model predicts the total settlement which is in good agreement with field measured settlement at the experimental landfill.

Keywords: constitutive model, finite element analysis, municipal solid waste, settlement

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Authors: Majid Al-Busafi, Alexe Cristina Ioana, Alexe Dan Iulian

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The specific competition and pre-competition stress in professional track and field determined an increasing engagement, from a biological and psychological point of view, of the middle distance and long distance runners, to obtain the top performances that would get them to win in a competition. Under these conditions, if the psychological stress is not properly managed, the negative effects can lead to a total drop in self-confidence, and can affect the value, the talent, and the self-trust, which generates an even higher stress. One of the means at our disposal is the psychological training, specially adapted to the athlete's individual characteristics, to the characteristics of the athletic event, or of the competition. This paper aims to highlight certain original aspects regarding the effects of a specific psychological training program on the mood states characterized by psychological activation, vigor, vitality. The subjects were represented by 12 professional middle distance and long distance runners, subjected to an applicative intervention to which they have participated voluntarily, over the course of 6 months (a competition season). The results indicated that The application of a psychological training program, adapted to the track and field competition system, over a period of time characterized by high competition stress, can determine an increase in the states of vigor and psychological activation, at the same time diminishing those moods that have negative effects on the performance, in the middle distance and long distance running events. This conclusion confirms the hypothesis of this research.

Keywords: competition stress, psychological training, track and field, vigor-activity

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Authors: Daniel Sava, Dragos Gudovan, Iulia Alexandra Gudovan, Ioana Ardelean, Maria Sonmez, Denisa Ficai, Laurentia Alexandrescu, Ecaterina Andronescu

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Graphene and graphene oxide have been intensively studied due to the very good properties, which are intrinsic to the material or come from the easy doping of those with other functional groups. Graphene and graphene oxide have known a broad band of useful applications, in electronic devices, drug delivery systems, medical devices, sensors and opto-electronics, coating materials, sorbents of different agents for environmental applications, etc. The board range of applications does not come only from the use of graphene or graphene oxide alone, or by its prior functionalization with different moieties, but also it is a building block and an important component in many composite devices, its addition coming with new functionalities on the final composite or strengthening the ones that are already existent on the parent product. An attempt to improve the mechanical properties of polyamide elastomers by compounding with graphene oxide in the parent polymer composition was attempted. The addition of the graphene oxide contributes to the properties of the final product, improving the hardness and aging resistance. Graphene oxide has a lower hardness and textile strength, and if the amount of graphene oxide in the final product is not correctly estimated, it can lead to mechanical properties which are comparable to the starting material or even worse, the graphene oxide agglomerates becoming a tearing point in the final material if the amount added is too high (in a value greater than 3% towards the parent material measured in mass percentages). Two different types of tests were done on the obtained materials, the hardness standard test and the tensile strength standard test, and they were made on the obtained materials before and after the aging process. For the aging process, an accelerated aging was used in order to simulate the effect of natural aging over a long period of time. The accelerated aging was made in extreme heat. For all materials, FT-IR spectra were recorded using FT-IR spectroscopy. From the FT-IR spectra only the bands corresponding to the polyamide were intense, while the characteristic bands for graphene oxide were very small in comparison due to the very small amounts introduced in the final composite along with the low absorptivity of the graphene backbone and limited number of functional groups. In conclusion, some compositions showed very promising results, both in tensile strength test and in hardness tests. The best ratio of graphene to elastomer was between 0.6 and 0.8%, this addition extending the life of the product. Acknowledgements: The present work was possible due to the EU-funding grant POSCCE-A2O2.2.1-2013-1, Project No. 638/12.03.2014, code SMIS-CSNR 48652. The financial contribution received from the national project ‘New nanostructured polymeric composites for centre pivot liners, centre plate and other components for the railway industry (RONERANANOSTRUCT)’, No: 18 PTE (PN-III-P2-2.1-PTE-2016-0146) is also acknowledged.

Keywords: graphene, graphene oxide, mechanical properties, dopping effect

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Authors: D. Gueribiz, F. Jacquemin, S. Fréour

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During their service life, composite materials are submitted to humid environments. The moisture absorbed by their matrix polymer induced internal stresses which can lead to multi-scale damage and may reduce the lifetime of composite structures. The estimation of internal stresses is based at a first on realistic evaluation of the diffusive behavior of composite materials. Generally, the modeling and simulation of the diffusive behavior of composite materials are extensively investigated through decoupled models based on the assumption of Fickien behavior. For these approaches, the concentration and the deformation (or stresses), the two state variables of the problem considered are governed by independent equations which are solved separately. In this study, a model coupling diffusive behavior with stresses state for a polymer matrix composite reinforced with impermeable fibers is proposed, the investigation of diffusive behavior is based on a more general thermodynamic approach which introduces a dependence of diffusive behavior on internal stresses state. The coupled diffusive behavior modeling was established in first for homogeneous and isotropic matrix and it is, thereafter, extended to impermeable unidirectional composites.

Keywords: composites materials, moisture diffusion, effective moisture diffusivity, coupled moisture diffusion

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Authors: Rady A., Elsheshai A., Eltawel M.

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Introduction and Aim of work: Literature suggest that antipsychotic medications may decrease cortisol level, an effect that seems to be more present with second generation antipsychotic. Our study aims at assessing effect of long term use of antipsychotics on cortisol level Subjects and Methods: 30 chronic schizophrenic patients on antipsychotics compared to 20 drug naive schizophrenic patients as regards serum cortisol level Results: Cortisol level was significantly lower in chronic schizophrenic patients receiving antipsychotics compared to drug naive patients (P=0.002 <0.05) Conclusion: Antipsychotic medications seem to have the potential to decrease cortisol level in blood. Among hypothesis proposed in literature is the good control of pseudo stress due to psychotic features.

Keywords: schizophrenia, antipsychotic, cortisol, HPA

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Authors: J. Palán, M. Zemko

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COMTES FHT has been active in a field of research and development of high-strength wires for quite some time. The main material was pure titanium. The primary goal of this effort is to develop a continuous production process for ultrafine and nanostructured materials with the aid of severe plastic deformation (SPD). This article outlines mechanical and microstructural properties of the materials and the options available for testing the components made of these materials. Ti Grade 2 and Grade 4 wires are the key products of interest. Ti Grade 2 with ultrafine to nano-sized grain shows ultimate strength of up to 1050 MPa. Ti Grade 4 reaches ultimate strengths of up to 1250 MPa. These values are twice or three times as higher as those found in the unprocessed material. For those fields of medicine where implantable metallic materials are used, bulk ultrafine to nanostructured titanium is available. It is manufactured by SPD techniques. These processes leave the chemical properties of the initial material unchanged but markedly improve its final mechanical properties, in particular, the strength. Ultrafine to nanostructured titanium retains all the significant and, from the biological viewpoint, desirable properties that are important for its use in medicine, i.e. those properties which made pure titanium the preferred material also for dental implants.

Keywords: CONFORM, ECAP, rotary swaging, titanium

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Authors: S. Dorbani, F. Kharchi, F. Salem, K. Arroudj, N. Chioukh

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The need for thermal comfort of buildings, with the aim of saving energy, has always generated a big interest during the development of methods, to improve the mode of construction. In the present paper, which is concerned by the valorization of locally abundant materials, mixtures of plaster and dune sand have been studied. To point out the thermal performances of these mixtures, a comparative study has been established between this product and the two materials most commonly used in construction, the concrete and hollow brick. The results showed that optimal mixture is made with 1/3 plaster and 2/3 dune sand. This mortar achieved significant increases in the mechanical strengths, which allow it to be used as a carrier element for buildings, of up to two levels. The element obtained offers an acceptable thermal insulation, with a decrease the outer-wall construction thickness.

Keywords: local materials, mortar, plaster, dune sand, compaction, mechanical performance, thermal performance

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Authors: L. Sánchez-Abella, I. Loinaz, H-J. Grande, D. Dupin

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Aseptic loosening remains as the principal cause of revision in total hip arthroplasty (THA). For long-term implantations, submicron particles are generated in vivo due to the inherent wear of the prosthesis. When this occurs, macrophages undergo phagocytosis and secretion of bone resorptive cytokines inducing osteolysis, hence loosening of the implanted prosthesis. Therefore, new technologies are required to reduce the wear of the bearing materials and hence increase the life-span of the prosthesis. Our strategy focuses on surface modification of the bearing materials with a hydrophilic coating based on cross-linked water-soluble (meth)acrylic monomers to improve their tribological behavior. These coatings are biocompatible, with high swelling capacity and antifouling properties, mimicking the properties of natural cartilage, i.e. wear resistance with a permanent hydrated layer that prevents prosthesis damage. Cartilage mimicking based coatings may be also used to protect medical device surfaces from damage and scratches that will compromise their integrity and hence their safety. However, there are only a few reports on the mechanical and tribological characteristics of this type of coatings. Clear beneficial advantages of this coating have been demonstrated in different conditions and different materials, such as Ultra-high molecular weight polyethylene (UHMWPE), Polyethylene (XLPE), Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK), cobalt-chromium (CoCr), Stainless steel, Zirconia Toughened Alumina (ZTA) and Alumina. Using routine tribological experiments, the wear for UHMWPE substrate was decreased by 75% against alumina, ZTA and stainless steel. For PEEK-CFR substrate coated, the amount of material lost against ZTA and CrCo was at least 40% lower. Experiments on hip simulator allowed coated ZTA femoral heads and coated UHMWPE cups to be validated with a decrease of 80% of loss material. Further experiments on hip simulator adding abrasive particles (1 micron sized alumina particles) during 3 million cycles, on a total of 6 million, demonstrated a decreased of around 55% of wear compared to uncoated UHMWPE and uncoated XLPE. In conclusion, CIDETEC‘s hydrogel coating technology is versatile and can be adapted to protect a large range of surfaces, even in abrasive conditions.

Keywords: cartilage, hydrogel, hydrophilic coating, joint

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Authors: Moohyun Lee, Soojung Hur, Yongwan Park

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In this paper is proposed a method uses only LIDAR system to classification an obstacle and determine its type by establishing database for classifying obstacles based on LIDAR. The existing LIDAR system, in determining the recognition of obstruction in an autonomous vehicle, has an advantage in terms of accuracy and shorter recognition time. However, it was difficult to determine the type of obstacle and therefore accurate path planning based on the type of obstacle was not possible. In order to overcome this problem, a method of classifying obstacle type based on existing LIDAR and using the width of obstacle materials was proposed. However, width measurement was not sufficient to improve accuracy. In this research, the width data was used to do the first classification; database for LIDAR intensity data by four major obstacle materials on the road were created; comparison is made to the LIDAR intensity data of actual obstacle materials; and determine the obstacle type by finding the one with highest similarity values. An experiment using an actual autonomous vehicle under real environment shows that data declined in quality in comparison to 3D LIDAR and it was possible to classify obstacle materials using 2D LIDAR.

Keywords: obstacle, classification, database, LIDAR, segmentation, intensity

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Authors: Gregory Schmidt

Abstract:

Solid-state lithium batteries are broadly accepted as promising candidates for application in the next generation of EVs as they should offer safer and higher-energy-density batteries. Nonetheless, their development is impeded by many challenges, including the resistive electrode–electrolyte interface originating from the removal of the liquid electrolyte that normally permeates through the porous cathode and ensures efficient ionic conductivity through the cell. One way to tackle this challenge is by formulating composite cathodes containing solid ionic conductors in their structure, but this approach will require the conductors to exhibit chemical stability, electrochemical stability, flexibility, and adhesion and is, therefore, limited to some materials. Recently, Arkema developed a technology called buffering layer which allows the transformation of any conventional porous electrode into a catholyte. This organic layer has a very high ionic conductivity at room temperature, is compatible with all active materials, and can be processed with conventional Gigafactory equipment. Moreover, this layer helps protect the solid ionic conductor from the cathode and anode materials. During this presentation, the manufacture and the electrochemical performance of this layer for different systems of cathode and anode will be discussed.

Keywords: electrochemistry, all solid state battery, materials, interface

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Authors: Harrys Purnama, Wardatul Jannah, Rizkia Nita Hawari

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In the development of the times, there are many materials used to plan a building structure. Steel became one of the most widely used materials in building construction that works as the main structure. Steel Castellated Beam is a type of innovation in the use of steel in building construction. Steel Castellated Beam is a beam that used for long span construction (more than 10 meters). The Castellated Beam is two steel profiles that unified into one to get the appropriate profile height (more than 10 meters). The profile is perforated to minimize the profile's weight, increase the rate, save costs, and have architectural value. The perforations shape in the Castellated Beam can be circular, elliptical, hexagonal, and rectangular. The Castellated beam has a height (h) almost 50% higher than the initial profile thus increasing the axial bending value and the moment of inertia (Iₓ). In this analysis, there are 3 specimens were used with 12.1 meters span of Castellated Beam as the sample with varied perforation, such us round, hexagon, and octagon. Castellated Beam testing system is done with computer-based applications that named Staad Pro V8i. It is to provide a central load in the middle of the steel beam span. It aims to determine the effect of perforation on bending behavior on the steel Castellated Beam by applying some form of perforations on the steel Castellated Beam with test specimen WF 200.100.5.5.8. From the analysis, results found the behavior of steel Castellated Beam when receiving such central load. From the results of the analysis will be obtained the amount of load, shear, strain, and Δ (deflection). The result of analysis by using Staad Pro V8i shows that with the different form of perforations on the profile of Castellated steel, then we get the different tendency of inertia moment. From the analysis, results obtained the moment of the greatest inertia can increase the stiffness of Castellated steel. By increasing the stiffness of the steel Castellated Beam the deflection will be smaller, so it can withstand the moment and a large strength. The results of the analysis show that the most effective and efficient perforations are the steel beam with a hexagon perforation shape.

Keywords: Castellated Beam, the moment of inertia, stress, deflection, bending test

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Authors: Chun-Yu Chen, Kua-Rong Wu, Yu-Cheng Chen, Perng-Jy Tsai

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Cooking fumes are known containing polycyclic aromatic hydrocarbons (PAHs) and aldehydes, and some of them have been proven carcinogenic or possibly carcinogenic to humans. Considering their chronic health effects, long-term exposure data is required for assessing cooking workers’ lifetime health risks. Previous exposure assessment studies, due to both time and cost constraints, mostly were based on the cross-sectional data. Therefore, establishing a long-term exposure data has become an important issue for conducting health risk assessment for cooking workers. An approach was proposed in this study. Here, the generation rates of both PAHs and aldehydes from a cooking process were determined by placing a sampling train exactly under the under the exhaust fan under the both the total enclosure condition and normal operating condition, respectively. Subtracting the concentration collected by the former (representing the total emitted concentration) from that of the latter (representing the hood collected concentration), the fugitive emitted concentration was determined. The above data was further converted to determine the generation rates based on the flow rates specified for the exhaust fan. The determinations of the above generation rates were conducted in a testing chamber with a selected cooking process (deep-frying chicken nuggets under 3 L peanut oil at 200°C). The sampling train installed under the exhaust fan consisted respectively an IOM inhalable sampler with a glass fiber filter for collecting particle-phase PAHs, followed by a XAD-2 tube for gas-phase PAHs. The above was also used to sample aldehydes, however, installed with a filter pre-coated with DNPH, and followed by a 2,4-DNPH-cartridge for collecting particle-phase and gas-phase aldehydes, respectively. PAHs and aldehydes samples were analyzed by GC/MS-MS (Agilent 7890B), and HPLC-UV (HITACHI L-7100), respectively. The obtained generation rates of both PAHs and aldehydes were applied to the near-field/ far-field exposure model to estimate the exposures of cooks (the estimated near-field concentration), and helpers (the estimated far-field concentration). For validating purposes, both PAHs and aldehydes samplings were conducted simultaneously using the same sampling train at both near-field and far-field sites of the testing chamber. The sampling results, together with the use of the mixed-effect model, were used to calibrate the estimated near-field/ far-field exposures. In the present study, the obtained emission rates were further converted to emission factor of both PAHs and aldehydes according to the amount of food oil consumed. Applying the long-term food oil consumption records, the emission rates for both PAHs and aldehydes were determined, and the long-term exposure databanks for cooks (the estimated near-field concentration), and helpers (the estimated far-field concentration) were then determined. Results show that the proposed approach was adequate to determine the generation rates of both PAHs and aldehydes under various fan exhaust flow rate conditions. The estimated near-field/ far-field exposures, though were significantly different from that obtained from the field, can be calibrated using the mixed effect model. Finally, the established long-term data bank could provide a useful basis for conducting long-term exposure assessments for cooking workers exposed to PAHs and aldehydes.

Keywords: aldehydes, cooking oil fumes, long-term exposure assessment, modeling, polycyclic aromatic hydrocarbons (PAHs)

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Authors: Abdullah Alsehaimi

Abstract:

Over decades, there have been many studies of delay in construction, and this type of study continues to be popular in construction management research. A synthesis and critical evaluation of delay studies in developing countries reveals that poor project management is cited as one of the main causes of delay. However, despite such consensus, most of the previous studies fall short in providing clear recommendations demonstrating how project management practice could be improved. Moreover, the majority of recommendations are general and not devoted to solving the difficulties associated with particular delay causes. This paper aims to demonstrate that the root cause of this state of affairs is that typical research into delay tends to be descriptive and explanatory, making it inadequate for solving persistent managerial problems in construction. It is contended that many problems in construction could be mitigated via alternative research approaches, i.e. action and constructive research. Such prescriptive research methods can assist in the development and implementation of innovative tools tackling managerial problems of construction, including that of delay. In so doing, those methods will better connect research and practice, and thus strengthen the relevance of academic construction management.

Keywords: construction delay, action research, constructive research, industrial engineering

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