Search results for: load test

Authors: Imad Buishi, Almabrouk Fares, Hallowma Helmi

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Infection with verocytotoxin-producing Escherichia coli O157 in humans can lead to mild or bloody diarrhea with the hemolytic uremic syndrome (HUS) as a possible complication. Cattle appear to be important reservoirs for VTEC O157. Epidemiologic studies on the prevalence of VTEC O157 in dairy cattle in Libya have never been conducted. To investigate the prevalence and the risk factors associated with VTEC O157 on dairy farms in Tripoli region, fecal samples from 200 apparently healthy cows were collected once from 15 randomly selected dairy farms in the period July 2010 through September 2010. All fecal samples were examined for the prevalence of VTEC O157 by conventional plating using Sorbitol-MacConkey agar (SMAC). Isolated of E. coli were subjected to slide agglutination test using E. coli O157 antiserum. The results pointed out that the prevalence within-herd and among herds were 9% and 60% respectively. The prevalence of VTEC O157 in fecal samples of dairy cattle was significantly associated with husbandry practices on farm-level such as signs of diarrhoea (p=0.02, OR=3.2) and sharing water trough (p= 0.03, OR=3.0). It was concluded that dairy cattle in Tripoli area are important reservoirs of VTEC O157 strains that are potentially pathogenic for humans. When aiming at reducing risks for human by intervention at farm-level, it is of importance to reduce the number of positive animals and farms. For this, more research is needed to devise mitigation strategies that will reduce the on-farm contamination of VTEC O157.

Keywords: VTEC O157, prevalence, dairy cattle, tripoli

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Authors: Zeineb Ben Salem, Wissem Frikha, Mounir Bouassida

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Liquefaction has been responsible for tremendous amounts of damage in historical earthquakes around the world. The installation of stone columns is widely adopted to prevent liquefaction. Stone columns provide a drainage path, and due to their high permeability, allow for the quick dissipation of earthquake generated excess pore water pressure. Several excess pore pressure generation models in silty sand have been developed and calibrated based on the results of shaking table and centrifuge tests focusing on the effect of silt content on liquefaction resistance. In this paper, the generation and dissipation of excess pore pressure variation of reinforced silty sand by stone columns during liquefaction are analyzedwith different silt content based on test results. In addition, the installation effect of stone columns is investigated. This effect is described by a decrease in horizontal permeability within a disturbed zone around the column. Obtained results show that reduced soil permeability and a larger disturbed zone around the stone column increases the generation of excess pore pressure during the cyclic loading and decreases the dissipation rate after cyclic loading. On the other hand, beneficial effects of silt content were observed in the form of a decrease in excess pore water pressure.

Keywords: stone column, liquefaction, excess pore pressure, silt content, disturbed zone, reduced permeability

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Authors: Jeremiah Madzimure

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In order to stay competitive in business and improve performance, Small and Medium Enterprises (SMEs) need to make use of business networking and logistics integration. Strategic networking and logistics integration in business companies have become critical as they allow supplier partnering, exchange of vital information/ access to valuable resources allowing innovation, gaining access to additional resources, sharing risks and costs which is required for enhancing company performance. The purpose of this study was to examine the influence of strategic networks and logistics integration on company performance: the case of small and medium enterprises in South Africa. A quantitative research design was adopted in this study, and 137 SMEs owners and managers completed and returned the survey questionnaire. Confirmatory Factor Analysis (CFA) was conducted using the Analysis of Moment Structures (AMOS), version 24.0 to assess psychometric properties of the measurement scales. Path modelling techniques were used to test the proposed hypothesis. Three research hypotheses were postulated. The results indicate that strategic networks had a positive and significant influence on logistics integration and company performance. As well logistics integration had a strong positive and significant influence on company performance. This study provides a useful model for analysing the relationship between strategic networks and logistics integration on company performance. Moreover, the findings of the study provide useful insights into how SMEs should benefit from business networking and logistics integration so as to improve their performance. The implications of the study are discussed, and finally, limitations and recommendations are indicated.

Keywords: strategic networking, logistics integration, company performance, SMEs

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Authors: Farnaz Firuzian, Farhad Choobdar, Ali Mazouri

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As Very Low Birth Weight (VLBW) neonates cannot tolerate enteral feeding, parenteral nutrition (PN) must be administered shortly after birth. To find an optimal combination of nutrition, in this study, we compare administering high glucose versus high protein intake as a component of total parenteral nutrition (TPN) to test their effect on birth weight (BW) regain in VLBW. This study employs a multi-arm randomized trial: 145 newborns with BW < 1500 g were randomized to control (C) or experimental groups: high glucose (G) or high protein (P). All samples in each group received the same TPN regimens except glucose and protein intake: Glocuse was provided by dextrose water (DW) serum: 7-15 g/kg/d (10% DW) in groups C and P versus 8.75-18.75 g/kg/d (12.5% DW) in group G. Protein provided by amino acids 3 g/kg/d for groups C and G versus 4 g/kg/d for group P. Outcomes (weight, height, and head circumference) was monitored on a daily basis until the BW was regained. Data has been gathered recently and is being processed. We hypothesize that neonates with higher amino acid intake will result in sooner BW regain than other groups. The result will be presented at the conference. The findings of this study not only can help optimize nutrition, cost reduction, and shorter NICU admission of VLBW neonates at the hospital level but eventually contribute to reduced healthcare-associated infections (HAIs) and an improved health economy.

Keywords: very low birth weight neonates, weight gain, parenteral nutrition, glucose, amino acids

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Authors: Praveena Nair Sivasankaran, Thomas Arthur Ward, Rubentheren Viyapuri

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Paper describes a methodology to fabricate a simplified dragonfly wing structure using balsa wood and red prepreg fibre glass. These simplified wing structures were created for use in Biomimetic Micro Air Vehicles (BMAV). Dragonfly wings are highly corrugated and possess complex vein structures. In order to mimic the wings function and retain its properties, a simplified version of the wing was designed. The simplified dragonfly wing structure was created using a method called spatial network analysis which utilizes Canny edge detection method. The vein structure of the wings were carved out in balsa wood and red prepreg fibre glass. Balsa wood and red prepreg fibre glass was chosen due to its ultra- lightweight property and hence, highly suitable to be used in our application. The fabricated structure was then immersed in a nanocomposite solution containing chitosan as a film matrix, reinforced with chitin nanowhiskers and tannic acid as a crosslinking agent. These materials closely mimic the membrane of a dragonfly wing. Finally, the wings were subjected to a bending test and comparisons were made with previous research for verification. The results had a margin of difference of about 3% and thus the structure was validated.

Keywords: dragonfly wings, simplified, Canny edge detection, balsa wood, red prepreg, chitin, chitosan, tannic acid

Procedia PDF Downloads 333

Authors: A. Myrzabekova, D. Nurmukhamed, K. Nurumov, A. Zhulbarissova

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It is widely believed that stress can affect teachers’ intention to change the workplace. While existing research primarily focuses on the intrinsic sources of stress stemming from the school climate, the current attempt analyzes educational policies as one of the determinants of teacher’s intention to leave schools. In this respect, Kazakhstan presents a unique case since the country endorsed several educational policies which directly impacted teaching and administrative practices within schools. Using Teaching and Learning International Survey 2018 (TALIS) data with the country specific questionnaire, we construct a statistical measure of stress caused by the implementation of educational policies and test its impact on teacher’s intention to leave through the logistic regression. In addition, we control for sociodemographic, professional, and students related covariates while considering the intrinsic dimension of stress stemming from the school climate. Overall, our results suggest that stress caused by the educational policies has a statistically significant positive effect on teachers’ intentions to transfer between schools. Both policy makers and educational scholars could find these results beneficial. For the former careful planning and addressing the negative effects of the educational policies is critical for the sustainability of the educational process. For the latter, accounting for exogenous sources of stress can lead to a more complete understanding of why teachers decide to change their schools.

Keywords: educational policies, Kazakhstani teachers, logistic regression factor analysis, sustainability education TALIS, teacher turnover intention, work stress

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Authors: N. L. S. Ahmad, Y. L. Thong, P. Nambiar

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An in vitro study was carried out to evaluate the feasibility of small field of view (FOV) cone beam computed tomography (CBCT) in determining endodontic working length. The objectives were to determine the accuracy of CBCT in measuring the estimated preoperative working lengths (EPWL), endodontic working lengths (EWL) and file lengths. Access cavities were prepared in 27 molars. For each root canal, the baseline electronic working length was determined using an EAL (Raypex 5). The teeth were then divided into overextended, non-modified and underextended groups and the lengths were adjusted accordingly. Imaging and measurements were made using the respective software of the RVG (Kodak RVG 6100) and CBCT units (Kodak 9000 3D). Root apices were then shaved and the apical constrictions viewed under magnification to measure the control working lengths. The paired t-test showed a statistically significant difference between CBCT EPWL and control length but the difference was too small to be clinically significant. From the Bland Altman analysis, the CBCT method had the widest range of 95% limits of agreement, reflecting its greater potential of error. In measuring file lengths, RVG had a bigger window of 95% limits of agreement compared to CBCT. Conclusions: (1) The clinically insignificant underestimation of the preoperative working length using small FOV CBCT showed that it is acceptable for use in the estimation of preoperative working length. (2) Small FOV CBCT may be used in working length determination but it is not as accurate as the currently practiced method of using the EAL. (3) It is also more accurate than RVG in measuring file lengths.

Keywords: accuracy, CBCT, endodontics, measurement

Procedia PDF Downloads 309

Authors: Elucir Gir, Myllena Nilce de Freitas Surmano, Laelson Rochelle Milanês Sousa, Mayra Gonçalves Menegueti, Ana Cristina de Oliveira E Silva, Renata Karina Reis

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Objective: To analyze the factors associated with the worsening of the quality of life of health professionals in the Southeast region of Brazil during the COVID-19 pandemic and its associated factors. Method: Analytical cross-sectional study carried out with health professionals from the southeastern region of Brazil. Data collection took place through an online survey with a form stored on the Survey Monkey platform. Bivariate analysis was used, and the chi-square test was adopted, followed by the multiple binary logistic regression model based on the stepwise method. Results: 3,493 health professionals participated in the study. Factors associated with worsening quality of life were: Professional Category (Nursing assistant) [OR 1.851 (95%CI 1.035-3.311) p= 0.038]; types of people who provided care (people in general) [OR 1.445 (95%CI 1.072-1.945) p=0.015]; Supply of good quality PPE by the institution where he works (no) [OR 1.595 (CI 95% 1.144-2.223) p= 0.006] and Supply of good quality PPE by the institution where he works (in part) [OR 1.563 (CI 95% 1.257-1.943) p < 0.001]. Conclusion: The factors associated with the worsening of the quality of life of health professionals during the COVID-19 pandemic were: Professional Category (Nursing assistant); types of people who provided assistance (people in general); Supply of sufficient PPE by the institution where you work (no) and Supply of good quality PPE by the institution where you work (in part). Future studies should investigate to what extent QoL can be improved based on modifiable factors.

Keywords: COVID-19, quality of life, health professionals, respiratory infections

Procedia PDF Downloads 93

Authors: Jarel Elgin Tolentino, Arby Denise Nera, Mary Rose Roco, Angela Vianca Aspa, Nikko Beltran, Else Dapat

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Drug resistance by cells has been the problem in the medical field for decades now. The use of medicinal plants as a source of creating powerful drugs has been nowadays recognized worldwide to treat such resistant diseases. In the present study, the potential for Diospyros philippinensis A. DC. to inhibit growth of both bacteria and cancer cell line was conducted. The leaf crude extracts were screened for the presence of phytochemicals and examined for potential bioactivities by employing several assays like Kirby-Bauer disc diffusion method, DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay for the antibacterial, antioxidant and cytotoxic activities of the extract, respectively. Phytochemical test results of the extracts revealed the presence of alkaloids, flavonoids, saponins, phenols, quinones, cardiac glycosides, phlobatannins, carbohydrate, cardenolides and proteins. The leaf extracts were found to exhibit antibacterial activity against gram-positive bacteria, high antioxidant activity (99.22% ± 0.005) but did not show any sign of cytotoxicity towards HCT116 (ATCC CCL-247). The study therefore concludes that D. philippinensis A. DC. leaf extract can be a source of antibacterial and chemopreventive agents. This claim may be used as basis for future investigation.

Keywords: bioassay, medicinal plants, plant crude extracts, phytochemical screening

Procedia PDF Downloads 287

Authors: Punam Shaw

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Relationship often refers to the acquaintance or association between two or more things, which are interrelated and interdependent. The socio-economic status is obviously a blending of two states, would, therefore, be a ranking of an individual by the society he or she lives in, and in terms of his/her material belonging, cultural possessions along with the degree of respect, power and influence wield. Hence, education, income and occupation of an individual play a significant role in society. Positive mental attitude leads to achieve the set goal, and improve performance particularly in team cohesiveness, which may be determined by various interrelated aspects, which can predict the future assessment in their respective field accordingly. The study intended to examine and explore the relationship between Socio-economic Status and Mental Toughness of cricketers. For the present study descriptive survey research method was used and selected 40 (male=20 female=20) U-17 years registered players under Cricket Association of Bengal (CAB), as the sample population. Modified Socio-Economic Status Scale was used to collect the data regarding players, socioeconomic Status and to assess the mental toughness; Scott Barry Kaufman questionnaire was used. The data had been analysed through applying Pearson’s Correlation Coefficient and t-test as statistical techniques. The findings of the study showed that there is a positive correlation between socioeconomic Status and Mental Toughness among cricketers, it was found that significant difference was presented between male and female SES group. It was further revealed that there is no significant difference between male and female cricketers and in their different socioeconomic class with respect to their mental toughness.

Keywords: cricketers, mental toughness, relationship, socio-economic status

Procedia PDF Downloads 125

Authors: Chadia Nasri

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Researches in the field of foreign language learning have indicated the importance of the mastery of the four language skills; speaking, listening, writing and reading. As far as writing is concerned, recent studies have shown that this skill is unavoidable for learning a second language successfully. Writing is characterized as a complex system not easy to achieve. Writing has been proved to be affected by a variety of factors, particularly psychological ones; anxiety, intrinsic motivation, aptitude, etc. Intrinsic motivation is said to be the most influential factors in the foreign language learning process and is considered as the key factor for success. To investigate these two aspects; writing and intrinsic motivation, and the positive correlation between them, our hypothesis is designed on the basis that the degree of learners’ intrinsic motivation helps in facilitating their engagement in the writing tasks. Two questionnaires, one for teachers and the other for students, have been carried out to check the validity of the research hypothesis. As for the teachers’ questionnaire, the results have indicated their awareness of the importance of intrinsic motivation in the learning process and the role it plays in the mastery of their students’ writing skill. In addition, teachers have mentioned various procedures aiming at raising their students’ intrinsic motivation to write. The students’ questionnaire, on the other hand, has investigated students’ reasons for learning a foreign language with regard to their attitudes towards writing as an important skill that they need to master. Their answers to the questionnaire together with the marks they got in the second term test they have had in the writing module have been compared to see whether students’ writing proficiency can be determined by the degree of their intrinsic motivation. The comparison of the collected data has shown the positive correlation between both aspects.

Keywords: foreign language learning, intrinsic motivation, motivation, writing proficiency

Procedia PDF Downloads 293

Authors: Nioushasadat Haji Seyed Javadi, Ailar Hajimohammadi, Nasser Khalili

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The common method to improve the performance of asphalt binders is through modification. The utilization of recycled plastics for asphalt modification has been the subject of research studies due to their environmental and economic benefits over using commercial polymers. Polypropylene (PP) is one of the most available recycled plastics in Australia. Unlike other plastics, its contamination with other plastics during the recycling process is negligible. Therefore, the quality of recycled plastic is high, which makes it a good candidate for road construction applications. To assess its effectiveness for bitumen modification, three different grades of PP were selected. The PP grades were compared for blendability with bitumen, and the best suitable grade was chosen for further studies. The PP-modified bitumen and the base bitumen were then compared through physical and rheological properties. The stability of the PP-modified bitumen at elevated temperatures was measured, and the morphology of the samples before and after the storage stability was characterized by fluorescent microscopy. The results showed that PP had a significant influence on reducing the penetration and increasing the viscosity and the rutting resistance of the virgin bitumen. Storage stability test results indicated that the difference between the softening point of the top and bottom section of the tube sample is below the defined limit, which means the PP-modified bitumen is storage stable. However, the fluorescence microscopy results showed that the distribution of the PP particles in the bitumen matrix in the top and bottom sections of the tube are significantly different, which is an indicator of poor storage stability.

Keywords: polypropylene, waste plastic, bitumen, road pavements, storage stability, fluorescent microscopy, morphology

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Authors: Mohammad Ali Fteiha, Ghanem Al Bustami

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The study aimed to identify the assessment of parents of children with Autism for services provided by the Center for special care in the United Arab Emirates, in terms of quality, comprehensive and the impact of some factors related to the diagnosis and place of service provision and efficient working procedures of service and the child age. In order to achieve the objective of the study, researchers used Parent’s Satisfaction Scale, and Parents Evaluation of Services Effectiveness, both the scale and the parents reports provided with accepted level of validity and reliability. Sample includes 300 families of children with Autism receiving educational and rehabilitation services, treatment and support services in both governmental and private centers in United Arab Emirates. ANOVA test was used through SPSS program to analyze the collected data. The results of the study have indicated that there are significant differences in the assessment of services provided by centers due to a place of service, the nature of the diagnosis, child's age at the time of the study, as well as statistically significance differences due to age when first diagnosed. The results also showed positive evaluation for the good level of services as international standard, and the quality of these services provided by autism centers in the United Arab Emirates, especially in governmental centers. At the same time, the results showed the presence of many needs problems faced by the parents do not have appropriate solutions. Based on the results the recommendations were stated.

Keywords: autism, evaluation, diagnosis, parents, autism programs, supportive services, government centers, private centers

Procedia PDF Downloads 559

Authors: V. Pizarro-Carmona, S. Castano-Solis, M. Cortés-Carmona, J. Fraile-Ardanuy, D. Jimenez-Bermejo

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The purpose of this article is to optimize the Equivalent Electric Circuit Model (EECM) of different orders to obtain greater precision in the modeling of Li-ion battery packs. Optimization includes considering circuits based on 1RC, 2RC and 3RC networks, with a dependent voltage source and a series resistor. The parameters are obtained experimentally using tests in the time domain and in the frequency domain. Due to the high non-linearity of the behavior of the battery pack, Genetic Algorithm (GA) was used to solve and optimize the parameters of each EECM considered (1RC, 2RC and 3RC). The objective of the estimation is to minimize the mean square error between the measured impedance in the real battery pack and those generated by the simulation of different proposed circuit models. The results have been verified by comparing the Nyquist graphs of the estimation of the complex impedance of the pack. As a result of the optimization, the 2RC and 3RC circuit alternatives are considered as viable to represent the battery behavior. These battery pack models are experimentally validated using a hardware-in-the-loop (HIL) simulation platform that reproduces the well-known New York City cycle (NYCC) and Federal Test Procedure (FTP) driving cycles for electric vehicles. The results show that using GA optimization allows obtaining EECs with 2RC or 3RC networks, with high precision to represent the dynamic behavior of a battery pack in vehicular applications.

Keywords: Li-ion battery packs modeling optimized, EECM, GA, electric vehicle applications

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Authors: Hang Ju, Changmin Zhu

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The development level of the BeiDou Navigation Satellite System (BDS) can strongly reflect national defense strength as an important spatial information infrastructure. BDS can be not only used for military purposes, such as intelligence gathering, nuclear explosion monitoring, emergency communications, but also for location services, transportation, mapping, precision agriculture. In order to ensure the national defense security and the wide application of BDS in civil and military areas, BDS must be autonomous and controllable. As a complex system of knowledge-intensive, knowledge transformation runs through the whole process of research and development, production, operation, and maintenance of BDS. Based on the perspective of knowledge transformation, this paper expounds on the meaning of socialization, externalization, combination, and internalization of knowledge transformation, and the coupling relationship of autonomy and control on the basis of analyzing the status quo and problems of the autonomy and control of BDS. The autonomous and controllable framework of BDS based on knowledge transformation is constructed from six dimensions of management capability, R&D capability, technical capability, manufacturing capability, service support capability, and application capability. It can provide support for the smooth implementation of information security policy, provide a reference for the autonomy and control of the upstream and downstream industrial chains in Beidou, and provide a reference for the autonomous and controllable research of aerospace components, military measurement test equipment, and other related industries.

Keywords: knowledge transformation, BeiDou Navigation Satellite System, autonomy and control, framework

Procedia PDF Downloads 186

Authors: France Phiri, Arnold Kanengoni, Dawood Hattas, Khanyisile Mbatha

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A study was carried out to determine seasonal changes in fiber composition and condensed tannin (CT) concentrations in Rhus lancea and Celtis africana and their effects on feed intake and blood metabolites in mixed-feeders. Rhus lancea and C. africana were analysed for dry matter (DM), acid detergent lignin (ADL), acid detergent fiber (ADF), neutral detergent fiber (NDF) and CT concentrations over four seasons; early wet (EWS), late wet (LWS), early dry (EDS) and late dry (LDS). Twelve indigenous male goats were kept in metabolic crates for periods of 21 days per season and fed one of two diet combinations; the test diet comprised R. lancea and C. africana (denoted as BROWSE) and the lucerne diet comprised lucerne (Medicago sativa and concentrates (CON). Feed intake, body weight and blood metabolites were determined in all goats over each study period. Goats fed BROWSE in the EDS, LDS and LWS lost weight while goats fed CON gained weight (P < 0.05). Goats fed CON had higher urea, alkaline phosphatase and gamma-glutamyl transferase concentrations than those fed BROWSE (P < 0.05). Creatinine and cholesterol concentrations in all goats across LWS, EDS and LDS were lower than the normal range, while total protein and globulin concentrations were higher. The goats fed BROWSE had higher creatinine concentrations (P < 0.05) than those fed CON. Cholesterol concentrations were higher (P < 0.05) in goats fed BROWSE than in those on CON fed. It was concluded that goats fed BROWSE lost weight, indicating insufficient nutrients for maintenance requirements.

Keywords: fiber, maintenance, condense tannins, blood metabolites

Procedia PDF Downloads 195

Authors: Hsi Wei

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Does the language we speak affect the way we think? This question has been discussed for a long time from different aspects. In this article, the issue is examined with an experiment on how speakers of different languages tend to do different sequencing when it comes to the size of general objects. An essential difference between the usage of English and Mandarin is the way we sequence the size of places or objects. In English, when describing the location of something we may say, for example, ‘The pen is inside the trashcan next to the tree at the park.’ In Mandarin, however, we would say, ‘The pen is at the park next to the tree inside the trashcan.’ It’s clear that generally English use the sequence of small to big while Mandarin the opposite. Therefore, the experiment was conducted to test if the difference of the languages affects the speakers’ ability to do the different sequencing. There were two groups of subjects; one consisted of English native speakers, another of Mandarin native speakers. Within the experiment, three nouns were showed as a group to the subjects as their native languages. Before they saw the nouns, they would first get an instruction of ‘big to small’, ‘small to big’, or ‘repeat’. Therefore, the subjects had to sequence the following group of nouns as the instruction they get or simply repeat the nouns. After completing every sequencing and repetition in their minds, they pushed a button as reaction. The repetition design was to gather the mere reading time of the person. As the result of the experiment showed, English native speakers reacted more quickly to the sequencing of ‘small to big’; on the other hand, Mandarin native speakers reacted more quickly to the sequence ‘big to small’. To conclude, this study may be of importance as a support for linguistic relativism that the language we speak do shape the way we think.

Keywords: language, linguistic relativism, size, sequencing

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Authors: A. D. Loureiro, L. Ventura

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Exposure to high-energy blue light has been strongly linked to the development of some eye diseases, such as age-related macular degeneration. Over the past few years, people have become more and more concerned about eye damage from blue light and how it can be prevented. We developed a prototype that allows users to self-check the blue light protection of their sunglasses and determines if the protection is adequate. Weighting functions approximating those defined in ISO 12312-1 were used to measure the luminous transmittance and blue light transmittance of sunglasses. The blue light transmittance value must be less than 1.2 times the luminous transmittance to be considered adequate. The prototype consists of a Golden Dragon Ultra White LED from OSRAM and a TCS3472 photodetector from AMS TAOS. Together, they provide four transmittance values weighted with different functions. These four transmittance values were then linearly combined to produce transmittance values with weighting functions close to those defined in ISO 12312-1 for luminous transmittance and for blue light transmittance. To evaluate our prototype, we used a VARIAN Cary 5000 spectrophotometer, a gold standard in the field, to measure the luminous transmittance and the blue light transmittance of 60 sunglasses lenses. (and Bland-Altman analysis was performed) Bland-Altman analysis was performed and showed non-significant bias and narrow 95% limits of agreement within predefined tolerances for both luminous transmittance and blue light transmittance. The results show that the prototype is a viable means of providing blue light protection information to the general public and a quick and easy way for industry and retailers to test their products. In addition, our prototype plays an important role in educating the public about a feature to look for in sunglasses before purchasing.

Keywords: blue light, sunglasses, eye protective devices, transmittance measurement, standards, ISO 12312-1

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Authors: Yu-Shan Wu, Po-Liang Lai, I-Ming Chu

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Poly(methylmethacrylate)(PMMA) is the most frequently used bone void filler for vertebral augmentation in osteoporotic fracture. PMMA bone cement not only exhibits strong mechanical properties but also can fabricate according to the shape of bone defect. However, the adhesion between the PMMA-based cement and the adjacent bone is usually weak and as PMMA bone cement is inherently bioinert. The combination of bioceramics and polymers as composites may increase cell adhesion and improve biocompatibility. The nano-hydroxyapatite(HAP) not only plays a significant role in maintaining the properties of the natural bone but also offers a favorable environment for osteoconduction, protein adhesion, and osteoblast proliferation. However, defects and cracks can form at the polymer/ceramics interface, resulting in uneven distribution of stress and subsequent inferior mechanical strength. Surface-modified HAP nano-crystals were prepared by chemically grafting poly(ε-caprolactone)(PCL) on surface-modified nano-HAP surface to increase the affinity of polymer/ceramic phases .Thus, incorporation of surface-modified nano-hydroxyapatite (EC-HAP) may not only improve the interfacial adhesion between cement and bone and between nanoparticles and cement, but also increase biocompatibility. In this research, PMMA mixing with 0, 5, 10, 15, 20, 25 and 30 wt% EC-HAP were examined. MC3T3-E1 cells were used for the biological evaluation of the response to the cements in vitro. Morphology was observed using scanning electron microscopy (SEM). Mechanical properties of HAP/PMMA and EC-HAP/PMMA cement were investigated by compression test. Surface wettability of the cements was measured by contact angles.

Keywords: bone cement, biocompatibility, nano-hydroxyapatite, polycaprolactone, PMMA, surface grafting

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Authors: Lobna Mnif Fakhfakh, Mohamed Chaieb

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Most ecological studies in North Africa arid bioclimate reveal a process of continuous degradation of pastoral ecosystems as a result of overgrazing during a long time. This degradation appears across the depletion of perennial grass species. Indeed, the majority of steppe ecosystems are characterized by a low density of perennial grasses. The objective of the present work is to examine the phenology and the above ground growth of several Stipagrostis ciliata accessions, growing under different arid bioclimate of North Africa (case of Tunisia). The results of the ANOVA test, next to the mean values of all measurements show significant differences in all morphological parameters of S. ciliata accessions. Plant diameter, biovolume, root biomass with protective sleeve and spike number show very significant. Differences between S. ciliata accessions. Significance tests for the differences of means indicate high distinctiveness of accessions. Pearson’s correlation analysis of the morphological traits suggests that these traits are significantly and positively correlated. Cluster analysis indicates overall differences among accessions and exhibits the presence of three clusters. The Principal component analysis (PCA) is applied on a table with four observations and 12 variables. Dispersion of Stipagrostis ciliata accessions on the first two axes of principal component analysis confirms the presence of three groups of plants. The characterization of Stipagrostis ciliata plants has shown that significant differences exist in terms of morphological and phenological parameters.

Keywords: accession, morphology, phenology, Stipagrostis ciliata

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Authors: Habib Alehossein, M. S. K. Fernando

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Soil density depends on the volume of the voids and the proportion of the water and air in the voids. However, there is a limit to the contraction of the voids at any given compaction energy, whereby additional water is used to reduce the void volume further by lubricating the particles' frictional contacts. Hence, at an optimum moisture content and specific compaction energy, the density of unsaturated soil can be maximized where the void volume is minimum. However, when considering a full compaction curve and permutations and variations of all these components (soil, air, water, and energy), laboratory soil compaction tests can become expensive, time-consuming, and exhausting. Therefore, analytical methods constructed on a few test data can be developed and used to reduce such unnecessary efforts significantly. Concentrating on the compaction testing results, this study discusses the analytical modelling method developed for some fine-grained and coarse-grained soils of Queensland. Soil properties and characteristics, such as full functional compaction curves under various compaction energy conditions, were studied and developed for a few soil types. Using MATLAB, several generic analytical codes were created for this study, covering all possible compaction parameters and results as they occur in a soil mechanics lab. These MATLAB codes produce a family of curves to determine the relationships between the density, moisture content, void ratio, saturation, and compaction energy.

Keywords: analytical, MATLAB, modelling, compaction curve, void ratio, saturation, moisture content

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Authors: S. Zith Dey Babu, S. Kour, S. Verma, C. Verma, V. Pathania, A. Agrawal, V. Chaudhary, A. Manoj Puthur, R. Goyal, A. Pal, T. Danti Dey, A. Kumar, K. Wadhwa, O. Ved

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Background: Skin cancer is now is the buzzing button in the field of medical science. The cyst's pandemic is drastically calibrating the body and well-being of the global village. Methods: The extracted image of the skin tumor cannot be used in one way for diagnosis. The stored image contains anarchies like the center. This approach will locate the forepart of an extracted appearance of skin. Partitioning image models has been presented to sort out the disturbance in the picture. Results: After completing partitioning, feature extraction has been formed by using genetic algorithm and finally, classification can be performed between the trained and test data to evaluate a large scale of an image that helps the doctors for the right prediction. To bring the improvisation of the existing system, we have set our objectives with an analysis. The efficiency of the natural selection process and the enriching histogram is essential in that respect. To reduce the false-positive rate or output, GA is performed with its accuracy. Conclusions: The objective of this task is to bring improvisation of effectiveness. GA is accomplishing its task with perfection to bring down the invalid-positive rate or outcome. The paper's mergeable portion conflicts with the composition of deep learning and medical image processing, which provides superior accuracy. Proportional types of handling create the reusability without any errors.

Keywords: computer-aided system, detection, image segmentation, morphology

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Authors: Mengjiao Fan, Thomson W. L. Wong

Abstract:

It is unavoidable that older adults may have to deal with aging-related motor problems. Aging is highly likely to affect motor learning and control as well. For example, older adults may suffer from poor motor function and quality of life due to age-related eye changes. These adverse changes in vision results in impairment of movement automaticity. Reaching is a fundamental component of various complex movements, which is therefore beneficial to explore the changes and adaptation in visuomotor behaviors. The current study aims to explore how aging affects visuomotor behaviors by comparing motor performance and gaze behaviors between two age groups (i.e., young and older adults). Visuomotor behaviors in reaching under providing or blocking online visual feedback (simulated visual deficiency) conditions were investigated in 60 healthy young adults (Mean age=24.49 years, SD=2.12) and 37 older adults (Mean age=70.07 years, SD=2.37) with normal or corrected-to-normal vision. Participants in each group were randomly allocated into two subgroups. Subgroup 1 was provided with online visual feedback of the hand-controlled mouse cursor. However, in subgroup 2, visual feedback was blocked to simulate visual deficiency. The experimental task required participants to complete 20 times of reaching to a target by controlling the mouse cursor on the computer screen. Among all the 20 trials, start position was upright in the center of the screen and target appeared at a randomly selected position by the tailor-made computer program. Primary outcomes of motor performance and gaze behaviours data were recorded by the EyeLink II (SR Research, Canada). The results suggested that aging seems to affect the performance of reaching tasks significantly in both visual feedback conditions. In both age groups, blocking online visual feedback of the cursor in reaching resulted in longer hand movement time (p < .001), longer reaching distance away from the target center (p<.001) and poorer reaching motor accuracy (p < .001). Concerning gaze behaviors, blocking online visual feedback increased the first fixation duration time in young adults (p<.001) but decreased it in older adults (p < .001). Besides, under the condition of providing online visual feedback of the cursor, older adults conducted a longer fixation dwell time on target throughout reaching than the young adults (p < .001) although the effect was not significant under blocking online visual feedback condition (p=.215). Therefore, the results suggested that different levels of visual feedback during movement execution can affect gaze behaviors differently in older and young adults. Differential effects by aging on visuomotor behaviors appear on two visual feedback patterns (i.e., blocking or providing online visual feedback of hand-controlled cursor in reaching). Several specific gaze behaviors among the older adults were found, which imply that blocking of visual feedback may act as a stimulus to seduce extra perceptive load in movement execution and age-related visual degeneration might further deteriorate the situation. It indeed provides us with insight for the future development of potential rehabilitative training method (e.g., well-designed errorless training) in enhancing visuomotor adaptation for our aging population in the context of improving their movement automaticity by facilitating their compensation of visual degeneration.

Keywords: aging effect, movement automaticity, reaching, visuomotor behaviors, visual degeneration

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Authors: Bavneet Kaur Sidhu, Manoj Tiwari

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Global Developmental Delay (GDD) is a common pediatric condition. Etiologies of GDD might, however, differ in developing countries. In the last decade, sporadic families are being reported in various countries. As to the author’s best knowledge, many risk factors and their correlation with the prevalence of GDD have been studied but its statistical correlation has not been done. Thus we propose the present study by targeting the risk factor, prevalence and their statistical correlation with GDD. FMR1 gene was studied to confirm the disease and its penetrance. A complete questionnaire-based performance was designed for the statistical studies having a personal, past and present medical history along with their socio-economic status as well. Methods: We distributed the children’s age in 4 different age groups having 5-year intervals and applied structural equation modeling (SEM) techniques, Spearman’s rank correlation coefficient, Karl Pearson correlation coefficient, and chi-square test.Result: A total of 1100 families were enrolled for this study; among them, 330 were clinically and biologically confirmed (radiological studies) for the disease, 204 were males (61.8%), 126 were females (38.18%). We found that 27.87% were genetic and 72.12 were sporadic, out of 72.12 %, 43.277% cases from urban and 56.72% from the rural locality, the mothers' literacy rate was 32.12% and working women numbers were 41.21%. Conclusions: There is a significant association between mothers' age and GDD prevalence, which is also followed by mothers' literacy rate and mothers' occupation, whereas there was no association between fathers' age and GDD.

Keywords: global developmental delay, FMR1 gene, spearman’ rank correlation coefficient, structural equation modeling

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Authors: Mehmet Erdem Uzun, Hande Şirin, Amela Kojic Ateş, Utku Beyazıt, Aynur Bütün Ayhan

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The aim of this study was to examine the health literacy of parents with children diagnosed with ADHD. The study group consisted of 394 parents with children diagnosed with ADHD who applied to the child and adolescent psychiatry outpatient clinic of a public hospital in Bursa, Turkey. 339 mothers and 52 fathers participated in the study. The parents were administered a questionnaire prepared by the researchers in addition to the European Health Literacy Scale-Short Form. Prior to the onset of the analyses, a normality test was performed, and it was determined that the data did not show normal distribution. In this regard, Mann-Whitney U and Kruskal Wallis tests were employed in the analyses. According to the results obtained, it was determined that the health literacy of the mothers (x2=21.015, p<.001) and fathers (x2=7.462, p<.05) differed according to their education levels; that is, the health literacy level of parents who graduated from primary school was lower than the other parents. In addition, it was determined that the level of health literacy differed according to the income level of the family (x2=14.308, p<.05), and the health literacy level of the parents in the low-income group was lower than the other parents. On the other hand, it was seen that the health literacy levels of mothers and fathers did not differ according to the variables of age, whether they had social security, whether the child diagnosed with ADHD was taking medication, and if so, how long the child had been taking medication; age and gender of the child; whether there were other individuals diagnosed with ADHD in the family, and whether the child or parents had a chronic disease (p>.05). The results obtained were discussed in the light of the literature findings.

Keywords: health literacy, parents, children, ADHD

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Authors: Anjali N. Shete, G. D. Mahajan, Nanda Somwanshi

Abstract:

Context: Smartphones are the new generation of mobile phones; they have emerged over the last few years. Technology has developed so much that it has become part of our life and mobile phones are one of them. These smartphones are equipped with the capabilities to display photos, play games, watch videos and navigation, etc. The advances have a huge impact on many walks of life. The adoption of new technology has been challenging for the elderly. But, the elder population is also moving towards digitally connected lives. As age advances, there is a decline in the motor and cognitive functions of the brain, and hence the reaction time is affected. The study was undertaken to assess the usefulness of smartphones in improving cognitive functions. Aims and Objectives: The aim of the study was to observe the effects of smartphone addiction on reaction time in elderly population Material and Methods: This is an experimental study. 100 elderly subjects were enrolled in this study randomly from urban areas. They all were using smartphones for several hours a day. They were divided into two groups according to the scores of the mobile phone addiction scale (MPAS). Simple reaction time was estimated by the Ruler drop method. The reaction time was then calculated for each subject in both groups. The data were analyzed using mean, standard deviation, and Pearson correlation test. Results: The mean reaction time in Group A is 0.27+ 0.040 and in Group B is 0.20 + 0.032. The values show a statistically significant change in reaction time. Conclusion: Group A with a high MPAS score has a low reaction time compared to Group B with a low MPAS score. Hence, it can be concluded that the use of smartphones in the elderly is useful, delaying the neurological decline, and smarten the brain.

Keywords: smartphones, MPAS, reaction time, elderly population

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Authors: Pawel Martynowicz

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Vibrations are a crucial problem for slender structures such as towers, masts, chimneys, wind turbines, bridges, high buildings, etc., that is why most of them are equipped with vibration attenuation or fatigue reduction solutions. In this work, a slender structure (i.e., wind turbine tower-nacelle model) equipped with nonlinear, semiactive tuned vibration absorber(s) is analyzed. For this study purposes, magnetorheological (MR) dampers are used as semiactive actuators. Several optimal-based approaches to structural vibration attenuation are investigated against the standard ‘ground-hook’ law and passive tuned vibration absorber(s) implementations. The common approach to optimal control of nonlinear systems is offline computation of the optimal solution, however, so determined open loop control suffers from lack of robustness to uncertainties (e.g., unmodelled dynamics, perturbations of external forces or initial conditions), and thus perturbation control techniques are often used. However, proper linearization may be an issue for highly nonlinear systems with implicit relations between state, co-state, and control. The main contribution of the author is the development as well as numerical and experimental verification of the Pontriagin maximum-principle-based vibration control concepts that produce directly actuator control input (not the demanded force), thus force tracking algorithm that results in control inaccuracy is entirely omitted. These concepts, including one-step optimal control, quasi-optimal control, and optimal-based modified ‘ground-hook’ law, can be directly implemented in online and real-time feedback control for periodic (or semi-periodic) disturbances with invariant or time-varying parameters, as well as for non-periodic, transient or random disturbances, what is a limitation for some other known solutions. No offline calculation, excitations/disturbances assumption or vibration frequency determination is necessary, moreover, all of the nonlinear actuator (MR damper) force constraints, i.e., no active forces, lower and upper saturation limits, hysteresis-type dynamics, etc., are embedded in the control technique, thus the solution is optimal or suboptimal for the assumed actuator, respecting its limitations. Depending on the selected method variant, a moderate or decisive reduction in the computational load is possible compared to other methods of nonlinear optimal control, while assuring the quality and robustness of the vibration reduction system, as well as considering multi-pronged operational aspects, such as possible minimization of the amplitude of the deflection and acceleration of the vibrating structure, its potential and/or kinetic energy, required actuator force, control input (e.g. electric current in the MR damper coil) and/or stroke amplitude. The developed solutions are characterized by high vibration reduction efficiency – the obtained maximum values of the dynamic amplification factor are close to 2.0, while for the best of the passive systems, these values exceed 3.5.

Keywords: magnetorheological damper, nonlinear tuned vibration absorber, optimal control, real-time structural vibration attenuation, wind turbines

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Authors: Taiwo Ebenezer Abioye, Alexis Medrano-Tellez, Peter Kayode Farayibi, Peter Kayode Oke,

Abstract:

Laser metal deposition by wire feedstock has been established as a process which can provide a high material deposition rate with good quality. Sound mechanical properties of the deposited parts are the pre-requisites for the real applications of this process. This paper investigates the laser metal deposition of 308LSi stainless steel wire within a process window. Single tracks and multiple layer thin-walls of 308LSi stainless steel wire were deposited on 304 stainless steel substrate. The grain structures of the built walls were examined using optical microscopy. The mechanical properties of the built walls including the micro-hardness and tensile properties along the transverse and longitudinal directions were investigated using Vickers hardness tester and tensile test machine. Long columnar grains were found growing in the wall building direction (transverse) and nucleation were observed at the boundary between two deposited layers due to remelting of the previously deposited layers. The results showed that the hardness values of the deposited walls (ranging between 194 HV and 167 HV) decreased from the track-substrate interface to the top of the wall. The ultimate tensile strength (UTS) of the wall (518 ± 7 MPa) showed dependence on wall building directions.

Keywords: laser metal deposition, ultimate tensile strength, hardness, wall, microstructure

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Authors: Parisa Shirzadeh

Abstract:

Drug delivery systems in which drugs are traditionally used, multi-stage and at specified intervals by patients, do not meet the needs of the world's up-to-date drug delivery. In today's world, we are dealing with a huge number of recombinant peptide and protean drugs and analogues of hormones in the body, most of which are made with genetic engineering techniques. Most of these drugs are used to treat critical diseases such as cancer. Due to the limitations of the traditional method, researchers sought to find ways to solve the problems of the traditional method to a large extent. Following these efforts, controlled drug release systems were introduced, which have many advantages. Using controlled release of the drug in the body, the concentration of the drug is kept at a certain level, and in a short time, it is done at a higher rate. Graphene is a natural material that is biodegradable, non-toxic, and natural compared to carbon nanotubes; its price is lower than carbon nanotubes and is cost-effective for industrialization. On the other hand, the presence of highly effective surfaces and wide surfaces of graphene plates makes it more effective to modify graphene than carbon nanotubes. Graphene oxide is often synthesized using concentrated oxidizers such as sulfuric acid, nitric acid, and potassium permanganate based on Hummer 1 method. In comparison with the initial graphene, the resulting graphene oxide is heavier and has carboxyl, hydroxyl, and epoxy groups. Therefore, graphene oxide is very hydrophilic and easily dissolves in water and creates a stable solution. On the other hand, because the hydroxyl, carboxyl, and epoxy groups created on the surface are highly reactive, they have the ability to work with other functional groups such as amines, esters, polymers, etc. Connect and bring new features to the surface of graphene. In fact, it can be concluded that the creation of hydroxyl groups, Carboxyl, and epoxy and in fact graphene oxidation is the first step and step in creating other functional groups on the surface of graphene. Chitosan is a natural polymer and does not cause toxicity in the body. Due to its chemical structure and having OH and NH groups, it is suitable for binding to graphene oxide and increasing its solubility in aqueous solutions. Graphene oxide (GO) has been modified by chitosan (CS) covalently, developed for control release of doxorubicin (DOX). In this study, GO is produced by the hummer method under acidic conditions. Then, it is chlorinated by oxalyl chloride to increase its reactivity against amine. After that, in the presence of chitosan, the amino reaction was performed to form amide transplantation, and the doxorubicin was connected to the carrier surface by π-π interaction in buffer phosphate. GO, GO-CS, and GO-CS-DOX characterized by FT-IR, RAMAN, TGA, and SEM. The ability to load and release is determined by UV-Visible spectroscopy. The loading result showed a high capacity of DOX absorption (99%) and pH dependence identified as a result of DOX release from GO-CS nanosheet at pH 5.3 and 7.4, which show a fast release rate in acidic conditions.

Keywords: graphene oxide, chitosan, nanosheet, controlled drug release, doxorubicin

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Authors: Mazouzi Nourdjihane, K. Boutemak, A. Haddad, Y. Chegreouche

Abstract:

In the last decades, biodegradable polymers have been considered as one of the most popular options for the delivery of drugs and various conventional doses. The film forming system (FFS) can be used in topical, transdermal, ophthalmic, oral and gastric applications. Recently this system has focused on improving drug delivery, which can promote drug release. In this context, the aim of this study is to create polymeric film-forming systems for the stomach and to evaluate and test their gastroprotective effects, comparing the effects of changes in composition on film characteristics. It uses a plant-derived polyphenol extract extracted from fennel to demonstrate anti-inflammatory activity in the film. The films are made from hydroxypropyl methylcellulose polymer and different types of plastic, glycerol and polyethylene glycol. The ffs properties show that MgO-glycerol-reinforced hydroxypropylmethylcellulose (HPMC-MgO-Gly) is better than that based on MgO-PEG-reinforced hydroxypropylmethylcellulose (HPMC-MgO-PEG). It is durable, has a faster drying time and allows for maximum recovery. Water vapor strength and blowing speed and other additions show another advantage of HPMC-MgO-Gly compared to HPMC-MgO-PEG, indicating good adhesion between the support (top) and film production. In this study, the gastroprotective effect of fennel phenol extract was found, showing that this plant material has a gastroprotective effect on ulcers and that the film can absorb the active substance.

Keywords: film formin system, hydroxypropyl methylcellulose, magnesium oxide, in vivo

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