Quantifying the injury of the human eye components due to tennis ball impact using a computational fluid–structure interaction model     

Alireza Karimi  Reza Razaghi  Mahdi Navidbakhsh  Toshihiro Sera  Susumu Kudo 《Sports Engineering》2016,19(2):105-115

Although it might be believed that the eye only comprised a very small area of the face, its injury due to the ball impacts in different sports seems to be severe enough to entice many researchers to determine the level of injury and then attempt to minimize it. Sports-related eye injuries, especially tennis, pose a substantial and preventable problem to the eye due to the high speed of the tennis ball (69 m/s). This is why many ophthalmologists provide a wide range of information for their patients regarding the risks of eye injuries in tennis to prevent the injury to well over 100,000 eyes each year. However, so far although there are some general information regarding the injury to the human eye components due to the tennis ball impact, the details of the stresses and deformations have not been well determined. Therefore, the goal of this study was to determine the stresses and deformations of the eye components, including cornea, aqueous body, iris, ciliary body, lens, vitreous body, retina, sclera, optic nerve, extra and intraconal fats, and muscles, attributable to the tennis ball impact via a Lagrangian–Eulerian computational coupling model. Magnetic resonance imaging was employed to establish a finite element model of the human eye according to a normal human eye. The numerical results revealed the highest amount of stress in the iris (19.2 MPa), whereas the lowest one was observed in the vitreous body (1.77 Pa). The cornea also experienced the stress of 8.27 MPa which might be high enough to invoke rupture in this delicate material. In addition, the results exhibited a decreasing and increasing of the radius of curvature for the cornea and lens, respectively. Finally, the collision of the tennis ball to the eye triggered the resultant displacement of 0.045 µm in the optic nerve which may imply a non-significant injury to that. The findings of this study may have implications not only for understating the values of stresses and deformations in the human eye components but also for helping the ophthalmologists to have a more precise diagnosis about the injury position in the eye due to the tennis ball impact.  相似文献   

Non-Descender and All-Cap Arabic Writing     

Mohammad Ali Yaghan 《Al-Masaq: Islam & the Medieval Mediterranean》2018,30(2):166-190

Contrary to the common belief of Arabic language users that the Arabic writing system has descenders as an inherent quality, some historical examples demonstrate that there were some artistic attempts to create non-descender, all-cap calligraphic systems, but they have never been studied as a phenomenon. This article draws attention to the existence of these examples, and analyses and classifies them according to their form.

The article begins with an analysis of the current Arabic writing system in terms of descenders, differentiating between artistic and functional writing, defining the need for harmonious balance in artistic writing, and demonstrating that descenders do disrupt the balance in Arabic writing, which could be considered as an ascender-system.

Then, historical examples of the non-descender system are introduced, categorised into four visual stages, and the descender handling for each stage is described; all-capital letter examples are then introduced.

Finally, some historical texts describing the beauty of calligraphy in this specific system of writing are analysed.

Abbreviations: MET: The Metropolitan Museum of Art, www.metmuseum.org; LACMA: The Los Angeles County Museum of Art, www.lacma.org; No. : Accession Number  相似文献   

Emotions and emotional energy in the science classroom: a discussion of measurement     

Feyzi Behnagh  Reza 《Cultural Studies of Science Education》2020,15(1):307-315

Cultural Studies of Science Education - In this commentary, I consider different theoretical and methodological aspects of Davis and Bellocchi’s study. I begin by identifying definitions of...  相似文献   

Livelihoods and informal trade at the Bangladesh border     

Mohammad Jalal Uddin Sikder  Barun Kumar Sarkar 《Inter-Asia Cultural Studies》2013,14(3):432-445

Abstract

Cross‐border informal trade is one of the most important issues between India and Bangladesh. It takes place between people who live a short distance apart, but who find themselves separated by an international boundary. The people of international border areas believe that cross‐border informal trade is a process to maintain a sustainable livelihood because it provides a livelihood to the unemployed. This research has analysed the nature and impact of informal border trade between India and Bangladesh. It has highlighted the sources of security and insecurity through the process of informal border trade. It also analyses the different socio‐economic conditions of informal border trade in border trade prone areas. This research argues that although informal border trade is considered illegal, it is necessary for the maintenance of the livelihood for the poor in the bordering areas. The state failures in fulfilling the needs of the poor force them to involve themselves in informal border trade.  相似文献   

The growth of higher institutions in Iran     

Reza Arasteh 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1961,7(3):327-334

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Flights of fancy     

Sahotra Sarkar 《Metascience》2012,21(2):425-426

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Inclusive assessment for linguistically diverse learners in higher education     

Amrita Kaur  Mohammad Noman  Hasniza Nordin 《Assessment & Evaluation in Higher Education》2017,42(5):756-771

As classrooms become increasingly diverse in higher education, educators are emphasising inclusive practices in teaching and learning to accommodate the needs of diverse learners. There is also an emerging need for an inclusive approach in assessment for accessibility, opportunity, relevance and engagement. This study, using design-based research guidelines with student–faculty partnership, designed, developed, implemented and evaluated contextually sensitive assessment protocol as inclusive and fair assessment. Data from students’ reflections and face-to-face interviews with open-ended questions suggested that, despite concerns such as potential bias, time and accommodation challenges, such assessment practices can make valuable contributions in creating a positive learning environment, improving relatedness and self-esteem and motivating and engaging students for better effort and effective learning. Implications for higher education practitioners with diverse learners are discussed.  相似文献   

Investigation and evaluation of ultrasound reactor for reduction of fungi from sewage     

Dehghani MH  Mahvi AH  Jahed GR  Sheikhi R 《Journal of Zhejiang University. Science. B》2007,8(7):493-497

The objective of the investigation was to study the application of ultrasound reactor technology （USRT） as a disinfectant for reduction of fungi from sewage effluent. Fungi are carbon heterotrophs that require preformed organic compounds as carbon sources. USRT is an attractive means to improve water quality because of the system simplicity and no production of toxic by-products. An ultrasound reactor produces strong cavitation in aqueous solution causing shock waves and reactive free radicals by the violent collapse of the cavitation bubble. These effects should contribute to the physical disruption of microbial structures and inactivation of organisms. There was significant reduction in fungal growth, with decreased fungal growth with increasing USRT. In this study, ultrasound irradiation at a frequency of 42 kHz was used to expose suspensions of fungi to evaluate the disinfection efficacy of the ultrasound reactor. Also, this study showed that in this system more than 99% reduction of sewage fungi was achieved after 60 min.  相似文献   

Publishing in predatory open access journals: Authors' perspectives     

Mohammad Salehi  Mohammad Soltani  Hadis Tamleh  Shohreh Teimournezhad 《Learned Publishing》2020,33(2):89-95

The proliferation of predatory or bogus journals has been recognized as a threat to academic research, and this study was conducted to discover the experiences of authors published in these journals. Eighty authors who had published in journals identified as predatory were surveyed. We asked how the authors learnt about these journals, what they thought about the reputation of the journals, their experiences of peer review and the quality of feedback provided, and whether publication was driven by PhD or job requirements. Our results showed that a third of authors discovered the journals by web searches or responding to email invitations. Over half said the reputation and name of the journal were important in selecting a journal, although a third admitted that the journal they published in did not have a good reputation. The main reason for selecting the journals was the promise of fast publication (31.2% respondents). Only half of the respondents said that publication was driven by PhD or job requirements. Just over a third reported that peer review was good or excellent, and only 17.5% said that peer review was poor or non‐existent – over 70% thought they had received good feedback from the journals. Although the research was somewhat limited, it does indicate general satisfaction with the journals in which the authors published. Fast publication coupled with good feedback and encouragement to submit can make publishing in predatory journals so tempting that few authors can resist.  相似文献   

Targeted yield concept and a framework of fertilizer recommendation in irrigated rice domains of subtropical India   总被引：1，自引：0，他引：1  

Bera R  Seal A  Bhattacharyya P  Das TH  Sarkar D  Kangjoo K 《Journal of Zhejiang University. Science. B》2006,7(12):963-968

Soil test crop response （STCR） correlation studies were carried out in Vindhyan alluvial plain during 2001 to 2004 taking IR-36 as test crop to quantify rice production in the context of the variability of soil properties and use of balanced fertilizers based on targeted yield concept. The soils were developed on gently sloping alluvial plain with different physiographic settings and notable variation in drainage condition. Soil properties show moderate variation in texture （loamy to clay）, organic carbon content （4.4 to 9.8 g/kg）, cation exchange capacity （10,2 to 22.4 cmol （p＋）/kg） and pH （5.3 to 6,4）, Soil fertility status for N is low to medium （224 to 348 kg/ha）, P is medium to high （87 to 320 kg/ha） and K ranges from medium to high （158 to 678 kg/ha）. Database regarding nutrient requirement in kg/t of grain produce （NR）, the percent contribution from the soil available nutrients [CS （%）] and the percent contribution from the applied fertilizer nutrients [CF （%）] were computed for calibrating and fbrmulating fertilizer recommendations. Validity of the yield target for 7 and 8 t/ha was tested in farmers＇ fields and yields targets varied at less than 10%. The percent achievement of targets aimed at different level was more than 90%, indicating soil test based fertilizer recommendation approach was economically viable within the agro-ecological zone with relatively uniform cropping practices and socio-economic conditions.  相似文献