21 research outputs found

    Loudness and acoustic parameters of popular children's toys

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    ObjectiveThis project was conducted to evaluate the loudness and acoustic parameters of toys designed for children. In addition, we investigated whether occluding the toys' speaker with tape would result in a significant loudness reduction; thereby potentially reducing the risk of noise induced hearing loss.MethodsTwenty-six toys were selected after an initial screening at two national retailers. Noise amplitudes at 0.25, 0.5, 1, 2, 4, and 8kHz were measured using a digital sound level meter at a distance of 0 and 30cm. The toys' speakers were then occluded using adhesive tape and the same acoustic parameters were re-measured.ResultsMean maximum noise amplitude of the toys at 0cm and 30cm was 104dBA (range, 97-125dBA) and 76dBA (range, 67-86dBA), respectively. Mean maximum noise amplitude after occlusion at 0cm and 30cm distances was 88dBA (range, 73-110dBA) and 66dBA (range, 55-82dBA), respectively, with a p-value <0.001.ConclusionsProper use of the loudest toys at a distant of 30cm between the speaker and the child's ear will likely not pose a risk of noise-induced hearing loss. However, since most toys are used at closer distances, use of adhesive tape is recommended as an effective modification to decrease the risk of hearing loss

    Visual consequences of electronic reader use: a pilot study.

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    Synthesis of Ketodiesters to Explore the Photodecarbonylation Reaction

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    II. Solid-state photodecarbonylation is a promising method for the preparation of functionalized ring systems of varying sizes. The recombination of the sigma-bonds yields a new ring system. The photochemical reactivity of dimethyl 11-oxobenzo[c,h]bicycle[4.4.1]undeca-3,8-dienel,6-dicarboxylate in the solid-state resulted in a highly efficient synthesis of the corresponding bicyclic compound. Additional functionalized ring systems were synthesized to investigate the limitations of the photodecarbonylation reaction. The objective of this project is to investigate the scope and limitation of the photodecarbonylation reactio

    Estimation of Nasal Tip Support Using Computer-Aided Design and 3-Dimensional Printed Models.

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    ImportancePalpation of the nasal tip is an essential component of the preoperative rhinoplasty examination. Measuring tip support is challenging, and the forces that correspond to ideal tip support are unknown.ObjectiveTo identify the integrated reaction force and the minimum and ideal mechanical properties associated with nasal tip support.Design, setting, and participantsThree-dimensional (3-D) printed anatomic silicone nasal models were created using a computed tomographic scan and computer-aided design software. From this model, 3-D printing and casting methods were used to create 5 anatomically correct nasal models of varying constitutive Young moduli (0.042, 0.086, 0.098, 0.252, and 0.302 MPa) from silicone. Thirty rhinoplasty surgeons who attended a regional rhinoplasty course evaluated the reaction force (nasal tip recoil) of each model by palpation and selected the model that satisfied their requirements for minimum and ideal tip support. Data were collected from May 3 to 4, 2014.ResultsOf the 30 respondents, 4 surgeons had been in practice for 1 to 5 years; 9 surgeons, 6 to 15 years; 7 surgeons, 16 to 25 years; and 10 surgeons, 26 or more years. Seventeen surgeons considered themselves in the advanced to expert skill competency levels. Logistic regression estimated the minimum threshold for the Young moduli for adequate and ideal tip support to be 0.096 and 0.154 MPa, respectively. Logistic regression estimated the thresholds for the reaction force associated with the absolute minimum and ideal requirements for good tip recoil to be 0.26 to 4.74 N and 0.37 to 7.19 N during 1- to 8-mm displacement, respectively.Conclusions and relevanceThis study presents a method to estimate clinically relevant nasal tip reaction forces, which serve as a proxy for nasal tip support. This information will become increasingly important in computational modeling of nasal tip mechanics and ultimately will enhance surgical planning for rhinoplasty.Level of evidenceNA
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