Sound Intensity and Sound Level

Sound Intensity and Sound Level tài liệu, giáo án, bài giảng , luận văn, luận án, đồ án, bài tập lớn về tất cả các lĩnh...

Int. J. Med. Sci. 2011, 8 http://www.medsci.org 456 IInntteerrnnaattiioonnaall JJoouurrnnaall ooff MMeeddiiccaall SScciieenncceess 2011; 8(6):456-460 Research Paper Trace Elements, Heavy Metals and Vitamin Levels in Patients with Coronary Artery Disease Aysegul Cebi1, Yuksel Kaya2, Hasan Gungor3, Halit Demir4, Ibrahim Hakki Yoruk4, Nihat Soylemez2, Yilmaz Gunes5, Mustafa Tuncer5 1. Giresun University Faculty of Health Sciences, Giresun, Turkey 2. Yuksek Ihtisas Training and Research Hospital, Department of Cardiology, Van, Turkey 3. Mus State Hospital, Department of Cardiology, Mus, Turkey 4. Yuzuncu Yil University Faculty of Science, Department of Chemistry, Van, Turkey 5. Yuzuncu Yil University, Faculty of Medicine, Department of Cardiology, Van, Turkey  Corresponding author: Aysegul Cebi, PhD, Giresun University Faculty of Health Sciences, Piraziz/Giresun, Turkey. Tel: +90.454.3613788, Fax: +90.454.3613544, e-mail: cebiaysegul@hotmail.com © Ivyspring International Publisher. This is an open-access article distributed under the terms of the Creative Commons License (http://creativecommons.org/ licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and p roperly cited. Received: 2011.05.12; Accepted: 2011.07.25; Published: 2011.08.02 Abstract Aim: In the present study, we aimed to assess serum concentrations of zinc (Zn), copper (Cu), iron (Fe), cadmium (Cd), lead (Pb), manganese (Mn), vitamins A (retinol), D (cho-lecalciferol) and E (α-tocopherol) in patients with coronary artery disease (CAD) and to compare with healthy controls. Methods: A total of 30 CAD patients and 20 healthy subjects were included in this study. Atomic absorption spectrophotometry (UNICAM-929) was used to measure heavy metal and trace element concentrations. Serum α-tocopherol, retinol and cholecalciferol were measured simultaneously by high performance liquid chromatography (HPLC). Results: Demographic and baseline clinical characteristics were not statistically different between the groups. Serum concentrations of retinol (0.3521±0.1319 vs. 0.4313±0.0465 mmol/I, p=0.013), tocopherol (3.8630±1.3117 vs. 6.9124±1.0577 mmol/I, p<0.001), chole-calciferol (0.0209±0.0089 vs. 0.0304±0.0059 mmol/I, p<0.001) and Fe (0.5664±0.2360 vs. 1.0689±0,4452 µg/dI, p<0.001) were significantly lower in CAD patients. In addition, while not statistically significant serum Cu (1.0164±0.2672 vs. 1.1934±0.4164 µg/dI, p=0.073) concentrations were tended to be lower in patients with CAD, whereas serum lead (0.1449±0.0886 vs. 0.1019±0.0644 µg/dI, p=0.069) concentrations tended to be higher. Conclusions: Serum level of trace elements and vitamins may be changed in patients with CAD. In this relatively small study we found that serum levels of retinol, tocopher-ol, cholecalciferol, iron and copper may be lower whereas serum lead concentrations may be increased in patients with CAD. Key words: coronary artery disease; trace element; heavy metal; vitamin INTRODUCTION Coronary artery disease (CAD) is a leading cause of morbidity and mortality in developed countries and is emerging as an epidemic in developing coun-tries (1). Traditional risk factors such as serum cho-lesterol, blood pressure and smoking account for not more than 50% of CAD mortality (2). There is strong evidence that oxidative free radicals have a role in the development of degenerative diseases including CAD Ivyspring International Publisher Sound Intensity and Sound Level Sound Intensity and Sound Level Bởi: OpenStaxCollege Noise on crowded roadways like this one in Delhi makes it hard to hear others unless they shout (credit: Lingaraj G J, Flickr) In a quiet forest, you can sometimes hear a single leaf fall to the ground After settling into bed, you may hear your blood pulsing through your ears But when a passing motorist has his stereo turned up, you cannot even hear what the person next to you in your car is saying We are all very familiar with the loudness of sounds and aware that they are related to how energetically the source is vibrating In cartoons depicting a screaming person (or an animal making a loud noise), the cartoonist often shows an open mouth with a vibrating uvula, the hanging tissue at the back of the mouth, to suggest a loud sound coming from the throat [link] High noise exposure is hazardous to hearing, and it is common for musicians to have hearing losses that are sufficiently severe that they interfere with the musicians’ abilities to perform The relevant physical quantity is sound intensity, a concept that is valid for all sounds whether or not they are in the audible range Intensity is defined to be the power per unit area carried by a wave Power is the rate at which energy is transferred by the wave In equation form, intensity I is P I = A, 1/10 Sound Intensity and Sound Level where P is the power through an area A The SI unit for I is W/m2 The intensity of a sound wave is related to its amplitude squared by the following relationship: I= (Δp) 2ρvw Here Δp is the pressure variation or pressure amplitude (half the difference between the maximum and minimum pressure in the sound wave) in units of pascals (Pa) or N/m2 (We are using a lower case p for pressure to distinguish it from power, denoted by mv2 P above.) The energy (as kinetic energy ) of an oscillating element of air due to a traveling sound wave is proportional to its amplitude squared In this equation, ρ is the density of the material in which the sound wave travels, in units of kg/m3, and vw is the speed of sound in the medium, in units of m/s The pressure variation is proportional to the amplitude of the oscillation, and so I varies as (Δp)2 ([link]) This relationship is consistent with the fact that the sound wave is produced by some vibration; the greater its pressure amplitude, the more the air is compressed in the sound it creates Graphs of the gauge pressures in two sound waves of different intensities The more intense sound is produced by a source that has larger-amplitude oscillations and has greater pressure maxima and minima Because pressures are higher in the greater-intensity sound, it can exert larger forces on the objects it encounters Sound intensity levels are quoted in decibels (dB) much more often than sound intensities in watts per meter squared Decibels are the unit of choice in the scientific literature as well as in the popular media The reasons for this choice of units are related to how we perceive sounds How our ears perceive sound can be more accurately described by the logarithm of the intensity rather than directly to the intensity The sound intensity level β in decibels of a sound having an intensity I in watts per meter squared is defined to be ( ), β (dB) = 10 log10 I I0 2/10 Sound Intensity and Sound Level where I0 = 10–12 W/m2 is a reference intensity In particular, I0 is the lowest or threshold intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz Sound intensity level is not the same as intensity Because β is defined in terms of a ratio, it is a unitless quantity telling you the level of the sound relative to a fixed standard (10–12 W/m2, in this case) The units of decibels (dB) are used to indicate this ratio is multiplied by 10 in its definition The bel, upon which the decibel is based, is named for Alexander Graham Bell, the inventor of the telephone Sound Intensity Levels and Intensities Sound intensity Intensity Example/effect level β I(W/m2) (dB) × 10–12 Threshold of hearing at 1000 Hz 10 × 10–11 Rustle of leaves 20 × 10–10 Whisper at m distance 30 × 10–9 Quiet home 40 × 10–8 Average home 50 × 10–7 Average office, soft music 60 × 10–6 Normal conversation 70 × 10–5 Noisy office, busy traffic 80 × 10–4 Loud radio, classroom lecture 90 × 10–3 Inside a heavy truck; damage from prolonged exposure Several government agencies and health-related professional associations recommend that 85 dB not be exceeded for 8-hour daily exposures in the absence of hearing protection 100 × 10–2 Noisy factory, siren at 30 m; damage from h per day exposure 110 × 10–1 Damage from 30 per day exposure 120 Loud rock concert, pneumatic chipper at m; threshold of pain 140 × 102 Jet airplane at 30 m; severe pain, damage in seconds 160 × 104 Bursting of eardrums 3/10 Sound Intensity and Sound Level The decibel level of a sound having the threshold intensity of 10 –12 W/m2 is β = dB, because log101 = That is, the ...Int. J. Med. Sci. 2004 1(3): 165-169 165 International Journal of Medical Sciences ISSN 1449-1907 www.medsci.org 2004 1(3): 165-169 ©2004 Ivyspring International Publisher. All rights reserved Comparative study of serum Na+ and K+ levels in senile cataract patients and normal individuals Short research paper Received: 2004.5.18 Accepted: 2004.7.20 Published: 2004.8.05 Mansour Mirsamadi1, Issa Nourmohammadi2, Manuchehr Imamian2 1 Department of Ophthalmology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran 2 Department of Biochemistry and Nutrition, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AAbbssttrraacctt Many factors such as aging, changes in blood electrolytes levels, and possibly family history are involved in senile cataract formation. Changes in serum electrolytes levels can induce changes in aqueous electrolytes levels and effect on lens metabolism and probably cataract formation. In this paper, we study serum level of Na+ and K+ in senile cataract patients and normal individuals. Methods and materials: 155 senile cataract patients scheduled for cataract surgery in eye clinic of Rasoul hospital and 155 normal individuals were selected. Serum Na+ and K+ levels were measured by Flame Photometry technique and means compared between two groups by t-test. Results: 1. Mean serum Na+ level in senile cataract patients and normal individuals was 144.96 ± 6.04 mEq/lit and 140.88 ± 2.27 mEq/lit respectively, and there was statistically significant difference (P<0.0001). 2. Mean serum K+ level in senile cataract patients and normal individuals was 4.20 ± 0.34 mEq/lit and 4.15 ± 0.32 mEq/lit respectively, and there was no statistically significant difference. Conclusion: Serum Na+ level in senile cataract patients was higher than normal individuals in this study. This result might suggest that diets with high Na+ content are a risk factor for age-related cataract formation, as high Na+ content of the diet leads to high level of serum Na+, which in turn contributes to formation of age-related cataract. KKeeyy wwoorrddss Senile cataract, Na+, K+ AAuutthhoorr bbiiooggrraapphhyy Mansour Mirsamadi obtained MD degree from University of Tehran in 1978, and then studied ophthalmology for three years in Iran University of Medical Sciences. He is currently an associate professor in Department of Ophthalmology, Iran University of Medical Sciences, with research interests in epidemiology in ophthalmology. Issa Nourmohammadi obtained BSc (Chemistry) from Langston University, Oklahoma, in 1976, MSc (Biochemistry) from University of Oklahoma in 1978, and PhD (Nutritional Biochemistry) from University of Arizona in 1981. He is currently an associate professor in Department of Biochemistry and Nutrition in Iran University of Medical Sciences. He is interested in study of nutrition and trace elements in human blood. Manuchehr Imamian obtained BSc in Chemistry from Payam-Nour University of IRAN in 1996 and MSc in Biochemistry from Iran University of Medical Sciences in 2001. His INTERNATIONAL STANDARD IEC 60076-10 First edition 2001-05 Power transformers – Part 10: Determination of sound levels Transformateurs de puissance – Partie 10: Détermination des niveaux de bruit Reference number IEC 60076-10:2001(E) COPYRIGHT 2002; International Electrotechnical Commission Document provided by IHS Licensee=Qatar Petroleum/5943408104, User=, 10/17/2002 02:56:14 MDT Questions or comments about this message: please call the Document Policy Management Group at 1-800-451-1584. -- || |||| | | || ||||| | | |||| || | ||| |||| || | ||| --- Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1. Consolidated editions The IEC is now publishing consolidated versions of its publications. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2. Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC, thus ensuring that the content reflects current technology. Information relating to this publication, including its validity, is available in the IEC Catalogue of publications (see below) in addition to new editions, amendments and corrigenda. Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication, as well as the list of publications issued, is also available from the following: • IEC Web Site (www.iec.ch) • Catalogue of IEC publications The on-line catalogue on the IEC web site (www.iec.ch/catlg-e.htm) enables you to search by a variety of criteria including text searches, technical committees and date of publication. On-line information is also available on recently issued publications, withdrawn and replaced publications, as well as corrigenda. • IEC Just Published This summary of recently issued publications (www.iec.ch/JP.htm) is also available by email. Please contact the Customer Service Centre (see below) for further information. • Customer Service Centre If you have any questions regarding this publication or need further assistance, please contact the Customer Service Centre: Email: custserv@iec.ch Tel: +41 22 919 02 11 Fax: +41 22 919 03 00 COPYRIGHT 2002; International Electrotechnical Commission Document provided by IHS Licensee=Qatar Petroleum/5943408104, User=, 10/17/2002 02:56:14 MDT Questions or comments about this message: please call the Document Policy Management Group at 1-800-451-1584. -- || |||| | | || ||||| | | |||| || | ||| |||| || | ||| --- INTERNATIONAL STANDARD IEC 60076-10 First edition 2001-05 Power transformers – Part 10: Determination of sound levels Transformateurs de puissance – Partie 10: Détermination des niveaux de bruit PRICE CODE  IEC 2001  Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch Q For price, see current catalogue Commission Electrotechnique Internationale International Electrotechnical Commission COPYRIGHT 2002; International Electrotechnical Commission Document provided by IHS Licensee=Qatar Petroleum/5943408104, User=, 10/17/2002 02:56:14 MDT Questions or comments about this message: please call the Document Policy Management Group at 1 - Sơ qua lý thuyết: Sóng âm thanh truyền trong không khí tạo ra một áp suất, đơn vị thường đo bằng Pascal (Pa), ngưỡng con người có thể nghe được là 20uPa. Để đo mức độ tiếng ồn (SPL- Sound Pressure Level), người ta thường dùng đơn vị Decibel (dB), tương quan giữa dB và Pa như hình dưới (H1) 1 Do đặc điểm tai người nghe không nhạy như nhau ở các tần số khác nhau (nhạy nhất ở khoảng tần số 2KHz), nên để đo mức độ ồn giống như tai người ghe được, người ta định nghĩa 3 tiêu chuẩn đo: A, B và C (mức độ âm tương ứng với 2 dải tần trong khoảng nghe được), được gọi là dB-A (hay LA), dB-B (LB), dB-C (LC), như sau: H2 chi tiết có thể tham khảo thêm ở wikipeida hoặc : Measuring Sound - Norsonic 3 2 - Mạch đo DIY: Trên cơ sở đồng hồ đo volt hiện số bị hỏng, mình dùng thang đo 2000mV, hiển thị từ ~40dB đến ~160dB (lý thuyết vậy, chứ chưa có nguồn âm nào lớn vậy) Mô tả khối: (Rất tiếc, làm lâu rồi, sơ đồ nguyên lý vẽ tay đã bị thất lạc mất) Đầu vào là micro, khuyếch đại Logarithm, dịch mức đầu ra DC sao cho tương ứng với số hiển thị trên đồng hồ (mV) Hiệu chỉnh: Dùng loa máy tính và phần mềm tạo âm thanh (có chỉnh tần số), 4 tạo ra 1 mức âm nhất định, đặt máy đo cùng với một máy đo thương mại để so sánh và chỉnh. (thực tế, công đoạn này cũng mất thời gian không kém gì chế mạch đo) Một số ảnh chụp sản phẩm (đã dùng thực tế), H4-H5 5 6 7 và máy đo thương mại (H6): Ps: Mình xin tặng bộ DIY này cho MOD nào thích và yêu cầu vẽ lại mạch nguyên lý, post lên cho mọi người tham khảo ! (hy vọng sẽ có cải tiến và SP made in Cơ điện tử). 8 2 - Mạch đo DIY: Trên cơ sở đồng hồ đo volt hiện số bị hỏng, mình dùng thang đo 2000mV, hiển thị từ ~40dB đến ~160dB (lý thuyết vậy, chứ chưa có nguồn âm nào lớn vậy) Mô tả khối: (Rất tiếc, làm lâu rồi, sơ đồ nguyên lý vẽ tay đã bị thất lạc mất) Đầu vào là micro, khuyếch đại Logarithm, dịch mức đầu ra DC sao cho tương ứng với số hiển thị trên đồng hồ (mV) 9 Hiệu chỉnh: Dùng loa máy tính và phần mềm tạo âm thanh (có chỉnh tần số), tạo ra 1 mức âm nhất định, đặt máy đo cùng với một máy đo thương mại để so sánh và chỉnh. (thực tế, công đoạn này cũng mất thời gian không kém gì chế mạch đo) 10 d ' t oo p #%% :?rr.,- @ : *- # j t )o s ) qy, 1'''' ' , , l jz - j.' lq ? z j l q j L ? k ? s '' k ' ( j J : q 'k t y s y ' , , , 'L', ' ' ,, , ( ' ' , ''' '; ii : t ' ) ? ù' b ' , # t , y t i ' ,' '' ' , ' ( ? ' ,, , ', l t , ' l , ) - '' '' , , # ? t ) ' T 1111 -111 : ' t f l I : ' l : ' )( - ', t ., Richard Northcott ' ll , 1i :l'' Introduction How Sound M oves Low Sounds,High Sounds YourVoice i M usicatlnstrum ents 10 M usic Around the W ortd 12 Orchestrasand Concerts Rhythm 14 16 Recordinj Music 18 Buying M usic 20 10 Sound and Noise 22 Activities 24 Projects 44 Picture Dictionary 46 AboutRead and Blscover 48 O X TO R D UNIVERSITYPRESS ' I f; '$' 'Yn'' '.'* -fd' i' j).,, v J !f ''''%: &' ''7 '1 'l ) 1' X.1/ ).) ;) ' '' a :; f ,.# ? jjyc ( r ijv v gtwy;jjở yrNxgyyoyo 'a ij y9k ' t < j A cộ(y tujjky:(p Ll ' * ' ( z = ' , , ; z ' ''' A , n z : f'( k ( , y t , j g n j t h ' ' ' % X ' ip, z.'.! r4p' 'f ợ t ' ' '.u.'; .,õ) l;qygjjttjjj( .a ' j j x j r , ' , y t e y jjy., , ,, z 1j,$ ỗ4ù ' ( - .x2'' )t t! ... Intensities and Corresponding Differences in Sound Intensity Levels I2 / I1 β – β 2.0 3.0 dB 5.0 7.0 dB 10.0 10.0 dB Calculating Sound Intensity Levels: Sound Waves 4/10 Sound Intensity and Sound Level. .. expressed in the sound pressure level, where the more familiar sound intensity level we use here would be something under 140 dB for the same sound 6/10 Sound Intensity and Sound Level Take-Home... decibel is based, is named for Alexander Graham Bell, the inventor of the telephone Sound Intensity Levels and Intensities Sound intensity Intensity Example/effect level β I(W/m2) (dB) × 10–12 Threshold