Categories
Asia Noise News Building Accoustics Building Acoustics Environment Home Industrial Noise and Vibration Product News Noise-th Uncategorized Vibration Virtual Data Room

Accelerometer mounting

One of the challenges in measuring vibration using accelerometer is how to mount the accelerometer on the surface of the object that is being measured. Choosing the proper mounting can affect both to the measurement results and practicality when we are conducting the measurement.

 

Accelerometer mounting affects the measurement results because it can shift the resonance frequency of the accelerometer. Accelerometers have a significant amplification factor at its resonance frequency. This implies that in conducting measurements using accelerometer, it is important to choose mounting techniques that does not shift the resonance frequency into our frequency of interest.

 

Generally, there are four ways to mount accelerometer which are:

  1. Stud mounting: this technique is done by bolting the accelerometer into the object. This option is often considered as the mounting technique that produces the best measurement result compared to other options. Stud mounting has a high resonance frequency that in most cases a lot higher than our frequency of interest. To increase the performance of stud mounting, coupling fluid such as oil, petroleum jelly or beeswax can be used.

The downside of this technique is that not all object has a possible location to be bolted at the surface. If this is the case, then we will need to modify the surface and might leave a hole on the object.

  1. Adhesive: there are few adhesives that are commonly used to mount accelerometers such as epoxy (usually chosen for permanent mounting), wax, glue, and double-sided tape. Use of adhesive has lower resonance frequency compared to stud mounting, but in majority of cases still high enough that it does not affect the measurement at the frequency of interest. Of course, this depends on the type of adhesive that is being used as well.

Usage of adhesive however, especially for temporary mounting, has its own problem which is it can leave stain on the surface of the object that we are measuring, as well as on the accelerometer itself.

Another option of mounting related with adhesive is to use adhesive mounting pad, which is a pad that can be mounted on the surface that we want to measure using adhesive, and then we can mount the accelerometer on the pad. This will allow us to move one accelerometer to few locations more easily. From practicality perspective, adhesive mounting pad has an advantage if we want to repeat the measurement. Also, by using adhesive mounting pad, we avoid direct contact of adhesive to the accelerometer so that it will not need cleaning.

  1. Magnet: For metal surfaces, one of the options that is easy and does not leave stain is by using magnetic mounting base on the accelerometer so that we can attach the accelerometer to metal. This is the reason magnetic base is one of the best options especially for short-term and temporary measurement on metal.

However, this mounting technique produces lower resonant frequency compared to the other two options that we have discussed above. If the frequency that we want to measure is high enough, say above 1 kHz, this mounting technique might influence the measurement results.

  1. Handheld: In some of the cases, the three options above are not possible to be chosen, and it leaves us with the last option which is holding the accelerometer by hand. In this kind of cases, a probe tip can be used so that we can put pressure by hand on the surface that we are measuring easier.

We will have to pay more attention to the frequency range that we are measuring if this mounting technique is used. Because this option will reduce our frequency range significantly, generally only in the range of 10 – 100 Hz. 

Categories
Asia Noise News Building Accoustics Building Acoustics Environment Home Industrial Noise and Vibration Product News Noise-th Uncategorized Vibration

Industrial Noise Control Measure

In industrial places that are normally full of machineries or mechanical systems, noise is definitely inevitable, and in fact, very loud. This can sometimes be harmful to the workers hence causing occupational health and safety hazard. Therefore, in this article, we will look into noise control measures that can be used to overcome industrial noise in workplace.

Noise sources

Let’s begin with a recap on how noise is being produced:

Sound in general, is produced by vibration, or sometimes due to aerodynamic systems. Vibration-induced noises can be caused by multiple reasons, for example:

  • Mechanical shocks and friction between machinery parts like hammering, rotating gears, bearings, cutting tools etc.
  • Moving parts that are off-balanced
  • Vibration of large and heavy structures

As for aerodynamic noises, they are caused by air or fluid flows through pipes, fans, or pressure drops in air distribution systems as well. Typical examples of aerodynamic noise sources are:

  • Steam released through exhaust valves
  • Fans
  • Combustion motors
  • Aircraft jets
  • Turbulent fluid flow through pipes

Steps to control noise in workplace

To properly control the noise in the workplace, these steps should be carried out:

  1. Identify the sound sources (i.e., vibrating sources or aerodynamic flow)
  2. Identify the noise path from source to worker
  3. Determine the sound level of each source
  4. Determine the relative contribution to the excessive noise of each source and proceed to rank the sources accordingly. The dominant source should always be prioritised and controlled first in order to obtain significant noise attenuation.
  5. Understand the acceptable exposure limits as written in the health and safety legislation and find out the necessary sound reduction.
  6. Find out solutions while taking the degree of sound attenuation, operation, productivity restrains and cost into consideration.

To reduce exposure to noise

In general, noise exposure can be reduced by the elimination of noise source if possible, otherwise substitution of source with a quieter one or the application of engineering modifications works too.

The most effective way to minimise the exposure of noise is to engineer it out at the very beginning: the design stage. It is suggested to always choose equipment features that can reduce noise level to an acceptable level. For new installations, again select a quiet equipment, and make sure to have a procurement policy that opts for using quiet equipment, and finally eliminate any design flaws that may lead to noise amplification.

Engineering modifications refer to changes that can affect the source, or the sound path. This is usually the preferred solution for noise control in already-established workplaces (those without noise protection measures during design stage). This is because engineering modifications are known to be more cost effective, especially to control the noise at the source than along the path.

Administrative controls and the use of personal protective equipment (PPE) are also effective as measures of noise control applicable on workers themselves. A combination of both may be taken into consideration when the noise exposure would not justify the implementation of engineering solutions that are more expensive. However, it is important to always note that administrative control and PPE may not be as effective as implementing engineering noise control during the starting stage or modifications of sound path. Therefore, they should be categorised as the last resort.

Engineering solutions to reduce noise

Different solutions can be applied for vibration-induced noise and aerodynamic-noise.

For vibration-induced noise, the key point is to reduce the amount of vibration at the source. The typical solutions include modification of the energy source such as lowering the rotating speed of fans, or reducing the impact force of hitting tools etc. Adding damping materials onto vibrating surfaces due to mechanical forces can help to reduce vibrational effects too, especially for thin structures. To prevent unwanted damage due to friction or impact, the damping material may be sandwiched between the surface of equipment and another material that is resistant to abrasion. This treatment is called the constraint layer treatment.

Other methods to reduce vibration-induced noise include minimising gaps in machine guards and cover them with acoustic-absorbent material, replacing metal parts with plastic parts whenever possible, and replacing motors with quieter ones.

On the other hand, to treat aerodynamic-induced noise, specialists recommended to implement engineering practices that are capable of reducing noise associated with unstable fluid flow, for example minimising fluid velocity, increasing pipe diameter or minimising turbulence by utilising large and low speed fans with curved blades.

Besides those mentioned above, there are also passive noise control measures that can be used. These include using enclosures and isolations by storing noisy equipment in enclosed spaces/rooms that have special acoustic features like isolation, louvres or sealings. Installations of acoustic barriers (sound-absorbing panels) in workplaces, or silencers inside ducts and exhausts works well in attenuating unwanted noise too.

General measures to keep in mind

Finally, here are some general methods that one can take to ensure that workplace noise is under controlled.

Regular maintenance should always be performed, where the focus should be on identifying and replacing any worn-off or loose parts, lubricating any moving parts, and make sure that the rotating equipment does not get off balance to avoid vibration-induced noise.

Noisy processes should be taken note about and be substituted with quieter ones. Sound reverberation in the room should be reduced. Reverberation is when sound produced in an enclosure hits reflective surfaces and reflects back into the room in addition to the original noise paths. In some cases, reverberated sounds may dominate the original sound. A good method to help in such conditions will be to add padding onto the reflective surfaces with sound absorbing materials so that noise level can be reduced. Another way will be to arrange the equipment in the room so that they are not too close to too many reflective structures.

Conclusion

In conclusion, always take measures to identify the sound sources in the industrial workplace and find out suitable ways to solve the noise issues to achieve noise limits in accordance with exposure limits set in the health and safety legislation published by the local authorities. It is utmost important to obey the noise exposure limits to ensure the hearing health of workers in the workplace.

Reference

https://www.ccohs.ca/oshanswers/phys_agents/noise_control.html

https://www.who.int/occupational_health/publications/noise10.pdf

Categories
Building Accoustics Building Acoustics Environment Home Industrial Noise and Vibration Product News Noise-th Uncategorized Vibration

Sound Absorption

What is Absorption?

Absorption refers to the process by which a material, structure, or object takes in energy when waves are encountered, as opposed to reflecting the energy. Part of the absorbed energy is transformed into heat and part is transmitted through the absorbing body. The energy transformed into heat is said to have been ‘lost’. (e.g. spring, damper etc.)

 

What is Sound Absorption?

When the sound waves encounter the surface of the material: part of them reflects; part of them penetrate, and the rest are absorbed by the material itself.

Formula for Sound Absorption: –

The ratio of absorbed sound energy (E) to incident sound energy (Eo) is called sound absorption coefficient (α). This ratio is the main indicator used to evaluate the sound-absorbing property of the material. A formula can be used to demonstrate this.

 

α (absorption coefficient) =E (absorbed sound energy)/ Eo (Incident sound energy)

 

In this formula: α is the sound absorption coefficient;

  E is the absorbed sound energy (including the permeating part);

  Eo is the incident sound energy.

 

Generally, the sound absorption coefficient of the materials is between 0 to 1. The larger the numeral is, the better the sound absorbing property. The sound absorption coefficient of suspended absorber may be more than one because its effective sound-absorbing area is larger than its calculated area.

 

Example: If a wall is absorbed 63% of incident energy and 37% of energy is reflected then the absorption coefficient of wall is 0.63.

 

How can we measure Absorption Coefficient?

 

The absorption coefficient and impedance are determined by two different methods according to the type of incident wave field.

 

  1. Kundt’s tube (ISO 10534-2)
  2. Reverberation room (ISO 354)

 

Kundt’s Tube Measurement Method: (ISO 10543-2)

For measurement of small specimen use Kundt’s tube or Impedance tube also called as Standing wave tube.  The result from measurement of absorption factor and acoustic impedance, using the standing wave method, obviously are meaningful only when assuming these to be independent of the size of the specimen, which is normally quite small.  The absorption factor for normal incidence is determined by measuring the measuring the maximum and minimum pressure amplitude in the standing wave set up in the tube by a loudspeaker. 

This basic technique is, an mentioned in the introduction, considered a little outdated in comparison with more modern methods based on transfer was implemented relatively late (1993) in an international standard, ISO 10534-1, after being used for al least 50 years.  Commercial equipment has also been available for many decades.  However, there exists a second part of the mentioned standard, ISO 10534-2, based on using broadband signals and measurement of the pressure transfer function between different positions in the tube.  ISO 10543-2, which implies the specified two microphone method is extended to spherical wave fields.

Normally Placid Impedance tube is used for absorption coefficient and transmission loss measurement. 

(https://www.placidinstruments.com/product/impedance-tube/)

The above fig shows Impedance tube

 

Click here to refer Placid Sound absorption measurement  

Click here to refer Placid Sound transmission loss measurement

 

 

Reverberation Room: (ISO 354)

 

              Reverberation Room method is traditional method, measurement of the absorption factor of larger specimens is performed in a reverberation room.  One then determines the average value over all angles of incidence under diffuse field conditions.  The product data normally supplied by producers of absorbers are determined according to the international standard ISO 354, required for measurement is 10-12 square meters and there are requirements as to shape of the area.  The reason of these requirements is that the absorption factor determined this method always includes an additional amount due to the edge effect, which is a diffraction phenomenon along the edge of the specimen.  This effect makes the specimen acoustically larger the geometric area, which may result in obtaining absorption factors larger than 1.0.  Certainly, this does not imply that the energy absorbed is larger than the incident energy.

 

 

Sound Absorption coefficient of different materials:

The sound absorption of the material is not only related to its other properties, its thickness, and the surface conditions (the air layer and thickness), but also related to the incident angle and frequency of the sound waves. The sound absorption coefficient will change according to high, middle, and low frequencies. In order to reflect the sound-absorbing property of one material comprehensively, six frequencies (125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz) are set to show the changes of the sound absorption coefficient. If the average ratio of the six frequencies is more than 0.2, the material can be classified as sound-absorbing material.

Application of Sound Absorber:

These materials can be used for sound insulation of walls, floors, and ceilings of concert hall, cinema, auditorium, and broadcasting studio. By using the sound absorbing material properly, the indoor transmittance of sound waves can be enhanced to create better sound effects.

Select your sound absorber from https://www.blast-block.com/

Categories
Asia Noise News Building Accoustics Building Acoustics Environment Home Industrial Noise and Vibration Product News Noise-th Uncategorized Vibration Virtual Data Room

Helmholtz Resonator

Resonate absorbers are the most powerful of low-frequency absorption technologies. Pound for pound and square foot per square foot, resonant absorbers can not be matched for low-frequency absorption. They are sometimes called resonance absorbers. We are speaking about real low-frequency absorption which represents all frequencies below 100 Hz. Resonant absorbers are different than other absorbers. They work best in areas of high room sound pressure not high sound velocity areas like porous absorbers that handle middle and high frequencies.

Vibrations & Sound Pressure
A resonant absorber is a vibrational system that “runs” on sound pressure. As vibrational science will tell us a resonant absorber is a mass vibrating against a spring. The mass is the cabinet and front wall or diaphragm. The spring is the air inside the cavity of the resonant absorber. If you change the vibrating mass and stiffness of the spring, you can control and tune the resonant absorber to the resonant frequency of choice. The internal mass or cabinet depth determines design frequency. The spring or internal air and cavity are used for achieving the rate of absorption above the unit’s designed for resonant frequency. There are three types of resonant absorbers: Helmholtz and Diaphragmatic and Membrane.

Helmholtz / Membrane
A Helm resonator is a box or tube with an opening or slot at its mouth. Air enters the slot which has a calculated width, length, and depth. The slot is attached to a cabinet or cylinder of different widths and depths. A glass coke bottle is a good example of a Helmholtz resonator. It is a resonant absorber or as some would term a resonance absorber. The frequency or resonance is determined by the slot dimensions along with the cabinet or cylinder depth. Helms are frequency specific and narrow frequency band coverage. A membrane absorber works similar to a diaphragmatic. It has a membrane than vibrates in sympathy to sound pressure. This vibrating membrane is attached to a cabinet which has a certain depth and fills material. A diaphragmatic absorber works similar to a membrane with more performance per square foot.

 

Calculate Resonant frequency of Helmholtz Slot Absorber

Resonant Frequency Formula
fo = 2160*sqrt(r/((d*1.2*D)*(r+w)))
fo = resonant frequency
r = slot width
d = slat thickness
1.2 = mouth correction
D = cavity depth
w = slat width
2160 = c/(2*PI) but rounded
c = speed of sound in inch/sec
If the gaps vary say 5mm, 10mm, 15mm, 20mm and the wall is angled as shown below, a broad band low mid resonator is created that still keeps the high frequencies alive.

Remember the cavity behind must be airtight!
By working out the different slat widths and slat gaps you can create a broadband low mid resonator at specific frequencies.

Credit : mh-Audio.nl , acousticfields

Categories
Noise-th

แผ่นดินไหวใกล้หมู่เกาะเคอร์มาเดค 6.3

แผ่นดินไหวใกล้หมู่เกาะเคอร์มาเดค 6.3

แผ่นดินไหวใกล้หมู่เกาะเคอร์มาเดค | เดลินิวส์
„เกิดแผ่นดินไหววัดแรงสั่นสะเทือนได้ 6.3 แมกนิจูด ในเขตมหาสมุทรแปซิฟิกตอนใต้ ห่างจากหมู่เกาะเคอร์มาเดคของนิวซีแลนด์ ซึ่งไม่มีผู้คนอาศัยอยู่“

แผ่นดินไหวใกล้หมู่เกาะเคอร์มาเดค 6.3

„สำนักข่าวต่างประเทศรายงานจากกรุงเวลลิงตันประเทศนิวซีแลนด์ เมื่อวันที่26มิ.ย.ว่าสำนักงานสำรวจธรณีวิทยาสหรัฐแจ้งเหตุแผ่นดินไหวรุนแรงวัดได้6.3แมกนิจูดเมื่อเวลา 01.45น.ของวันศุกร์ที่26มิ.ย.ตามเวลาในประเทศไทยโดยมีจุดศูนย์กลางอยู่ในเขตมหาสมุทรแปซิฟิกตอนใต้และอยู่ลึกลงไป 10กม.ศูนย์กลางแผ่นดินไหวยังอยู่ห่าง369กม.ไปทางใต้ถึงตะวันออกเฉียงใต้ของหมู่เกาะเคอร์มาเดคซึ่งไม่มีผู้คนอาศัยอยู่ของนิวซีแลนด์“

„ทั้งนี้หมู่เกาะเคอร์มาเดคอยู่ห่างจากชายฝั่งเกาะเหนือของนิวซีแลนด์800-1,000กม.“

ที่มา : เดลินิวส์

Categories
Noise-th

ญี่ปุ่นเตรียมติดตั้ง “ส้วม” ในลิฟท์ รับมือเหตุแผ่นดินไหวที่เกิดบ่อยครั้ง!

ญี่ปุ่นเตรียมติดตั้ง “ส้วม” ในลิฟท์ รับมือเหตุแผ่นดินไหวที่เกิดบ่อยครั้ง!

จากรายงานของเอเอฟพี ญี่ปุ่นเตรียมติดตั้งส้วม รวมถึงน้ำดื่มในกรณีฉุกเฉิน สำหรับผู้ที่ต้องติดอยู่ในลิฟท์ ซึ่งอาจเกิดขึ้นจากเหตุแผ่นดินไหวซึ่งพบได้บ่อยครั้่งในญี่ปุ่น

ทั้งนี้จากการเปิดเผยของเจ้าหน้าที่เมื่อวันพุธที่ผ่านมา ข้อเสนอดังกล่าวมีขึ้นหลังประชาชนจำนวนมากติดอยู่ในลิฟท์นานนับชั่วโมงหลังเกิดแผ่นดินไหวด้วยความรุนแรงระดับ7.8 แมกนิจูดเมื่อวันเสาร์ที่ผ่านมา ทำให้ลิฟท์หลายตัวหยุดทำงาน

จากรายงานของเอเอฟพี ญี่ปุ่นเตรียมติดตั้งส้วม รวมถึงน้ำดื่มในกรณีฉุกเฉิน สำหรับผู้ที่ต้องติดอยู่ในลิฟท์ ซึ่งอาจเกิดขึ้นจากเหตุแผ่นดินไหวซึ่งพบได้บ่อยครั้่งในญี่ปุ่น

ทั้งนี้จากการเปิดเผยของเจ้าหน้าที่เมื่อวันพุธที่ผ่านมา ข้อเสนอดังกล่าวมีขึ้นหลังประชาชนจำนวนมากติดอยู่ในลิฟท์นานนับชั่วโมงหลังเกิดแผ่นดินไหวด้วยความรุนแรงระดับ7.8 แมกนิจูดเมื่อวันเสาร์ที่ผ่านมา ทำให้ลิฟท์หลายตัวหยุดทำงาน

โดยลิฟท์ส่วนใหญ่จะหยุดทำงานอัตโนมัติ โดยจะหยุดในชั้นที่ใกล้ที่สุดพร้อมเปิดประตูออก แต่ในเหตุเมื่อวันเสาร์มีลิฟท์ 14 ตัวที่จอดข้างระหว่างชั้น

หลังเกิดเหตุดังกล่าวเจ้าหน้าที่รัฐจึงได้ร่วมประชุมกับบรรดาผู้ผลิตลิฟท์และเห็นร่วมกันที่จะต้องจัดหาส้วมสำหรับกรณีฉุกเฉินไว้ในลิฟท์ พนังงานของสมาคมผู้ผลิตลิฟท์กล่าวกับผู้สื่อข่าวเอเอฟพี

สำหรับเหตุการณ์แผ่นดินไหวเมื่อวันเสาร์ที่ผ่านมามีจุดศูนย์กลางอยู่ในมหาสมุทรแปซิฟิกทางตอนใต้ของกรุงโตเกียวห่างออกไปเป็นระยะทางราว 900 กิโลเมตร แต่แรงสั่นสะเทือนสามารถรับรู้ได้ทั้งประเทศ โดยมีผู้ได้รับบาดเจ็บ 12 ราย รวมถึงสตรีวัย 56 ปี ที่ได้รับบาดเจ็บถึงขนาดซี่โครงหัก แต่ไม่มีผู้ใดเสียชีวิต

ที่มา : จากมติชนออนไลน์

Categories
Asia Noise News Noise-th

cambodian-villagers-say-dam-construction-is-forcing-endangered-dolphins-upstream-due-to-noise-from-the-dam-construction-site

Cambodian villagers are worried that the few remaining Irrawaddy dolphins in a pool in the Mekong River could die off as they are forced to migrate upstream into Laos to escape disturbances caused by the construction of a massive hydropower dam project, local residents and activists said Thursday.

Only three endangered Irrawaddy dolphins, also known as Mekong River dolphins, are now left in the Cheuteal transboundary pool between southern Laos and northern Cambodia’s Stung Treng province, whereas eight were in the area in 2010.

Members of the Preah Rumkel ecotourism community in the province’s Thalaborivat district said Irrawaddy dolphins have been moving two miles upstream into Laotian waters because of noise from explosions at the construction of the 260-megawatt Don Sahong Dam along the Mekong River in southern Laos, less than a mile from the Cambodian border.

The small Mekong River village of Preah Rumkel was set up in 2007 with assistance from an environmental NGO as a community-based ecotourism site to support the local community and improve residents’ livelihoods. Community members manage the tourism site themselves. The half-completed dam lies about one kilometer (0.6 mile) away from the community.

Besides the noise from the dam construction site, the chemicals discarded into the river by construction workers have also forced the dolphins upstream, said Phay Vanna, a member of the Preah Rumkel ecotourism community.

He said he wants the Cambodian government to hold Laos, which is building the dam, accountable.

“I would like the prime minister and civil society organizations to send some experts to conduct additional feasibility studies to hold Laos accountable for the impact caused by the dam’s construction,” he said. “I am a community member. I have witnessed the real impact.”

Gone for good?

Residents are also concerned that their incomes will fall as fewer tourists visit the area when the dolphins are gone for good.

Once in Laotian waters, the Irrawaddy dolphins may succumb to gill nets—vertical panels of nets lined up across a river to catch fish—whose use is not prohibited in Laotian waters as it is in Cambodian ones.

Switzerland-based World Wide Fund for Nature (WWF) says use of the nets is one of the main reasons for the decline in the population of Irrawaddy dolphins, which become entangled in the nets and drown.

The organization wants gill nets banned from a two-kilometer (1.2-mile) radius around the Cheuteal Pool, where they are currently in use, and increased enforcement against fisherman who violate the ban.

Huoth Seng, a Preah Rumkel villager, said he is not happy with recent remarks by Cambodian Prime Minister Hun Sen regarding his approval of the Don Sahong Dam.

On Nov 23, during a meeting in Siem Reap with leaders from Laos and Vietnam about development in the Golden Triangle area, Hun Sen said feasibility studies had been conducted and that the dam project would have no impact in terms of lack of water or fish migrations.

But the dam construction is affecting several thousand families who rely on selling souvenirs, accessories, and food to tourists who come to see the dolphins, he said.

“I didn’t see any transnational studies or research on the impact of the dam project,” he told RFA’s Khmer Service. “What I have seen is that the project is implemented. Now that the communities have been impacted, I wonder who will be held accountable.”

irrawaddy dolphin scared from noise of dam construction site cambodia
irrawaddy dolphin scared from noise of dam construction site cambodia

‘We don’t agree with him’

Civil society groups also accuse the prime minister of turning a blind eye to other issues related to the dam’s construction that are affecting thousands of people in the area.

Ek Chamroeun, coordinator of the Fisheries Action Coalition Team (FACT), a group of NGOs that advocate for fisheries issues and monitor policy reforms, said the dam project has also been a disaster for food security.

“Though Hun Sen said there is no impact, we don’t agree with him,” he said. “We are concerned because we see the real impact on the communities regarding the dam project.”

According to WWF, the Irrawaddy dolphin population has dropped by 50 percent this year in Cambodia, and the large aquatic mammals are functionally extinct in Laos with too few potential breeding pairs available to ensure the population’s survival.

About 80 Irrawaddy dolphins remain in the Mekong River in Cambodia.

Reported by Sothy Men for RFA’s Khmer Service. Translated by Nareth Muong. Written in English by Roseanne Gerin.

Source: http://www.rfa.org/english/news/cambodia/cambodia-villagers-say-dam-construction-is-forcing-endangered-dolphins-upstream-12082016162753.html

Categories
Noise-th

แผ่นดินไหว 6.4 แมกนิจูดในปากีสถาน- copy

แผ่นดินไหวขนาด 5.1 แมกนิจูดเขย่าธรณีเมียนมาร์ซ้ำ หลังเหตุอุทกภัยครั้งใหญ่ หลายจังหวัดทางเหนือของไทยรับรู้ได้ถึงแรงสั่นสะเทือน แต่ไม่มีรายงานสำนักอุตุนิยมวิทยาเปิดเผยว่า เกิดเหตุแผ่นดินไหวซึ่งสามารถวัดแรงสั่นสะเทือนได้ 6.4 แมกนิจูดในปากีสถาน ในเขตจังหวัดปันจาบ ไคเบอร์-ปักตุนวา และอิสลามาบัด เมืองหลวงของปากีสถาน เมื่อวานนี้ (10 ส.ค.)

–นายปีเตอร์ ดรายส์เดล นักเศรษฐศาตร์ประจำมหาวิทยาลัยออสเตรเลียเนชั่นแนล ระบุในรายงานล่าสุดของมหาวิทยาลัยว่า ญี่ปุ่นควรจะระบุถึงเรื่องราวในอดีตให้ถูกต้อง ไม่ใช่เพียงเพื่อการตัดสินคดีและศักดิ์ศรีของเหยื่อความโหดร้ายรุนแรงในประวัติศาสตร์ญี่ปุ่นเท่านั้น แต่เพื่อยุติความเคลือบแคลงใจในเอเชียตะวันออกเฉียงเหนือเช่นกัน

ขอขอบคุณที่มา : http://www.ryt9.com/s/iq29/2225272

Categories
Noise-th

แผ่นดินไหว 6.4 แมกนิจูดในปากีสถาน

แผ่นดินไหวขนาด 5.1 แมกนิจูดเขย่าธรณีเมียนมาร์ซ้ำ หลังเหตุอุทกภัยครั้งใหญ่ หลายจังหวัดทางเหนือของไทยรับรู้ได้ถึงแรงสั่นสะเทือน แต่ไม่มีรายงานสำนักอุตุนิยมวิทยาเปิดเผยว่า เกิดเหตุแผ่นดินไหวซึ่งสามารถวัดแรงสั่นสะเทือนได้ 6.4 แมกนิจูดในปากีสถาน ในเขตจังหวัดปันจาบ ไคเบอร์-ปักตุนวา และอิสลามาบัด เมืองหลวงของปากีสถาน เมื่อวานนี้ (10 ส.ค.)

–นายปีเตอร์ ดรายส์เดล นักเศรษฐศาตร์ประจำมหาวิทยาลัยออสเตรเลียเนชั่นแนล ระบุในรายงานล่าสุดของมหาวิทยาลัยว่า ญี่ปุ่นควรจะระบุถึงเรื่องราวในอดีตให้ถูกต้อง ไม่ใช่เพียงเพื่อการตัดสินคดีและศักดิ์ศรีของเหยื่อความโหดร้ายรุนแรงในประวัติศาสตร์ญี่ปุ่นเท่านั้น แต่เพื่อยุติความเคลือบแคลงใจในเอเชียตะวันออกเฉียงเหนือเช่นกัน

ขอขอบคุณที่มา : http://www.ryt9.com/s/iq29/2225272

Categories
Noise-th

ธรณีพิโรธเขย่าเมียนมาซ้ำ ‘5.1แมกนิจูด-ไทยรับรู้ได้’

แผ่นดินไหวขนาด 5.1 แมกนิจูดเขย่าธรณีเมียนมาร์ซ้ำ หลังเหตุอุทกภัยครั้งใหญ่ หลายจังหวัดทางเหนือของไทยรับรู้ได้ถึงแรงสั่นสะเทือน แต่ไม่มีรายงานความเสียหาย.

ที่มา : เดลินิวส์

 

ธรณีพิโรธเขย่าเมียนมาซ้ำ ‘5.1แมกนิจูด-ไทยรับรู้ได้’