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Reverse osmosis diagram

Schematic diagram:
Reverse osmosis is one possible physical method for purifying water using membrane filters.

In this process, pressure is applied to salty water, pressing it against a semi-permeable membrane with extremely small pores. The pore size allows water molecules of around 0.28 nm to pass through, while salt ions are kept back. (Although salt ions in and of themselves are smaller than water molecules, in this case they are significantly larger due to their bonded hydration shell).
This process is used in large plants around the world to desalinate seawater in areas with shortages of drinking water.

Information and ideas:
In addition to reverse osmosis, there are other membrane filter procedures that differ in the pore size of the membrane:
· Microfiltration
· Ultrafiltration
· Nanofiltration

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Normal audiometric audibility limit

Chart:
Audiometric audibility limit of a person with normal hearing with typical frequency and loudness ranges for speech and music.

The speech range is that range of frequency and loudness where speech communication usually takes place. Within the audiometric audibility limit it is the kidney-shaped range. In our diagram it is coloured blue.

Information and ideas:
An attempt at comparing diagrams showing normal hearing and reduced hearing can be done by students individually - as homework. It is useful for testing written expression (English) as well as for testing basic skills from Mathematics or Physics (how to interpret a diagram, for example).

Relevant for teaching:
Hearing defects/hearing impairment
How hearing functions
Sound/acoustics

Audio

Siemens Stiftung

Can you hear digital data?

Recording:
Is digital data audible?


A digital phone call (DSL, ISDN) is transmitted as an audio frequency. If you listen in to the transmission signal, though, all that you can hear is an incomprehensible twittering noise. This is because the signal is digitized and coded in binary form. At the beginning you will hear the dialing tone, a sequence of different pitches containing the call number in coded form. The subsequent twittering noise is then the digital call signal.

Information and ideas:
Students can carry out their own experiments with a classic analog modem with a monitor speaker which is a very good way to study the transmission of digital data in the audio frequency range. If you carry out the connection test with T-Online, for example, you can see what is happening and being transmitted at that moment in a text log displayed on the screen parallel to the audible sound.

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Xenon auto light bulb

Photo:
A Xenon auto light bulb.


Information and ideas:
An example of the conversion of electrical energy into radiant energy.

Medientypen

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Lernalter

6-18

Schlüsselwörter

Energy

Sprachen

Englisch

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Siemens Stiftung

Ultrasound materials testing - principle

Labeled graphic:
From the delay differences of the echoes recorded, layer thicknesses, errors and consistency can be calculated with oscilloscope graphs.

In engineering the checking of the quality of materials is an important task. A cheap way of testing materials where the material to be tested is not destroyed is based on the reflection of sound on interfaces.

Information and ideas:
These tasks are good for showing how behaviour of sound is used in practice.
Furthermore, internet research is good for explorative learning.

Relevant for teaching:
Sound/acoustics: parameters
Vibration and waves

Medientypen

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Lernalter

11-18

Schlüsselwörter

Electroacoustics Sound Wave (physics)

Sprachen

Englisch

Primärmaterial/Quelle

Siemens Stiftung

Experimentos y proyectos sobre pilas (en inglés)

Recurso de web:
Una colección de ejercicios interactivos de química sobre el funcionamiento de una pila.

El recurso ofrece varios ejercicios interactivos sobre el tema, los cuales se puede llevar a cabo en línea:
· Una tarea de rotulación sobre la configuración del experimento
· Un ejercicio sobre formulación de ecuaciones parciales
· Dos ejercicios multiopción
· Un crucigrama.

Primärmaterial/Quelle

Siemens Stiftung

Partes de la planta Grüneck de tratamiento de aguas cloacales (en alemán)

Recurso de web:
Descripción de las partes individuales de la planta de tratamiento de aguas cloacales de Grüneck, cerca de Múnich.


Se puede invocar información detallada sobre cada parte de la planta y sobre la tecnología del proceso.

Anderer Ressourcentyp

Siemens Stiftung

Conversión de energía

Gráfico interactivo:
Vista general de las formas de energía y las maneras posibles de conversión.


La conversión entre dos formas de energía en ambas direcciones no es siempre posible. Al hacerse clic en una forma de energía se pueden ver todas las posibles conversiones a otras formas de energía. Para cada conversión posible también hay un ejemplo de un convertidor de energía. Asimismo, se pueden visualizar las interrelaciones de todas las formas de energía.

Medientypen

Anderer Ressourcentyp

Lernalter

13-18

Schlüsselwörter

Energía

Sprachen

Spanisch

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Siemens Stiftung

Burning candle

Photo:
A burning candle.


Information and ideas:
An example of the conversion of chemical energy into thermal energy.

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Siemens Stiftung

Bicycle dynamo

Photo:
A bicycle dynamo.


Information and ideas:
An example of an electricity generator that converts mechanical energy into electrical energy.