You've done it! The negotiations for your new home in Bath have been successful, and the moving in date is set. Now all you need to do is pack everything up and get those new keys in your hands. If only it were that simple. Moving to a new town or city can be a daunting task to undertake, and it's important to avoid leaving anything until the last minute.
The one thing that will make your upcoming relocation easier is planning. The more you plan and break things up into smaller tasks, the lower your stress levels will be. At Thomas Firbank, we understand just how chaotic moving can be. Packing everything is no easy task and can cause all sorts of anxiety. That's why we offer a full packing service.
Thomas Firbank has over twenty years of experience in removals and storage. Our track record of providing the best customer service in Bath stems from our ability to pack things correctly. It's what we refer to as the cornerstone of our business. By doing packing things correctly, we know that our customer's belongings will be safe in transit.
We know the right boxes to use, what items to separate, and how to pack fragile objects. Our team have all the right packaging materials and equipment to pack and move things without causing damage. Every item will be listed, and each box will be labelled. That way, everyone will know the exact contents of each box.
The Thomas Firbank team leave nothing to chance. It's crucial that every item is packed correctly to avoid breakages. We'll also unpack your priority items when we arrive at your new home. This is the best packing service in Bath, and it's another reason why we're the area's favourite removals company.
No matter what service you need when moving, it pays to be vigilant and only uses reliable companies. At Thomas Firbank, we have a lot of satisfied customers who return to use us for removals and storage. We always encourage our clients to check online to see our past reviews and testimonials. It's not only crucial before you book with us, but it's something you should do with every company you use.
When it comes to services, price comparison sites may get you a bargain deal, but the quality of service is often inadequate. Many of our customers have spoken to us about their horror stories of using companies via comparison sites.
The reason for this is most of these companies don't comply with the necessary industry standards. By booking Thomas Firbank, you're in safe hands. We're a member of the BAR (British Association of Removers), which means that we promise to attain a certain level of service.
Thomas Firbank has over twenty-one years' worth of experience in removals and storage. In that time, we've become masters of packing to ensure that each item is safe when in transit. It's just as critical to make sure each packed box doesn't cause damage when we move it. That's why we take extra care with fragile and valuable items.
Thomas Firbank operates with the ethos that every customer has different needs. That's why we get to know every person and company we work with as much as we can. This helps us create a picture of what they need from us. We're always happy to talk through our range of services, even if it's just a first inquiry. From the first time you phone us, you'll feel at ease with our friendly members of staff.
At Thomas Firbank, we believe that packing services should be available to everyone. That's why our rates for packing, removals and storage are the best in today's market.
If you're planning your next relocation, don't take chances by doing the packing yourself. Contact us today, and we'll go through our packing services, as well as our other packages.


If you love food and travel, then you can't go wrong with Travel Bites by the Hungry Traveller, a travel enthusiast who loves food.
Travel Bites is a collection of short stories that crisscross the globe, highlighting the Hungry Traveller's journeys around the world over a period of 15 years. Through his unique storytelling, you'll hear all of his delicious tales as well as recipes inspired by his adventures in each location.
Travel Bites features a wealth of delicious destinations including: Vietnam, Morrocco, Singapore, Italy, Australia, England, Tanzania, Italy, Turkey,Greece, Ireland, Cambodia, Eastern Africa, Thailand and USA.
From Salt & Pepper Squid in Vietnam to Singapore Slings in its namesake land to fish and chips in Brighton to Cheese Saganaki in Greece, the Hungry Traveller takes you through all of his experiences - bite by bite. It's enough to make you hungry just reading about the cuisine!
Travel Bites is published by Wattle Publishing (www.wattlepublishing.com), an independent publisher. Travel Bites is available now in paperback and digital format.
Available from Amazon.co.uk for £8.50.


Here is a picture of a future hydrologist studying how water from the surface infiltrates into the ground to become groundwater. Fido assists by making depressions in the ground to demonstrate how low points in the ground will accumulate water, allowing it to recharge groundwater.
Many things influence how much and how fast water from the land surface infiltrates into the ground. What are some that you see in this picture?
Amount of precipitation: How much water is falling (not much from the hose)? Is it falling in one spot or over the whole yard?
Slope of the land: This yard is flat, so water will not runoff so easily. Thus it will be easier for the water to sink in straight down. On hilly land, less water tends to sink in, as it runs off more.
Vegetation: Grass needs water to survive, and it gets water through its roots. The water from this hose saturates the ground close to the land surface, which makes this grass very happy.
Heat and the sun: The sun causes water to evaporate back into the sky. The hotter and sunnier it is, the more water evaporates. The longer water stays on the surface, the more it evaporates.
Animals: Fido will get thirsty running around in circles here and will go grab a drink from the hose soon.
Humans: This young man is a huge part of the water cycle! People have totally transformed the world and the billions of people demand lots of water for their uses. The water cycle we describe in this Web site is mainly the "natural water cycle", the water cycle without human influence. A diagram of the true water cycle as it happens in today's world would have a lot of human influence on it.


The Sony Cyber-shot DSC-RX1 has generated quite a bit a buzz for offering a full-frame sensor and an outstanding 35mm f/2.0 Zeiss lens in a camera that's about the same size as your average point and shoot. This is the technological breakthrough that many have been anxiously waiting for – true full frame performance in a compact package. However, the real question is is it worth its staggering $2,798 USD price (at the time this article was published)?
Bokehlicious – yes, this is what a great f/2 lens on a full frame camera should look like!
Based on what I'm seeing I'd call the dynamic range of this camera as average with today's DSLR's. I don't think it blows any away, but it's very good – and way better than anything in its class. The above shot was a normal exposure and the shot below was an in-camera HDR. On a wide gamut display the orange feels more vibrant on the shot below, but on a sRGB display they are about the same. Both shots were hand held.
This camera has a love affair with 1/80 sec. It seems that the only speed it wants to shoot at when in creative, program mode or aperture priority is 1/80 sec. 99% of my shots in those modes when auto ISO was engaged were at 1/80 second which is odd given the fact that with a full-frame 35mm lens on a DSLR would typically drop down to 1/40 sec under these same conditions. Now, I can understand Sony's desire to keep the shutter speed a little higher to avoid blurry subjects, but I'd prefer that to be a camera setting for minimum shutter speed.
It amazes me when I talk to students who seem to think that smaller f-stop numbers only mean lower ISO's and more light. They are often quick to run out and buy a 50mm f/1.8 lens thinking that they can shoot f/1.8 all day indoors and avoid having to use a flash. Sure, that might be true if you are only doing very shallow DOF shots, but the reality is that you'll probably miss a lot more shots doing that due to the challenges of shooting at f/1.8.
The RX1 can go to f/2.0 which typically on a camera this small means nothing due to its small sensor, but this is a real full-frame sensor so f/2 means you do get dreamy bokeh AND shallow depth of field. Given the back focusing issue and this reality, it means it's easy to foul up shots if you go to a shallow depth of field.
Of course distance from the subject and focal length also come into play when it comes to creating dreamy bokeh, so f/2 isn't going to give you that if you take in larger scenes (as shown above). With 35mm you have to physically get close to your subject to get the dreamy bokeh like shown below and the top of this article, but if you can you'll be rewarded.
f/2 creates dream bokeh, but shallow depth of field makes it tough to use.
This camera convinced me that I will never again own a fixed length lens camera again – especially a measly 35mm. I'll make sacrifices for the ability to optically zoom and longer focal lengths are a must to me.
That said there are occasions where 35mm is the right focal length and having f/2 available can be just the ticket to blur out ugly backgrounds and make lights dazzle.
Even with support and 1/250 sec shutter speed it couldn't focus properly on this big stationary Christmas tree. It seemed that if given a light and dark subject in the scene, it will always focus on the light subject no matter what you tell the camera you want it to do with the flexible focus point. This can work to your advantage sometimes, but many times it can frustrate.
I'm not a video guy so there's not much for me to report here beyond the fact that the video looks great for basic work. The auto focus was a little slow, but that's common for DSLR's and the steady shot is no substitute for an external stabilization solution – just like with a DSLR. It's still no camcorder, so your cheaper point and shoot or cell phone will be much more mom/user friendly, but this will give the real videographer much better results.
It did a decent job of aligning the images and getting the shot. Naturally a tripod would be best for the sharpest result, but with no light in this room directly (only spill from outside and an adjacent room) I thought the results were very good – especially for hand held.
Sadly it doesn't keep each of the exposures it takes either, so you only get the final output. This means a decision to go in-camera HDR is a final one.
My bookshelf test clearly demonstrated what a great sensor this camera has. The colors are excellent, the detail is very good and the performance across the full spectrum of ISO's from 100 to 25,600 is on par with the best DSLR's on the market.
Visit http://www.ronmartinsen.com/sony/rx1 for more in-camera JPEG images that have only been renamed with zero modifications. All shots except the bookshelf shots and where mentioned are hand held.
Overall I'd have to say this is a great beginning, but not something I'm interested in at this time. I loved the image quality and I commend Sony for using such a great lens. However, I need a zoom lens on a form factor like this and this is one camera that I'd actually consider buying if it had interchangeable lenses.
It's just lame being stuck at 35mm only at this day and age, so at this price point it's more of a proof of concept camera than something I desire to own. Hopefully Sony will respond to feedback like this and come up with an interchangeable lens version or one that has a decent 24-100mm zoom. Current lens physics dictate that a 24-100mm on any full frame camera at a decent aperture (like f/4) would be roughly the same size as Canon or Nikons 24-70 2.8mm lenses, so it's no wonder Sony chose to go with a 35mm prime, but that just doesn't fly with me.
If you are someone who only uses 35mm and think that the only thing that matters is a combination of size and image quality, then this is the perfect camera for you. The RX1 has a brilliant sensor and a fantastic lens in a compact package so you won't be disappointed.
Keep trying Sony – this was a great start!
Click here to visit B&H and get the RX1 today. Your purchase helps support this blog, so if you are going to get this camera we'd appreciate if you cleared your cart and used this link. It doesn't cost you a penny extra and it helps support this blog – thanks!
If you make a purchase using links found in this article, I may make a commission. It doesn't cost you a penny more (the retailers just keep the commission otherwise), but it does help sustain this blog so I can bring more articles like this and the ones found on the right side of this blog. Thanks for your support!
B&H loaned me the camera used for this review.
- The photographer can not decide for himself - have to go for 1/80 sec.
Sell it for half the price and build a new camera from this platform, you have showed the way, well done for a start, now make a perfect for this price.
Well, I'm far from being a professional photographer so I really don't know anything much about the specs but I just got a Sony DSC-RX100 as a gift and it is absolutely amazing! It produces great picture and it's compact so what more can I ask for?
Tilda - I prefer the RX100 over the RX1 for everyday real world use too!
Can this camera take auto bracketed raw shots?


text:
namespace Envoy {

INSTANTIATE_TEST_SUITE_P(Protocols, IntegrationAdminTest,
                         testing::ValuesIn(HttpProtocolIntegrationTest::getProtocolTestParams(
                             {Http::CodecClient::Type::HTTP1, Http::CodecClient::Type::HTTP2},
                             {FakeHttpConnection::Type::HTTP1})),
                         HttpProtocolIntegrationTest::protocolTestParamsToString);

TEST_P(IntegrationAdminTest, HealthCheck) {
  initialize();

  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("http"), "POST", "/healthcheck", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/healthcheck/fail",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());

  response = IntegrationUtil::makeSingleRequest(lookupPort("http"), "GET", "/healthcheck", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("503", response->headers().Status()->value().getStringView());

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/healthcheck/ok", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());

  response = IntegrationUtil::makeSingleRequest(lookupPort("http"), "GET", "/healthcheck", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
}

TEST_P(IntegrationAdminTest, HealthCheckWithBufferFilter) {
  config_helper_.addFilter(ConfigHelper::DEFAULT_BUFFER_FILTER);
  initialize();

  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("http"), "GET", "/healthcheck", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
}

TEST_P(IntegrationAdminTest, AdminLogging) {
  initialize();

  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "POST", "/logging", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());

  // Bad level
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/logging?level=blah",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("404", response->headers().Status()->value().getStringView());

  // Bad logger
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/logging?blah=info",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("404", response->headers().Status()->value().getStringView());

  // This is going to stomp over custom log levels that are set on the command line.
  response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "POST", "/logging?level=warning", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  for (const Logger::Logger& logger : Logger::Registry::loggers()) {
    EXPECT_EQ("warning", logger.levelString());
  }

  response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "POST", "/logging?assert=trace", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ(spdlog::level::trace, Logger::Registry::getLog(Logger::Id::assert).level());

  spdlog::string_view_t level_name = spdlog::level::level_string_views[default_log_level_];
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST",
                                                fmt::format("/logging?level={}", level_name), "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  for (const Logger::Logger& logger : Logger::Registry::loggers()) {
    EXPECT_EQ(level_name, logger.levelString());
  }
}

namespace {

std::string ContentType(const BufferingStreamDecoderPtr& response) {
  const Http::HeaderEntry* entry = response->headers().ContentType();
  if (entry == nullptr) {
    return "(null)";
  }
  return std::string(entry->value().getStringView());
}

} // namespace

TEST_P(IntegrationAdminTest, Admin) {
  initialize();

  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "GET", "/notfound", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("404", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));
  EXPECT_NE(std::string::npos, response->body().find("invalid path. admin commands are:"))
      << response->body();

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/help", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));
  EXPECT_NE(std::string::npos, response->body().find("admin commands are:")) << response->body();

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/html; charset=UTF-8", ContentType(response));
  EXPECT_NE(std::string::npos, response->body().find("<title>Envoy Admin</title>"))
      << response->body();

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/server_info", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?usedonly", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  // Testing a filter with no matches
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?filter=foo", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  // Testing a filter with matches
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?filter=server",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET",
                                                "/stats?filter=server&usedonly", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response =
      IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?format=json&usedonly",
                                         "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));
  validateStatsJson(response->body(), 0);

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?format=blah",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("404", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?format=json",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("application/json", ContentType(response));
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  validateStatsJson(response->body(), 1);

  // Filtering stats by a regex with one match should return just that match.
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET",
                                                "/stats?format=json&filter=^server\\.version$", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("application/json", ContentType(response));
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  validateStatsJson(response->body(), 0);
  EXPECT_THAT(response->body(),
              testing::Eq("{\"stats\":[{\"name\":\"server.version\",\"value\":0}]}"));

  // Filtering stats by a non-full-string regex should also return just that match.
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET",
                                                "/stats?format=json&filter=server\\.version", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("application/json", ContentType(response));
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  validateStatsJson(response->body(), 0);
  EXPECT_THAT(response->body(),
              testing::Eq("{\"stats\":[{\"name\":\"server.version\",\"value\":0}]}"));

  // Filtering stats by a regex with no matches (".*not_intended_to_appear.*") should return a
  // valid, empty, stats array.
  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET",
                                                "/stats?format=json&filter=not_intended_to_appear",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("application/json", ContentType(response));
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  validateStatsJson(response->body(), 0);
  EXPECT_THAT(response->body(), testing::Eq("{\"stats\":[]}"));

  response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "GET", "/stats?format=prometheus", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_THAT(response->body(),
              testing::HasSubstr(
                  "envoy_http_downstream_rq_xx{envoy_response_code_class=\"4\",envoy_http_conn_"
                  "manager_prefix=\"admin\"} 2\n"));
  EXPECT_THAT(response->body(), testing::HasSubstr("# TYPE envoy_http_downstream_rq_xx counter\n"));
  EXPECT_THAT(response->body(),
              testing::HasSubstr(
                  "envoy_listener_admin_http_downstream_rq_xx{envoy_response_code_class=\"4\","
                  "envoy_http_conn_manager_prefix=\"admin\"} 2\n"));
  EXPECT_THAT(response->body(),
              testing::HasSubstr("# TYPE envoy_cluster_upstream_cx_active gauge\n"));
  EXPECT_THAT(
      response->body(),
      testing::HasSubstr("envoy_cluster_upstream_cx_active{envoy_cluster_name=\"cluster_0\"} 0\n"));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats/prometheus", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_THAT(response->body(),
              testing::HasSubstr(
                  "envoy_http_downstream_rq_xx{envoy_response_code_class=\"4\",envoy_http_conn_"
                  "manager_prefix=\"admin\"} 2\n"));
  EXPECT_THAT(response->body(), testing::HasSubstr("# TYPE envoy_http_downstream_rq_xx counter\n"));
  EXPECT_THAT(response->body(),
              testing::HasSubstr(
                  "envoy_listener_admin_http_downstream_rq_xx{envoy_response_code_class=\"4\","
                  "envoy_http_conn_manager_prefix=\"admin\"} 2\n"));
  EXPECT_THAT(response->body(),
              testing::HasSubstr("# TYPE envoy_cluster_upstream_cx_active gauge\n"));
  EXPECT_THAT(
      response->body(),
      testing::HasSubstr("envoy_cluster_upstream_cx_active{envoy_cluster_name=\"cluster_0\"} 0\n"));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/clusters", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_THAT(response->body(), testing::HasSubstr("added_via_api"));
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/cpuprofiler", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("400", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/hot_restart_version",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "POST", "/reset_counters", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("text/plain; charset=UTF-8", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/certs", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/runtime", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/runtime?format=json",
                                                "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/listeners", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));

  Json::ObjectSharedPtr json = Json::Factory::loadFromString(response->body());
  std::vector<Json::ObjectSharedPtr> listener_info = json->asObjectArray();
  auto listener_info_it = listener_info.cbegin();
  auto listeners = test_server_->server().listenerManager().listeners();
  auto listener_it = listeners.cbegin();
  for (; listener_info_it != listener_info.end() && listener_it != listeners.end();
       ++listener_info_it, ++listener_it) {
    EXPECT_EQ(listener_it->get().socket().localAddress()->asString(),
              (*listener_info_it)->asString());
  }

  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/config_dump", "",
                                                downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  EXPECT_EQ("application/json", ContentType(response));
  json = Json::Factory::loadFromString(response->body());
  size_t index = 0;
  const std::string expected_types[] = {
      "type.googleapis.com/envoy.admin.v2alpha.BootstrapConfigDump",
      "type.googleapis.com/envoy.admin.v2alpha.ClustersConfigDump",
      "type.googleapis.com/envoy.admin.v2alpha.ListenersConfigDump",
      "type.googleapis.com/envoy.admin.v2alpha.RoutesConfigDump"};
  for (Json::ObjectSharedPtr obj_ptr : json->getObjectArray("configs")) {
    EXPECT_TRUE(expected_types[index].compare(obj_ptr->getString("@type")) == 0);
    index++;
  }

  // Validate we can parse as proto.
  envoy::admin::v2alpha::ConfigDump config_dump;
  MessageUtil::loadFromJson(response->body(), config_dump);
  EXPECT_EQ(4, config_dump.configs_size());

  // .. and that we can unpack one of the entries.
  envoy::admin::v2alpha::RoutesConfigDump route_config_dump;
  config_dump.configs(3).UnpackTo(&route_config_dump);
  EXPECT_EQ("route_config_0", route_config_dump.static_route_configs(0).route_config().name());
}

TEST_P(IntegrationAdminTest, AdminOnDestroyCallbacks) {
  initialize();
  bool test = true;

  // add an handler which adds a callback to the list of callback called when connection is dropped.
  auto callback = [&test](absl::string_view, Http::HeaderMap&, Buffer::Instance&,
                          Server::AdminStream& admin_stream) -> Http::Code {
    auto on_destroy_callback = [&test]() { test = false; };

    // Add the on_destroy_callback to the admin_filter list of callbacks.
    admin_stream.addOnDestroyCallback(std::move(on_destroy_callback));
    return Http::Code::OK;
  };

  EXPECT_TRUE(
      test_server_->server().admin().addHandler("/foo/bar", "hello", callback, true, false));

  // As part of the request, on destroy() should be called and the on_destroy_callback invoked.
  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "GET", "/foo/bar", "", downstreamProtocol(), version_);

  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  // Check that the added callback was invoked.
  EXPECT_EQ(test, false);

  // Small test to cover new statsFlushInterval() on Instance.h.
  EXPECT_EQ(test_server_->server().statsFlushInterval(), std::chrono::milliseconds(5000));
}

TEST_P(IntegrationAdminTest, AdminCpuProfilerStart) {
  config_helper_.addConfigModifier([&](envoy::config::bootstrap::v2::Bootstrap& bootstrap) -> void {
    auto* admin = bootstrap.mutable_admin();
    admin->set_profile_path(TestEnvironment::temporaryPath("/envoy.prof"));
  });

  initialize();
  BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "POST", "/cpuprofiler?enable=y", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
#ifdef PROFILER_AVAILABLE
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
#else
  EXPECT_EQ("500", response->headers().Status()->value().getStringView());
#endif

  response = IntegrationUtil::makeSingleRequest(
      lookupPort("admin"), "POST", "/cpuprofiler?enable=n", "", downstreamProtocol(), version_);
  EXPECT_TRUE(response->complete());
  EXPECT_EQ("200", response->headers().Status()->value().getStringView());
}

class IntegrationAdminIpv4Ipv6Test : public testing::Test, public HttpIntegrationTest {
public:
  IntegrationAdminIpv4Ipv6Test()
      : HttpIntegrationTest(Http::CodecClient::Type::HTTP1, Network::Address::IpVersion::v4) {}

  void initialize() override {
    config_helper_.addConfigModifier(
        [&](envoy::config::bootstrap::v2::Bootstrap& bootstrap) -> void {
          auto* socket_address =
              bootstrap.mutable_admin()->mutable_address()->mutable_socket_address();
          socket_address->set_ipv4_compat(true);
          socket_address->set_address("::");
        });
    HttpIntegrationTest::initialize();
  }
};

// Verify an IPv4 client can connect to the admin interface listening on :: when
// IPv4 compat mode is enabled.
TEST_F(IntegrationAdminIpv4Ipv6Test, Ipv4Ipv6Listen) {
  if (TestEnvironment::shouldRunTestForIpVersion(Network::Address::IpVersion::v4) &&
      TestEnvironment::shouldRunTestForIpVersion(Network::Address::IpVersion::v6)) {
    initialize();
    BufferingStreamDecoderPtr response = IntegrationUtil::makeSingleRequest(
        lookupPort("admin"), "GET", "/server_info", "", downstreamProtocol(), version_);
    EXPECT_TRUE(response->complete());
    EXPECT_EQ("200", response->headers().Status()->value().getStringView());
  }
}

// Testing the behavior of StatsMatcher, which allows/denies the  instantiation of stats based on
// restrictions on their names.
class StatsMatcherIntegrationTest
    : public testing::Test,
      public Event::TestUsingSimulatedTime,
      public HttpIntegrationTest,
      public testing::WithParamInterface<Network::Address::IpVersion> {
public:
  StatsMatcherIntegrationTest() : HttpIntegrationTest(Http::CodecClient::Type::HTTP1, GetParam()) {}

  void initialize() override {
    config_helper_.addConfigModifier(
        [this](envoy::config::bootstrap::v2::Bootstrap& bootstrap) -> void {
          *bootstrap.mutable_stats_config()->mutable_stats_matcher() = stats_matcher_;
        });
    HttpIntegrationTest::initialize();
  }
  void makeRequest() {
    response_ = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats", "",
                                                   downstreamProtocol(), version_);
    ASSERT_TRUE(response_->complete());
    EXPECT_EQ("200", response_->headers().Status()->value().getStringView());
  }

  BufferingStreamDecoderPtr response_;
  envoy::config::metrics::v2::StatsMatcher stats_matcher_;
};
INSTANTIATE_TEST_SUITE_P(IpVersions, StatsMatcherIntegrationTest,
                         testing::ValuesIn(TestEnvironment::getIpVersionsForTest()),
                         TestUtility::ipTestParamsToString);

// Verify that StatsMatcher prevents the printing of uninstantiated stats.
TEST_P(StatsMatcherIntegrationTest, ExcludePrefixServerDot) {
  stats_matcher_.mutable_exclusion_list()->add_patterns()->set_prefix("server.");
  initialize();
  makeRequest();
  EXPECT_THAT(response_->body(), testing::Not(testing::HasSubstr("server.")));
}

TEST_P(StatsMatcherIntegrationTest, ExcludeRequests) {
  stats_matcher_.mutable_exclusion_list()->add_patterns()->set_regex(".*requests.*");
  initialize();
  makeRequest();
  EXPECT_THAT(response_->body(), testing::Not(testing::HasSubstr("requests")));
}

TEST_P(StatsMatcherIntegrationTest, ExcludeExact) {
  stats_matcher_.mutable_exclusion_list()->add_patterns()->set_exact("server.concurrency");
  initialize();
  makeRequest();
  EXPECT_THAT(response_->body(), testing::Not(testing::HasSubstr("server.concurrency")));
}

TEST_P(StatsMatcherIntegrationTest, ExcludeMultipleExact) {
  stats_matcher_.mutable_exclusion_list()->add_patterns()->set_exact("server.concurrency");
  stats_matcher_.mutable_exclusion_list()->add_patterns()->set_regex(".*live");
  initialize();
  makeRequest();
  EXPECT_THAT(response_->body(), testing::Not(testing::HasSubstr("server.concurrency")));
  EXPECT_THAT(response_->body(), testing::Not(testing::HasSubstr("server.live")));
}

// TODO(ambuc): Find a cleaner way to test this. This test has two unfortunate compromises:
//
// - a) `listener_manager.listener_create_success` must be instantiated, because BaseIntegrationTest
//      blocks on its creation (see waitForCounterGe and the suite of waitFor* functions), and
// - b) `stats.overflow` isn't blocked from instantiation, because it occurs at ThreadLocalStore
//      construction time, before setStatsMatcher() is called.
//
// If either of these invariants is changed, this test must be rewritten.
TEST_P(StatsMatcherIntegrationTest, IncludeExact) {
  stats_matcher_.mutable_inclusion_list()->add_patterns()->set_exact(
      "listener_manager.listener_create_success");
  initialize();
  makeRequest();
  EXPECT_EQ(response_->body(), "listener_manager.listener_create_success: 1\n");
}

} // namespace Envoy

redpajama_set_name: RedPajamaGithub


Canyon de Chelly is located in the state of Arizona in the southwest United States. It was dug millions of years ago by powerful rivers that have deposited silt and also made the land very fertile.
To the 10th century, the Pueblo Indians have found a rich land to develop a food crop. The numerous water sources they have also ensured the survival of families who had settled in the canyon. The first houses were simple huts built on the ground. The technique was to dig a hole to enjoy the cool soil and plant stakes that provided the super structure construction. Gradually the tribes have grown and the houses became too small. The Indians had the idea to build shelters in the cliffs bordering the canyon. These buildings which ensured a more effective protection against the sun and the flood are still visible today. In the mid-14th century, the Hopi Indians brought corn fields and peach orchards. Today the canyon is still inhabited by the Navajo. They continue to cultivate the fields in the canyon as the ancients did. Farms, livestock herds are visible from the cliffs.
For photographers, the Canyon de Chelly is a great place because of the red rocks and geometric shapes formed by the lava. The best time of day to take pictures is the late afternoon with the sun in the west. The time is short, about 2 hours. You must start at the top of the cliffs to successfully capture the atmosphere and grandeur of the place. Then you have to descend into the canyon by a steep path. The most typical place is undoubtedly the White House that was built in the 13th century. Most striking is the richness of cultures, many species of trees that line the bottom of the canyon. It is a stark contrast because the region is rather arid.


International friendlies – Follow the Football match between England and Italy live with Eurosport. The match starts at 21:00 on 27 March 2018. Our live coverage lets you follow all the key moments as they happen.


text:
(Redirected from Magnetic properties)
"Magnetic" and "Magnetized" redirect here. For other uses, see Magnetic (disambiguation), Magnetism (disambiguation), and Magnetized (disambiguation).
A magnetic quadrupole
Part of a series of articles about
Electric charge
Electric dipole moment
Electric field
Electric flux / potential energy
Polarization density
Triboelectricity
Magnetostatics
Ampère's law
Biot–Savart law
Gauss's law for magnetism
Magnetic flux
Magnetic dipole moment
Magnetization
Magnetomotive force
Electrodynamics
Lorentz force law
Faraday's law
Lenz's law
Displacement current
Magnetic potential
Maxwell's equations
Maxwell tensor
Poynting vector
Liénard–Wiechert potential
Jefimenko's equations
Eddy current
London equations
Mathematical descriptions of the electromagnetic field
Electrical network
Electric potential
Electromotive force
Ohm's law
Parallel circuit
Resonant cavities
Series circuit
Covariant formulation
Electromagnetic tensor
(stress–energy tensor)
Four-current
Electromagnetic four-potential
Coulomb
Heaviside
Ørsted
Savart
Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Only a few substances are ferromagnetic; the most common ones are iron, cobalt and nickel and their alloys such as steel. The prefix ferro- refers to iron, because permanent magnetism was first observed in lodestone, a form of natural iron ore called magnetite, Fe3O4.
Although ferromagnetism is responsible for most of the effects of magnetism encountered in everyday life, all other materials are influenced to some extent by a magnetic field, by several other types of magnetism. Paramagnetic substances such as aluminum and oxygen are weakly attracted to an applied magnetic field; diamagnetic substances such as copper and carbon are weakly repelled; while antiferromagnetic materials such as chromium and spin glasses have a more complex relationship with a magnetic field. The force of a magnet on paramagnetic, diamagnetic, and antiferromagnetic materials is usually too weak to be felt and can be detected only by laboratory instruments, so in everyday life, these substances are often described as non-magnetic.
The magnetic state (or magnetic phase) of a material depends on temperature and other variables such as pressure and the applied magnetic field. A material may exhibit more than one form of magnetism as these variables change. As with magnetizing a magnet, demagnetizing a magnet is also possible. "Passing an alternate current, or hitting a heated magnet in an east-west direction are ways of demagnetizing a magnet", quotes Sreekethav.
3 Types of Magnetism
3.1 Diamagnetism
3.2 Paramagnetism
3.3 Ferromagnetism
3.3.1 Magnetic domains
3.4 Antiferromagnetism
3.5 Ferrimagnetism
3.6 Superparamagnetism
3.7 Other types of magnetism
4 Electromagnet
5 Magnetism, electricity, and special relativity
6 Magnetic fields in a material
7 Magnetic force
8 Magnetic dipoles
8.1 Magnetic monopoles
9 Quantum-mechanical origin of magnetism
10.1 SI
10.2 Other
11 Living things
Main article: History of electromagnetism
Lodestone, a natural magnet, attracting iron nails. Ancient humans discovered the property of magnetism from lodestone.
An illustration from Gilbert's 1600 De Magnete showing one of the earliest methods of making a magnet. A blacksmith holds a piece of red-hot iron in a north-south direction and hammers it as it cools. The magnetic field of the Earth aligns the domains, leaving the iron a weak magnet.
Drawing of a medical treatment using magnetic brushes. Charles Jacque 1843, France.
Magnetism was first discovered in the ancient world, when people noticed that lodestones, naturally magnetized pieces of the mineral magnetite, could attract iron.[1] The word magnet comes from the Greek term μαγνῆτις λίθος magnētis lithos,[2] "the Magnesian stone,[3] lodestone." In ancient Greece, Aristotle attributed the first of what could be called a scientific discussion of magnetism to the philosopher Thales of Miletus, who lived from about 625 BC to about 545 BC.[4] The ancient Indian medical text Sushruta Samhita describes using magnetite to remove arrows embedded in a person's body.[5]
In ancient China, the earliest literary reference to magnetism lies in a 4th-century BC book named after its author, The Sage of Ghost Valley.[6] The 2nd-century BC annals, Lüshi Chunqiu, also notes: "The lodestone makes iron approach, or it attracts it."[7] The earliest mention of the attraction of a needle is in a 1st-century work Lunheng (Balanced Inquiries): "A lodestone attracts a needle."[8] The 11th-century Chinese scientist Shen Kuo was the first person to write—in the Dream Pool Essays—of the magnetic needle compass and that it improved the accuracy of navigation by employing the astronomical concept of true north. By the 12th century, the Chinese were known to use the lodestone compass for navigation. They sculpted a directional spoon from lodestone in such a way that the handle of the spoon always pointed south.
Alexander Neckam, by 1187, was the first in Europe to describe the compass and its use for navigation. In 1269, Peter Peregrinus de Maricourt wrote the Epistola de magnete, the first extant treatise describing the properties of magnets. In 1282, the properties of magnets and the dry compasses were discussed by Al-Ashraf, a Yemeni physicist, astronomer, and geographer.[9]
In 1600, William Gilbert published his De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on the Great Magnet the Earth). In this work he describes many of his experiments with his model earth called the terrella. From his experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses pointed north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass).
An understanding of the relationship between electricity and magnetism began in 1819 with work by Hans Christian Ørsted, a professor at the University of Copenhagen, who discovered by the accidental twitching of a compass needle near a wire that an electric current could create a magnetic field. This landmark experiment is known as Ørsted's Experiment. Several other experiments followed, with André-Marie Ampère, who in 1820 discovered that the magnetic field circulating in a closed-path was related to the current flowing through the perimeter of the path; Carl Friedrich Gauss; Jean-Baptiste Biot and Félix Savart, both of whom in 1820 came up with the Biot–Savart law giving an equation for the magnetic field from a current-carrying wire; Michael Faraday, who in 1831 found that a time-varying magnetic flux through a loop of wire induced a voltage, and others finding further links between magnetism and electricity. James Clerk Maxwell synthesized and expanded these insights into Maxwell's equations, unifying electricity, magnetism, and optics into the field of electromagnetism. In 1905, Einstein used these laws in motivating his theory of special relativity,[10] requiring that the laws held true in all inertial reference frames.
Electromagnetism has continued to develop into the 21st century, being incorporated into the more fundamental theories of gauge theory, quantum electrodynamics, electroweak theory, and finally the standard model.
See also: Magnetic moment
Magnetism, at its root, arises from two sources:
Electric current.
Spin magnetic moments of elementary particles.
The magnetic properties of materials are mainly due to the magnetic moments of their atoms' orbiting electrons. The magnetic moments of the nuclei of atoms are typically thousands of times smaller than the electrons' magnetic moments, so they are negligible in the context of the magnetization of materials. Nuclear magnetic moments are nevertheless very important in other contexts, particularly in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).
Ordinarily, the enormous number of electrons in a material are arranged such that their magnetic moments (both orbital and intrinsic) cancel out. This is due, to some extent, to electrons combining into pairs with opposite intrinsic magnetic moments as a result of the Pauli exclusion principle (see electron configuration), and combining into filled subshells with zero net orbital motion. In both cases, the electrons preferentially adopt arrangements in which the magnetic moment of each electron is canceled by the opposite moment of another electron. Moreover, even when the electron configuration is such that there are unpaired electrons and/or non-filled subshells, it is often the case that the various electrons in the solid will contribute magnetic moments that point in different, random directions so that the material will not be magnetic.
Sometimes, either spontaneously, or owing to an applied external magnetic field—each of the electron magnetic moments will be, on average, lined up. A suitable material can then produce a strong net magnetic field.
The magnetic behavior of a material depends on its structure, particularly its electron configuration, for the reasons mentioned above, and also on the temperature. At high temperatures, random thermal motion makes it more difficult for the electrons to maintain alignment.
Types of Magnetism[edit]
Hierarchy of types of magnetism.[11]
Diamagnetism[edit]
Main article: Diamagnetism
Diamagnetism appears in all materials and is the tendency of a material to oppose an applied magnetic field, and therefore, to be repelled by a magnetic field. However, in a material with paramagnetic properties (that is, with a tendency to enhance an external magnetic field), the paramagnetic behavior dominates.[12] Thus, despite its universal occurrence, diamagnetic behavior is observed only in a purely diamagnetic material. In a diamagnetic material, there are no unpaired electrons, so the intrinsic electron magnetic moments cannot produce any bulk effect. In these cases, the magnetization arises from the electrons' orbital motions, which can be understood classically as follows:
When a material is put in a magnetic field, the electrons circling the nucleus will experience, in addition to their Coulomb attraction to the nucleus, a Lorentz force from the magnetic field. Depending on which direction the electron is orbiting, this force may increase the centripetal force on the electrons, pulling them in towards the nucleus, or it may decrease the force, pulling them away from the nucleus. This effect systematically increases the orbital magnetic moments that were aligned opposite the field and decreases the ones aligned parallel to the field (in accordance with Lenz's law). This results in a small bulk magnetic moment, with an opposite direction to the applied field.
Note that this description is meant only as a heuristic; the Bohr-van Leeuwen theorem shows that diamagnetism is impossible according to classical physics, and that a proper understanding requires a quantum-mechanical description.
Note that all materials undergo this orbital response. However, in paramagnetic and ferromagnetic substances, the diamagnetic effect is overwhelmed by the much stronger effects caused by the unpaired electrons.
Paramagnetism[edit]
Main article: Paramagnetism
In a paramagnetic material there are unpaired electrons; i.e., atomic or molecular orbitals with exactly one electron in them. While paired electrons are required by the Pauli exclusion principle to have their intrinsic ('spin') magnetic moments pointing in opposite directions, causing their magnetic fields to cancel out, an unpaired electron is free to align its magnetic moment in any direction. When an external magnetic field is applied, these magnetic moments will tend to align themselves in the same direction as the applied field, thus reinforcing it.
Ferromagnetism[edit]
Tip of permanent magnet with coins demonstrating ferromagnetism
Main article: Ferromagnetism
A ferromagnet, like a paramagnetic substance, has unpaired electrons. However, in addition to the electrons' intrinsic magnetic moment's tendency to be parallel to an applied field, there is also in these materials a tendency for these magnetic moments to orient parallel to each other to maintain a lowered-energy state. Thus, even in the absence of an applied field, the magnetic moments of the electrons in the material spontaneously line up parallel to one another.
Every ferromagnetic substance has its own individual temperature, called the Curie temperature, or Curie point, above which it loses its ferromagnetic properties. This is because the thermal tendency to disorder overwhelms the energy-lowering due to ferromagnetic order.
Ferromagnetism only occurs in a few substances; common ones are iron, nickel, cobalt, their alloys, and some alloys of rare-earth metals.
Magnetic domains[edit]
Main article: Magnetic domains
Magnetic domains boundaries (white lines) in ferromagnetic material (black rectangle)
Effect of a magnet on the domains
The magnetic moments of atoms in a ferromagnetic material cause them to behave something like tiny permanent magnets. They stick together and align themselves into small regions of more or less uniform alignment called magnetic domains or Weiss domains. Magnetic domains can be observed with a magnetic force microscope to reveal magnetic domain boundaries that resemble white lines in the sketch. There are many scientific experiments that can physically show magnetic fields.
When a domain contains too many molecules, it becomes unstable and divides into two domains aligned in opposite directions, so that they stick together more stably, as shown at the right.
When exposed to a magnetic field, the domain boundaries move, so that the domains aligned with the magnetic field grow and dominate the structure (dotted yellow area), as shown at the left. When the magnetizing field is removed, the domains may not return to an unmagnetized state. This results in the ferromagnetic material's being magnetized, forming a permanent magnet.
When magnetized strongly enough that the prevailing domain overruns all others to result in only one single domain, the material is magnetically saturated. When a magnetized ferromagnetic material is heated to the Curie point temperature, the molecules are agitated to the point that the magnetic domains lose the organization, and the magnetic properties they cause cease. When the material is cooled, this domain alignment structure spontaneously returns, in a manner roughly analogous to how a liquid can freeze into a crystalline solid.
Antiferromagnetism[edit]
Antiferromagnetic ordering
Main article: Antiferromagnetism
In an antiferromagnet, unlike a ferromagnet, there is a tendency for the intrinsic magnetic moments of neighboring valence electrons to point in opposite directions. When all atoms are arranged in a substance so that each neighbor is anti-parallel, the substance is antiferromagnetic. Antiferromagnets have a zero net magnetic moment, meaning that no field is produced by them. Antiferromagnets are less common compared to the other types of behaviors and are mostly observed at low temperatures. In varying temperatures, antiferromagnets can be seen to exhibit diamagnetic and ferromagnetic properties.
In some materials, neighboring electrons prefer to point in opposite directions, but there is no geometrical arrangement in which each pair of neighbors is anti-aligned. This is called a spin glass and is an example of geometrical frustration.
Ferrimagnetism[edit]
Ferrimagnetic ordering
Main article: Ferrimagnetism
Like ferromagnetism, ferrimagnets retain their magnetization in the absence of a field. However, like antiferromagnets, neighboring pairs of electron spins tend to point in opposite directions. These two properties are not contradictory, because in the optimal geometrical arrangement, there is more magnetic moment from the sublattice of electrons that point in one direction, than from the sublattice that points in the opposite direction.
Most ferrites are ferrimagnetic. The first discovered magnetic substance, magnetite, is a ferrite and was originally believed to be a ferromagnet; Louis Néel disproved this, however, after discovering ferrimagnetism.
Superparamagnetism[edit]
Main article: Superparamagnetism
When a ferromagnet or ferrimagnet is sufficiently small, it acts like a single magnetic spin that is subject to Brownian motion. Its response to a magnetic field is qualitatively similar to the response of a paramagnet, but much larger.
Other types of magnetism[edit]
Metamagnetism
Molecule-based magnets
Single-molecule magnet
Spin glass
Electromagnet[edit]
An electromagnet attracts paper clips when current is applied creating a magnetic field. The electromagnet loses them when current and magnetic field are removed.
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.[13] The magnetic field disappears when the current is turned off. Electromagnets usually consist of a large number of closely spaced turns of wire that create the magnetic field. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Electromagnets are widely used as components of other electrical devices, such as motors, generators, relays, solenoids, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment. Electromagnets are also employed in industry for picking up and moving heavy iron objects such as scrap iron and steel.[14] Electromagnetism was discovered in 1820.[15]
Magnetism, electricity, and special relativity[edit]
Magnetism from length-contraction.
Main article: Classical electromagnetism and special relativity
As a consequence of Einstein's theory of special relativity, electricity and magnetism are fundamentally interlinked. Both magnetism lacking electricity, and electricity without magnetism, are inconsistent with special relativity, due to such effects as length contraction, time dilation, and the fact that the magnetic force is velocity-dependent. However, when both electricity and magnetism are taken into account, the resulting theory (electromagnetism) is fully consistent with special relativity.[10][16] In particular, a phenomenon that appears purely electric or purely magnetic to one observer may be a mix of both to another, or more generally the relative contributions of electricity and magnetism are dependent on the frame of reference. Thus, special relativity "mixes" electricity and magnetism into a single, inseparable phenomenon called electromagnetism, analogous to how relativity "mixes" space and time into spacetime.
All observations on electromagnetism apply to what might be considered to be primarily magnetism, e.g. perturbations in the magnetic field are necessarily accompanied by a nonzero electric field, and propagate at the speed of light.[citation needed]
Magnetic fields in a material[edit]
See also: Magnetic field § H and B inside and outside of magnetic materials
In a vacuum,
B = μ 0 H , {\displaystyle \mathbf {B} \ =\ \mu _{0}\mathbf {H} ,}
where μ0 is the vacuum permeability.
In a material,
B = μ 0 ( H + M ) . {\displaystyle \mathbf {B} \ =\ \mu _{0}(\mathbf {H} +\mathbf {M} ).\ }
The quantity μ0M is called magnetic polarization.
If the field H is small, the response of the magnetization M in a diamagnet or paramagnet is approximately linear:
M = χ H , {\displaystyle \mathbf {M} =\chi \mathbf {H} ,}
the constant of proportionality being called the magnetic susceptibility. If so,
μ 0 ( H + M ) = μ 0 ( 1 + χ ) H = μ r μ 0 H = μ H . {\displaystyle \mu _{0}(\mathbf {H} +\mathbf {M} )\ =\ \mu _{0}(1+\chi )\mathbf {H} \ =\ \mu _{r}\mu _{0}\mathbf {H} \ =\ \mu \mathbf {H} .}
In a hard magnet such as a ferromagnet, M is not proportional to the field and is generally nonzero even when H is zero (see Remanence).
Magnetic force[edit]
Magnetic lines of force of a bar magnet shown by iron filings on paper
Detecting magnetic field with compass and with iron filings
Main article: Magnetic field
The phenomenon of magnetism is "mediated" by the magnetic field. An electric current or magnetic dipole creates a magnetic field, and that field, in turn, imparts magnetic forces on other particles that are in the fields.
Maxwell's equations, which simplify to the Biot–Savart law in the case of steady currents, describe the origin and behavior of the fields that govern these forces. Therefore, magnetism is seen whenever electrically charged particles are in motion—for example, from movement of electrons in an electric current, or in certain cases from the orbital motion of electrons around an atom's nucleus. They also arise from "intrinsic" magnetic dipoles arising from quantum-mechanical spin.
The same situations that create magnetic fields—charge moving in a current or in an atom, and intrinsic magnetic dipoles—are also the situations in which a magnetic field has an effect, creating a force. Following is the formula for moving charge; for the forces on an intrinsic dipole, see magnetic dipole.
When a charged particle moves through a magnetic field B, it feels a Lorentz force F given by the cross product:[17]
F = q ( v × B ) {\displaystyle \mathbf {F} =q(\mathbf {v} \times \mathbf {B} )}
q {\displaystyle q} is the electric charge of the particle, and
v is the velocity vector of the particle
Because this is a cross product, the force is perpendicular to both the motion of the particle and the magnetic field. It follows that the magnetic force does no work on the particle; it may change the direction of the particle's movement, but it cannot cause it to speed up or slow down. The magnitude of the force is
F = q v B sin  θ {\displaystyle F=qvB\sin \theta \,}
where θ {\displaystyle \theta } is the angle between v and B.
One tool for determining the direction of the velocity vector of a moving charge, the magnetic field, and the force exerted is labeling the index finger "V", the middle finger "B", and the thumb "F" with your right hand. When making a gun-like configuration, with the middle finger crossing under the index finger, the fingers represent the velocity vector, magnetic field vector, and force vector, respectively. See also right-hand rule.
Magnetic dipoles[edit]
Main article: Magnetic dipole
A very common source of magnetic field found in nature is a dipole, with a "South pole" and a "North pole", terms dating back to the use of magnets as compasses, interacting with the Earth's magnetic field to indicate North and South on the globe. Since opposite ends of magnets are attracted, the north pole of a magnet is attracted to the south pole of another magnet. The Earth's North Magnetic Pole (currently in the Arctic Ocean, north of Canada) is physically a south pole, as it attracts the north pole of a compass. A magnetic field contains energy, and physical systems move toward configurations with lower energy. When diamagnetic material is placed in a magnetic field, a magnetic dipole tends to align itself in opposed polarity to that field, thereby lowering the net field strength. When ferromagnetic material is placed within a magnetic field, the magnetic dipoles align to the applied field, thus expanding the domain walls of the magnetic domains.
Magnetic monopoles[edit]
Main article: Magnetic monopole
Since a bar magnet gets its ferromagnetism from electrons distributed evenly throughout the bar, when a bar magnet is cut in half, each of the resulting pieces is a smaller bar magnet. Even though a magnet is said to have a north pole and a south pole, these two poles cannot be separated from each other. A monopole—if such a thing exists—would be a new and fundamentally different kind of magnetic object. It would act as an isolated north pole, not attached to a south pole, or vice versa. Monopoles would carry "magnetic charge" analogous to electric charge. Despite systematic searches since 1931, as of 2010[update], they have never been observed, and could very well not exist.[18]
Nevertheless, some theoretical physics models predict the existence of these magnetic monopoles. Paul Dirac observed in 1931 that, because electricity and magnetism show a certain symmetry, just as quantum theory predicts that individual positive or negative electric charges can be observed without the opposing charge, isolated South or North magnetic poles should be observable. Using quantum theory Dirac showed that if magnetic monopoles exist, then one could explain the quantization of electric charge—that is, why the observed elementary particles carry charges that are multiples of the charge of the electron.
Certain grand unified theories predict the existence of monopoles which, unlike elementary particles, are solitons (localized energy packets). The initial results of using these models to estimate the number of monopoles created in the Big Bang contradicted cosmological observations—the monopoles would have been so plentiful and massive that they would have long since halted the expansion of the universe. However, the idea of inflation (for which this problem served as a partial motivation) was successful in solving this problem, creating models in which monopoles existed but were rare enough to be consistent with current observations.[19]
Quantum-mechanical origin of magnetism[edit]
While heuristic explanations based on classical physics can be formulated, diamagnetism, paramagnetism and ferromagnetism can only be fully explained using quantum theory.[20][21] A successful model was developed already in 1927, by Walter Heitler and Fritz London, who derived, quantum-mechanically, how hydrogen molecules are formed from hydrogen atoms, i.e. from the atomic hydrogen orbitals u A {\displaystyle u_{A}} and u B {\displaystyle u_{B}} centered at the nuclei A and B, see below. That this leads to magnetism is not at all obvious, but will be explained in the following.
According to the Heitler–London theory, so-called two-body molecular σ {\displaystyle \sigma } -orbitals are formed, namely the resulting orbital is:
ψ ( r 1 , r 2 ) = 1 2 ( u A ( r 1 ) u B ( r 2 ) + u B ( r 1 ) u A ( r 2 ) ) {\displaystyle \psi (\mathbf {r} _{1},\,\,\mathbf {r} _{2})={\frac {1}{\sqrt {2}}}\,\,\left(u_{A}(\mathbf {r} _{1})u_{B}(\mathbf {r} _{2})+u_{B}(\mathbf {r} _{1})u_{A}(\mathbf {r} _{2})\right)}
Here the last product means that a first electron, r1, is in an atomic hydrogen-orbital centered at the second nucleus, whereas the second electron runs around the first nucleus. This "exchange" phenomenon is an expression for the quantum-mechanical property that particles with identical properties cannot be distinguished. It is specific not only for the formation of chemical bonds, but as one will see, also for magnetism, i.e. in this connection the term exchange interaction arises, a term which is essential for the origin of magnetism, and which is stronger, roughly by factors 100 and even by 1000, than the energies arising from the electrodynamic dipole-dipole interaction.
As for the spin function χ ( s 1 , s 2 ) {\displaystyle \chi (s_{1},s_{2})} , which is responsible for the magnetism, we have the already mentioned Pauli's principle, namely that a symmetric orbital (i.e. with the + sign as above) must be multiplied with an antisymmetric spin function (i.e. with a − sign), and vice versa. Thus:
χ ( s 1 , s 2 ) = 1 2 ( α ( s 1 ) β ( s 2 ) − β ( s 1 ) α ( s 2 ) ) {\displaystyle \chi (s_{1},\,\,s_{2})={\frac {1}{\sqrt {2}}}\,\,\left(\alpha (s_{1})\beta (s_{2})-\beta (s_{1})\alpha (s_{2})\right)} ,
I.e., not only u A {\displaystyle u_{A}} and u B {\displaystyle u_{B}} must be substituted by α and β, respectively (the first entity means "spin up", the second one "spin down"), but also the sign + by the − sign, and finally ri by the discrete values si (= ±½); thereby we have α ( + 1 / 2 ) = β ( − 1 / 2 ) = 1 {\displaystyle \alpha (+1/2)=\beta (-1/2)=1} and α ( − 1 / 2 ) = β ( + 1 / 2 ) = 0 {\displaystyle \alpha (-1/2)=\beta (+1/2)=0} . The "singlet state", i.e. the − sign, means: the spins are antiparallel, i.e. for the solid we have antiferromagnetism, and for two-atomic molecules one has diamagnetism. The tendency to form a (homoeopolar) chemical bond (this means: the formation of a symmetric molecular orbital, i.e. with the + sign) results through the Pauli principle automatically in an antisymmetric spin state (i.e. with the − sign). In contrast, the Coulomb repulsion of the electrons, i.e. the tendency that they try to avoid each other by this repulsion, would lead to an antisymmetric orbital function (i.e. with the − sign) of these two particles, and complementary to a symmetric spin function (i.e. with the + sign, one of the so-called "triplet functions"). Thus, now the spins would be parallel (ferromagnetism in a solid, paramagnetism in two-atomic gases).
The last-mentioned tendency dominates in the metals iron, cobalt and nickel, and in some rare earths, which are ferromagnetic. Most of the other metals, where the first-mentioned tendency dominates, are nonmagnetic (e.g. sodium, aluminium, and magnesium) or antiferromagnetic (e.g. manganese). Diatomic gases are also almost exclusively diamagnetic, and not paramagnetic. However, the oxygen molecule, because of the involvement of π-orbitals, is an exception important for the life-sciences.
The Heitler-London considerations can be generalized to the Heisenberg model of magnetism (Heisenberg 1928).
The explanation of the phenomena is thus essentially based on all subtleties of quantum mechanics, whereas the electrodynamics covers mainly the phenomenology.
Units[edit]
SI[edit]
SI electromagnetism units
Symbol[22]
Name of quantity
Q electric charge coulomb C A⋅s
I electric current ampere A A (= W/V = C/s)
J electric current density ampere per square metre A/m2 A⋅m−2
U, ΔV, Δφ; E potential difference; electromotive force volt V J/C = kg⋅m2⋅s−3⋅A−1
R; Z; X electric resistance; impedance; reactance ohm Ω V/A = kg⋅m2⋅s−3⋅A−2
ρ resistivity ohm metre Ω⋅m kg⋅m3⋅s−3⋅A−2
P electric power watt W V⋅A = kg⋅m2⋅s−3
C capacitance farad F C/V = kg−1⋅m−2⋅A2⋅s4
ΦE electric flux volt metre V⋅m kg⋅m3⋅s−3⋅A−1
E electric field strength volt per metre V/m N/C = kg⋅m⋅A−1⋅s−3
D electric displacement field coulomb per square metre C/m2 A⋅s⋅m−2
ε permittivity farad per metre F/m kg−1⋅m−3⋅A2⋅s4
χe electric susceptibility (dimensionless) 1 1
G; Y; B conductance; admittance; susceptance siemens S Ω−1 = kg−1⋅m−2⋅s3⋅A2
κ, γ, σ conductivity siemens per metre S/m kg−1⋅m−3⋅s3⋅A2
B magnetic flux density, magnetic induction tesla T Wb/m2 = kg⋅s−2⋅A−1 = N⋅A−1⋅m−1
Φ, ΦM, ΦB magnetic flux weber Wb V⋅s = kg⋅m2⋅s−2⋅A−1
H magnetic field strength ampere per metre A/m A⋅m−1
L, M inductance henry H Wb/A = V⋅s/A = kg⋅m2⋅s−2⋅A−2
μ permeability henry per metre H/m kg⋅m⋅s−2⋅A−2
χ magnetic susceptibility (dimensionless) 1 1
Other[edit]
gauss – the centimeter-gram-second (CGS) unit of magnetic field (denoted B).
oersted – the CGS unit of magnetizing field (denoted H)
maxwell – the CGS unit for magnetic flux
gamma – a unit of magnetic flux density that was commonly used before the tesla came into use (1.0 gamma = 1.0 nanotesla)
μ0 – common symbol for the permeability of free space (4π × 10−7 newton/(ampere-turn)2)
Living things[edit]
Some organisms can detect magnetic fields, a phenomenon known as magnetoception. In addition to detection, biomagnetic phenomena are utilized by organisms in a number of ways. For instance, chitons, a type of marine mollusk, produce magnetite to harden their teeth, and even humans produce magnetite in bodily tissue.[23] Magnetobiology studies magnetic fields as a medical treatment; fields naturally produced by an organism are known as biomagnetism.
Coercivity
Gravitomagnetism
Magnetic hysteresis
Magnetic bearing
Magnetic circuit
Magnetic cooling
Magnetic field viewing film
Magnetic structure
Magnetism and temperature
Micromagnetism
Neodymium magnet
Plastic magnet
Rare-earth magnet
Spin wave
Spontaneous magnetization
Vibrating-sample magnetometer
^ Du Trémolet de Lacheisserie, Étienne; Damien Gignoux; Michel Schlenker (2005). Magnetism: Fundamentals. Springer. pp. 3–6. ISBN 978-0-387-22967-6.
^ Platonis Opera, Meyer and Zeller, 1839, p. 989.
^ The location of Magnesia is debated; it could be the region in mainland Greece or Magnesia ad Sipylum. See, for example, "Magnet". Language Hat blog. 28 May 2005. Retrieved 22 March 2013.
^ Fowler, Michael (1997). "Historical Beginnings of Theories of Electricity and Magnetism". Retrieved 2008-04-02.
^ Kumar Goyal, Rajendra (2017). Nanomaterials and Nanocomposites: Synthesis, Properties, Characterization Techniques, and Applications. CRC Press. p. 171. ISBN 9781498761673.
^ The section "Fanying 2" (反應第二) of The Guiguzi: "其察言也,不失若磁石之取鍼,舌之取燔骨".
^ Li, Shu-hua (1954). "Origine de la Boussole II. Aimant et Boussole". Isis (in French). 45 (2): 175–196. doi:10.1086/348315. JSTOR 227361. un passage dans le Liu-che-tch'ouen-ts'ieou [...]: "La pierre d'aimant fait venir le fer ou elle l'attire."
From the section "Jingtong" (精通) of the "Almanac of the Last Autumn Month" (季秋紀): "慈石召鐵,或引之也]"
^ In the section "A Last Word on Dragons" (亂龍篇 Luanlong) of the Lunheng: "Amber takes up straws, and a load-stone attracts needles" (頓牟掇芥,磁石引針).
^ Schmidl, Petra G. (1996–1997). "Two Early Arabic Sources On The Magnetic Compass". Journal of Arabic and Islamic Studies. 1: 81–132.
^ a b A. Einstein: "On the Electrodynamics of Moving Bodies", June 30, 1905.
^ HP Meyers (1997). Introductory solid state physics (2 ed.). CRC Press. p. 362; Figure 11.1. ISBN 9781420075021.
^ Catherine Westbrook; Carolyn Kaut; Carolyn Kaut-Roth (1998). MRI (Magnetic Resonance Imaging) in practice (2 ed.). Wiley-Blackwell. p. 217. ISBN 978-0-632-04205-0.
^ Purcell 2012, p. 320,584
^ Merzouki, Rochdi; Samantaray, Arun Kumar; Pathak, Pushparaj Mani (2012). Intelligent Mechatronic Systems: Modeling, Control and Diagnosis. Springer Science & Business Media. pp. 403–405. ISBN 978-1447146285.
^ Sturgeon, W. (1825). "Improved Electro Magnetic Apparatus". Trans. Royal Society of Arts, Manufactures, & Commerce. 43: 37–52. cited in Miller, T.J.E (2001). Electronic Control of Switched Reluctance Machines. Newnes. p. 7. ISBN 978-0-7506-5073-1.
^ Griffiths 1998, chapter 12
^ Jackson, John David (1999). Classical electrodynamics (3rd ed.). New York: Wiley. ISBN 978-0-471-30932-1.
^ Milton mentions some inconclusive events (p. 60) and still concludes that "no evidence at all of magnetic monopoles has survived" (p.3). Milton, Kimball A. (June 2006). "Theoretical and experimental status of magnetic monopoles". Reports on Progress in Physics. 69 (6): 1637–1711. arXiv:hep-ex/0602040. Bibcode:2006RPPh...69.1637M. doi:10.1088/0034-4885/69/6/R02. .
^ Guth, Alan (1997). The Inflationary Universe: The Quest for a New Theory of Cosmic Origins. Perseus. ISBN 978-0-201-32840-0. OCLC 38941224. .
^ The magnetism of matter, Feynman Lectures in Physics Ch 34
^ Ferromagnetism, Feynman Lectures in Physics Ch 36
^ International Union of Pure and Applied Chemistry (1993). Quantities, Units and Symbols in Physical Chemistry, 2nd edition, Oxford: Blackwell Science. ISBN 0-632-03583-8. pp. 14–15. Electronic version.
^ Kirschvink, Joseph L.; Kobayashi-Kirshvink, Atsuko; Diaz-Ricci, Juan C.; Kirschvink, Steven J. (1992). "Magnetite in Human Tissues: A Mechanism for the Biological Effects of Weak ELF Magnetic Fields" (PDF). Bioelectromagnetics Supplement. 1: 101–113. Retrieved 29 March 2016.
David K. Cheng (1992). Field and Wave Electromagnetics. Addison-Wesley Publishing Company, Inc. ISBN 978-0-201-12819-2.
Furlani, Edward P. (2001). Permanent Magnet and Electromechanical Devices: Materials, Analysis and Applications. Academic Press. ISBN 978-0-12-269951-1. OCLC 162129430.
Griffiths, David J. (1998). Introduction to Electrodynamics (3rd ed.). Prentice Hall. ISBN 978-0-13-805326-0. OCLC 40251748.
Kronmüller, Helmut. (2007). Handbook of Magnetism and Advanced Magnetic Materials, 5 Volume Set. John Wiley & Sons. ISBN 978-0-470-02217-7. OCLC 124165851.
Purcell, Edward M. (2012). Electricity and magnetism (3rd ed.). Cambridge: Cambridge Univ. Press. ISBN 9781-10701-4022.
Tipler, Paul (2004). Physics for Scientists and Engineers: Electricity, Magnetism, Light, and Elementary Modern Physics (5th ed.). W.H. Freeman. ISBN 978-0-7167-0810-0. OCLC 51095685.
Wikiquote has quotations related to: Magnetism
Look up magnetism in Wiktionary, the free dictionary.
The Exploratorium Science Snacks – Subject:Physics/Electricity & Magnetism
Magnetism and magnetization – Astronoo
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diamagnetism
superdiamagnetism
paramagnetism
superparamagnetism
ferromagnetism
superferromagnetism
antiferromagnetism
ferrimagnetism
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You Are Currently Here:Home > news > Behind the scenes of education in the UAE
Behind the scenes of education in the UAE
It's no secret that the UAE is a rapidly developing country. With its vast oil reserves and abundance of natural gas, the country has become a regional powerhouse in recent years. But what many people don't know is that the country is also making strides in education. In this blog post, we will take a look at behind the scenes of education the UAE. From its world-class universities to its innovative approaches to learning, the UAE is quickly becoming a leader in education. Read on to learn more about the UAE's educational successes.
The education system in the UAE
The United Arab Emirates has a highly centralized education system, which is free and compulsory for all children between the ages of 6 and 18. The education system in the UAE is divided into Four stages:Early Childhood, primary, secondary, and tertiary.
Early Childhood Education: The education in UAE offers a variety of early childhood education programs for children aged 3-5 years old. These programs aim to develop the child's social, emotional, physical, and cognitive skills. The UAE's early childhood education programs are based on international best practices and standards.
The primary stage of education in the UAE lasts for six years, during which time students are taught the basics of mathematics, science, Arabic, English, and social studies. At the end of the primary stage, students take a national exam known as the Emirates General Secondary Education Examination (EGSEE).
The secondary stage of education in the UAE lasts for three years, during which time students complete their EGSEE and choose one of three educational tracks: scientific, literary, or technical. Students who choose the scientific track study biology, chemistry, physics, and mathematics; those who choose the literary track study Arabic literature, English literature, and history; and those who choose the technical track study engineering or computer science.
After completing their secondary education, students take another national exam known as either the Tawjihi (for those who studied the scientific or literary tracks) or the Thanawiya Amma(for those who studied the technical track).
The challenges of education in the UAE
Education in the UAE has come under fire in recent years for a number of reasons. One of the biggest criticisms is that it is not preparing students for the real world. There is a growing belief that the education system in the UAE is too focused on academic achievement and not enough on developing life skills. This has led to a situation where many students are struggling to cope with the demands of university and work.
Another issue that has been raised is the lack of diversity in the education system. There are concerns that not enough attention is being paid to other cultures and religions, which can lead to social disharmony. Finally, there is a feeling that the education system is becoming too competitive. With private schools charging high fees, many parents feel they have to push their children harder than ever before just to keep up.
The successes of education in the UAE
The successes of education in the UAE cannot be understated. The country has made incredible strides in recent years to provide quality education to its citizens, and the results are clear. The UAE's educational system is now ranked as one of the best in the world, and its students consistently outperform their peers in international assessments.
There are many factors that have contributed to the success of education in the UAE.
One is the strong commitment of the government to investing in education. The government has poured billions of dollars into building world-class facilities and recruiting top-notch educators from around the globe.
Another factor is the introduction of innovative educational methods and technologies. UAE schools have embraced cutting-edge teaching approaches and make use of state-of-the-art infrastructure and resources. This has allowed them to provide a truly world-class education to their students.
Finally, it is worth noting that the successes of education in the UAE are not limited to academic achievement. The country's educational system also promotes values such as tolerance, respect for diversity, and a sense of national pride. These are essential qualities that will help shape the future leaders of the UAE.
The future of education in the UAE
The future of education in the UAE is exciting and full of opportunities. The country is investing heavily in education, with a strong focus on quality and excellence. This commitment to education is evident in the construction of new schools and universities, as well as the introduction of initiatives such as the Abu Dhabi Education Council's (Teachers for Tomorrow) program.
The UAE recognizes that a high-quality education system is essential for the country's future success. In addition to preparing students for successful careers, education also helps to promote social cohesion and build an informed and tolerant society. The UAE's vision for the future of education is therefore one that is dynamic, innovative, and inclusive.
What the UAE do to improve the education?
The United Arab Emirates has been working hard to improve education in the UAE in recent years. The UAE government has invested heavily in education, both in terms of infrastructure and resources. The country now has some of the best schools and universities in the world.
However, the UAE government recognizes that there is still room for improvement. In order to continue to compete on a global scale, education in the UAE needs to provide its students with a world-class education. To this end, the UAE government has put in place a number of initiatives to improve the education in UAE.
One of the most important initiatives is the Abu Dhabi Education Council's Strategic Plan for Education 2030. This plan sets out a number of ambitious goals for the education system, including increasing the proportion of Emiratis who hold a university degree from 5% to 20% by 2030.
The UAE government is also working on improving the quality of teaching in schools. A new curriculum is being introduced which will place greater emphasis on critical thinking and problem-solving skills. In addition, all teachers in the UAE will be required to have a minimum of a bachelor's degree by 2020.
Finally, the UAE government is providing financial support to students who wish to study abroad. Through programs such as scholarships and loans, students will be able to access quality education at some of the best universities in the world.
As we've seen, education in the UAE is quite different from what we're used to in the West. However, it's clear that the UAE is committed to providing a high-quality education for all its citizens. The country has made great strides in recent years, and it's now home to some of the best schools and universities in the world. The future looks bright for the education in UAE, and we can't wait to see what the country achieves next.
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"Nine Princes in Amber", "The Guns of Avalon", "Sign of the Unicorn", "The Hand of Oberon", "The Courts of Chaos"
Amber is the one real world, casting infinite reflections of itself - Shadow worlds, that can be manipulated by those of royal Amberite blood. But the royal family is torn apart by jealousies and suspicion; the disappearance of the Patriach Oberon has intensified the internal conflict by leaving the... read more throne apparently up for grabs. In a hospital on the Shadow Earth, a young man is recovering from a freak car accident; amnesia has robbed him of all his memory, even the fact that he is Corwin, Crown Prince of Amber, rightful heir to the throne - and he is in deadly peril...The five books, Nine Princes in Amber, The Guns of Avalon, Sign of the Unicorn, The Hand of Oberon and The Courts of Chaos, together make up The Chronicles of Amber, Roger Zelazny's finest work of fantasy and an undisputed classic of the genre.


text:
Транзитное сообщение между Западным Берлином и ФРГ осуществлялось по территории советской зоны оккупации Германии и в последующем ГДР. Стороны придерживались разных взглядов на юридический статус транзита, что неоднократно приводило к обострению в отношениях, а в 1948—1949 годах вылилось в блокаду. В начале 1970-х и 1980-х годов ГДР возвела транзитные автомагистрали, соединявшие Берлин с пограничными переходами. Самыми крупными из них являлись КПП в Древице и Мариенборне, каждый из которых обслуживало около тысячи военнослужащих пограничных войск, сотрудников паспортного и таможенного контроля ГДР.

Германская Демократическая Республика издала специальные нормативные акты, регулировавшие транспортное сообщение между ФРГ и Западным Берлином через внутригерманскую границу и ограничила количество транзитных маршрутов. Соответствующее законодательство действовало также в отношении транзита через ГДР в скандинавские страны, ПНР и ЧССР. Воздушное сообщение осуществлялось строго по выделенным воздушным коридорам.

Правовой основой по вопросу транзита в ГДР считалось положение, принятое державами-победительницами на Потсдамской конференции 1945 года, согласно которому на период оккупации Германия считалась единой в экономическом отношении, в связи с чем предполагалось согласовать общие предписания в отношении транспортного сообщения. Контрольному совету было поручено издать правило передвижения между зонами оккупации. Позднее были определены транзитные маршруты между западными секторами Берлина через советскую зону оккупации в западные зоны оккупации Германии. Приказом Советской контрольной комиссии в Германии от 5 мая 1952 года были чётко установлены меры по обеспечению и контролю, радикально ограничившие свободу передвижения.

После подписания Московского договора правительство ФРГ подчёркивало, что его ратификация состоится только при наличии позитивных результатов в отношении Берлина. В переговорах наметился прогресс, и 3 сентября 1971 года послы подписали Четырёхстороннее соглашение по Берлину. Впервые с 1945 года в нём СССР гарантировал беспрепятственное транзитное сообщение автомобильного, железнодорожного и водного транспорта между ФРГ и Западным Берлином. Договор предусматривал самостоятельное согласование деталей правительствами двух германских государств.

Вопросы передвижения лиц и товаров между ФРГ и Западным Берлином урегулировало Транзитное соглашение, согласно которому транзит между ФРГ и Западным Берлином впредь будет осуществляться беспрепятственно и в «самой простой, быстрой и удобной форме». Были согласованы основные направления организации и осуществления сообщения, паспортного контроля ГДР и пошлины за эксплуатацию транзитных магистралей. 17 декабря 1971 года в Бонне Транзитное соглашение, ставшее первым на уровне правительства двух германских государств, подписали Эгон Бар (от ФРГ) и Михаэль Коль (от ГДР). На транзитных магистралях ГДР в значительной степени отказалась от своих суверенных прав, в частности, по проведению задержаний. Исключение составляли случаи злоупотреблений, в частности дорожные происшествия. Арест лиц, объявленных полицией в розыск, не допускался.

В отношении западных оккупационных войск в 1945—1990 годах действовало особое соглашение: их досмотр при пересечении границы, если и осуществлялся, то исключительно военнослужащими Советской армии.

По пути следования по транзитным магистралям запрещалось покидать их пределы. Транзитному транспорту предписывалось двигаться по возможности без остановок, разрешались лишь краткие остановки на специально оборудованных площадках для отдыха или АЗС. Контакты с гражданами ГДР запрещались. Все транзитные магистрали находились патрулировали гражданские автомобили с сотрудниками МГБ ГДР, которые осуществляли постоянный контроль и вели фотоотчётность. Иногда для этих целей использовались автомобили западного производства с автомобильными номерами ФРГ. Наблюдение за транзитными магистралями вели также внештатные сотрудники МГБ ГДР, работавшие, например, на автозаправочных станциях, а также сотрудники таможни ГДР, Народной полиции и их добровольные помощники.

При въезде на магистраль транзитные пассажиры предъявляли для регистрации на контрольном пункте удостоверения личности (граждане ФРГ и иностранцы — заграничные паспорта, жители Западного Берлина — «временные удостоверения личности», иностранцы, постоянно проживающие в Западном Берлине, — справку с фотографией, выдаваемую Сенатом Берлина) и водительское удостоверение. На основании этих документов выдавалась однократная транзитная виза с указанием персональных данных и штампом с датой въезда. При съезде с магистрали этот документ подлежал сдаче. На основании штампа можно было установить, следовал ли транзитный пассажир с соблюдением установленных правил. Длительное пребывание на площадках отдыха следовало подтверждать чеками об оплате, выданными в ресторанах Mitropa.

Транзитное соглашение позволило выдавать транзитные визы ГДР в следующих по маршруту поездах железной дороги ГДР. Со стороны Западного Берлина пограничный контроль не производился. Транзитные поезда пользовались большой популярностью, составы нередко имели 15 вагонов. Им предоставлялся приоритет следования, на территории ГДР им запрещались остановки вне расписания. Составы обязательно имели патруль транспортной полиции. После 1990 года стало известно, что транзитные поезда часто использовались агентами ГДР в качестве тайников на колёсах для переправки разведывательной информации.

Прямое воздушное сообщение, позволявшее избежать паспортного контроля ГДР, осуществлялось только между Западным Берлином и ФРГ по трём согласованным воздушным коридорам. Право совершать полёты в Западный Берлин имели только самолёты западных держав-победительниц.

Литература
 Jürgen Ritter, Peter J. Lapp: Die Grenze. Ein deutsches Bauwerk. 9. Auflage. Ch. Links Verlag, Berlin 2015, ISBN 978-3-86153-560-7
 Friedrich Chr. Delius, Peter J. Lapp: Transit Westberlin. 2. Auflage. Ch. Links Verlag, Berlin 2000, ISBN 3-86153-198-4.
 Hans-Dieter Behrendt: Guten Tag, Passkontrolle der DDR. GNN-Verlag, Schkeuditz, ISBN 978-3-89819-243-9.
 Kim Christian Priemel (Hrsg.): Transit, Transfer. Politik und Praxis der Einwanderung in die DDR 1945—1990. be.bra wissenschaft verlag, Berlin 2011, ISBN 978-3-937233-87-1.
 Peter Joachim Lapp: Rollbahnen des Klassenfeindes. Die DDR-Überwachung des Berlin-Transits 1949—1990. Helios, Aachen 2015, ISBN 978-3-86933-136-2.
 Markus Schubert: Ein neues Hinterland für Berlin (West)? : Die Regionen im Umkreis d. Transitübergänge als neues Einzugsgebiet von Berlin (West), Forschungsprojekt (= Berlin-Forschung, Band 18: Themenbereich Stadt- und Regionalplanung). Berlin-Verlag Spitz, Berlin 1987, ISBN 3-87061-918-X

Транспорт в Германии
История ГДР
Международный транспорт
Западный Берлин

redpajama_set_name: RedPajamaWikipedia


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