Author: Kyle

After a years long drought in the Western Cape region of South Africa that started in 2015, and despite attempts at conserving water, the city of Cape Town is nearing “Day Zero” in April 2018. When the nearby water reservoirs collectively reach this critical point, municipal water supplies will be depleted and the city’s taps will run dry.

The region’s water supplies are normally replenished by rainfall during the winter months of May-August, and drop during the dry summer months of December-February as urban and agricultural water use also increases. Over the past three years, the region has had its driest period since at least 1933 and possibly earlier, statistically this is a 300 year drought. Cape Town’s population has grown significantly as well, around 75% in the past 20 years. Despite water saving measures attempting to keep consumption below 1999 levels, and adding a new dam to increase capacity, it was determined that demand would exceed normal supply starting in 2013. Five years later, these conditions have coalesced to the breaking point.

Right now water is rationed to 50 liters a day, with water running out from stores and public natural springs crowded at all times. At “Day Zero” this allotment will drop to 25 liters per person daily. Long term plans include upgrading water systems, building desalination plants, tapping new aquifers, and developing water-recycling projects, but none of these are instant solutions.

References:

Wikipedia: Cape Town water crisis

CNN: Cape Town cuts water use limit by nearly half

Not long after the first manned flight in a hot air balloon in 1783 were the possibilities of its military benefits realized. The 1794 Battle of Fleurus, south of Brussels, took place during the French Revolutionary Wars between the army of the First French Republic and the Coalition Army. The French side possessed a reconnaissance balloon, l’Entreprenant, which was operated by the Aerostatic Corps. The French Aerostatic Corps was founded in 1794 operate and maintain these hydrogen-filled balloons for the French army.

During prelude to the battle, the corps received orders to move their already inflated balloon in front of the Austrian troops, and need 20 soldiers to hold on to and move it the 30 miles into place. For three days an officer would ascend and make observations. On the the fourth day, the start of the battle, the balloon remained afloat for nine hours with observations of troop movements provided by notes dropped to the ground and via flag semaphore.

The French won the battle decisively, but with uncertain benefits. The Aerostatic Corps were deployed for three more major battles. One balloon company was captured by the Austrians in 1796 after a French defeat, with L’Intrépide still on display in Vienna’s Military History Museum today. Under a new General, the Corps was largely prevented from operating, and during the Napoleonic Campaign in Egypt the ballooning equipment was destroyed in the Battle of the Nile. After this point the Aerostatic Corps only conducted a few demonstrations, mainly for entertainment purposes, before being completely disbanded in 1802.

References:

Wikipedia: Battle of Fleurus

By forge-welding differing types of metal pieces together and working and manipulating the result, a distinct pattern can result in the final product. Pattern welding, the result of which can b e identified by their banded patterns, can be utilized for cosmetic effect and can be embellished by polishing or acid etching. A more functional use is for combing steels of differing compositions to achieve the desired mix of hardness and toughness.

Early use of pattern welding resulted from the need to produce high strength steel despite the limitations in iron smelting at the time. Bloomeries, furnaces consisting of a chimney and entrances for air near the bottom, could reduce iron oxide ore into pure iron but could not melt it. The resulting mass of “sponge iron” could be processed into wrought iron by continuously working it with hammers and folding it over to remove the slag, impurities in the metal. Carburizing the metal, adding carbon and causing it to be absorbed into the metal while under heat treatment, can form high carbon steel. Forging resulting bars or plates together results in the layered patterns seen in pattern welded metal.

One of the earliest known uses of pattern welding occurred in Europe in between the 2nd and 3rd century by the Celts. The Viking Ulfberht swords were also pattern welded. These swords tended to be durable, and less likely to bend or snap when used.

References:

Wikipedia: Pattern welding

The earliest known unmanned aerial attack actually took place in the mid-19th century. In the summer of 1849, during which Venice was involved in a brief revolt against Austrian rule that established the Venetian Republic one year prior, the Austrians had the city under siege. In an attempt to force a surrender, the Austrians tried using balloons in a new way 66 years after the French made use of large-scale hot air balloons for manned flight.  The Austrians loaded up unpiloted balloons with explosives, launching several from the ship Vulcano. The balloons, each about 23 feet (5.7 meters) in diameter, were armed with bombs, possibly triggered by timed fuses or other electrical activation method, and released in favorable winds in the direction of Venice. Once triggered the balloon dropped its small load of bombs, which then exploded upon reaching the ground. It was reported that some of the balloons operated as planned, dropping bombs over the city, but several were blown back over Austrian lines. The ultimate impact on the siege was likely small, and ultimately the Venetians agreed to surrender on August 22, 1849.

References:

Remote Piloted Air Vehicles

Linear A (c. 2500 – 1450 BCE) is an undeciphered writing system, and was the primary script used in palace and religious writings of the Minoan civilization of Greece. Though it is the origin of the Linear B script (c. 1450 – 1200 BCE), which has been deciphered to discover it is an early form of Greek, and shares some of the same symbols, attempting to apply Linear B syllabic values to Linear A results in unintelligible words that appear unrelated to any known language. Archaeologist Arthur Evans, who was the first to define the Linear scripts named them after the characters that consisted as lines inscribed in clay, contrasted with the pictographic Cretan hieroglyphs (c. 2100 – 1700 BCE) used during the same period. The difficulty in deciphering the script is due to a lack of points of reference for reading the inscriptions, with 80% of its symbols being unique and not shared with Linear B.

Most of the artifacts containing Linear A script have been unearthed at three sites on Crete, but has also been found at other sites in Greece, as well as in Turkey and Israel. A total of 1427 specimens have been discovered so far, containing a total of 7362 to 7396 symbols – described as being equivalent to two sheets of paper worth of text.

References:

Wikipedia: Linear A

Phenols are aromatic organic compounds. This chemical, known also as carbolic acid with molecular formula C₆H₅OH, is an important precursor to many materials and useful compounds, which makes it a key commodity. Some examples include plastics (polycarbonates, epoxies, nylon), herbicides, detergents, and pharmaceutical drugs. The global phenol market is estimated to grow to $32 billion by 2025.

Phenol was first discovered in 1834 after it was extracted from coal tar, and first purified in 1841. One early notable use was as an antiseptic during surgery by Dr. Joseph Lister at a time when the medical community criticized and mocked the concept.

References:

Wikipedia: Phenol

Lake islands are pretty much what you think they are, a landmass within a lake. Sometimes however, some of these island support a lake within themselves, and sometimes those lakes contain an island of their own, and so on. These islands in a lake on an island in a lake, and so on, can also be known as recursive lake islands. Some of the most stark of these islands occur as the result of volcanic activity, with caldera lakes and lake islands forming from resurgent domes and multiple eruptions over a long period of time. Most of the recursive islands though tend to appear in the Canada.

Some of the largest of these are listed below:

• Largest lake on an island: Nettilling Lake on Baffin Island, Canada
• Largest island on a lake: Manitoulin Island in Lake Huron, Canada
• Largest island in a lake on an island: Pulau Samosir in Danau Toba on Sumatra, Indonesia
• Largest lake on an island in a lake: Lake Manitou on Manitoulin Island in Lake Huron
• Largest lake on an island in a lake on an island: a nameless lake on a nameless island in Nettilling Lake on Baffin Island, Canada
• Largest island in a lake on an island in a lake: Treasure Island in Mindemoya Lake on Manitoulin Island in Lake Huron, Canada
• Largest island in a lake on an island in a lake on an island: is a nameless island in a lake on an island in Nettilling Lake on Baffin Island, Canada

References:

Wikipedia: Lake island

NASA Earth Observatory: Island in a Lake on an Island in a Lake on an Island, Image of the Day

Tiltwing aircraft have wings that are horizontal for forward flight and are capable of tilting to a vertical position with their engines to allow for vertical takeoffs and landings.  Tiltwings are similar to but differ from tiltrotors, like the V-22 Osprey, which maintains the horizontal position of its wing when transitioning between vertical and horizontal flight. The positive aspect of this is improved hover lift efficiency due to less interference from the wings. A negative impact is an increased impact from crosswinds in hover due to the large surface area of the vertical wing.

Some early tiltwing concepts were the Vertol VZ-2 (1957), Hiller X-18 (1959), Kaman K-16B (1959), and LTV XC-142 (1964).

The Vertol VZ-2 was a research aircraft built for NASA to investigate tiltwings. Of note were small ducted fans in the tail to improve controllablity at low speeds. The VZ-2 successfully made 450 flights with 34 transition flights before the program ended in 1965.

The Hiller X-18 was another tiltwing testbed developed for the U.S. Air Force, and received an X-series experimental plane designation. The aircraft was constructed using parts obtained from Chase YC-122 Avitruc, Lockheed XFV-1, and Convair XFY-1 Pogo aircraft. The X-18 diverted is thrust at the tail to provide pitch control at low speeds. There were 20 flights, with the last occurring in 1961 during which the pilots lost control during hover at 10,000 feet before safely landing. It was eventually cancelled in 1964 and cut up for scrap.

The Kaman K-16B was developed for the U.S. Navy to evaluate the tiltwing concept, and was converted from the Grumman Goose amphibious aircraft. Of note was that the wing could only obtain a maximum of a 50 degree angle of incidence, and did not go completely vertical, but was estimated to have sufficient thrust to allow for essentially vertical takeoffs and landings. The K-16B only underwent wind tunnel testing and several tethered tests before the project was cancelled in 1962.

The Ling-Temco-Vought LTV XC-142 was an experimental tiltwing aircraft that was the result of a joint effort between the U.S. Army, Navy, and Air Force. After building five aircraft and successfully demonstrating its capabilities over several hundred flights, the program ended as each of the services pulled out due to a lack of interest in pursuing the capability.

References:

Wikipedia: Tiltwing

To enter Kenya, most international travelers will need to obtain a visa for entry.  While at this time it is still possible to obtain one on arrival, it is recommended to use the eVisa system to apply for one online to avoid any delays – plus I’ve seen some mentions that Kenya may soon switch entirely to online registrations.

First you’ll need to create an account. Click on the Create Account button on the homepage, and scroll down to eVisa Visitors.

When creating an account, be sure to have your passport number in hand and an email address and password in mind for your login credentials.

Once you’ve logged in, look under the Popular Services under Immigration Services for a link to the Single Entry Visa application.

The requirements for the visa are listed on this page, noting that you’ll need a valid passport with six months of validity upon arrival, a complete application form, blank pages, and a return ticket. The fees add up to $51. Of note is that children aged 16 or less do not need to apply for a visa, and only need to provide a valid passport on arrival.

The first part of the application needs some of your vital information, such as your name, gender, date of birth, place of birth, country of birth, current occupation, and the names of parents and spouse. Any information you provide should match anything present in your passport.

The second page needs your nationality, residence, and contact information.

The third page needs your passport/travel document issuance information. One of the fields requires the “place of issue” and “issued by.” In my passport under Authority, “United States, Department of State” is listed. “United States” and “U.S. Department of State” should be the appropriate responses.

The fourth page requires your travel information, including reason, entry and departure dates, and information about locations of arranged lodging and places to be visited.

The fifth page needs information on your travel history, including 3 months of recent travel and past travel to Kenya.

The sixth page is where you’ll need to upload supporting documents. This includes a scan or photo of your passport’s bio data page, various additional documents split by business/family/tourist visits, and a passport size photo. The photo of your passport must be of the original, entire bio page and in color. As a tourist, the additional documents needed can include your travel itinerary of places to be visited and hotel bookings. The passport size photo must be 500×500 pixels, meet similar requirements as passport photos with regard to appearance, but also must have been taken in the past 6 months and cannot be the same photograph that is in your passport.

Finally, you can submit your information and pay using a credit or debit card. You will then have to wait for notification of approval via email (should take at least two business days), then you can download and print the eVisa from your account page. Then all you’ll need to do is present it to the immigration officer at the port of entry, along with your passport and other required documents for entry.

References:

U.S. Department of State: International Travel Information for Kenya

Kenya eVisa Service

Despite being the highest point in the continent and relatively remote, Mount Kilimanjaro apparently has good telephone and data service coverage, even at the peak.

Considering most carriers charge quite a bit for international roaming, your best bet would be to pick up a SIM card locally to swap into your phone. There are apparently a number of locations where you can buy and register a SIM card from retailers and re-sellers, with international visitors required to show their passport.

Some of the carriers reported to work on the mountain and surrounding parks include Vodacom, Airtel, and Halotel, each with 2G and 3G service, and 4G/LTE to a lesser extent. The SIM card itself typically costs on the order of TSH 1000 ($0.45), with 1 GB of data over one week of access costing TSH 5000 ($2.25). The SIM cards may be offered at the standard size, which few phones accept these days, but may be pre-cut to easily remove the extra material or manually trimmed down on location.

Be sure to obtain the text activation codes for receiving phone service and buying or applying credit. Additionally to ensure you can get connected to the network for Internet access, be sure to obtain the APN (Access Point Name) configuration settings.

There should be 2G and 3G service at a number of the camps, and the guides and porters typically know where to find service otherwise. With ascents taking around a week, it would be a good idea to bring along a high capacity power bank to ensure you have a charged phone to use.

References:

Stay Connected on Mount Kilimanjaro: Telephone and Internet Access

Prepaid Data SIM Card Wiki: Tanzania