These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
"Scientists
at Tokyo Institute of Technology have demonstrated the potential of a new, thin-film
ferroelectric material that could improve the performance of next-generation
sensors and semi-conductors. 'Ferroelectric' materials can switch between different states of electrical
polarization in response to an external electric field. This flexibility means they show promise for
many applications, for example in electronic devices and computer
..."
The
TA1149 is designed for Ku band UAV data and video links for both GCS and air vehicle
installation. The unit contains many standard features including auto gain leveling, fault detection,
and operates from a wide 12-30V DC input range. This class A GaAs module is designed for both military
and commercial applications. It is capable of supporting any signal type and modulation format, including
but not limited to 3-4G telecom, WLAN
...
Contained in this obituary honoring Alexander Graham Bell's assistant,
Dr. Thomas A. Watson,
which appeared in the March 1935 issue of Radio-Craft, is a bit of information about a serendipitous
event that led to the invention of the telephone. I do not recall having heard of it. This is just one
more reason why perusing historical material like these magazines is so important for keeping alive
the details of the other world's momentous events. Many demonstrations have shown how as stories get
passed on from person to person, generation to generation
...
"We're not being cocky, engineers
are really better than everyone else. Well, technicians and designers are still cool too, but engineers
are on top. Other than just saying that, what are some ways in which we can actually prove that
engineers are better than everyone? Engineers are a unique breed
of human, our ability to process data and work together on teams is unique to our profession as a whole.
That 4 to 6 years of engineering education shapes
..."
"Researchers
at the University of St Andrews, have developed a device that can detect what an object is by placing
it on a small radar sensor. The device, called
RadarCat (Radar Categorisation for Input and
Interaction), can be trained to recognise different objects and materials, from a drinking glass
to a computer keyboard, and can even identify individual body parts. The system, which employs a radar
signal, has a range of potential applications, from helping blind
..."
"Yet-to-be-developed Federal Aviation Administration rules stemming
from the recent passage in Congress of H.R. 636, the FAA Reauthorization Act, could pose additional
marking requirements for a small number of
Amateur Radio towers. The bill instructs the FAA to enact rules similar
to state-level statutes now in place that are aimed at improving aircraft safety in the vicinity of
meteorological evaluation towers set up in rural areas. In the wake of fatal crop dusting aircraft collisions
with METs, often erected
..."
On the
page following an article titled "TVI
and the Novice," the National Company ran one of its conventional full-page informational advertisements
- on the subject of TVI.
This is number 234, and it is the newest one I have so there likely were many more. National's suggestion
for curing TVI issues was to use a shielded chassis with chokes in series and bypass capacitors in parallel
with power leads ...
Federal
Custom Cable (a Coaxsol
distributor) is a relatively new advertiser, and has chosen to continue supporting RF Cafe.
Please visit their website 
today to see whether their cable prepping, kitting, and labeling services,
or rack & panel, modular assemblies, delay lines, inductors and toroids, semi rigid, stripping and
bending, custom molding, Ø-matched, power and multi-conductor and shielded cables can help with your
project ...
"Energy storage devices called supercapacitors have become a
hot area of research, in part because they can be charged rapidly and deliver intense bursts of power.
However, all supercapacitors currently use components made of carbon, which require high temperatures
and harsh chemicals to produce. Now researchers at MIT and elsewhere have for the first time developed
a supercapacitor that uses no conductive carbon at all, and that could potentially produce more power
than existing versions ..."
Saelig Company announces the Windfreak
SynthHD PRO
- a temperature-compensated, dual-channel, software-tunable RF signal generator and frequency sweeper,
controlled and powered via a USB port on a device running Windows or Android software. The SynthHD PRO's
dual, independent 54 MHz to 13.6 GHz channels can be configured to run at two different frequencies,
or at the same frequency with different phases. This allows its use in antenna beam steering applications
or quadrature signal generation commonly used in image-reject
...
For
Sale: Würth Electronics SMD 0402 Multilayer Ceramic Capacitor Design Kit, SMD Air
Coil Inductor Design Kit, and Power Elements Design Kit. These are the kits - all unused - graciously
provided by Würth for a product review. I have no need for them at this time, so this could be your
lucky day. Full details are available
here. They sell on Digi-Key
for about $110 each, but you can buy all three for a mere
...
"Publishing their findings
in the journal Science, a research team led by faculty scientist Ali Javey at the Department of Energy's
Lawrence Berkeley National Laboratory (Berkeley Lab) have devised the
smallest transistor ever reported. The feat was realized by embedded a
single carbon nanotube, 1nm in diameter in a thin layer of zirconium
dioxide (ZrO 2) under atomically thin sheets of molybdenum disulphide
(MoS 2), about 0.65 nanometers thick
..."
Nokia is a
very fine and respected Finnish company. I benefitted greatly from their engineering and marketing prowess
during my years with RFMD. I was somewhat taken aback, though, when I learned that yet another non-American
company now owns the historical Bell Labs,
in Murray Hill, New Jersey. French firm Alcatel bought
Lucent Technologies in 2006, owner
of Bell Labs at the time. Then, this past January, Nokia bought Alcatel-Lucent, thereby inheriting Bell
Labs. It has been out of American hands for a decade now, and likely will someday be owned by China
as American greatness wanes.
Where There Are Power Lines, There Can Be Broadband
It's
like the in The Matrix
Reloaded where Sentinels (utilities companies) relentlessly seek
out and attack the Nebuchadnezzar (Ham radio operators): "Imagine WiFi
everywhere. Bringing fast, reliable internet connectivity to the world is the dream of many, manifesting
in a range of technologies including internet.org's Aquila unmanned aircraft. Now, US telecom giant
AT&T has thrown its hat in the ring with
Project
AirGig. They hope the technology will one day bring 'low-cost, multi-gigabit wireless internet speeds
using power lines' ..."
"Alcatel-Lucent Submarine Networks and Nokia Bell Labs have jointly
announced they've broken another record which very few people knew about in the first place. The pair
have achieved a record
transmission capacity over a 6,600 km single mode fibre, demonstrating
a total 65 Tbps transmission using 'submarine grade dual band erbium doped fibre amplifiers.' Seriously,
that's an actual quote. You couldn't make it up. 'This new record is the latest in a long series of
achievements by Alcatel
..."
Television interference
(TVI) was a major concern for amateur radio operators back in the heyday of broadcast TV. Other
than radio broadcasts, magazines, and newspapers, it was the only other major form of media available;
there was no Internet. Even the lowest priced TV sets represented a significant portion of a typical
family's disposable income. There was no government handout program that provided every household with
a television set and antenna. Consequently, people were very irritated by nearby electrical or electronic
equipment that dared to interfere with their reception
...
Sivers IMA Intros RFIC for FCC's New V-Band Frequencies
"'It
is with great pleasure Sivers IMA now can launch a fully integrated RFIC in Silicon-Germanium. On top
of this, we are proud to announce that we are the first in the world to include coverage of the new
FCC
V-band frequencies 64-71 GHz, which was recently made available in
the United States. I am excited to see how this new circuit will be received by the market. Having the
full transceiver in Silicon-Germanium for V-band, provides a fundamental platform, including the relevant
..."
"Weaving
two types of specially designed fibres with cotton yarn and conductive copper-coated threads, a team
of researchers from China and Singapore has devised a smart fabric that can both harvest energy from
light and store it as a supercapacitor would do. As its main threads (used as
flying shuttle), the textile combines fibre-shaped photo-anodes interlaced with counter electrodes
(CEs) for the energy harvesting functionality, with TiN nanowire-based
fibre for
..."
Since 1961, MECA Electronics has designed
and manufactured an extensive line of RF / Microwave
components with industry leading performance including attenuators, directional & hybrid couplers,
isolators, circulators, dividers, combiners, RF loads, DC 
blocks, bias Ts and adapters &
cables. MECA has long been the 'backbone' of high performance wired and air-interfaced networks such
as in-building, satellite, radar, radio, telemetry, mobile radio, aviation & air traffic communications.
"Bill Schweber points out
that sometimes the old ways are best ways and sometimes the only ways, although they can be sometimes
dressed in new formats. There's the transformer, the electromechanical relay and the
gas discharge tube (GDT) is still alive
and well. What is a GDT? In essence, it's a sealed version of the automotive spark plug, as a spark-gap
device in a sealed, gas-filled glass or ceramic enclosure, which offers near-infinite resistance
..."
"While transitioning toward an upgraded, electronic system, the
Navy is continuing to invest in its
Consolidated Automated Support System, which it uses to test the
electronics systems on aircraft, surface ships and submarines. The service has awarded Lockheed Martin,
a longtime vendor for CASS, a $214.5 million contract for up to 400 CASS stations and 150 reconfigurable
transportable CASS stations for the Navy
..."
Southwest Antennas has released the first in their new product
line of
filtered omni-directional antennas, giving users additional operational flexibility in radio placement
while helping to attenuate disruptive frequencies outside of their operational frequency band. This
is particularly important for users who will be operating in close proximity to high-powered transmitters,
such as military radio systems. A 3-pole RF bandpass filter is securely fitted inside of the antenna
radome and integrated
...
Radio-Craft magazine used to run a feature where readers
would write in with questions, and someone on the staff would respond. This month's query requested
that a table containing
current carrying capacities for various wire gauge sizes. Values of fusing current were provided
for 10 through 40 GA, for copper, German silver, and iron. The "B. & S. Gauge" wire size scale refers
to Brown & Sharpe, which now goes by the designation of American Wire Gauge
(AWG)
...
"Google
just launched its new Pixel and
Pixel XL smartphones, complete with Google Assistant and virtual
reality capabilities. The Pixel and Pixel XL are powered by Snapdragon 821 processors and a new version
of Google's Android software. The software includes capabilities with Daydream virtual reality platform,
which Google announced over the summer. Both phones are built by HTC, but Google takes full credit for
the design
..."
Skyworks
has broadened its antenna tuner portfolio with two new Mobile Industry Processor Interface (MIPI®)-controlled
devices that support ultra-low Ron (SKY19247-686LF)
and ultra-high Vpeak (SKY19237-001). These new tuners are ideal for smartphones, data cards and MiFi®
hotspots and improve antenna efficiency, as well as Total Radiated Power (TRP) and Total Isotropic Sensitivity
(TIS) performance. They deliver high linearity for carrier
...
The
Instrument Landing System (ILS) has been around for an amazingly long time - almost as long as commercial
airlines have been operating. This 1937 article in the October issue of Radio-Craft magazine
reports on the current state of the art. The Douglas DC-3 twin-engine airliner
(my all-time favorite airplane) entered service in 1936 and is credited
with creating widespread public acceptance of the safety and comfort of airplanes. Much of the content
for this article also appeared in "The
History and Development of the Washington Institute of Technology," by
...
"A team
led by Cory Dean, at Columbia University, Avik Ghosh, professor of electrical and computer engineering
at the U. of Virginia, and James Hone, Wang Fong-Jen, at Columbia Engineering, has directly observed
- for the first time -
negative refraction for electrons passing across a boundary between
two regions in a conducting material. First predicted in 2007, this effect has been difficult to confirm
experimentally. The researchers were able to observe the effect
..."
everythingRF has been a long-time supporter of RF cafe through
their advertising.
everythingRF is a product discovery platform for RF & Microwave
Products/Services. We currently have 231,624 Products from more
than
1,053 Companies across 225 Categories in our database and enable engineers to search for them using
our customized parametric search tool. Please visit everythingRF now to see how they can help you
...
"Reiterating a stance popular with U.S. wireless carriers, AT&T
is telling the FCC that '5G' and 'mmW' spectrum are not, and should not be, synonymous, reminding regulators
that to fully realize the potential of 5G, the nation needs access to low-, mid- and high-band capacity.
While AT&T commended the FCC's efforts with respect to
millimeter wave (mmW) spectrum, 'it should not lose sight of the
need to continue to allocate more spectrum below 6 GHz,' the company said
..."
This
engineering crossword
puzzle contains words and clues related to topics that appeared in the past week's technical headline
news (clues with an asterisk* after them). If you paid attention to the
items in the upper left-hand column on the RF Cafe homepage, you'll have a bit of an easier time with
the answers. An archive page is maintained of all the headlines posted, so you can look there if you
get stuck (or you can look at the bottom of this page for the puzzle's complete
solution). Enjoy!
...
Special Snowflake alert on this article
from a 1939 edition of QST! Do not read the first paragraph if you are easily offended or easily
induced to self-flagellation over misplaced guilt for statements made by people you had no relation
to or control over. If you are brave and decide to continue, author George Grammer provides a very good
guide regarding how to be safe around
high
voltage, high power electronics equipment. A lot of the opportunity for harm has been removed with
modern transistorized circuits and improved chassis
...
"Graphene
Flagship researchers used layers that included transition metal dichalcogenides (TMDs), graphene, and
boron nitride to build thethin LEDs that can be used in quantum communications and network applications.
The research was reported in Nature Communications, and was led by the University of Cambridge, UK.
According to the paper, 'The diverse materials are layered forming a heterostructure. As electrical
current is injected into ..."
QST
magazine occasionally used to run a feature titled "Quist Quiz" that was a short test
of knowledge in the areas of antennas, impedance matching, amplifier biasing, etc. I'm not sure where
the "Quist" part of the title comes from. A guess about it possibly being the last name of the author
could not be confirmed or ruled out based on a quick Internet search. The only definition I could find
for 'quist' is one meaning a wooden pigeon. If anyone knows the origin of "Quist," please let me know
...
"The
negative refraction of electrons in graphene has been seen for the
first time in experiments done by physicists in the US. The work represents an important advance in
the fabrication of graphene electronic devices, and could lead to new applications of graphene such
as low-power transistors. Negative refraction can occur when light or other waves cross an interface
between two different materials. The term 'negative' is used when the direction of the light is bent
in the
..."
Saelig Company has introduced the
PSU-Series of
single output programmable switching DC power supplies that can provide up to 200 A current and
cover a power range up to 1520 W. These high efficiency, high power density supplies include five models
from 6 V to 60 V rated voltages. The PSU-series can be connected in series for increased power capacity:
up to two units in series or up to four in parallel to cover a broad coverage of applications
...
AccuWeather has a story titled "A world without Twitter and iPhones: What has changed since the last major hurricane
hit the US?" A bullet list included the following:
- The average price of a gallon of gas was $2.60. The current price is $2.24.
- Facebook had been
around for only 18 months.
- Twitter would not launch for another 5 months.
- Apple and Steve
jobs were still developing the first iPhone.
- YouTube had launched just 8 months prior.
Passive Plus (PPI) Intros Series of Broadband Capacitors
"Passive Plus, Inc.
(PPI) has developed a series of Broadband Capacitors available in 4 different case sizes; 01005BB, 0201BB, 0402BB,
and the 0603BB. Values available are 10nF (103) and 100nF (104) These capacitors are intended primarily
for coupling RF signals or, occasionally, for bypassing them to ground, while blocking DC. The applications
for which they are intended require small, surface-mountable devices that provide low RF impedances
..."
These two "Radio Service Data Sheets" appeared in the August 1931
edition of Radio-Craft magazine. They bring my total thus far to 122. The
Bosch Models 60 and
61 and the
RCA-Victor
Radiola "Superette" Model R7 Superheterodyne radios were superheterodyne sets. It had only been
a dozen years since Edwin Armstrong devised the circuitry in 1918.
"The Navy is moving forward
with its incremental upgrades to shipboard
electronic warfare systems with a $148.9 million contract award to
Lockheed Martin for Surface Electronic Warfare Improvement Program (SEWIP) Block 2 subsystems. The roughly
three-year deal, part of the Navy's ongoing improvements to the AN/SLQ-32 electronic warfare system,
calls for full-rate production of the system to improve electronic warfare for early detection, analysis,
threat
..."
"Peregrine Semiconductor, founder of RF SOI and pioneer of advanced
RF solutions, announces the UltraCMOS® PE42525 and PE426525, the industry's first
RF SOI switches to operate up to 60 GHz. These two switches set a
new standard for RF SOI at microwave frequencies and significantly extend Peregrine's high frequency
portfolio into frequencies previously dominated by GaAs technology. Both 60 GHz switches deliver exceptional
performance in all key RF ..."
"Humans have harnessed large portions
of the electromagnetic spectrum for diverse technologies, from X-rays to radios, but a chunk of that
spectrum has remained largely out of reach. This is known as the
terahertz gap, located between radio waves and infrared radiation, two parts of the spectrum we
use in everyday technologies including cell phones, TV remotes and toasters. A theory developed by the
late Stanford professor and Nobel laureate Felix Bloch
..."
Resistors,
probably the most common electronic components in existence, have undergone significant evolution since
first being mass produced in the late 19th century. Amazingly, less than two centuries have passed since
the concept electrical resistance was first published in 1827 by Georg Simon Ohm, a German physicist.
As with most products of the era, and well into the 20th century, resistor manufacturing involved a
degree of human labor. Resistors (and capacitors and inductors for that matter)
found in your grandparents' old vacuum tube radios were most
...
VidaRF offers
new a pair of high performance, Low-PIM coaxial
cable adapters in 4.3-to-10 and 4.1-to-9.5 configurations. Features include: Excellent PIM performance,
superior electrical performance, compact design (40% less than 7/16), screw / hand screw / quick lock
coupling, light weight. Full line of in-series and between-series adapters catalog
...
"For the first time beginning next month, forecasts of the regional
effects of
solar storms will help protect the power grid and communications
satellites, thanks to a new tool developed by researchers at the University of Michigan and Rice University.
Solar storms are torrents of charged particles and electromagnetic fields from the Sun that rattle the
planet's magnetic field. Major disturbances can send harmful current into power lines, hampering operations
and putting expensive transformers at risk
..."
"Superconductors are the holy grail of energy efficiency. These
mind-boggling materials allow electric current to flow freely without resistance. But that generally
only happens at temperatures within a few degrees of absolute zero, making them difficult to deploy
today. However, if we're able to harness the powers of
superconductivity at room temperature, we could transform how energy is produced,
stored ..."
This
is a true story. When I was in 9th grade, the class was being shown a film (yes,
the kind on a reel, on a projector, circa 1972-73) where the narrator mentioned how some person
committed a 'boner.' A girl in the class busted out laughing so hard that she actually wet herself.
That made the rest of the class laugh. I guess she had never heard the word used in that context before
- remember, we're talking teenagers here. Sorry for the rude reference, but for some reason the incident
came to mind when reading the section labeled 'Radio Boners' in
this article from a 1935 edition of Radio-Craft magazine. Funny what triggers a particular
memory. All that
...
"Qorvo,
a leading provider of innovative RF solutions that connect the world, today introduced two new power
amplifiers (PAs) including the industry's first 500-watt,
L-Band PA internally matched to 50 ohms. These high-power devices
are optimized for use in defense and civilian radar systems, with features designed to shorten and simplify
system implementation. Built on Qorvo's high-performance GaN
..."
"The
military of the future, in addition to the well-known goal of being better connected, will also be a
lot lighter, if current work by researchers comes to fruition. Lighter aircraft, for example, could
be faster and more agile while requiring less fuel. As for the
electronics carried, or worn, by troops in the field, the lighter
the better. Two examples involve breakthrough work being led by the Army Research Laboratory and the
Defense
..."
"Our planet
is nestled in the center of two doughnut-shaped regions of powerful, dynamic radiation: the
Van Allen belts, where high-energy particles are trapped by Earth's
magnetic field. Depending on incoming radiation from the sun, they can gain energetic particles. On
the other hand, the belts can lose energized particles too. We are familiar with rapid changes in weather,
and the radiation belts can experience these too - particles can be depleted
..."
I was surprised to not find in this story any mention of military
training as a possible pathway to a career in electronics. 1948 was a year when a plethora of highly
trained and competent cadre of
electronics technicians were available for exploitation by commercial industries. During the years
of World War II, which came to a close in the Fall of 1946, most research, development, and production
of high tech equipment resulted in major advancements in radio, television, radar, teletype, medicine,
and creature comforts was operated and maintained by
...
"A
nitrogen-vacancy (NV) defect in diamond has been used to create a
magnetometer that can measure the broadband magnetic fields generated by hard-disk write heads. The
work was done by researchers in Germany and the UK who have shown that a single NV can detect the oscillating
and static magnetic fields associated with write heads at nanometre resolution. The new work could help
further miniaturize hard-disk drives, thereby increasing their data-storage capacity. 'The hard-disk
industry
..."
Anatech Electronics offers the industry's largest portfolio of
high-performance standard and customized RF and microwave filters and filter-related products for military,
commercial, aerospace and defense, and industrial applications up to 40 GHz. Anatech has introduced
3 new filter designs:
a 2025-2120 MHz / 2200-2230 MHz / 1750-1850 MHz triplexer with N connectors, a 1000 MHz LC lowpass filter
with SMA connectors, and an L1 / L2 GPS duplexer / combiner with SMA connectors. Custom design are available
...
"The FCC
Thursday voted to adopt rules to update its
Wireless Emergency Alerts (WEA) system, which delivers messages to
mobile users regarding severe weather, missing children and other critical situations. The move follows
a chorus of officials calling for major changes to the program in response to recent bombings in New
York and New Jersey. But wireless carriers say the Commission may actually be moving too quickly. The
new rules increase the maximum length
..."
The free whitepapers,
pamphlets, books, magazines, and chapter examples listed here are a small sample of a lot of new items
that are offered for FREE through TradePub. The publishers make them available to qualifying people
as a promotional campaign for their full line of offerings. Note: I earn a few pennies
(literally) when you download one of these or the many other pubs available,
so please help yourself.
"Previously, the
high-k dielectric has always been too lossy to be of use, according to researchers at University of
California, Santa Barbara. 'The catch is that the deposition of complex oxides, such as barium strontium
titanate, is problematic because of the high temperatures and oxygen-rich environment involved,' said
the University. 'The team's work clarifies that early work within the field
..."
Technology advancement has always been about research and development
in all fields related to the concept, be it any combination of mechanical, electrical, programming,
implementation, usage, or training. Television went fundamentally unchanged from the time of its commercial
implementation in the early part of the last century until the advent of plasma screens in the latter
part of the last century. Color tubes added complexity to the signal, but it was still an analog signal.
Then came digital broadcasting in the early part of this century. The same sort of evolution occurred
with telephones and to some extent with radio. This
Television
I.Q. Quiz from a 1948
...
"The Nobel Prize winner spent a decade trying to create a household
solar energy system - and failed. In the summer of 1958, a new employee at Texas Instruments,
Jack St. Clair Kilby, had not yet accrued enough time off to take
a company-wide vacation. Alone in the lab, Kilby pondered the then-current 'tyranny of numbers' problem:
the time-consuming and imperfect process of soldering connections between very large numbers of discrete
solid-state components. Within a few short weeks, Kilby came up with
..."
San-tron,
a designer and manufacturer of RF coaxial connectors and cable assemblies, will be discussing their
latest innovations at European Microwave Week in London, UK October 3-7th in stand #67. The pSeries
family of pressurized cable assemblies is highlighted in San-tron's latest case study: London Underground
Keeps Trains Moving. The case study explores how San-tron's engineering team custom designed an IP68
rated pressurized connector to keep
...
For the sake of avid cruciverbalists amongst us, each week I create
a new science themed crossword
puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical
words. You will never be asked the name of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Enjoy!
...
"Mark Zuckerberg has given a rare glimpse inside one of Facebook's
secretive server farms. The Facebook boss said he is going to reveal more pictures from Facebook's facilities
around the world. To kick off the project, he revealed a stunning series of pictures of the firm's gigantic
Luleå data center in Sweden. 'Over the next few months, I'm going
to start posting some rare photos of the most advanced technology Facebook is building around the world,'
Zuckerberg posted
..."
EDI CON USA 2016, a conference that
brings together engineers working on high-frequency analog and high-speed digital designs, had a successful
inaugural event in the US on September 20-22 in Boston, MA. "We are very pleased with our first EDI
CON USA, which exceeded our expectations in number of exhibitors and submitted abstracts for the conference
program. We appreciate the support of the EDI CON USA exhibitors, received very positive feedback from
conference attendees, and look forward to building on these strengths for next year
..."
Sal ammoniac is a new term for me; it appeared in this 1935 issue
of Radio-Craft magazine. It is a rare mineral composed of ammonium chloride. I suppose I should
have been familiar with it because of its use for cleaning soldering iron tips. This compound is another
example of how two otherwise lethal elements can form a molecule that is safe for human consumption,
like sodium chloride (table salt). Per Wikipedia, sal ammoniac is used the Netherlands, it is still
widely used in the production of salty licorice candy known as Salmiak. Sal ammoniac was also used in
solution with sulphuric acid as a battery electrolyte. Anyway, the main theme of this article positive
...