omniomni/omni-engineering huggingface dataset:
Increment borer. An increment borer is a specialized tool used to extract a section of wood tissue from a living tree with relatively minor injury to the plant itself.  The tool consists of a handle, an auger bit and a small, half circular metal tray ( the core extractor) that fits into the auger bit; the last is usually manufactured from carbide steel.  It is most often used by foresters, researchers and scientists to determine the age of a tree. This science is also called dendrochronology. The operation enables the user to count the rings in the core sample, to reveal the age of the tree being examined and its growth rate.  After use the tool breaks down: auger bit and extractor fit within the handle, making it highly compact and easy to carry.

Use

Effective use of an increment borer requires specialized training.  Samples are taken at breast height or stump height of the tree trunk, depending on the user's objectives;  during use the borer should be well lubricated, thus making it easier to use and preventing it from becoming stuck in the wood.

Maintenance
As with any other tools, increment borers should be properly maintained to keep them in good working condition; should be thoroughly cleaned after each use and dried before storing.  Sharpening kits are available and should be used regularly, before such bits become dull.

Types
Increment borers come in different lengths and diameters and have different types of threads.  The most common diameters are the 4, 4.3, and 5.15 millimeter borers in the range of 3.8 millimeters to 12 millimeters,  and they are available with two or three threads. The two-threaded type is more appropriate for hard woods, because it cuts at a slower rate, which applies more torque. The three-threaded auger will penetrate the wood at a faster rate than the former.

References

External links

Increment borer, Virginia Tech

Forest modelling
Dimensional instruments
Forestry tools
1974 in spaceflight. On 29 March 1974 Mariner 10 became the first spacecraft to fly by Mercury, that saw a spacecraft for the first and last time in the 20th century.

Orbital launches

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Deep Space Rendezvous

EVAs

References

Footnotes

 
Spaceflight by year
Type S. Type S may refer to:
 Acura Type-S, the high-performance division of Acura
 Driving Emotion Type-S, a racing game
 FBA Type S, a French flying boat
 Handley Page Type S, a prototype British carrier-based fighter
 Lohner Type S, an Austro-Hungarian flying boat
 NW S, an Austro-Hungarian automobile introduced in 1906
 Seversky A8V1 Type S Two Seat Fighter
 Toyota Type S engine, a straight-4 automobile engine
 a type S thermocouple

See also 
 S class (disambiguation)
 S-Type (disambiguation)
 Class S (disambiguation)
Selenium hexafluoride. Selenium hexafluoride is the inorganic compound with the formula SeF6. It is a very toxic colourless gas described as having a "repulsive" odor. It is not widely encountered and has no commercial applications.

Structure, preparation, and reactions
SeF6 has octahedral molecular geometry with an Se−F bond length of 168.8 pm.  In terms of bonding, it is hypervalent.

SeF6 can be prepared from the elements.  It also forms by the reaction of bromine trifluoride (BrF3) with selenium dioxide.  The crude product can be purified by sublimation.

The relative reactivity of the hexafluorides of S, Se, and Te follows the order TeF6 > SeF6 > SF6, the latter being completely inert toward hydrolysis until high temperatures. SeF6 also resists hydrolysis.  The gas can be passed through 10% NaOH or KOH without change, but reacts with gaseous ammonia at 200 °C.

Safety
Although selenium hexafluoride is quite inert and slow to hydrolyze, it is toxic even at low concentrations, especially by longer exposure. In the U.S., OSHA and ACGIH standards for selenium hexafluoride exposure is an upper limit of 0.05 ppm in air averaged over an eight-hour work shift. Additionally, selenium hexafluoride is designated as IDLH chemical with a maximum allowed exposure limit of 2 ppm.

References

External links
 ATSDR ToxFAQs - Selenium Hexafluoride U.S. Department of Health and Human Services
 CDC - NIOSH Pocket Guide to Chemical Hazards U.S. Department of Health and Human Services
 WebBook page for SeF6

Selenium(VI) compounds
Hexafluorides
Octahedral compounds
Chalcohalides
Selenium halides
Foul-smelling chemicals
Angle gauge. An angle gauge is a tool used by foresters to determine which trees to measure when using a variable radius plot design in forest inventory. Using this tool a forester can quickly measure the trees that are in or out of the plot.  An angle gauge is similar to a wedge prism though it must be held a fixed distance from the eye to work properly. Unlike the wedge prism, which is held over the plot center, the surveyor's eye is kept over plot-center when using an angle gauge.

Use
When using an angle gauge the user must count trees that are larger than the width of the angle gauge, as viewed from the center of the plot.  The angle gauge is held a set distance from the eye of the surveyor. Most angle gauges have a string or chain that lets the user know the set distance. Each angle gauge is set at a certain basal area factor (BAF). Each tree that is in the plot represents this number, the BAF, of square footage. It is multiplied by the number of trees on the plot to give basal area per acre. In the United States BAF is measured in units of square feet. For example, using a BAF 10 angle gauge a forester measures 12 trees that are in trees. Therefore, this plot represents .

Borderline trees

Some trees are on the borderline of the plot and must be checked to be sure they are to be included. The limiting distance must be calculated to see if the trees are in or out. The equation to calculate the limiting distance in feet is diameter at breast height, DBH, in inches times plot radius factor, PRF, in feet/area Dlim = DBH×PRF.

For example, using a BAF 10 angle gauge a forester needs to know the limiting distance for a  tree.  The PRF using a 10 BAF angle gauge is  for every inch of tree diameter. Therefore, 20 inches × 2.75 ft/inch = .  This means that a  tree must be over  away from the center of the plot using a BAF 10 angle gauge to be out of the plot.

References

Further reading
Avery and Burkhart.  Forest Measurements.  Fifth Edition, McGraw Hill, New York, New York:  2002.

Forest modelling
Dimensional instruments
Forestry tools
Stubroutine. A stubroutine (also known as a stub function, null script, null subroutine, or null function) is a command script or program subroutine which does nothing but return a constant value. The term itself is a portmanteau of "stub" and "subroutine", and typically refers to a placeholder function or subroutine that is not yet fully implemented but provides the necessary interface (like inputs and outputs) for the rest of the program to function. 

They are used during program development, where the functional implementation of routines is delayed while other routines are developed, which allows developers to continue building and testing other parts of the software even when certain functions or subroutines are not fully developed. This is also one of the techniques used by the software cracking community to bypass callbacks and license-checking code: the target program is disassembled and the appropriate code is substituted for a null subroutine that just returns the value expected by the caller.

Subroutines
Concorde TSP Solver. The Concorde TSP Solver is a program for solving the travelling salesman problem. It was written by David Applegate, Robert E. Bixby, Vašek Chvátal, and William J. Cook, in ANSI C, and is freely available for academic use.

Concorde has been applied to problems of gene mapping, protein function prediction, vehicle routing, conversion of bitmap images to continuous line drawings, scheduling ship movements for seismic surveys, and in studying the scaling properties of combinatorial optimization problems.

According to , Concorde “is widely regarded as the fastest TSP solver, for large instances, currently in existence.” In 2001, Concorde won a 5000 guilder prize from CMG for solving a vehicle routing problem the company had posed in 1996.

Concorde requires a linear programming solver and only supports QSopt and CPLEX 8.0.

Notes

References

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External links
Concorde website
Online access to Concorde solver at Arizona State University

Travelling salesman problem
Mathematical optimization software
Segmented spindle. A segmented spindle, also known by the trademark Kataka, is a specialized mechanical linear actuator conceived by the Danish mechanical engineer Jens Joerren Soerensen during the mid-1990s.  The actuator forms a telescoping tubular column, or spindle, from linked segments resembling curved parallelograms.  The telescoping linear actuator has a lifting capacity up to 200 kg (~440 pounds) for a travel of 400 mm (~15.75 inches).

A short elongated housing forms the base of the actuator and includes an electrical gear drive and storage magazine for the spindle segments.  The drive spins a helically grooved wheel that engages the similarly grooved inside face of the spindle segments.  As the wheel spins it simultaneously pull the segments from their horizontal arrangement in the magazine and stacks them along the vertical path of a helix into a rigid tubular column.  The reverse process lowers the column.

See also
 Helical band actuator
 Rigid belt actuator
 Rigid chain actuator

References

External links
Kataka web site

Actuators
Hardware (mechanical)
Gears
S20. S20 may refer to:

Aviation
 Letov Š-20, a Czechoslovak fighter
 Rans S-20 Raven, an American light-sport aircraft
 SABCA S-20, a Belgian aircraft
 Short S.20 Mercury, a British parasite seaplane
 Sikorsky S-20, a Russian biplane fighter
 SPAD S.XX, later the Blériot-SPAD S.20, a French fighter

Electronics
 Canon PowerShot S20, a digital camera
 Chrome S20 series, a graphics accelerator
 Samsung Galaxy S20, a series of smartphones
 Akai S20, an Akai synthesizer

Rail and transit

Lines 
 S20 (Long Island bus), in Suffolk County, New York, United States
 S20 (Munich), in Germany
 S20 (RER Fribourg), in Switzerland
 S20 (TILO), in Ticino, Switzerland
 S20 (ZVV), of the Zürich S-Bahn, Switzerland

Stations 
 Kamisawa Station (Nagoya), in Midori-ku, Nagoya, Aichi, Japan
 Imazato Station (Osaka Metro), in Japan
 Shikaribetsu Station, in Niki, Yoichi District, Hokkaidō, Japan
 Shinozaki Station, in Edogawa, Tokyo, Japan

Roads
 S20 Shanghai Outer Ring Expressway, China
 County Route S20 (California), United States

Submarines 
 
 , a submarine of the Royal Navy
 , a submarine of the Indian Navy
 Type S20 submarine, an export version of China's Type 039A submarine
 , a submarine of the United States Navy

Homoglyphic errors for S2O
 S2O, disulfur monoxide
 S2O, Subscribe to Open, one of dozens of business models for open access

Other uses
 40S ribosomal protein S20
 British NVC community S20, a natural habitat of swamps and tall-herb fens in the British National Vegetation Classification system
 Nissan S20 engine, an automobile engine
 S20: When using do not eat or drink, a safety phrase
 Sako S20, a Finnish bolt-action rifle
 Toyota Crown (S20), a luxury sedan
 Venda language
 S20, a postcode district in Sheffield, England
S26. S26 may refer to:

Aviation 
 Blériot-SPAD S.26, a French racing seaplane
 Philippine Air Lines Flight S26, which crashed in 1969
 Short S.26, a British flying boat transport
 Sikorsky S-26, a Russian biplane bomber

Rail and transit 
 S26 (Berlin), a line of the Berlin S-Bahn
 Konbu Station, in Rankoshi, Isoya District, Hokkaido, Japan
 Rheineck–Walzenhausen mountain railway, a line of the St. Galen S-Bahn in Switzerland
 Tösstal railway line, a line of the Zürich S-Bahn in Switzerland

Roads 
 Shanghai–Changzhou Expressway, China
 County Route S26 (California), United States
 U.S. Route 1 in New Jersey, partially numbered S26 until 1953

Submarines 
 , of the Royal Navy
 , of the Indian Navy
 , of the United States Navy

Other uses 
 40S ribosomal protein S26
 British NVC community S26, a swamps and tall-herb fens community in the British National Vegetation Classification system
 Djabwurrung language
 S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice, a safety phrase
 S26, a postcode district in Sheffield, England
PSPP. PSPP  is a free software application for analysis of sampled data, intended as a free alternative for IBM SPSS Statistics. It has a graphical user interface and conventional command-line interface. It is written in C and uses GNU Scientific Library for its mathematical routines. The name has "no official acronymic expansion".

Features
This software provides a comprehensive set of capabilities including frequencies, cross-tabs comparison of means (t-tests and one-way ANOVA), linear regression, logistic regression, reliability (Cronbach's alpha, not failure or Weibull), and re-ordering data, non-parametric tests, factor analysis, cluster analysis, principal components analysis, chi-square analysis and more.

At the user's choice, statistical output and graphics are available in ASCII, PDF, PostScript, SVG or HTML formats. A range of statistical graphs can be produced, such as histograms, pie-charts, scree plots, and np-charts.

PSPP can import Gnumeric and OpenDocument spreadsheets, Postgres databases, comma-separated values and ASCII files. It can export files in the SPSS 'portable' and 'system' file formats and to ASCII files.  Some of the libraries used by PSPP can be accessed programmatically; PSPP-Perl provides an interface to the libraries used by PSPP.

Origins
The PSPP project (originally called "Fiasco") was born at the end of the 1990s as a free software replacement for SPSS, which is a data management and analysis tool, at the time produced by SPSS Inc. The nature of SPSS's proprietary licensing and the presence of digital restrictions management motivated the author to write an alternative which later became functionally identical, but with permission for everyone to copy, modify and share.

Third Party Reviews
In the book "SPSS For Dummies", the author discusses PSPP under the heading of "Ten Useful Things You Can Find on the Internet". Another review of free to use statistical software also finds that the statistical results from PSPP match statistical results for SAS, for frequencies, means, correlation and regression.

Research about PSPP
One study found that students who used PSPP became more positive about learning statistics while using PSPP.

Examples of Research Performed using PSPP
Among the studies done using PSPP are one about posttraumatic stress in adolescents, another about nutrition software, and another about internet addiction.

See also

Free statistical software
Comparison of statistical packages

External Resources
 PSPP for Beginners

References

External links

PSPP on Free Software Directory
Source code at Savannah

Third-party resources
Review by UK SPSS user group (as of version 0.1.22)
Using PSPP to import SPSS data into R
PSPP review in Slovene (English translation via Google)
User review from communication research info
Yet another user review

Free educational software
Free software programmed in C
Free statistical software
GNU Project software
Science software that uses GTK
Lamborghini Alar. The Lamborghini Alar was a concept for a mid-engined sports car to be produced by Lamborghini LatinoAmerica. A unit was rumored to cost $750,000 each. The Alar was heavily based on the Diablo especially in the areas of chassis and engine. Other components are made locally by the company. The Alar has yet to be produced.

Performance 
The engine of the Alar is a heavily modified Lamborghini Diablo engine, it is a 7.7 L V12 able to produce  and can redline at about 7500 rpm. Its body weighs relatively the same as a Diablo at . Initial Reports suggest the Alar could top  and could reach 0- in 4 seconds, subsequent official brochures have outlined its specifications. The estimated top speed of the Alar is  although these figures are highly debatable.

Styling 
Although it shares the same platform and engine as the Lamborghini Diablo its outer styling is completely different. Its styling is reminiscent of the Lamborghini Coatl, which is another car produced by Lamborghini Latinoamérica and designed by Joan Ferci. Like the Alar the Coatl is also based on the earlier Diablo.

References 

Rear mid-engine, rear-wheel-drive vehicles

Alar
Otto (disambiguation). Otto is a given name of Germanic origin, including a list of persons and fictional characters with the name.

Otto or otto may also refer to:

Arts and entertainment
 Otto – Der Film, a 1985 German movie
 Otto (Greyhawk), a wizard in the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game
 Otto; or, Up with Dead People, a 2008 zombie movie

Business
 Otto (company), an autonomous trucking company
 OTTO Motors, self-driving factory robots
 Otto., Finland's interbank network
 Otto GmbH (Otto Group), a German retailer
 Otto Flugmaschinenfabrik, a 1910s German aircraft manufacturer

People
 Otto the Great (912–973), East Frankish king and Holy Roman Emperor
 Otto II, Holy Roman Emperor (955–983)
 Otto III, Holy Roman Emperor (980–1002)
 Otto IV, Holy Roman Emperor (1175/1176–1218)
 Otto, Count of Cleves (1278–1310)
 Otto, Count of Lippe-Brake (1589–1657)
 Otto, Duke of Lolland and Estonia (1310–1346)
 Otto, Count of Looz (fl. 980-1000)
 Otto, Count of Vermandois (979–1045)
 Otto, Landgrave of Hesse-Kassel (1594–1617)
 Otto, Lord of Arkel (1330–1396)
 Otto, Lord of Lippe (1300–1360)
 Otto, Margrave of the Nordmark (died 1057)
 Otto (singer) (born 1968), Brazilian singer
 Otto Waalkes (born 1948), known mononymously as Otto, German comedian
 Otto (surname)

Places
 Otto, Indiana, US
 Otto, New York, US
 Otto, North Carolina, US
 Otto, West Virginia, US
 Otto, Wyoming, US
 Otto Township (disambiguation)
 Mount Otto, a mountain in Colorado, US
 2962 Otto, a main-belt asteroid

World War II
 Operation Otto, the Axis operational codename for the 1938 annexation of Austria
 Operation Otto (1943), an Axis 1943 anti-partisan operation in Croatia

Other uses
 Hurricane Otto (disambiguation)
 Otto (dog breed), a breed also known as the Alapaha Blue Blood Bulldog
 Otto the Orange, the mascot of Syracuse University
 Otocinclus, genus of sucking catfish, often known as 'Otto'
 MV Otto, a German coaster
 Otto Celera 500L, an experimental American business and utility aircraft built by Otto Aviation

See also
 Otto cycle, the thermodynamic cycle of a typical reciprocating piston engine
 Otto engine, an early internal combustion engine invented by Nicolaus Otto
 Auto (disambiguation)
 Otho (disambiguation)
 Oto (disambiguation)
 Otto's (disambiguation)
Blue (queue management algorithm). Blue  is a scheduling discipline for the network scheduler developed by graduate student Wu-chang Feng for Professor Kang G. Shin at the University of Michigan and others at the Thomas J. Watson Research Center of IBM in 1999.

Functioning
Like random early detection (RED), Blue operates by randomly dropping or marking packet with explicit congestion notification mark before the transmit buffer of the network interface controller overflows. Unlike RED, however, it requires little or no tuning to be performed by the network administrator. A Blue queue maintains a drop/mark probability p, and drops/marks packets with probability p as they enter the queue.  Whenever the queue overflows, p is increased by a small constant pi, and whenever the queue is empty, p is decreased by a constant pd < pi.

If the mix of traffic on the interface does not change, p will slowly converge to a value that keeps the queue within its bounds with full link utilization.

Stochastic fair Blue
The main flaw of Blue, which it shares with most single-queue queuing disciplines, is that it does not distinguish between traffic flows, but treats all flows as a single aggregate.  Therefore, a single aggressive flow can push packets out of the queue belonging to other, better behaved, flows.

Stochastic fair Blue (SFB)  is a stochastically fair variant of Blue which hashes flows and maintains a different mark/drop probability for each hash value.  Assuming no hash collisions, SFB is able to provide a fair share of buffer space for every flow.  In the presence of hash collisions, SFB is only stochastically fair.

Unlike other stochastically fair queuing disciplines, such as SFQ (Stochastic Fairness Queuing), SFB can be implemented using a bloom filter rather than a hash table, which dramatically reduces its storage requirements when the number of flows is large.
When a flow's drop/mark probability reaches 1, the flow has been shown to not react to congestion indications from the network.  Such an inelastic flow is put in a "penalty box", and rate-limited.

Resilient stochastic fair Blue
Many scheduling algorithms, including the fairness-aimed ones, are notably vulnerable to spoofing distributed denial-of-service (DDoS) attacks. A resilient stochastic fair Blue (RSFB) algorithm was proposed in 2009 against spoofing DDoS attacks. The basic idea behind RSFB is to record the responsive normal TCP flows and rescue their dropped packets. RSFB algorithm is effective in preserving the TCP throughput in the presence of spoofing DDoS attacks.

Implementations
An implementation of Blue is part of ALTQ, the network scheduler for BSD Unix.

An implementation of SFB for Linux was included in the Linux kernel in version 2.6.39.

References

Packets (information technology)
Network performance