omniomni/omni-engineering huggingface dataset:
Calima (Saharan sand). Calima or Kalima is a term used to describe a meteorological phenomenon that occurs when fine sand and dust particles from the Sahara are lifted into the atmosphere and transported by prevailing winds. 

It usually happens in the summer and lasts 3-5 days.

Meteorological causes 
The primary cause of Kalima is the movement of air masses over the Sahara. The region near the surface in the Sahara undergoes strong warming through heat transfer from the underlying layer. This extreme diurnal warming creates instability in the lowest layer of the atmosphere, warming and drying the air near the surface and cooling while humidifying the air near the top of the layer through convective mixing. 

The desert's arid environment causes the soil to become fine and easily lifted by strong winds, such as those associated with the Harmattan or the trade winds. These winds can lift millions of tons of sand and dust into the atmosphere, creating a dense, suspended cloud that can travel thousands of kilometers. Some of clouds of sand reach up to 6,000 meters in altitude. The raised dust can then move in the eastward atmospheric circulation while being captured above a marine inversion as it passes over the ocean, reaching the Canary Islands.

Effects 

The humid air in the inversion layer is often associated with fog or drizzle covering the Canary Islands. The dust particles that settle also cause respiratory problems, especially for people with pre-existing respiratory conditions. It is therefore, best for people to wear respiratory masks if they have to go outdoors when there is Calima. 

Aside from affecting people's health, when there is Kalima, weather conditions can become very poor and force the suspension of some public services, including transportation. For example, on January 8, 2002, the Santa Cruz International Airport had to be closed because visibility fell to less than 50 meters.

In 2020 the wind spread three wildfires, forcing about 2,000 residents to evacuate in Tenerife and Gran Canaria. Gran Canaria had the worst air quality in the world that weekend due to the dust, with about 40 times the particle density considered safe by the World Health Organization. This resulted in 745 flights being canceled and 84 others diverting to different airports.

Calima also affects other countries such as Malta, Italy (especially Sicily), and Greece (especially Crete) mostly during the spring months when strong southerly winds bring Saharan dust over the Mediterranean.

References

Regional climate effects
Geography of the Canary Islands
Gabar dams. Gabar dams are a series of walls and dams found in Sindh and Balochistan provinces of Pakistan, constructed to store rainwater and divert the flow of rivers. Some of them date to the 4th and 3rd millennia BCE. There are around 15 such dams present in the Kirthar Mountains in the Sindh and Balochistan plateau.

Gallery

References

P
Dams in Pakistan
Berkelium(III) fluoride. Berkelium(III) fluoride is a binary inorganic compound of berkelium and fluorine with the chemical formula .

Synthesis
The compound can be prepared by treating  with a gaseous mixture of  and HF at 600 °C.

Physical properties
Berkelium trifluoride forms a yellow-green solid with two structures. At low temperature, it is orthorhombic ( structure), with lattice parameters a  = 670  pm, b = 709 pm, and c = 441 pm. At high temperature, it is trigonal ( structure), with lattice parameters a = 697 pm and c = 714 pm. The transition temperature of  is between 350 and 600 °C.

Chemical properties
Berkelium trifluoride is reduced by lithium to obtain metallic berkelium:

References

Fluorides
Berkelium compounds
Actinide halides
Pamireddy Pitchi Reddy. P.P. Reddy is an Indian industrialist and executive chairman of Megha Engineering and Infrastructures Limited (MEIL). As per the report of Forbes, He is one of the richest persons in Hyderabad, India.

Life and career
P.P. Reddy was born into a farmer family in 1957 in Dokiparru village, Krishna district, Andhra Pradesh, India.

P.P. Reddy founded Megha Engineering Enterprises in 1989 with his two staff in Balanagar, Medchal district, Hyderabad to construct tiny pipes for municipalities.

In 2006, he changed the company's name from "Megha Engineering Enterprises" to "Megha Engineering and Infrastructure Limited (MEIL)".

2019 saw the start of the construction of Telangana's largest lift irrigation project by value, which Reddy and his business MEIL are building.

Reddy oversees the company's operations in renewable energy, irrigation, power, and water supply under MEIL. He acquired assets to enter the defense industry and launch ventures abroad in Bangladesh, Jordan, Tanzania, Zambia, and Kuwait.

Philanthrophic Work
Reddy adopted his birthplace of Dokiparru in the Gudlavalleru Mandal, where he established the first free, solar-powered program for clean drinking water in the nation. The project's construction cost Rs 4 crore. Additionally, he pledged to build a hospital and school for the neighborhood. In addition to Dokiparru, Reddy has welcomed many more villages.

Reddy had previously settled at Jamulapalle, a village in the East Godavari district's Pithapuram mandal. Even a mineral water factory was built to offer the inhabitants access to clean drinking water. As part of the Swachh Bharat campaign, he took up cleaning and hygienic duties in numerous communities. He also built a wedding ceremony hall in Jamulapalli.

Additionally, Reddy built the Oncology Center at the NIMS Hospital in Hyderabad, equipped it with contemporary amenities, and offered free meals at the Osmania, Niloufer, and MNJ cancer hospitals.

Personal life
Reddy is married to Rama Reddy, and the couple has two daughters, Manjali and Megha. Rama Reddy Pamireddy is one of the directors of MEIL.

References

Living people
Indian billionaires
Indian chairpersons of corporations
Businesspeople from Andhra Pradesh
Year of birth missing (living people)
Polestar 4. The Polestar 4 is a battery electric compact luxury crossover SUV marketed by Polestar, an affiliate of Geely Holding and Volvo Cars, since 2023. The vehicle is manufactured by Geely Holding in a factory in Hangzhou Bay, China. The 4 is the third vehicle to use the rear- and all-wheel drive based platform, Sustainable Experience Architecture. The vehicle is marketed as a coupe SUV that went into production in November 2023 and has two powertrain options.

Overview 
The vehicle was unveiled in April 2023 at the 2023 Auto Shanghai, as part of Geely's new SEA platform, where it underpins primarily battery electric vehicles, such as the Zeekr X and the Polestar 5. Positioned between the smaller Polestar 2 compact executive liftback and the larger Polestar 3 mid-size luxury crossover, it belongs to the British D-segment size segmentation. Having no rear window, it instead showcases a roof-mounted camera system. Polestar claims it is the fastest production car the brand has made, accelerating from  in 3.8 seconds.

The 4 is a two-row coupe crossover, that has a choice of the rear-wheel drive model where the motor is placed at the rear axle, or the performance all-wheel drive model where the motors are placed at both the front and rear axles.

The vehicle is to be available in Europe, North America and the Asia-Pacific from 2024.

Equipment 
Standard equipment includes the 15.4-inch landscape touchscreen which consists of the Android Automotive, which is used on the Polestar 2. A 10.2-inch digital instrument cluster, and a 14.7-inch head-up display come standard. A full-length glass roof, and a digital rear-vision mirror are available, and interior, which according to Polestar, is made from 100 per cent recycled polyester. The 4 will feature 20- to 22-inch wheels, depending on the trim chosen.

Powertrain 
The 4 consists of 2 models, the Single Motor RWD, and the Dual Motor AWD. The Single Motor generates  and , with a top speed of  and a  of 7.4 seconds. The Dual Motor generates a combined output of  and  using both of its motor, with a top speed of  and a  of 3.8 seconds. Both models use a 400V, 102 kWh lithium nickel manganese cobalt battery.

Charging

References 

Compact sport utility vehicles
Luxury crossover sport utility vehicles
Production electric cars
2020s cars
Cars introduced in 2023
Cars of China
4
H&R (company). H&R Spezialfedern GmbH & Co KG (English: H&R Special Springs, LP) is a German company that specializes in the development and production of suspension and chassis systems for the automotive industry and for motorsport applications.

History 
The company was founded in 1980 by Werner Heine and Heinrich Remmen with the purpose of making aftermarket suspension for lowering road cars. The family-owned business began designing, manufacturing, and producing springs that would effectively lower a car and give it enhanced performance, handling, and aesthetics.

H&R was the first manufacturer to submit a lowering spring to the Technischer Überwachungsverein certification body, and helped pioneer the aftermarket spring industry in Europe. The early effort by the company led to gaining a TÜV certification for its products, which it continues to meet. With this spearheading approach of H&R springs, the viability of aftermarket lowering springs in Germany was proven, thus launching a new market for Germany and Europe. H&R later also achieved the Allgemeine Betriebs Erlaubnis (ABE) certification in 1993.

Since the beginning, H&R products are wholly designed and manufactured in Germany. The company focuses on exceeding ISO quality assurance standards in production.

Company 

In the present day, H&R produces multiple spring lines, cup kits, coilovers, ETS electronic lowering modules, VTF adjustable lowering springs, race springs, sport sway bars, and various accessories. H&R also has the largest wheel spacer and adapter program in the industry. The company currently produces over 48,500 products for over 4,000 vehicles from over 60 brands.

The company has officially partnered with car manufacturers such as Volkswagen and Ford to produce specially modified demo vehicles for motor shows such as the Essen Motor Show and SEMA Show.

H&R has also partnered in original equipment applications, such as by partnering with Volkswagen to produce the springs for all Golf R32 models.

Motorsport 

H&R also has extensive research and development through motorsport usage, with its products being used in various forms of sports car racing and touring car racing. The company has produced suspension and chassis components for race applications on manufacturers such as Porsche, BMW, and Duqueine. H&R has both sponsored teams and entered their own works teams in the IMSA SportsCar Championship, IMSA Prototype Challenge, Nürburgring Endurance Series, and 24 Hours of Daytona.

References

External links 

Auto parts suppliers of Germany
Automotive motorsports and performance companies
Shock absorber manufacturers
1980 establishments in West Germany
German brands
German companies established in 1980
Manufacturing companies established in 1980
Companies based in North Rhine-Westphalia
Jinyun Zhang. Jinyun Zhang is an electrical engineer whose work has included wireless networks, sensor networks, ultra-wideband networks, multi-hop routing, and network broadcasting. Originally from China, she was a doctoral student in Canada and works in the US, as a vice president and director at Mitsubishi Electric Research Laboratories in Cambridge, Massachusetts.

Education and career
Zhang has a bachelor's degree in radio electronics from Tsinghua University in China, and taught as a lecturer at Tsinghua University until 1985. She went to the University of Ottawa in Canada for doctoral study in electrical engineering, and completed her Ph.D. there in 1991.

Next, she worked for ten years in Canada at Nortel. She moved from there to the US and to Mitsubishi Electric Research Laboratories in 2001.

Recognition
Zhang was named an IEEE Fellow in 2008, as a member of the IEEE Communications Society, "for contributions to broadband wireless transmission and networking technology". She is also a Fellow of the Mitsubishi Electric Research Laboratories.

Personal life
Zhang has a daughter, Lan Yang, who also studied electrical engineering at the University of Ottawa, earning a master's degree there in 2005.

References

Year of birth missing (living people)
Living people
Electrical engineers
Tsinghua University alumni
Academic staff of Tsinghua University
University of Ottawa alumni
Nortel employees
Mitsubishi Electric people
Fellows of the IEEE
Chinese women engineers
Canadian women engineers
Trofimov Reaction. In organic chemistry, the Trofimov Reaction is a reaction used to synthesize [2,3] disubstituted pyrroles from ketoximes and acetylene using the superbase medium potassium hydroxide and dimethyl sulfoxide. The reaction is named after Boris Trofimov who first reported it in the 1970's.

Mechanism

The mechanism begins with the deprotonation of the ketoxime by potassium hydroxide. The negative charge on the oxygen can then attack the acetylene. This forms the O-vinylketoxime which can tautomerize to a vinyl hydroxylamine. The molecule then undergoes a [3,3]-sigmatropic rearrangement to from an aldehyde-imine intermediate. The lone pair on the imine can then attack the carbonyl. Water is then lost forming an alkene. The final pyrrole is then formed by a [1,3] sigmatropic rearrangement.

Synthetic Applications
The Trofimov reaction is a powerful reaction for building pyrroles in total synthesis. The starting ketoxime can be prepared simply by condensing hydroxylamine on a ketone. Starting from a ketone allows for a wide range of starting materials as ketones are one of the most common functional groups in organic chemistry. The condensation reaction can be shown below:
After the condensation, the pyrrole formation can proceed as normal.

The Trofimov reaction can produce both N-H and N-vinyl pyrroles depending on the reaction conditions used. The N-vinyl pyrrole can be formed by the deprotonation of the pyrrole nitrogen which then attacks a second acetylene molecule. In general, higher temperatures, pressures, and higher concentrations of base favor the formation of the N-vinyl product.

Examples 
The Trofimov reaction was used to build N-vinylpyrrolocholestene. Starting from 5-Cholesten-3-one, hydroxylamine was condensed onto the ketone, forming the intermediate ketoxime. The ketoxime was then reacted with KOH and acetylene in DMSO at high temperature and pressure. Only one regioisomer was observed. In this case, the reaction conditions were sufficient to form the N-vinyl pyrrole2-mesityl-3-methylpyrrole was synthesized in 2004 via the Trofimov reaction. The reaction of the ketoxime with acetylene yielded a mixture of products with the primary one being the N-H pyrrole. Small amounts of the N-vinyl product were also observed as well as O-vinylketoxime. The N-vinyl product was then used in the synthesis of a new BODIPY.

Variations
In 2005 a version of the Trofimov reaction was reported where both the hydroxylamine condensation and pyrrole formation occur in one pot. This variation uses the hydroxylamine HCl salt rather than hydroxylamine and sodium bicarbonate to perform the condensation onto a ketone. After the condensation, the reaction is warmed to 100 °C and the atmosphere in the flask is changed to acetylene. KOH is then added to form the pyrrole.

References
Simon de la Bretèche. Simon de la Bretèche  (7 August 1982 – 12 April 2022) was a pilot, aeronautical engineer and international aerobatic competitor.

Biography 
Simon spent his youth in Ancinnes, Sarthe. He made his debut in aeronautics at the age of 14 at the Aéroclub d'Alençon to which he will always remain attached. Then, he trained in aerobatics at the regional aeroclub of Caen with his instructor/mentor: Patrick Gigot. In 2005, he obtained a Master of Science degree in aeronautics from the Institut polytechnique des sciences avancées. He then worked in Toulouse for Sogeclair Aerospace, an Airbus subcontractor.

In May 2020, he was hired by the company Aura Aero as an engineer to work on an aerobatic plane called Integral R. He died with his colleague and friend Baptiste Vignes following the crash of a prototype of this plane at during a test flight. The BEA-É released an investigation report. A judicial investigation by the Ariège gendarmerie group and the air transport gendarmerie. is still underway.

Achievements

With the french national team

Individual

References 

1982 births
2022 deaths
Aerobatic pilots
Institut Polytechnique des Sciences Avancées alumni
Sportspeople from Le Mans
Victims of aviation accidents or incidents in 2022
Victims of aviation accidents or incidents in France
Aviators killed in aviation accidents or incidents in France
AVIC AC332. The AVIC AC332 is a Chinese civil helicopter that is under development by the Aviation Industry Corporation of China (AVIC). The AC 332's chief designer at AVIC is Li Shengwei. The aircraft is intended to be type certified for production.

The design prototype had its first flight on 7 April 2023.

The AC332 designation was previously applied to an unrelated project for a scaled down version of the Russian Mil Mi-26 that was to have first flown in 2032.

Design and development
The aircraft is intended as a utility helicopter for personnel transport, search and rescue and law enforcement, including high density altitude operations. The design features a single, four-bladed main rotor, a fenestron tail rotor, twin engines, an enclosed cabin and skid-type landing gear.

The design has seating for two crew members and ten passengers. It is expected to have a lower price than comparable western helicopters.

The aircraft has a gross weight of , a maximum cruising speed of , a service ceiling of  and a range of . Maximum take-off altitude is .

The prototype was first flown on 7 April 2021 and type certification is forecast to be completed in 2025.

Aviation writer Mark Huber described the design as "stylistically a cross between the Bell 429 and the Airbus H145".

Operators
In April 2023, the company reported that it had orders for 24 aircraft, including six for an aircraft leasing company based in Xiamen and 18 for a consortium of Chinese general aviation operators.

Specifications (AC332)

See also

References

AC332
2020s Chinese helicopters
2020s Chinese civil aircraft
Twin-engined aircraft
Aircraft first flown in 2023
Lewis Tunnicliffe. Lewis Tunnicliffe is an Atlanta-based product design and development manager at Birla Carbon, who has been recognized internationally for his scientific research in the area of carbon black filler applications to elastomers.

Early life 
Tunnicliffe is originally from the West Midlands in Staffordshire, England and grew up in the small village of Haughton.

Education 
Tunnicliffe earned a BS in chemistry at the University of Durham in 2005. He then worked in industry for three years, returning to graduate school and completing a Ph.D. in 2015 at Queen Mary University of London under advisors James Busfield and Alan G. Thomas.

Career 

Tunnicliffe's first position following his undergraduate degree was with Sibelco Europe as a research scientist. He joined Birla Carbon in February 2016 as a materials scientist. He currently heads a product design and development group at Birla.  Tunnicliffe won a grant from USDA to investigate the application of cellulose nanoparticles in tires.

His most cited academic work produced a method for simultaneous dielectric/dynamic mechanical characterization of a filled elastomer. The technique produces information about the presence of dipoles on the polymer-filler interface, useful in understanding origins of the Mullins and Payne effects. He has also characterized the size distribution of crack precursors in carbon black filled rubber.

Awards and recognition
 2011 - James S. Walker award from Institute of Materials, Minerals and Mining
 2013 - Best Young Scientist award from Tire Technology International.
 2023 - Sparks–Thomas award from the ACS Rubber Division.

References 

Polymer scientists and engineers
Living people
Year of birth missing (living people)
Alumni of Queen Mary University of London
Catuscia Palamidessi. Catuscia Palamidessi (born 1959) is a computer scientist whose research topics have included differential privacy, location obfuscation, fairness in machine learning, the logic of concurrent systems, and the design of programming languages that combine logic programming and functional programming. Originally from Italy, she has worked in Italy, the US, and France, where she is a director of research for the French Institute for Research in Computer Science and Automation (Inria).

Education and career
Palamidessi was born in 1959 in Fucecchio, a small village in Tuscany, and when she began her studies at the University of Pisa, despite the discouragement of her parents, she became the first woman from that village to go to a university. Continuing her studies there, she earned a laurea in 1982 and a Ph.D. in 1988, with Giorgio Levi as her doctoral advisor.

She was an assistant professor at the University of Pisa from 1988 to 1992, an associate professor at the University of Genoa from 1992 to 1994, and a full professor at Genoa from 1994 to 1997. From 1998 to 2002 she worked as a professor at Pennsylvania State University in the US, and in 2002 she and her husband moved together to France as directors of research at Inria. At Inria, she is the leader of the Comète team, based at Paris-Saclay University, focused on formal methods in computer security and privacy.

Recognition
In 2022, Palamidessi was awarded the .

Personal life
Palamidessi is married to Dale Miller, an American computer scientist who also works at Inria Saclay.

References

External links
Home page

Living people
Italian computer scientists
Italian women computer scientists
University of Pisa alumni
Academic staff of the University of Pisa
Academic staff of the University of Genoa
Pennsylvania State University faculty
1959 births