Nano, nano; we’re hearing that morkish prefix a lot these days. It means 10-9 of something: most often, of meters (see powers of ten). A nanometer is a billionth of a meter. This gets down into the range of protein molecules and small cellular components. A DNA molecule, for instance, is about 20 nanometers across; an ATP synthase rotary motor is about 8 x 12 nanometers, and a bacterial flagellum about 10 times larger. Now that imaging technology is reaching into realms of just a few nanometers, scientists are keen to understand nature’s engineering in hopes of doing their own. The premiere issue of Nature Nanotechnology made its debut this month.1 It contains a centerpiece review article by Wesley R. Browne and Ben L. Feringa entitled, “Making molecular machines work.”2 Though the article focuses on human progress and potential in the world of nanotechnology, it contains numerous ecstasies about biological machines unmade by human hands:Consider a world composed of nanometre-sized factories and self-repairing molecular machines where complex and responsive processes operate under exquisite control; where translational and rotational movement is directed with precision; a nano-world fuelled by chemical and light energy. What images come to mind? The fantastical universes described in the science fiction of Asimov and his contemporaries? To a scientist, perhaps the ‘simple’ cell springs more easily to mind with its intricate arrangement of organelles and enzymatic systems fuelled by solar energy (as in photosynthetic systems) or by the chemical energy stored in the molecular bonds of nucleotide triphosphates (for example, ATP).Biological motors convert chemical energy to effect stepwise linear or rotary motion, and are essential in controlling and performing a wide variety of biological functions. Linear motor proteins are central to many biological processes including muscle contraction, intracellular transport and signal transduction, and ATP synthase, a genuine molecular rotary motor, is involved in the synthesis and hydrolysis of ATP. Other fascinating examples include membrane translocation proteins, the flagella motor that enables bacterial movement and proteins that can entrap and release guests through chemomechanical motion.Whereas nature is capable of maintaining and repairing damaged molecular systems, such complex repair mechanisms are beyond the capabilities of current nanotechnology.In designing motors at the molecular level, random thermal brownian motion must therefore be taken into consideration. Indeed, nature uses the concept of the brownian ratchet to excellent effect in the action of linear and rotary protein motors. In contrast to ordinary motors, in which energy input induces motion, biological motors use energy to restrain brownian motion selectively. In a brownian ratchet system the random-molecular-level motion is harnessed to achieve net directional movement, and crucially the resulting biased change in the system is not reversed but progresses in a linear or rotary fashion.Biosystems frequently rely on ATP as their energy source, however very few examples of artificial motors that use exothermic chemical reactions to power unidirectional rotary motion have been reported to date.That biological motors perform work and are engaged in well-defined mechanical tasks such as muscle contraction or the transport of objects is apparent in all living systems.It is clear that the biological machines are inspiring the human drive toward exploiting the possibilities of mimicking, if not duplicating, what already exists in nature. They say in conclusion,The exquisite solutions nature has found to control molecular motion, evident in the fascinating biological linear and rotary motors, has served as a major source of inspiration for scientists to conceptualize, design and build – using a bottom-up approach – entirely synthetic molecular machines. The desire, ultimately, to construct and control molecular machines, fuels one of the great endeavours of contemporary science….….As complexity increases in these dynamic nanosystems, mastery of structure, function and communication across the traditional scientific boundaries will prove essential and indeed will serve to stimulate many areas of the synthetic, analytical and physical sciences. In view of the wide range of functions that biological motors play in nature and the role that macroscopic motors and machines play in daily life, the current limitation to the development and application of synthetic molecular machines and motors is perhaps only the imagination of the nanomotorists themselves.1Nature Nanotechnology, Vol. 1, No. 1, October 2006.2Wesley R. Browne and Ben L. Feringa, “Making molecular machines work,” Nature Nanotechnology, 1, pp25-35 (2006), doi:10.1038/nnano.2006.45.These superlatives call for an explanation: how did nature achieve this level of technology, a level our best scientists can only view with awe as they attempt to catch up, using their brightest intelligence applied to design? Here is the simplistic, hand-waving explanation. In what should have been a paper permeated with unadulterated intelligent design, both human and biological, they slipped into the old Darwinian bad habit. Get ready with your baloney breathalyzer.Understanding and harnessing such phenomenal biological systems provides a strong incentive to design active nanostructures that can operate as molecular machines, and although our current efforts to control motion at the molecular level may appear awkward compared with these natural systems, it should not be forgotten that nature has had a 4.5 billion year head start.This is bad breath caused by Dar-wine. No matter the object under consideration, from a nanoscopic rotary motor with near perfect efficiency to a narwhal’s antenna or a butterfly’s photonic crystals, Darwin-drunk researchers continue to ascribe these wonders to blind, aimless, materialistic processes. If nature’s advantage were merely a head start, then Nature Nanotechnology would do better to tell its researchers to close their labs, put on blindfolds, and wander aimlessly about, bumping into each other, till something interesting happens. As we wag our heads at the inebriation of scientists believing such things, let’s not forget what they said about biological machines. Those machines really do exist. They’re keeping you functioning. They’re enabling your brain to think. So think. Don’t try to drink and think, lest your breath stink and your common sense shrink.(Visited 221 times, 1 visits today)FacebookTwitterPinterestSave分享0
10 April 2015Kathu solar thermal plant, the latest solar plant to be constructed in sunny Northern Cape, will be built by engineering and construction group Sener and the infrastructure, renewable energy and services corporation Acciona.Together the two international companies form the consortium chosen to develop the Kathu turnkey project. The complex is led by GDF Suez, with South African partners comprising Sishen Iron Ore Company Community Development Trust, Investec Bank, Lereko Metier and Public Investment Corporation.It has been selected by the South African Department of Energy to form part of the country’s renewable energy development programme (REIPPP), with a forecast investment of more than €500-million (R6.4-billion).Kathu Solar Park, along with Redstone Solar Thermal Power, which will both build 100MW capacity, were the preferred bidders in the third round of the government’s REIPPPP, the department said.Concentrated solar thermal power is able to store solar power generated during daylight hours.Storage capacityKathu is a 100MW plant with parabolic troughs – specifically, the SenerTrough-2 system, designed and patented by Sener, and a thermal energy storage capacity of 4.5 hours, thanks to the use of molten salts. Located in the town of Kathu, near Upington, in Northern Cape Province, the plant will begin operations in 2018 and will be able to supply electricity to 80 000 homes.Because of the nature of the contract, Sener and Acciona will carry out the engineering, construction and commissioning of the entire facility. The building consortium will also use local suppliers, as the project is fully committed to contributing to the local community.It is the companies’ second solar thermal project in South Africa, the first being the Bokpoort plant in Upington, in which they also form part of the building consortium. It will be operational later this year. It is also a turnkey project that uses SenerTrough technology and a molten salt storage system.Kathu is near KaXu Solar One, the first solar thermal electricity plant in South Africa, which was formally opened by Ebrahim Patel, the economic development minister, on 2 March. KaXu, which means “open skies” in the loca Nama language, is outside Pofadder.Total investment in KaXu, the largest parabolic trough project in the southern hemisphere, was $891-million (R10.7-billion).International experienceThe international partners bring with them a wealth of experience. Sener has been involved in 29 solar plants, most of them turnkey projects, in Spain, the USA, South Africa, and Morocco. Together these represent an installed capacity of more than 2 000MW and carbon dioxide savings of more than one million tons annually.Some of its projects are technological milestones, such as Gemasolar and Valle 1 and Valle 2, in Spain, and the Noor complex in Morocco, where Sener also forms parts of the building consortium for Noor 1 and for the second phase (Noor 2 and Noor 3).Acciona is one of the world’s biggest renewable energy operators, and owns an installed capacity of 8 500MW. It is a turnkey provider of electricity generating facilities using wind, solar and photovoltaic technology. In solar thermal energy, it operates 315MW in the USA and Spain, and has built more than 12 plants. It is currently working on projects such as Noor 1 in Morocco and Bokpoort in South Africa.It has had a presence in South Africa since September 2012 through its energy and infrastructures divisions, working on three renewable energy projects:Sishen Solar Photovoltaic Plant: Acciona owns and operates the plant, which has the largest output of any plant of its type in Africa (214 gigawatt hours per year). The project is a joint venture with Aveng, Soul City and Dibeng Community Trust. It became operational in December 2014.Gouda Wind Farm: Acciona Energy, in partnership with Aveng, Soul City and Local Community Trust, is building the Gouda wind farm (138MW), its first wind farm in South Africa.Bokpoort Thermosolar Power Plant: Awarded to Acciona and its partners in June 2012, construction is expected to finish this year. The 50MW facility will use parabolic troughs and will have a molten salt energy storage system.Sener is a private engineering and technology group founded in Bilbao, Spain, in 1956. It was the first Spanish engineering company. Acciona is one of Spain’s largest corporations, operating in the fields of infrastructure, energy, water, and services in more than 30 countries.SAinfo reporter
Buoyed by the return of Niranjan Patnaik as president of the Odisha Pradesh Congress Committee along with three working presidents, the party has started gearing up for the next year’s simultaneous Lok Sabha and Assembly polls in the State.The Congress leaders are working overtime not only to retain their party’s number two position in the State by blocking the Bharatiya Janata Party but also to take on the ruling Biju Janata Dal in a big way. The saffron party had emerged number two in the Zilla Parishad elections in 2017.The new team of leaders has already initiated a series of measures to strengthen the party organisation at the grassroots level. In a recent meeting of district presidents, the party decided to dismantle block level committees and strengthen Zilla Parishad zones as new organisational blocks.At the end of the two-day deliberations, Mr. Patnaik has made it clear that those leaders who are working with the people in rural areas will be given tickets to contest the next elections. Indiscipline will not be tolerated in the party and leaders having grievances should raise the issue in party forum instead of going to the media, he has said.Mr. Patnaik, who has already appointed presidents and working presidents in as many as 28 of the 33 organisational districts, is now planning to organise massive rallies in all districts to galvanise the party workers up to the booth level. He along with the party in-charge of Odisha has also visited all districts to activate the district units.
The Uttar Pradesh Police’s Special Task Force (STF) on Friday arrested a notorious sharpshooter, who was allegedly planning to kill BJP MLA Sushil Singh, after a brief encounter in Varanasi, an official statement said. Shiv Prakash Tiwari alias Dhoni Tiwari was carrying a cash reward of ₹1 lakh on his head, it said. Following a tip off, Tiwari and two of his associates — Manish Kesarwani and Ajnana Singh — were arrested from Varanasi’s Cantt police station area, the STF statement said. During interrogation, Tiwari revealed he had come to Varanasi with his associates to kill Singh, the BJP MLA from Saiyadraja assembly constituency. His associates were doing a recce for it, the statement said. Tiwari was convicted in the sensational murder of Hindu Yuva Vahini leader Bishnu Dutt Ojha in 2011 in Basti district but was absconding, it said.