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EARTHQUAKE RESISTANCE STRUCTURES AND THEIR IMPORTANCE

It’s not just about buildings. Many non-structural measures are needed to ensure survivability in earthquakes. Appliances such as televisions, microwaves, hot water boilers, and refrigerators (which do not always exist in Nepalese homes) must be securely fastened to the floors and the walls. Otherwise, they move and topple, killing as readily as building collapse. Even in affluent earthquake-prone locations such as New Zealand and California, we see shockingly low rates of households enacting these basic measures.

These efforts saved hundreds of lives, if not more, during the recent tremors. With a few more decades, a mere instant in geological time, they could have made Nepal comparatively safe from earthquake disasters despite earthquakes. In that time, so many more buildings would have been retrofitted, we might have had adequate building code enforcement, and most importantly, an earthquake-educated and vulnerability-educated generation would have started to take power.

In light of the fact that it remains impossible to accurately predict earthquakes, Mr. Barbat made the following observation: "Buildings are the structures where most risk is concentrated. When an earthquake strikes an urban area, most losses -- meaning both the loss of human life and economic, cultural and social losses -- are caused by the deficient seismic behavior of buildings." The immediate conclusion that can be drawn from all this is the need to design earthquake-resistant structures.

New techniques The vibrations produced by strong earthquakes can cause serious damage to structural elements. As a general rule, structures hold up due to their strength, their capacity to withstand deformation and their ability to dissipate energy. In conventional design, beams become deformed, are damaged or even break in order to prevent buildings from collapsing. As an alternative to this practice, a new design philosophy known as vibration control has emerged.

In civil engineering, this is an area of knowledge that treats structures as dynamic systems -- that is, as systems subject to external actions that, over the course of their useful lives, respond by exhibiting particular behaviors. These actions often take the form of undesired agitation that causes movements in the structure that should be reduced in the most appropriate manner possible. "In the case of earthquakes specifically, the external action is the movement of the ground, and the dynamic system or structure tends to be a building," explained José Rodellar, director of the Control, Dynamics and Applications research group in the Department of Applied Mathematics III at the UPC-Barcelona Tech.

"In essence," Mr. Rodellar continued, "the idea is to consider the structure as a 'living' system that is subjected to agitations. We are interested in connecting some sort of additional mechanism to the structure in order to improve its behavior and strength in the event of an earthquake."

The first alternative is to use passive control systems such as base isolators or energy dissipators -- that is, to retrofit the structure with devices that will absorb some energy in the event of an earthquake. Today, the most mature and widely used technology is base isolation, which consists in adding special supports that decouple the movement of the structure's base from the movement of the ground. A flexible device is installed that allows the base to move. The friction that this causes dissipates some of the energy that would otherwise directly enter the structure. Another system is to support the structure on flexible elements made from materials such as neoprene. In this method, the deformation of the support elements is what allows the base to move.

Eergy-dissipation systems essentially consist of dampers placed at the joints between structural elements -- for example, where beams meet diagonal supports. During an earthquake, these devices, made from very weak steel, may undergo plastic deformation or even break, but only in very specific, predefined areas of the building.

The ain advantages of these control systems are their simplicity, the possibility of replacing them if they age or break, and the fact that they do not require an external energy source, since they work by reacting to the movement of the structure. Nevertheless, when the force of an earthquake exceeds a certain magnitude, the limitations of these systems become clear.

Another alternative is to employ an active control system, which is designed to apply a force that counteracts that of the earthquake. Active systems differ from passive systems in that they apply force to the structure by means of a real-time process. A series of sensors begin by measuring the structure's response (displacement, velocity and acceleration). The measurements are digitized and sent to a computer that carries out a control algorithm. This algorithm calculates the value of the necessary displacement and governs the mechanism of the actuators, which transform the signal into effective force. Active systems have great potential but are difficult to implement in practice. The main difficulty is a technological one, having to do with the way in which forces can be applied to large structures such as buildings.

This is why much of the research in the field is focused on developing semi-active strategies.

This intermediate line of work consists in designing passive control devices whose characteristics, rather than being fixed at the time of their construction, can be adjusted by a controller in real time on the basis of the structure's response, as measured by the sensors.

Smart materials

Smart materials are materials that respond to specific external stimuli and carry out particular functions as a result of their intrinsic properties. These materials have had a major impact on the field of vibration control.

For example, electrorheological or magnetorheological materials are fluids that can change very quickly, in milliseconds, from liquid to solid (and vice versa) when exposed to an electrical or magnetic field. Magnetorheological fluids contain suspended magnetic particles that are distributed randomly. When an electrical or magnetic field is applied, these particles realign themselves, thereby increasing the material's resistance to vibrations and making it less likely to be deformed in the direction in which the particles are aligned. These characteristics make magnetorheological fluids appropriate for use in the design of semi-active control devices, especially dampers containing these fluids.

Smart materials are most frequently used to absorb vibrations in vehicle suspensions. Attempts are being made to transfer this technology to civil engineering, where it has thus far only been used experimentally. The remaining challenge is to engineer a way to automatically modify the voltage required to cause changes in the properties of the materials, with a view to achieving a rapid, effective and lasting response. As a result, a recent line of research has focused on the design of devices, mathematical modeling and the formulation of algorithms.

[aisher-e]

How the fight for profit can delay the making of an antivirus

As most of us are stuck are in home with a downward economy at his path anticipating for a global release for a vaccine.here is another reason why it can delay to reach among the midst of commoners.

  On the same day, in a rare bit of good news, the US National Institute of Allergy and Infectious Diseases (NIAID) announced it had already received the first candidate for a vaccine against the novel virus, now being called Sars-CoV-2 – produced by a company called Moderna – and that trials could begin as early as April. Anthony Fauci, the institute’s director, said that just three months between discovery and trials was a new record, noting that “nothing has ever gone that fast”, before dropping the other shoe: even with the rapid start, completing the trials and scaling up production would take until at least next year, and there was no guarantee it would even get to that stage.

Vaccines remain science’s best – and virtually only – weapon against viruses, and yet the timeline for developing a vaccine, measured in years, seems hopelessly mismatched to a pandemic, which can spread, kill and often disappear in a matter of weeks or months. The modern record doesn’t inspire much confidence. There have been multiple international viral outbreaks over the past two decades – Sars-CoV-1, Mers, Zika, Ebola – that all provoked similar races to produce a vaccine. Yet to date only the efforts on Ebola have been successful, with a vaccine being approved last year.

Why is this? Vaccines for epidemics have to overcome the same scientific and regulatory hurdles as other promising treatments, but they also suffer from a near total lack of interest from the markets that drive the pharmaceutical industry. Only a few massive companies retain the ability to develop and produce a vaccine from start to finish, partly because of the expense and the timescales involved and partly because they’ve consolidated the patents on manufacturing processes – a situation analysts openly call an oligopoly. A success for one of these companies is a treatment for a widespread, persistent disease that they can sell every single year in perpetuity. The last industry blockbuster was Merck’s HPV vaccine Gardasil, in development for nearly 20 years, released in 2006, and still bringing in over £1bn annually. There is no way to easily apply their slow-burn research and profit model to an epidemic. As the leader of the UK’s Ebola response, Adrian Hill, told the Independent in 2014, “Unless there’s a big market it’s not worth the while of a mega-company … There was no business case to make an Ebola vaccine for the people who needed it most.”

The current setup is often the worst of both worlds – too slow to pick up research on new threats because the money isn’t there, and too quick to drop it if it can’t be sure the money will be there in the future. It’s a highly market-dependent system, and the market usually fails us. Peter Piot, head of the London School of Hygiene and Tropical Medicine, previously declared the entire research and development system “not fit for purpose” for epidemics.

The question is, how can we fix it? The quick delivery of the first Sars-CoV-2 vaccine candidate suggests that some recent efforts are paying off. The Moderna vaccine is in part backed by the Coalition for Epidemic Preparedness Innovations (CEPI), an organisation based in Norway and funded by governments and foundations such as the Welcome Trust. Its goal is to keep research attention on potentially epidemic diseases, even when there isn’t an outbreak, and to develop broader treatments it calls “platforms” that could be tailored to multiple virus variants. For example, the vaccine sent to NIAID is RNA-based, making it far easier to customise and faster to produce than traditional protein-based vaccines. And CEPI was already funding a DNA-based vaccine for another coronavirus, as well as a platform to block viral cell entry, that it hopes to quickly adapt to Sars-CoV-2.

These kinds of programmes can maintain long-term vision and planning, foster international collaboration and supercharge vaccine research – but they still can’t deliver a vaccine at pandemic scale, because the biotech firms and universities they work with are simply too small, working on the order of millions of doses.

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REVIEW of Harper Lee’s To Kill a Mockingbird

The narrator of the book is Scout (Jean Louise) Finch, who is discussing childhood events with her adult brother, Jem, as the story begins. She then slips effortlessly into the role of the six-year-old tomboy who matures over the three years of the book’s action. In the first half of the novel, Scout and Jem, along with their childhood companion, Dill, are fascinated by their mysterious neighbor, Boo (Arthur) Radley. Because no one has seen Boo in many years, the youngsters construct a gothic stereotype of him, imagining him as huge and ugly, a monster who dines on raw squirrels, sports a jagged scar, and has rotten yellowing teeth and bulging eyes. They make plans to lure Boo from his “castle” (in reality the dark, shuttered Radley house), but in the course of their attempts to breach the boundaries of his life, they begin to discover the real Boo, an extremely shy man who has attempted to reach out to the children in a number of ways, and who, in the final chapters of the book, saves their lives.

Throughout both sections of To Kill a Mockingbird Lee skillfully shows other divisions among people and how these barriers are threatened. Obviously, it is not a matter of race alone that sets societal patterns in their provincial Alabama town. For example, when Atticus’s sister, Alexandria, visits the family, she makes it clear that she is displeased by Scout’s tomboyish appearance, since she feels a future “southern belle” should be interested in more ladylike clothing and more feminine behavior. Furthermore, as Jem tells Scout later, there is a strict caste system in Maycomb, with each group threatened by any possible abridgements of the social order. As Jem suggests, there are the “old” families—the gentry, who are usually educated, frequently professional, but, given the era, often cash-poor. On the next level down are the “poor but proud” people, such as the Cunninghams. They are country folk who pay their bills with crops and adamantly refuse all charity. Beneath them is the group commonly called “poor white trash,” amply represented by Bob Ewell, “the only man ever fired by the WPA for laziness,” and his pitiful daughter Mayella, the supposed victim of the rape. At the lowest rung of the social ladder are African Americans, although many are clearly superior to some of the poor white trash, who have only their skin color as their badge of superiority. They are represented by Tom Robinson, the accused rapist, and Calpurnia, the housekeeper for the motherless Finch family.

In addition to the clearly defined social castes, there are deviants, such as Dolphus Raymond, a white man involved in a long relationship with a black woman. He pretends to be an alcoholic to “give himself an excuse with the community” for his lifestyle. There is Mrs. Henry Lafayette Dubose, a member of the upper class who became a morphine addict, whose one desire is to overcome her habit before her death. Also featured is Miss Maudie, the friendly neighbor who seems to represent, along with Atticus, the best hope for change in the community.

[aisher-e]

Review of the film ‘The Lighthouse’

 I wouldn’t necessarily qualify The Lighthouse as a total departure from his previously established style, as there’s a definitely a shared DNA between his works. Thematically, cosmic horror remains a big focus of Eggers’, as the all-consuming “light” that drives lighthouse keepers mad with its revelations of… well, whatever, is alluring and creepy in the same way that Satan’s grasp was in The Witch. There’s a creepy-ass animal, as well, though this film’s seagulls don’t have, say, the Funko POP marketability that Black Philip did. The emphasis on preserving long-dormant aspects of New England culture manifests itself in plenty of ways, especially within the shanties and slang that Dafoe’s character peppers his often incomprehensible speech. Once again, it rewards you with what you bring to it, especially in how it colors your perceptions of its ending, though some may accuse Eggers of being purposefully abstract to conceal a perfunctory or absent meaning.

I still haven’t totally come down on whether or not the film has a greater point or if it is simply content with being a functional old school surrealist depiction of madness, but I’m looking forward to discovering more on a second viewing. And, depending on where you stand, it’s “elevated” genre, though the film itself works without the pretension that often defines others of its ilk. It’s sort of the anti-Midsommar, and given that A24 themselves want to stress that Eggers and Ari Aster are on equal footing, the comparison is invited and is found suitably lacking. 

But most notably, the tone is totally different, as the tragedy of his first film is fully replaced in The Lighthouse by a pitch-black and often uproariously funny comedy, which the slow burn serves just as well as the corruption (or liberation) of Thomasin did. It cannot be stressed just how wacky this incredibly goofy movie is, with Pattinson and Dafoe both playing into the patent ridiculousness of their characters and their individual variations on drunken madness. It perfectly clashes with the photography It’s also refreshing, oddly, to see just how low-brow Eggers is willing to go with his gags as well. There are copious amounts of fart jokes, a memorable piss-and-shit gag plucked from The Big Lebowski (think Folgers, not living room decor), and a series of monologues by Dafoe that are so ridiculous and pitch-perfect that it’s hard not to imagine him getting some sort of recognition for them.

The Lighthouse really feels like it shouldn’t exist as it does, as this movie is just so wild and out there that it’s hard to believe it’s getting pushed to as many theaters as it will. At points, it almost seems like Eggers and his co-writer decided to just write out a lengthy sea-themed “and then” improv session, and did a bunch of research and work around it to obscure its origins. It is buckwild and vivid, funny and freaky. These are all good attributes to have, as more directors with the kind of newfound clout that Eggers has should use their power to push out their wildest fantasies to as broad an audience as possible.