Post 322 ⇒   by Gautam Shah 


At a very elementary level a contract could be matter of intensely felt mutual faith, which is not necessarily expressed orally or spelt in writing. A contract is, yet a very formal document, that must be credible and legal. It is often mandatory to be registered with an appropriate authority, in terms of its date of signing, and in few instances even the contents. All contracts once signed, and registered or not, cannot be cancelled.

Joséphine, first wife of Napoleon, obtained the civil dissolution of her marriage under the Napoleonic Code of 1804.

Advantages of legal contracts are many. A legal contract makes it easier for the parties to register the document, enforce the terms and conditions as specified within the contract document, add, delete or modify the terms of contract, continue the contract beyond the lifespan or terms of the signatories (after death of a party), solve the disputes and discharge the relationship.

Contracts are promises that the law will enforce. The law provides remedies if a promise is breached or recognizes the performance of a promise as a duty.

Contracts arise when a duty is due, because of a promise was made by one of the parties. To be legally binding as a contract, a promise must be exchanged for adequate consideration. Adequate consideration is a benefit or detriment that a party receives. For example, promises that are purely gifts are not considered enforceable because for the personal satisfaction the grantor of the promise, ‘may receive’ is normally not a consideration.

Contracts are very formal and binding documents, which if once signed cannot be easily dissolved. Some contracts become void, after particular time set, others become useless once required actions are carried out, or considerations are given. Some contracts like marriage, and understandings like partnership, require execution of another contract or understanding to dissolve the original.

A contract may be discharged (done away, dissolved) in any of the following ways:

  • Performance: Contracting parties fully discharge their obligations.
  • Agreement: Contracting parties with mutual consent, and as per the terms laid down in a contract, agree to cancel, reduce, or alter, the effects of a contract. Such agreements take into consideration consequences of such actions.
  • Law: On judgement over a dispute, or bankruptcy (insolvency) of either of the parties.
  • Circumstances: Due to change in legislation (of higher order), and declared war like conditions.
  • Lapse of time: Most contracts have arrangement for automatic time closure specifications.
  • Breach of a contract: Intentionally or unintentionally either of the party fail to fulfil the obligations as per the contract and takes recourse to law for enforcement of a contract or redress.



Post 321 ⇒   by Gautam Shah 


A person possesses and occupies a place for inhabitation. This is simply a territorial spread, which when marked for its extent becomes a personal place in the universe. The personal place is the place-identity of the individual (or family). The terrain has been possessed, occupied, measured and identified because it has the potential of becoming a locus for behaviour. To turn the place into a meaningful entity its place identity is reinforced with a spatial character. The spatial features are conceived to satisfy biological, social, psychological and cultural needs.

Creek South New Caledonia

How an individual establishes a Role Locus (a stage) is one of the most important features of behavioural responses. A place has neighbours, no matter how few, and far apart. Possession and occupation of a place, immediately transforms into degree of social reactivity. One may not have any physical contact, may be just empathetic recognition. The social reactivity regulates the nature of interaction with others, privacy, degree of accessibility or isolation, as reflected in aloofness, loneliness, alienation, participation, leadership, devotion, cohabitation, etc.

Taos Pueblo, an ancient pueblo belonging to a Taos speaking Native American tribe of Pueblo people.

The place, once a wide and wild terrain, as soon as it is possessed, occupied, measured and identified, is marked. Markings that define a place are physical, like posts, signs, change of landscape, residues (food, ash, excreta, trash, pots, odours-enzymes) are intentionally left. A marked place has defined extent, by way of defined corners and edges. For a human being it is an intentional activity but many beings do it with intuition. Selection of a place often an irrational process, one cannot explain why, and how it actualised.

Three_chiefs and the territory

A place is given a spatial character. The place itself offers inherent possibilities in this regard. One begins to endow this with a set of purposes. A place has three essential qualities, A location value, as seen in the nature of its connections. The connections are due to both proximity and convergence of other places or neighbourhoods. The place has features like dimensions, orientations, environment, terrestrial character, amenities and facilities. It also includes associations that personalise the space, such as history, neighbours, precincts, etc. A place also has potential for improvisation due to pre-existing conditions.

Settlement Orkney Skara Brae

The spatial features once developed in a place create place attachment. The place attachment is due to the effort and rarity of opportunity. It soon turns into pride, awe, prestige, discipline, belief, fear, and legacy of personal values, attitudes, feelings and beliefs.

Shanty housing Hong Kong

A place attachment is an activity that endows one with knowledge how to handle the issues given another opportunity. The knowledge directly passes on from one to another generation or through the imprints.

Village in Rajasthan, India

  • Harold Proshansky, etc. of City University of New York have explored the concept of place identity as a ‘substructure of the self-identity of the person consisting of broadly conceived cognition about the physical world in which the individual lives’. Tuan (1980), Relph (1976) and Buttimer (1980), share a couple of basic assumptions. As a person lives and creates memories within a place, attachment is built and it is through one’s personal connection to a place, that he or she gains a sense of belonging and purpose, which then gives significance and meaning to their life.
  • ‘There is reciprocal interaction between people and their physical environment; people affect places, and places (and the way places are affected) influence how people see themselves’.
  • Casey (2001) states that identity is created both internally in the mind, and through the body’s interaction with the outside world -there is no place without self, and no self without place.

Gaza 2003


SOLVENTS and THINNERS for coatings

SOLVENTS and THINNERS for coatings

Post 320 ⇒   by Gautam Shah 


Thinners are specific mixtures of different solvents to achieve desired viscosity for the film forming constituents of a coating system. Solvents are liquids that have power of dissolving or formulation with something.

Viscosity of a medium can be adjusted by including a low viscosity medium into a high viscosity material, or by solvents and diluents. Solvents dissolve by entering the inter-molecular space and changing the intermolecular forces. Diluents are non dissolving low viscosity substances, do not enter the inter-molecular spaces but extend the action of a solvent as a liquid to liquid-phase. Often in a multi medium formulation, one material that acts as a solvent to a particular medium, may act as a dilutent for the other medium. Solvents and diluents both increase the fluidity of a medium.


Various thinning media for oil paint –by Ellywa – Own work. Licensed under CC BY-SA 4.0 via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Various_thinning_media_for_oil_paint

The solution of the film forming substances of a coating helps in manufacturing and application processes. Solvents or thinners are also required to clean up tools (brushes) and equipments (spray nozzles and containers) of application. These are also used for removal of patches, over-sprays and body parts.

Solvents convert resin and polymer molecules into smaller clusters, and it is a process of separating the molecules. In solution, the molecules of solute and the solvents are dispersed into each other.

Solvents on evaporation help in formation of a solid film. The coating may be deposited, and solvent evaporates to form a solid film (non-convertible system). Alternatively the coating undergoes one or many processes of chemical conversion (such as oxidation, chemical reaction on application of heat or catalyst reaction), while solvents get evaporated (convertible system).


Most solvents, including the most versatile one the water, evaporate at some temperature. There are two classes of solvents: Hydrocarbon (Petroleum) solvents and Chemical or oxygenated solvents, though these terms are overlapping due to complex process of manufacturing. Hydrocarbon solvents theoretically have only Carbon and Hydrogen but other substances such as Sulphur and heavy metals may be present as trace elements.

Coating formulations are in consideration of Solvents’ cost, flameability and the environmental effects. The solvent-power or solvency is very important aspect. The formulation must achieve a viscosity that is correct for manufacturing or application processes with a minimum amount of solvent. For a coating formulator, another important aspect is the rate of evaporation of solvent. If a solvent evaporates too rapidly, the applied coating will not get sufficient time to level out. Faster evaporation also induces early start for cross linking, and may seal the face, trapping part of the solvent. In spraying a fast evaporating solvent hinders even spray and may cause condensation of water around spraying nozzle and sprayed surface.

Thinners are mix of solvents and other carriers or non-solvent material. Thinners are formulated and proposed by the coating manufacturer, as competent authority they know what forms the coating. Often Thinners of different qualities are suggested such as for application and for cleaning of tools, equipments, patches and over-sprays. Some even provide specific thinners or special additives for monsoon seasons to counter effect of excess moisture and condensation.

For the later purpose, a well proportioned an economic blend of solvents and diluents, suitable for specific categories of coatings are marketed as Thinner or Reducer.

Hydrocarbon cracking Lab plant


Following categories of solvents are used in coatings:

  • Aliphatic hydrocarbons: white spirit (mineral turpentine), kerosene (superior and fuel grade)
  • Aromatic hydrocarbons: benzene, toluene, xylene
  • Alcohols: methanol, ethanol, butanol, isopropanol
  • Chlorinated hydrocarbons: carbon tetrachloride
  • Ketone: acetone, methyl ethyl ketone (MEK), methyl iso-butyl ketone
  • Esters: methyl acetate, ethyl acetate, butyl acetate
  • Ethers: methyl cellulose, cello-solve, cello-solve acetate
  • Terpene: turpentine (genuine), di-pentene, pine oils



Post 319 ⇒   by Gautam Shah 


Augmented Reality is enhancing or supplementing one’s current perception of reality. This is in contrast to virtual reality where the real world is replaced with a simulated one. Both have digital connection, today but even without it, they have been part of our experience in various measures for ages. Augmented reality (mainly with digital media) has its origins as early as the 1950s, and has progressed with virtual reality since then, but it’s most significant advanced have been since the mid 1990s.

Deadly Dustland Scorpion -animation and other effects

Realities have been augmented by altering the perception capacities through consumption of certain substances. The alteration was for both, dulling or diffusing and to enhance the perceptive faculties. Pain, diffusers, inducers, enhancer and bearers have been known. These augmentations were not rational or consistently predictable. Virtual reality was used as part of magic ceremonies, in religion and entertainment. Simulations were enforced through light and sound, as well as sleight of hand.

Drawn animation

In earlier days the play was interpreted by the interpreter or Sutradhar (conductor in Sanskrit). It could be simplistic language translation, elaboration of complex philosophical content, or bridging of time elements. These interventions augmented the reality being enacted, by compacting the time-space. In the bi-scope or silent movie era, the story and music were played live. Foreign language movies, TV plays, programmes and presentations, carry sub titles for translated dialogues or audio, video and textual augmentative effects.

Tickers on News TV augmenting information

Nominally augmentation occurs in real-time, and in one of the two basic frames, the context is rational or literal. It has till now a distinctive identity, where the additional information about the environment and its objects is overlaid or underlaid with reference to the base frame. But this differentiation is likely to diminish in near future.

a heavy-wheeled-vehicle driver simulator.

The augmented reality is going a step further by including zoom-in and out effects to show respectively details and overall perspective views. This is further augmented by use of wider scope and panoramic views. The usual experience with glass-based lenses, of the differential clarity between foreground and background can be eliminated with use of charged couple devices.

Augmented reality in Smart Phones

Variety of devices, such as mobiles, i-pads, computers, wrist watches, etc. use computer-generated sounds, graphics or video clips for additional information about products, spaces and places. Currently these are the compilations as offered by the device manufacturer, or application providers. Many of these manifest as customised offers, but none recognises the changing needs or moods. Artificial intelligence will automatically figure out the behaviour of the subject (the user), and accordingly augment the experience of reality.

Total Immersion Augmented Reality

A person may not dwell in a real world all the time. One occasionally needs to visit the virtual or simulated domain, like architectural 3D renderings, and see how it functions with the augmented reality. Here the virtual reality is augmented with all the sensorial experiences. Typical of this are the echoes and reverberation effects as one walks through the rendered space. This may not come first to architecture, but has begun to enter the games, sports and other learning simulators. The subject gets the vibrations, shocks, and other touch-feel effects. In medical surgeries a surgeon, can practice the procedure, as if on a live being rather then on a cadaver (dead body).

Google Glasses

The chief sensorial experience that constructs reality is the visual perception. A smart eye glass or contact lens can be overlaid with not only textual and graphics information, but can ‘scope’ the view by selective zoom-in-out. It can also have night vision or selective spectrum vision. Artificial Intelligence will be able to prejudge the nature of support required by the subject, and tailor the augmented reality.

Oculus Rift

It is expected that augmented reality and virtual reality will converge. It will come as soon as when an interface begins to interact with our perception faculties.




Post 318 ⇒   by Gautam Shah 


Architectural history is full of different forms of windows. Of these three forms have matured over the ages to reach level of classical antiquity. These are Palladian window (16th to 18th C), Rose window (17th to 19th C) and Colonial Georgian sash window (1720 to 1830). All three windows have different size, shape, form, purpose, placement and related architectural styles.


Galleria Vittorio Emanuele


Palladian opening is a three-part window. The central circular arched gap is supported by columns, which are offset from the wall thus creating two smaller width gaps on sides. Smaller side openings are flat headed. The window form is also called Serliana or Serlian motif from its originator Sebastiano Serlio (1475–1554) an Italian Mannerist architect, theorist and painter, who published a treatise as Serlio’s L’Architettura (1537–75) to introduce the principles of ancient Roman architecture into France. The triple window form was refined and used by architect Andrea Palladio in the Venice region. So, it is also known as the Venetian window.

Palazzo Te Mantova

A Palladian window is a classical, well proportioned and symmetrical architectural entity that is used as a window as well as a motif. A Palladian motif is placed as a decoration, window, door-window combination and simply as gap in an exterior passage or as part of a colonnade, such as in Basilica Vicenza, Italy. Palladian motifs were placed on the ground floor as entrance to portico, but in later period began to be placed over the entrance doors, on upper floors as the focus element of the building’s facade. Palladio used the motif in many creative ways. For Palazzo della Ragione, he created depth by using double columns and wider barrel arch shell.

Philip Johnson Museum of Television and Radio

The Palladian form on an upper floor is characteristic of the Federal style, but has also been used on other buildings from Victorian to modern times. Architect Philip Johnson used it as a doorway (for University of Houston College of Architecture building in 1985, and also at the Museum of Television and Radio building in 1991, New York City). He said ‘I think Palladian windows have a prettier shape. I wasn’t trying to make any more important point than that’.


Rose window is a circular window usually found in Gothic period churches. It is divided into segments by stone mullions and tracery. Rose windows are also called Catherine windows after Saint Catherine of Alexandria who was sentenced to be executed on a spiked wheel. Rose Window is fairly complex and evolved design, whereas its simpler and earlier version of Medieval period was called a wheel window, as it was divided by linear elements like spokes, radiating from a central solid boss. Circular windows called eye or ocular window or Oculus, in ceilings and high up in walls have been use since Roman times. Smaller circular openings also were placed over door and window openings.

Rose Window At York Minster taken from Minster Gates

Rose window Notre Dame

Rose windows are mainly placed on the West front of the church building and over the entrance door. Most common subject of the stained glass is the Christ seating in the centre and within the lights around him are placed four Gospel writers, Apostles, Prophets, Saints and Angels. Some windows show God’s dominion over skies by including heavenly bodies such as the zodiacal signs and Labours of the Months.

San Pedro, Ávila, Spain.


Georgian Architecture was widely used in the English colonies of the time. In the American colonies, colonial Georgian blended with the neo-Palladian style to become known as Federal style architecture. American Georgian houses typically have well-organised facade with five windows on the first floor and four windows plus a central colonnaded entrance door on the ground floor. The Georgian window is a double-hung sash window. Early in the 18th C, a classic style Georgian window was made of two sashes, each with 3 x 2 =6 glass panes. This remained in use even after the advent of larger glass panes in the 19th C. These sash windows, placed almost flush with the outer face of the walls, were painted white. The white colour over glazing bars also reduced their presence against the glass, making the window look more elegant. The preference for white colour sash windows has continued till today even though materials have changed from wood to plastics, steel and aluminium.

Federal style Maizefield Red Hook NY front view

Vertically sliding window or sash windows are favoured for the ease of opening and controlled ventilation. Sash windows are less susceptible to warping due to moisture, as the shutter is bounded by a frame. Sash windows open by remaining within their frames, so do not distract, as do the hanging shutters of the casement windows. A Georgian sash window remained very widely used form till the use of steel casement windows as a cheaper and functionally superior option became acceptable.

Clifford Double hung Sash Window




Post 317 ⇒   by Gautam Shah 


A rope is composition of fibres, filaments, yarns, thin stripes or wires, twisted or braided or kept together by ties, over winding, binders like an adhesive or fused partially. The geometric composition (it is not a composite, as there is no matrix agent) that remains flexible yet becomes lengthier and stronger in form. The composition retains its ‘winding’ or compactness through its manipulations such as bending, pulling, twisting, etc. Rope of very a thin diameter, is called string twine or a strand. Wire ropes are also called cables.

Natural fiber two strand twisted rope

Rope twister machine

Rope is formed by several methods. The basic technique involves twisting fibres (short-staples or long-filaments) to form yarn. Twisted ropes are made by twisting the yarn into strands, then three or more strands further twisted into rope. For Braided ropes the yarn is braided. Double-braided rope has a core of braided yarn and covered with braids. In the basic twisted rope structure, alternate stages are twisted in opposite directions to give torsional stability. In the right-laid or Z-twist, (compared with left-laid or S-twist), the rope twist is seen as a spiral in upward direction.

S & Z twist in ropes

Climbers Rope with braided sheath and twisted ropes inside

The braided or plaited rope structure provides torsional balance by crossing and re crossing rope components in maypole fashion. Smaller or thin diameter ropes are called cords. Cordage was made by braiding two or three strands of yarns of same thickness, and then combining several of them by twisting in the opposite direction. The ends of twisted rope were tied up to keep them from unravelling. The finished rope was beaten with a wooden implement or brushed to even out the stresses.

Braided rope with shackle

Manila mooring rope

The texture and the nature of a rope are determined by the fineness, stiffness, strength, and stretchability of the fibres or filaments used in its construction. Strength of a rope is chiefly governed by the degree of twist in the rope and strands. A greater twist, normally lowers the strength. Rope strength is not affected by repeated pulls or tensions, on the contrary it induces inner spatial adjustment of the yarn. Ropes of natural-fibres deteriorate mainly due to fibre degradation caused by mould growth, whereas synthetic ropes deteriorate due to exposure to sunlight, elevated temperatures, and chemicals. Ropes when mishandled develop strand kinks (cockles). These are also caused by irregular twisting of rope.

Three strand rope

Ropes are made from natural fibres like, Cotton, Manila (hemp), coir, jute or sisal. Cotton ropes are, weaker and stretch, but being soft is used for drawing water from wells and similar handling purposes. Manila ropes are stronger and have good salt water resistance. Short-staple fibres of cotton, wool, Rayon and long-filaments of synthetics like Nylon, polypropylene, polyester and acrylic are spun into ropes. A heavier fiber or wire creates a stiffer rope than raw fibres that are finer. Wire ropes are stronger, stiffer, heavier, and less extensible when compared to fiber ropes. Early wire ropes were strands of wires strapped together by clips, and to prevent individual wires from flaying on breaking, a slight twist was given during the clipping. Electric sky grid wires are conductive ropes.

Wire rope with thimble and ferrule

cross section of high tension grid wire

Ropes and cables are used for their tensile capacity, such as in cranes, elevators, draggers, barges, tents, animal harness, curtains, for sails for the boats, suspension bridges, and pre-stressed concretes.




Post 316 ⇒   by Gautam Shah 


Screen printing is process of spreading a viscous colourant through partially an occluded screen. The occluded screen represents a pattern where opaque sections do not allow any transfer of the colourant. This was a process once used for duplicating artwork sections with Cartoons.

Cartoons are in the form of an opaque plane created with a sized cloth, parchment or paper. The outlines of the figure or pattern were drawn and the outlines of it were pricked by pin. The cartoon was placed over the wall, canvas or drawing panel and powder or liquid colour was rubbed on it with a rag. The impression created by closely spaced pinholes were joined by charcoal lines. With this technique artist used to create copies of figures and pattern within the same painting, across several paintings and also across carpets, tapestries, ceramic tiles, etc. Such cartoons were sold to others or borrowed from others.

Screens for printing uses a process, similar to the cartoon-copying. For screen printing a fine mesh of silk fabric (in earlier ages) was tautly held over a frame to form the screen. Screen blocking was once done with non water soluble medium such as bone glue or paint. Actual printing occurred by placing the screen over fabric, paper or ceramic tile, and rubbing the colourant paste with rag, flat brush, squeegee or wide spatula. For running patterns like borders or lengths of fabrics, the screens were sequenced. It was possible to create many different colour and pattern combinations.

Screen for printing

The Silk screens were very fragile, and the screen blocking materials were even more delicate. Screens could be used for very few repeat operations. This problem was solved with the production very fine and durable fabrics of Nylon and later polyesters. Today screens are made with synthetic fine gauze fabrics, wire gauze (phosphor bronze, stainless steel, nickel) or of combinations (nylon-copper, nylon-bronze). These are called bolting cloths (of 200 to 800 mesh).

An enlarged image of a screen print with a photographically produced stencil. The ink will be printed where the stencil does not cover the substrate.

Screen with metal frame s

The modern day screens could be one for each of the colour to be printed. The colours of the image to be printed are section-separated as black and white transparency image, where the Black represents area to be printed with the particular colour. The transparency in hard copy or as digital-photo image is projected over a light sensitive chemical coated screen. The black area does not sensitize the chemical coating, so can be washed off, leaving the light reacted area intact. The screen is then coated with a screen-paint a two-pack formulation, commonly of amine resins. This screen paint is tough, and can take frequent rubbing of colour spatula or strike plate. A screen often can print up to 100,000 times.

Screen print hand bench

The fabrics are printed on a long printing tables which have screen registration stops, ensuring accurate pattern overlapping and fitting. Screen tables are of many types such as plain rubber felted, vacuum suctioned, warmed or heated, etc. For single page print-work such as letterheads, visiting cards, invitations, envelopes etc. are printed with lifting a screen table. For bottles, tins, etc. the product is rotated under the screen or rotary screens with round printing facilities are used.

Colours for screen printing are pigment paste colours mixed with high viscosity acrylic binders. Often mordants (certain metal compounds), warmed wax, gums, are printed on fabrics by the screen process. The mordant printed fabric is reacted with various dyestuffs, waxed fabrics are over printed with dyestuff (in a batik like format), and gum prints are covered by finely chopped staples of fibres (flocking) or metallic dust or flakes.