STORAGE CABINETS

Post 493  by Gautam Shah

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Storage systems have been with us from very ancient times. These systems have helped in spatial organization of living, commercial and manufacturing areas. Organized storage primarily means segregation and stacking of entities for the purpose visual identification and easy access. Storage systems for foods have been conceived for isolation, preservation and maturation. Commercial and manufacturing storage systems serve the same purposes, but for former visual merchandising and for the later goods and tools, access was important issues.

Storage Cabinets have been known by many names. Almirah is a Portuguese word, Hindi = Alamari, describing a free standing closet. It was a place to keep vestments in the sacristy of a church. Almirahs in modern sense are synonymous with cabinet, cupboard, wardrobe etc. A cabinet could be an open or shuttered-storage entity, so may not be equated with open storage systems with shelves in niche, alcove, bay or recess.

Scroller

The Sandook, Patara, Manjusha (Hindi), Chest or Box, are all storage units of ancient origin, and considered predecessors of Almirah. Manjusha generally means a box for jewels, or treasure chest. These are associated with nomadic life, so were compact but were multi-functional. These were accessible only from the top and so were cumbersome for storing. These storage units, like the almirah, had few compartments or cells to store small things, and secret chambers for the valuables.

Nagamochi kuruma wheeled trunks are the oldest documented category of tansu.

An important category of storage systems includes a chest of drawers, bureaus (French word for office), secretary, secretaire, or escritoire, and desks. These were primarily used for home-based offices, personal study areas, as communication console by officers, ministers and scholars. The units were independent entities, placed against a wall, and often on a raised platform of 100 to 200 mm height. The drawers were for minuscule in size for storing pins and pens, to very large ones for books and manuscripts.

Chippendale Desk

The efficiency of access and ergonomic size made them very popular and began to be used in bed rooms, dining rooms, pantry areas, shops, hotel lobbies, restaurants and bars. In bedrooms these were used as personal craft-station, as Lingerie chest for storing socks, underwear, hands kerchiefs, napkins, as a parlour for make-up things. Lingerie chests were of highboys or tall design where a set of drawers as a tall chest of were mounted on legs. Parlour chests were comparatively lower volume chests, of a bureau-dressing table in combination with a pivoted mirror on an integrated stand or as a wall-mounted frame.

Personal work area Sherlock Holmes Museum

In entrance halls the chests had drawers for shoes but low enough to sit on it to tie shoelaces. Entrance hall chests were accompanied by long wall mirror, a coat stand, and umbrella tray. In dining rooms these became cutlery and linen station taking away the functions of silver room.

The bureaus made their formal appearance in 17th C across Europe. These were similar to modern day office desks, with a set of drawers or shuttered cabinets on sides and knee-space in the center. The knee space often had a drawer, or a flat pull out board for writing. Europe bureaus as a writing desk had no knee space, but the top section had a fold-down flap that rested at both edges on sliding vertical supports. The projecting fold-down flap provided sufficient knee space. The fold-down flap covered a set of pigeon holes or micro-sized drawers.

geograph-3968551-by-Suzanne-Mischyshyn

Castle Ward Interior -Classical Palladian Library for J5749 >© Copyright Suzanne Mischyshyn and licensed for reuse under Creative Commons Licence

Design and construction of bureaus was considered a challenge for furniture makers of the times. But as the time progressed designs became lighter, hardware superior and finishing techniques elaborate. The nominal inclined top was replaced with an accordion like folding flaps, or a curved tambour top. By 19th C it essentially became either delicate feminine furniture or robust commercial-use facility.

Dining room cabinet

Shelved storage systems were used for storing scrolls, manuscripts and arms. These were mostly open systems, to permit aeration and in colder climates prevent water condensation, but the same need some enclosure in other climates. The enclosure was provided to the entire room containing such shelves, rather then group of shelves. Almirahs were used where storage requirements of smaller volume. Shelving storage systems were in built niches or alcoves and formed within panelling system. From later part of 18th C it became fashionable to stock famous books in tea-coffee rooms, drawing rooms. Real and false libraries (with slices of books spines) were created as part of room panelling design. With availability of good quality of glass in late 19th C these were covered with wood framed glass shutters.

slotted angle shelving Industrial warehousing

The industrial revolution period saw streamlining of production processes. These required huge warehousing systems for raw materials and finished products. New storage devices such as steel-angle racks, steel almirahs, file cabinets, index card drawers, were now available.

next article in series > Almirah

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SOLVENTS for THINNERS

Post 492  by Gautam Shah

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Thinners are combination of ‘solvents’ whereas a solvent is single liquid material. Thinners and solvents are used for many purposes. These can be categorized in roughly THREE categories: 1 as a solvent for reducing the viscosity, 2 as a diluent an intermediating agent, and 3 as a non active carrier agent.

As a viscosity reduction agent it is used with resins, coating materials, adhesives, etc. As a diluent it is used as an extender medium in thinners to extend thereby reduce the cost of costly solvents. As non active material it is used with pesticides, chemicals to achieve greater spread. Some solvents of very low boiling point temperature are used as carrier for sprays etc. Thinners or solvents are used for cleaning surfaces such as restoration of artwork, removal of oil-grease deposits, removal of moisture from very thin crevices such as electronic circuits.

Distillation of crude oil at different temperatures

One of the earliest needs for a solvent was to reduce the viscosity of wax without warming it with heat. Wax was one of the best and easily available waterproofing material, but required heat for softening, a highly dangerous fire prone processes. Similar problems were encountered while thinning vegetable oils, tallow and other fats. These issues were solved with some of the earliest solvent materials the turpentine and the spirits (crude ethanol-based products from fermentation-distillation processes). Turpentine has been known as: spirit of turpentine, natural turpentine, genuine turpentine, oil of turpentine, wood turpentine and turps.

Oil_of_turpentine

Turpentine is a steam distillation product from leaves of pine trees which also yields gum turpentine, turpentine oil and colophony (rosin). All these products have been used by artist for artwork and by crafts persons. The primary use of turpentine has been as a solvent for paints. During last century menthol and camphor were produced for turpentine, of this camphor was used for early Nitro-cellulose lacquer (NC Lacquer). Artists preferred distilled Turpentine as paint medium as it was more viscous than white spirit, and for being slow to evaporate. The later property was useful for ‘touching’ the colours, and keep it alive (green or wet) for longer duration. Residues or trace gum rosin in Turpentine prevents fast drying of film and keeps it tacky for along time.

White_spirit

During the last century Genuine Turpentine has been replaced by Mineral Turpentine. Mineral Turpentine is petroleum distillate and is also known as white spirit, petroleum spirits, solvent naphtha. It is a very efficient solvent for oil and alkyd-based paints and varnishes. It is as low cost as Kerosene and so used for cleaning oil-grease from engineering products and other dry-cleaning (non-water cleaning of garments, wools) purposes. Turpentine has very little or no odour, so for paint thinner of domestic use, little terpene oil or genuine turpentine is added as a flavouring agent.

ethanol1Alcohol is produced through fermentation-distillation. The resultant product is Ethyl alcohol (Ethanol). The word Ethyl derives from French word ether, meaning a substance that evaporates fast at room temperature. Alcoholic drinks through fermentation of grapes, berries, honey and rice were produced since 7000 BC. Spirit or ethanol was used to dissolve plant gums. Ethanol is miscible with water and its presence reduces the surface tension of water. Pure ethanol is misused for consumption, so many countries have made it compulsory to denature it adding 5% or more methanol. This is also called methylated spirit. Denatured spirits are used for dissolving gums and shellac to formulate ‘French Polish’ and Lac and rosinated Varnishes. It is also used as cleaning agent.

Kerosene is chiefly used as a fuel. There are commercial and superior grades available. It has very strong solvent properties. In far off regions where Mineral turpentine is not available, Kerosene is used as oil paint solvent.

Naphtha sold as Camp-fuel

Naphtha is a flammable liquid mixture consisting of hydrocarbons, and it is very similar to kerosene or gasoline. It is a feed material for fertilizer and chemical plants. It is used for cleaning(flushing out) petroleum product tankers and as a tool machine cleaning solvent.

Gasoline is basically a fuel product, but is used for removing grease, tars and waxes from tools, parts and equipments. It is not used for paints.

Water is universal solvent. Water was used for water-based coatings produced from gums, casein, egg-whites etc. and with cementious compounds like lime, gypsum, etc. Water emulsified, polymer paints are able to meet the ecological concerns for VOC (Volatile organic compounds are organic chemicals that has a high vapour pressure at ordinary room temperature).

Acetone

Acetone is a simplest ketone and called mother of solvents. It is colourless and flammable liquid utilized as an important constituent of lacquer thinner, nail polish remover and grease-oil cleansing. In restoration and conservation practices acetone is often used to clean dirt, soot and grime and old varnishes from paintings and furniture.

Olivia Boteler Porter before and after restoration – removal of yellowing due to dirt and ageing

Methyl ethyl ketone (MEK) is an industrial solvent which is easily miscible with water. It is used as thinner solvent and as a remover-softener of stubborn paints.

Carbon tetra-chloride fire extinguisher 1930

Carbon tetra-chloride is also known as tetrachloromethane, carbon tet (cleaning industry), Halon-104 (firefighting) and Refrigerant-10 (HVACR). It was very popular cleaning agent for amateur electronics people. It is a colourless liquid with a sweet smell detectable at low levels. It is no longer preferred as a solvent or cleaning fluid.

 Sistine Chapel, the prophet Daniel before and after Restoration

>> A decision was made that all of the shadowy layer of animal glue and “lamp black”, all of the wax, and all of the over-painted areas were contamination of one sort or another: smoke deposits, earlier restoration attempts, and painted definition by later restorers in an attempt to enliven the appearance of the work. Based on this decision, according to Arguimbau’s critical reading of the restoration data that have been provided, the chemists of the restoration team decided upon a SOLVENT that would effectively STRIP the ceiling down to its paint-impregnated plaster.

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BLACK – Part – I

Post 211 ⇒   by Gautam Shah 

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Black is ‘no colour’, as it represents the absence of light. Black is the lack of all colours of light, or an exhaustive combination of multiple colours of pigments. It is opposite of white and often represents darkness in contrast with light. Blacks has its origin with fire or its residual product charcoal, ash and deposit as ‘Lamp black’.

Charcoal

Charcoal

Old English blæc =dark, is from Proto-Germanic > blakaz =burned. Etymologically Surprisingly other cognates of ‘blac’ include: Blæc, Bleak, Blake, Bleach, Blanch. Black can be traced back to ancient Greek phlegein =to burn, scorch and its proto Indo-European origins through ‘bhleg’ =to burn with black smoke or to burn black with smoke. ‘Bhleg’ was incorporated into Old High German as ‘blah’, Dutch blaken =to burn.

Presentation1

Black colours are not all equal Black, some are slightly bluish, reddish, and so on. True tinge can be seen on diluting it with white

If BLACK (Blæc) > burning bright, or burning, burnt, blackened by burning, pale, wan, colourless, or albino. The associated word (to Blæc) was BLEACH > burning bright, bright and shining, make shining white. So Black is associated with shining white. In Middle English the word was spelt as “blaec (Blæc)” same thing as the modern word ‘black’, only at that time, around 1051 AD, it still meant a fair skin, or so-called white person.

Lascaux painting with Black

Lascaux painting with Black

The Ancient Greeks sometimes used the same word to name different colours, if they had the same intensity. Kuanos’ could mean both dark blue and black. The Ancient Romans had two words for black: ater was a flat, dull black, while niger was a brilliant, saturated black. Ater has vanished from the vocabulary, but niger has come to country name Nigeria, for Nigger or Negro in English and for black in most modern Romance languages (French: noir; Spanish: negro; Italian: nero). Old High German had two words for black: swartz for dull black and blach for a luminous black. This distinctive usage also occurs in Middle English, swart for dull black and blaek for luminous black.

Ceramic Black

Ceramic Black

 It was in 16th C the semantic broadening of Black occurred, both figurative connotations as well as literal. From ‘blacken’ and its literal meaning ‘to stain black’ came the figurative meaning ‘to stain some ones’ reputation, or defame’. This incorporation of black was beginning of negative intensifier, and meant malignant, deadly purpose and involving death.

Lascaux cave painting in Black

Black has many cognates in modern usage such as for suit of spades or clubs as black, Coffee without milk is black, economic loss as being in black, truth was dilemmatic black or white. Black colour is physically associated with fire, and metaphorically with the night sky. Black is associated with the negative, such as Black market, Black mail, Black list, Black (Fri) day, Black deed, Black flag, Black hole, Black mood, Black fever, etc.

Portrait of Jessica Chambers, charcoal John Murdoch

Portrait of Jessica Chambers, charcoal John Murdoch

 Even though black is associated with fire, it was used even before the fire was used or domesticated. Black was available as charcoal of charred woods of natural fires, ashes, minerals including coal deposits and Magnesium Oxide. Black was one of the first few colours used by artists in neolithic cave paintings. It was used for outlining and for highlighting the image. In neolithic paintings, and later day wall-art Black was used as the contrasting colour to Red, and not the White. What black could cover or hide that weak white could not do, perhaps white, at that point of time was not that intense or opaque. Blacks colours are Carbon, and absorb light, so appear dark in infra-red reflecto-graph scanning, to reveal the starting outlines under the painting.

Spirit_Rover-Mars_Night_SkyCarbon black is very ancient Black colour pigment. It is produced by heating wood, or other plant material, in a closed chamber with very restricted supply of air. Carbon black was used, mixed with oil or water. Lamp black is a form of carbon black, but obtained from the soot of burned fat, oil, tar, or resin. Lamp black has varied tinge, soft brownish, bluish, or pitch-black. It is one of the most stable pigments unaffected by light, acids and alkalis. Bone black has bluish tinge, but is intense than lamp black. It is made from charring of bones or ivory. Vine black was produced by charring desiccated grape vines and stems.

CGA NTSC Colours

CGA NTSC Colours

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DESIGN DOCUMENTS and Liabilities – Part – I

Post 491  by Gautam Shah

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Design Documents consists of Views such as Plans, sections, elevations, Write-ups in the form of sheets, files or books, for explanations about things that cannot be adequately represented through views and for people who are not trained to interpret drawings (such government officials and law agencies), Structured Documents such as estimate sheets, reports, etc., and Enhanced Views such as isometrics, perspectives, walk-throughs to reinforce the perception of elements or their compositions which are generally not used as valid means of execution.

1024px-Peter_Behrens,_Atlantropa_Pantropa_01

Peter Behrens Tower building

Design Documents created in a design office have a well-defined purpose, specific exposure and so vulnerable to various levels of liabilities.

Design Documents are of Following types:

  • Personal
  • In-house
  • For clients’
  • For consultants’
  • For permissions – approvals by authorities
  • For presentations – publications
  • For job award or execution
Manchester_Town_Hall_working_drawings

Manchester Town Hall Drawings

1 PERSONAL DOCUMENTS are created by the designer or scheme formulator. These are concept sketches drawn impressionistically and often like doodles or bubble diagrams. These are for designer’s personal references or reminders. Sketch or preliminary drawings are too small in size, not to exact scale, lacking in details, and do not carry all the graphical views to convey the intentions. These documents are not meant for anyone else, and are thin in content, or just indicative and abstract in nature. Similarly materials, components, procedures and design parameters which have not been fully conceived, or not crystallized into a formal structure, are all placed as notings. The sketches may not have any apparent order, and contain any trade, technique or material specific details. The orientation, scale, format, language, signs, metaphors, symbols, etc., are very much subjective and so illegible to others. This are very personal, un-interpretable or mis-interpretable documents. Yet these are ‘intellectual properties’ documents (copyright, patent, exclusivity).

2 IN-HOUSE DOCUMENTS are created to explore various aspects of the project. These documents always remain within the office and accessible to only authorized staff members. The composition is very casual as the contents are private and not binding to anyone. The contents can be altered at any time without any liability. Here options regarding materials, finishes, parts / subsystems, techniques, are explored. The methods of indication follow the traditions prevalent in the office, and as a result its format and language are very abbreviated. However, some sort of standard format is required, to create documents that are comparable and interpolating with other such documents within the organization. Such documents are never exposed to consultants, clients or anyone else. As whatever is shown or implied in the drawings may be construed to be a promise to deliver.

Grenfell_Tower,_London_in_2009

3 DOCUMENTS FOR CLIENTS are in the form of presentations. Clients’ are shown (and given) drawings and other documents at several stages of the project such as First for the approval of concept, then with intermediate improvisations, and finally for the execution worthy scheme. Besides these clients require presentation for marketing the spaces, which are being, created or altered. Few clients, however, understand all the technical drawings, but in case of a dispute every sketch, drawing or document will be reinterpreted by someone else (lawyer, arbitrator, judge, etc.) and that can create liabilities. The clients consider the design documents as Bench-Mark during the post project evaluation. Presentations should be simple and in non-mechanical form, as the essential purpose is to impress the client and solicit a required response. These documents may additionally convey broad policy of operational modalities and related structure for guarantees and warranties. The presentation format is open, allowing several options and possible interpretations. A client needs two basic things through the initial presentations: 1. A layout scheme that shows how the project relates to the site and 2. A sketch / view showing the form of the building, with reference to the surroundings. On later date presentations other details (materials, colour, textures, etc.) may be included. Clients’ presentations are for information and for initiating a debate. Whereas, a set of all drawings, submitted just before the invitation of bids, is a formal ‘transfer of records’.

FL Wright Heurtley House Lower Floor

Trump_Tower_2012-04-29_(cropped)

Next part of the article will cover remaining Design Documents such as >> 4 Documents for Consultants’ Assignment, 5 Documents for Permissions or Approvals, 6 Documents for Presentation and Publications, 7 Documents for Job Award or Execution.

And also Layout drawing, Working drawings, Detail drawings, Component drawings, Written details, Written details within the drawings, As a separate document but attached or referenced through the drawings, Memos and Short Messages to and from the site, Certificates for completion of a trade specific item, component, stages, payment of bills, etc.Santelia03.

FRAMING of OPENINGS

Post 490  –by Gautam Shah

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512px-Akbar's_Tomb_at_Sikandra

Openings systems like gaps, doors, and windows are see-through entities. These are transit routes for many purposes. The openings are framed and masked with supplementary elements to doctor the transition taking place. The transitions to be proctored are two-way of people, other beings, goods, illumination, view, privacy, air-ventilation, moisture, rains, snow, dust, smell, noise, etc. Other purposes include, imposition of patterns, grids, proportions, contrasts, styles, make or break monotony of compositions, create or diffuse focuses.

Corner point view from Flatiron Building NY > Wikipedia pic by Author : nautical2k

cathedral-2425336_1280

Framing is distinct from Masking of openings, though at some level they assimilate to serve the similar purposes. Framing is an obvious characteristic of an opening. Openings have their sides and mid members within the view cone depending on the point of observation. In high-rise buildings where an exterior surface is formed of many and extensive windows framing of openings in a coordinated grid and may follow the discipline of the structure, or ignore it, and mount a false facade.

Gate d’Amboise in the Old town of Rhodes, Greece >Pic Author : Bernard Gagnon Wikipedia

The main gate, Schloss Belvedere, Vienna

An opening or a gap, be it a natural one or formed into built-form, has an implicit frame. The frame is defined by the strong surroundings, and through the depth of the gap or passage. For framing, natural openings have only sides and no head, but in built form openings, the head and threshold, both are as essential as the sides. Framing delineates an opening. Gates have dominant bastions to frame its importance. Egyptian temple doors have abutting pylons. Gothic doors are framed with several layers of receding serrations. The frame not only delineates an opening but enhances its size manifold. Fatehpur Sikri Mosque, India, has a real entry door of human scale, but that has been framed by very large portal. Architraves, borders, trims, casings, beading and masonry elements such as pilasters are used to reinforce the framing.

Buland Darwaza gate to Jami mosque, Fatehpur Sikiri, India. Pic Author: Marcin Bialek Wikipedia

asia-2215357_1280

Framing effect of opening is enhanced by highlighting the depth-sides. The sides are fluted, serrated or panelled, vaulted or chamfered to increase the surface area. The opening structures such as the frame are placed either on outside or inside the edge to increase the effect of bounding. The exterior niches get enhanced due to deeper shadows in locations where Sun is usually bright. Interior bays must be matched with interior space making elements. Strong interior bay of openings disturb the wall mural painting. Interior alcoves in clerestory openings are not preferred as these arrangement forms highly articulated an interior surface, often diffusing the importance of architectural elements like domes, vaults, etc.

windows-red-medieval-buildings

Windows of Secretariat Building Le Corbusier Chandigarh India

Openings are framed to capture, enhance or specify a view, both outside and inside. The framing here works like a mask to mould the view. Nominally a landscape has three horizontal segments, consisting of view down of terrain, straight taking in the horizon and upwards capturing the sky. These three are modelled in the opening gap by way of actual framing or metaphoric clues. View-out presents a wide spectrum, and to model it from an interior focal point is difficult for modelling or framing, however view-in a fixed and narrow scene, framing is easier, provided in-view is brighter like of Chowk or courtyard.

Inside the 360 Restaurant in the CN Tower Wikipedia

Jeronimos Monastery Lisbon Portugal

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COMMITTING a CLIENT for JOB

Post 489  by Gautam Shah

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For a young and fresh professional, a new client is like a girl (or boy) friend. You look for the right occasion and mood to propose. And perhaps discuss the terms and conditions. The client may not run away, but will also not indicate any commitment. A fresh professional is always very eager to secure the job, and may not wish to disturb the budding but fragile relationship with the client. But a client detests any formalization of relationship so early with an age-old excuse, ‘does not fully know the professional yet’. That translates to the reality that client wants to delay the decision. Clients are also shrewd enough to have a free taste of thing to come before formalizing the relationship.

When a professional and client decide to establish a relationship, it usually occurs very gradually. An established professional will not show any haste. Rather, express a desire to know more about the project and perhaps the client, before establishing a relationship. All seasoned professionals expect new clients to be familiar with the design field and their projects. This is quite different from fresh professionals who are required to establish their bonafide.

All design professionals (fresh and established) need to know, if they decide to take on a project —what will be their gain, and if they do not take a project —would there be a loss ? To accommodate (accept) an odd project or unusual client, a professional may not only shed profits, but end-up disturbing the routine work and culture of the practice.

Ecrivains_consult_-_Texte_4_mainsFor all professionals, requisition of a formal commitment (consent) from a client, for a job, is a very difficult exercise. Formal commitment binds a professional to deliver the expected services. A professional begins a job, by investing in labour, stationary and intellectual skills. Whereas, a client awaits with uncertainty whether the professional will at all deliver the project with required quality, and in time. When a professional fails to deliver, not only client’s time, but effort expended reaching to this stage are wasted. Clients’ time and efforts both are non-calculable and recoverable entities. And when the client fails to appreciate a professional’s work, all the labour, stationary and intellectual skills are wasted. Few of these can ever be determined.

A variety of problems manifest, till a client formally commits a job to the professional. In case of an individual client (private), only a personal whim can cause a problem in the job. In case of a client representing a formal or informally constituted group, the leader’s relations and position with the group, if changes, it can necessitate recasting of negotiations. In case of group clients or committees, all decisions and actions are necessarily formal, and so job commitment is not a major problem, though there are inevitable delays.

Pic Wikipedia Uploaded by russavia, Author: Richter Frank-Jurgen

Ideally a client and a professional should enter into a contract as per the law of the land. But a contract is a very formal expression of intent. It is too much to expect a client and a professional to formalize their relationship with a contract, when they hardly know each other, or have not formulated the project. Just the same, even in the absence of a contract, they must nurture the relationship. In a normal course this is not very difficult, as both the parties are willing. However, at a later stage if there is a problem, either of the parties may refuse to recognize the fact that there was a budding relationship between them. In such a situation a professional will lose all that was invested in understanding, preliminary working, planning of the project. This could include not only labour, stationary but patent ideas. On the other hand a client will never recover the time that wasted in searching, identifying, convincing the professional and waiting for solution.

Angelo Litrico 1957 Italian fashion designer

It is very natural that clients and professional are extremely careful about things they say and do. For a professional, (who is operating in the absence of a very formal commitment), it is necessary to create an evidence that, a client did commit the job or at least was aware that the professional is working on it. The evidence in such a case is usually circumstantial. Circumstantial evidences are not generally tenable in court of law, unless corroborated by other circumstantial or real evidences.

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Best commitment, next to a legal contract is payment of a Retainer amount. A retainer fee, however small, signifies establishment of a relationship, between a client and a professional. (retainer amount or fee should not be confused with retention money). Ideally a retainer amount should be large enough to cover not only the labour, stationary and skill, but the cost of patent (original or exclusive) ideas required to generate a schematic design (or such other stage when fees again become due). The cost of patent or unique idea is collected at first go, because a unique idea or a concept once exposed to an outsider like a client, loses its originality and so the value.

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COPPER 3 -Bronze alloys

Post 488  by Gautam Shah

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The alloy of copper with arsenic or tin is called bronze. First metal of human history was copper, to be developed about 5000 BC. First copper was produced from naturally available nodules, which were of pure copper. Search for ores that had properties like copper led to Copper-Arsenic mixed ores. At nearly same time Copper mixed with zinc yielded Brass. Copper ores were invariably with Arsenic contents, and produced a bronze alloy of Copper-Arsenic-Tin mix. Due to problems of distinctive classifications of prehistoric objects, scholars use an all-inclusive term ‘copper-based alloys’.

Chinese bells (476–221 BC) > from Wikipedia Uploaded by Spiritia

Copper-based alloys had many local variants, in terms of constituents and smelting-processing. But the achievements across many regions of the world were important enough to be a marked era as Bronze age. This period saw production of harder and more durable tools than any thing available in preceding stone and copper (Chalcolithic) ages.

Bronze flag, Shahdad Kerman, Iran 3rd millennium BC

Bronze may be perceived as an improvised material than a new discovery. It was a material, which could be cast, formed by beating, and treated with heat to change the properties. Bronze-making, soon outpaced the copper production. Bronze alloys were produced from direct refining of arsenic and tin containing ore materials. Tin bronze was superior to Arsenic bronze in that the alloying process was controlled, and the resulting alloy was stronger and easier to cast. But Arsenic copper was easily and widely available, compared to Tin. During the Bronze age period bronze or brass were not neatly delineated terms.

Bronze cuirass 7th-6th C. BC> Pic from Wikipedia by PHGCOM

There are more than 400 types of copper-based alloys. Many of these are in use since prehistoric period, but with only realization at that point in history that some are different from others. There was no clear awareness as to what is a pure copper, tin or Zinc. It was believed to be another variety or version of the metal. The qualitative peculiarities were attributed to the raw material sources and methods of processing. Both of these attributes were however, exploited to achieve distinctive results. Copper form alloys more freely than most other metals, and mixes with wide range of alloying elements (metals and metalloids) to produce many alloys.

Ancient Greek Bronze Helmet, mid 4th-3rd C. B.C. >originally posted to Flickr as Bronze Helmet Author Claire H.

Modern day Bronze is an alloy consisting primarily of copper with about 12% tin. Some of the bronze alloys often contain other metals such as aluminium, manganese, nickel or zinc, and nonmetal or metalloids such as arsenic, phosphorus or silicon. Bronzes make a wide range alloy metals with peculiar properties like stiffness, wearing, ductility or machine-ability.

China cooking tripod 1046-771 BC. > Wikipedia pic by “Editor at Large”

Copper-based alloys are of many types. The chief categories include Brass and Bronze alloys. Other are Arsenic copper, Beryllium copper, Brass, Dutch metal, Monel, Muntz metal (zinc), Bronze, Arsenic bronze, Aluminum bronze, Bell metal, Gunmetal, Phosphor bronze.

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