Welder World Blog

Archive for November, 2010

Welding technology in the electronics assembly occupies an extremely important position. General Welding divided into two categories: one is mainly applied to through-hole electronic components and PCB welding? Wave, the so-called wave (wavesoldering) that is soft solder melting solder by electric pump or electromagnetic pump jet peak into the design requirements of the solder, so that pre-printed board with electronic components by solder wave crest to achieve components with the PCB solder pad or pin end of the mechanical and electrical connection between the soft soldering welding; the other is mainly applied to surface mount components and PCB welding? reflow (reflowsoldering), also known as re-flow soldering, reflow soldering is through the so-called re-melted pre-assigned to the PCB pad of soft solder solder paste, solder-side components for surface mount or pin and the PCB pad mechanical and electrical connections between the soldering, to achieve a certain reliability of the circuit functions. With surface mount components in electronic products widely used surface mount reflow soldering techniques and technology into a major technology. Its main technology features: The flux of metal to be welded surface cleaning (removal of oxide), to make good on the solder wetting; supply of molten solder to wet the metal surface; in the solder and welding metal intermetallic compounds formed between ; also enables micro-soldering.

Reflow soldering is in advance of PCB Welding parts (pad) cast proper and appropriate forms of solder paste release surface mount components, solder reflow using an external heat source to the welding required by the group or by point welding. Reflow and wave soldering in comparison with the following features:

1, do not like the wave soldering components as needed to direct immersion in molten solder, so parts are subject to the thermal impact;

2, reflow the site only need to solder on the cast, a significant reduction in the use of solder;

3, solder reflow can control who discharge to avoid defects such as bridging the generation;

4, when the components have a certain deviation from posted up here, because the role of molten solder surface tension, cast in the correct position as long as the solder, reflow soldering can automatically correct this minor error, so that components fixed in position on;

5, can use local heating source, which can be used in the same substrate for different reflow soldering process;

6, solders are generally not mixed with impurities, the use of solder paste for reflow solder can be formed to maintain the right.

Reflow soldering techniques are classified according to heating methods are: vapor phase reflow, infrared reflow, infrared hot air reflow, laser reflow, hot air reflow soldering, and tools such as heating.

Reflow temperature curve theory: From the temperature curve (see Figure 1) of reflow principle: When the PCB into the heating zone (dry zone), the solder paste in the solvent, the gas evaporate, while the flux solder paste wetting pad component terminal and pin, solder paste softening, collapse, covering the pad, the pad, component pins and oxygen separation; PCB into the heat zone, so that PCB and components are fully preheated suddenly into the welding zone against PCB excessive heat damage to PCB and components; when PCB into the welding zone, the temperature rose rapidly to reach molten solder paste, liquid solder pad on the PCB, components and pin ends wet , diffusion, overflow or return mixed to form the solder joint; PCB into the cooling zone, so that solder solidification, to complete the soldering.

Temperature curve is critical to ensure welding quality, the actual temperature curve and solder paste temperature profile of the temperature slope and the peak temperature should be consistent. 160 temperature rise before the speed control in 1 / s ~ 2 / s, if the temperature slope too fast, on the one hand and the PCB heating component fast, easy to damage the components, could easily lead to PCB deformation; the other hand, solder paste in the solvent evaporation rate is too fast, easily spilled metal components, resulting solder ball. Peak temperature is set higher than the melting temperature of solder paste 20 ~ 40 or so (for example, the melting point of solder paste Sn63/Pb37 183 , the peak temperature should be set at about 205 ~ 230 ), back (again) flow time for the 10s ~ 60s, the peak temperature is low or back (re) flow time is short, will not fully welded, solder paste does not cause serious melting; peak temperature is too high or back (re-) long stream, resulting in oxidation of metal powder, affect the welding quality, and even damage to components and PCB.

Reflow temperature profile, and back under the principles of the reflow soldering machines currently on the market are generally simple four-zone reflow machine, there are six large, eight-or 12-zone reflow soldering machine, which model QHL320A reflow soldering machine 20 programmable temperature control, the equivalent of 20-zone reflow machine, it will return the temperature curves, and thus more precise temperature control, more fitting ideal reflow profile to achieve optimal welding.

Where good welding quality protection? QHL320A reflow machine in addition to full compliance with reflow in the control of outside temperature curve, but also allows users to truly understand the principle of reflow soldering. QHL320A reflow machine with the functions of large transparent window, users can have transparent windows throughout the entire welding process control, solder paste can be observed simultaneously in the whole state of the welding process changes, easy to find the problems in the welding process, through the parameters adjustments to improve, to ensure good quality of welding. Meanwhile QHL320A reflow soldering machine for small desktop machine, all-static soldering, effectively prevent a large-scale multi-zone reflow machine crawler transfer resulting from small vibrations, the vibration may be in the flow of molten solder paste soldering area state of the small space between IC (Such as distance 0.5mm) and components (such as 0603,0402 and 0201, etc.) affect the welding, leading to the drift component, solder balling, solder bridges welding defects, and all welding is still completely avoid these potential defects.

Set back (again) reflow soldering temperature profile of the authority:

1, according to the temperature curve using the solder paste to set. Different metal content of the solder paste has a different temperature profile, solder paste manufacturers should be provided in accordance with the temperature curve of the specific product set back (again) reflow soldering temperature profile;

2, under the PCB material, thickness, whether the multilayer, size, etc.;

3, under the surface mount board carrying components of the density, size and availability of components of BGA, CSP and other special components set.

4, according to the specific equipment, such as: the length of heated area, plus

Dewitt, NY – April 26, 2010: Machine & Welding Supply Company traces its roots back to 1925 when William Aldredge opened a machine shop in Dunn, North Carolina. Now in its fourth generation of family ownership, the company has 23 branch locations and more than 200 employees throughout North Carolina and South Carolina.

In the current issue of Welding & Gases Today, the journal of the Gases and Welding Distributors Association (GAWDA), Emmett Aldredge Jr., grandson of the founder, along with his sons Emmett III and Christopher, who both work for the company, talk about the legacy they were given and the future of distribution.

In the beverage CO2 business for almost 20 years, mini-bulk technology has enabled the company to take advantage of a growing market. A fleet of vehicles transport CO2 in its liquid state across the Carolinas. The company is capitalizing on the restaurant industry’s move to switch from standard 50-pound compressed cylinders to bulk CO2.

Aggressive growth is a hallmark of Machine & Welding Supply Company, and with a product mix of gases and hardgoods, the company has worked hard to diversify into a one-stop shop for customers. Read how they are meeting the needs of customers and growing their business in the Spring issue of Welding & Gases Today, the leading trade journal for the welding, welding equipment, industrial gases, medical gases and specialty gases industry. You can read it at www.WeldingAndGasesToday.com.

For more information, contact Carole Jesiolowski, Senior Editor of Welding & Gases Today, at editor@weldingandgasestoday.org or 315-445-2347.

New & Revolutionary Product — Oxyhydrogen Cutting & Welding Machine will bring you super function and convenience in cutting anc welding metal work. This machine is our newly product which we have the patent of it. It’s a invironmental machine which is only need water as resource. Gain hydrogen and oxydren by electrolyzing water, after light it and produce as high temperature as 3000 degree centigrade so that to cut and weld metal. And the cutting thickness can reach no less than 100mm,and upmost is 120mm. That’s nearly 5 inches thick. And welding thickness can reach no less than 5mm which is far beyond normal machines. This machine can generate 2000 liters per hour, and another is 1000 liters per hour. For further information, please contact me via: MSN: darren4213@hotmail.com Email: darren4213@gmail.com Or you can log on our website: www.china-niuli.com, and I belevie there are many more stuff interest you.

The lucrative salaries that are offered for welders is one reason why so many people consider learning the welding trade. Welding can be taken as an apprentice or as a craft that you learn in a trade or vocational school. With an economy that isn’t pristine and so many people out of work, welding is one of the few crafts that still pays a higher salary and seems to be relatively secure.

Welders join metal and work in shipyards, in industry, in car and auto manufacturing, in oil refineries and in oil fields as well as in offshore oil rigs. The welding industry is quite secure and jobs are generally stable because good welders are difficult to replace and are needed in nearly every kind of industry that is available. That statement is doubly true for the rig welding jobs.  Offshore oil rigs are up and coming.

While that sounds hard to believe in light of recent events, the reality is that offshore oil rigs are fast rising parts of the oil industry and will continue to grow as our need for the energy that they provide will continue to grow. Rig welding jobs are in particularly high demand because there are so few people who have the skills that it requires to do rig welding. In some cases the job entails being beneath the water while you accomplish your tasks.  This means that a rig welding job will require both well honed skills as a welder, but also the addition of diving skills. In most cases the requirement is that you must be a commercial diver, well able to attend to your diving in a nearly automatic way, while also using a welder beneath the water. Sound like something that is an easy job? Think again.

Rig welding jobs are hard to come by for most people because they simply don’t qualify for the job. Maybe you do. If you’re a commercial diver who has skills as a welder that surpass the norm, if you’ve got well documented experience as an offshore welder, the lucrative compensation that you can gain from rig welding jobs is literally amazing.

It isn’t at all uncommon for the underwater rig welding jobs to pay out more than 500 dollars per day, and in many cases much more. These positions aren’t an easy job to attain and in reality they aren’t an easy job to do. They involve underwater welding as much as they do above ground welding. It can be dangerous, but it can also be exciting and very lucrative. If you’re a commercial diver who has sound skills in welding, it would pay you to try your hand at application for some of the many rig welding jobs that exist. With so many new wells coming on, and so many old ones now being decommissioned, there are rig welding jobs in plentiful supply for those who are qualified to take them.

Jobs on offshore oil rigs are among the most sought after in the oil and gas industry, and for good reason. It is exciting work, and an adventure. The pay is extreme (experienced offshore drilling jobs can pay upwards of 100k). Even entry level offshore jobs can pay over 60k. The camaraderie is like being in the military; your buddy has your back, and you have his. You get to work in new and exotic places. And you get 6 months off a year to enjoy all of these benefits.

Most, if not all, jobs on offshore oil rigs do come with a good benefits package – health and life insurance, 401k, medical, dental, long-term care, and other retirement benefits. Travel is paid for, and of course room and board while on the offshore rig are covered. The exception are highly paid positions such as underwater welder; you are paid a day rate or a per job rate (that can approach 0.00 a day in some locations). With that kind of wage, one can buy his own benefits.

Jobs on offshore oil rigs are dangerous – before you set foot on the rig, you will have to undergo safety training and helicopter survival training. The importance of this training can be seen by a recent helicopter crash; the chopper was transporting 19 workers to the offshore rig, and went down. All 19 workers survived. You will find that the competition to obtain a high paying oil rig job is tough, especially for entry level positions, but if you know where to send your CV or Resume, and who to speak to, then it all becomes a lot easier.

The hardest thing about getting jobs on offshore oil rigs is landing the first hitch – it seems most employers want offshore experience more than even oil rig experience. Fortunately, there are companies that hire for entry level offshore jobs, such as roustabouts and roughnecks. Your best bet is to apply in person, at the onshore managing facility for the offshore rigs. In the United States, this will be in Houston, Texas, and Lafourche, Louisiana. If that isn’t possible, the next best choice is to either find the hiring web pages of all the offshore drilling contractors yourself and submit your resume, or hire someone to do it for you.

If you have relevant experience in the major trades (welding, electrician, mechanic), try the Danos Corporation. Transocean is always hiring for those with experience. There are literally hundreds of offshore drilling contractors worldwide; if you apply at all of them, you are bound to get a job, because in the end, it’s a numbers game – but persistence is required, especially in this economy.

In the intermediate-long term, the demand for jobs on offshore oil rigs is only going to go up. World energy demand will resume skyrocketing as we emerge from this recession, and the wage rates for offshore workers will resume their upward spiral as well. It’s an amazing career, full of adventure and stories that will last a lifetime.

Arc Welders

Arc welding is nothing more than a process of joining two pieces of metal into a single solid piece. To achieve this, the heat of an electric arc is concentrated on the edges of two pieces of metal that are to be joined. The metal melts, while the edges are still molten, additional melted metal is added.

Arc welders generally come with a load of helpful features. Equipments with unlimited amperage control enable you to create professional welds. The lightweight and yet sturdily built models make this type of welder convenient to carry around and durable enough to withstand tough use. There are some models of arc welders that have thermostatic heat protection features and a roll bar design to give the unit full protection against damage.

MIG Welding Equipment

MIG Welding equipments are available in various sizes ranging from a small, portable 115v, 20 amp model to full sized shop automotive service equipment. MIG welders are widely known for high quality performance, though economically priced. You can exercise control over the quality of the weld with the aid of many different settings. MIG Welding equipments come with cold running temperatures. The machines also offer beneficial warranty options.

It is common knowledge that MIG welders use a wire feed and produce a lower heat. This prevents metal distortion and allows for a high quality job on thinner metals such as those involved in auto body work.

MIG welders feed a constant stream of wire with a pull of the trigger. You must be extra careful in choosing the consumables. Wire, for example, comes in easy-to-use flux core wire for a quick job on thicker materials, or a gas/solid wire combination for all other work.

TIG Welders

Most TIG welding machines come with several attractive features. With push button control panels, the machines are extremely user-friendly and some high-end models give you the option to easily adjust for repeatable weld cycles, start, and weld crater. To customize the shape and size of the bead, you can choose models with true square wave AC output and pulse mode. Buy models that have safety features like warning code circuitry and voltage protection.

One of the biggest advantages of TIG welder is it heats and joins the two metal pieces together without the need for filler materials. Most operators know that MIG welders join metals much faster than TIG welders. But, TIG welders produce greater degree of accuracy, so essential for certain types of jobs. The possibility of preventing cracked seals or damaging the weld is also significantly decreased in TIG machines.

Plasma Cutters

Some latest models of plasma cutters come with a host of features – single-dial controls for easy adjustments, pressure gauges and air pressure regulators – all aimed at cleaner and sharper cuts. Other features include parts-in-place indicators, line voltage compensation, and thermostatic protection. Above all, if you wish to do repetitive work with complicated cuts, CNC robotic interfaces will ensure consistent and precise cuts every time. Please know that latest types of plasma cutters have an inverter in place of the transformer.

With several different styles of plasma cutters available, your choice becomes wider. Duty cycle is a key factor in your buying decision. Generally, you will find that bigger machines can handle thicker metals and run longer to give it a bigger duty cycle. Also watch for the rating that is assigned to plasma cutters by the manufacturer. This will tell you how long each unit can cut through mild steel before needing to be cooled down.

THE EFFECTS OF PRONUNCIATION ON SPELLINGS AND COMPREHENSION

By Johnnie J. Lim

Introduction

I conducted this study to find answers to the problem whether or not pronunciation affects spelling and comprehension of the students in learning English as a Foreign Language.

As a researcher, I tried to prove if learners of the English language from Middle East had common errors in writing correct spelling of words with letter ‘r’, be it in the middle or at the end of the word, and if their comprehension was affected by pronunciation. Specifically, I aimed to answer the questions: (1.) Is there significant effect of pronunciation on spelling? (2.) Does pronunciation affect comprehension?

I conducted this study in Non-Destructive Testing Technology Institute, 2nd Industrial City of Dammam, Kingdom of Saudi Arabia, for eleven (11) weeks on the 2nd quarter of SY 2008-2009. The participants involved were thirty (30) Arab students enrolled in my General English class. They were all first year college students taking up Welding course. These participants had previously learned and acquired British English.

My purpose of conducting the study was to provide an output that will be of help to teachers to understand if the same problem is encountered or will be encountered by them, and to encourage them to use teaching strategies appropriate to the learning style of the learners. Likewise, the result will be beneficial for them to help students improve their spelling and comprehension in learning the English language.

Discussion

My attempt to do the study was inspired by my own experience as an English teacher in dealing with the non-native speakers of English in a vocational school particularly Non-Destructive Testing Technology Institute where I taught General English to Arab students who had been exposed to British English, or who had previously acquired and learned the language. Since I was using American English, a minimal confusion occurred on both parties in the teaching-learning situation.

There was confusion in the production of the ‘r’ sound in words with middle, or final ‘r’ (i.e., welder, worker, world, marker, car, cutter, etc…) and in spelling of words like center, color liter, meter, and the like. The problem is similar to the ‘intrusive r’ mentioned in the study conducted by Bryan Gick of the University of British Columbia (cited in http://camba.ucsd.edu/files/phonoloblog/gick-intrusive-l-amsp02.pdf.).

Considering this experience, as a researcher, I conducted the study immediately after a week of teaching.

Accordingly, linguists have long been interested in intrusive r for a variety of reasons. The importance of early descriptions of the phenomenon as it appeared in early British RP, such as that provided by Jones (1917). Intrusive r was first recognized as relevant to phonological theory by a group composed mostly of American Structuralists, who identified it as bearing crucially on contemporary discussions of the phonemicization of low vowels and glides (Bloomfield 1935; Trager 1943; Whorf 1943; Swadesh 1947). Although somewhat later, and with a more dialectological focus, Kurath’s (1964) analysis should also be included in this category. Interest was renewed by the Generativists and following generations, beginning with Kahn’s (1976) dissertation on syllable structure and continuing to the present day (e.g., Mohanan 1985; Vogel 1986; Broadbent 1991; McCarthy 1991, 1993; Harris 1994, chap. 5; McMahon,Foulkes, and Tollfree 1994; McMahon and Foulkes 1995; Giegerich 1997; Halle and Idsardi 1997; Gick 1999).

“Intrusive r” says Gick, “may be viewed simplistically as the extension by analogy of a historically attested final /r/ to words historically ending in a vowel (generally this applies only to the set of non-glide-final vowels: /@, a, O/). Thus, in dialects with intrusive r, normally word-final r and zero alternate, depending on whether the word is vowel-initial, as in the following examples.”

“1. R ~ Ø alternation in historically r -final words (e.g., E Mass.)

a. tuner [tun@] ü tuner is [tun@r Iz]

b. spar [spa:] ü spar is [spar Iz]

c. pore [pO:] ü pore is [pOr Iz].”

Gick also explains that “in some dialects, this process has extended to all words ending in /a/, /O/, and /@/,. as shown below which is commonly known as intrusion.”

“2. R ~ Ø alternation in historically vowel-final words (e.g., E Mass.)

a. tuna [tun@] ü tuna is [tun@r Iz]

b. spa [spa:] ü spa is [spar Iz]

c. paw [pO:] ü paw is [pOr Iz].”

But Gick emphasized that “in most dialects, this alternation never occurs following other vowels. Gick (1999) points out that “the historical development of intrusive r followed an identifiable and necessary sequence of linguistic events: vocalization, linking, merger ( or near merger), reanalysis (intrusion), and generalization.”

In the study conducted by Gick of which he aimed to determine if intrusive r has the same pattern with intrusive l, he found out that “the same pattern is reflected in existing dialect typologies as well. He said, “such an ordering is valuable in pinpointing the present stage of development of the highly parallel intrusive l. This sequence proceeds historically as follows.”

“Postvocalic liquids undergo vocalization. Philadelphia (S Pa.) is well known for this behavior: “In Philadelphia, word-final /l/ is vocalized with great frequency” (Ash 1982b, 162). This process, by definition, applies only to liquids (and possibly glides). Vocalization may be thought of as one instantiation of a more general phonetic process known as final reduction (or, conversely, initial strengthening), which may apply to any consonant. Final reduction is a property of apparently all consonants in all dialects of English studied to date, whereby the articulatory movements of postvocalic allophones tend to be “reduced,” or less constricted, compared with those of prevocalic allophones (Browman and Goldstein 1995; Gick forthcoming a). Liquid consonants, however, are unusual in that they involve multiple lingual articulations (e.g., the tongue front raising gesture and tongue root retraction for /r/; Delattre and Freeman 1968). When liquid consonants undergo ?nal reduction, it is only the anterior articulations (i.e., the coronal constriction for /l/ and the tongue front raising for /r/) that are affected (Giles and Moll 1975; Ash 1982a, 1982b; Hardcastle and Barry 1989, 15; Sproat and Fujimura 1993; Gick 1999, forthcoming a).”

However, according to Gick “the posterior articulations, that is, the tongue dorsum retraction for /l/ and the tongue root retraction for /r/, remain more or less unaffected (see Gick forthcoming b and Gick, Kang, and Whalen forthcoming for further evidence in support of this analysis of liquid vocalization in English). The result is that final allophones tend perceptually to have a stronger “vocalic” component (Sproat and Fujimura 1993) than initial allophones (hence the term vocalization). In its most extreme manifestation, vocalization may result in a complete loss of the anterior articulation.”

On the part of the students, trouble came from the way how I pronounced the words, spoke and wrote the spelling of words using American English. On my part as the teacher, trouble came from the way how the students pronounced the words, spoke and wrote the spelling of the words using British English.

Focusing on pronunciation and spelling as a teacher-researcher, I noticed that when some students wrote, they occasionally omitted letter ‘r’ from the word that ends with letter ‘r’ and even changed the spelling following their own pronunciation. (i.e., ‘otha’ instead of ‘other’; ‘neva’ instead of ‘never’; ‘welda’ instead of ‘welder’; ‘computa’ instead of ‘computer’; ‘teacha’ instead of ‘teacher’). Another observation was students’ pronunciation of few words with letter ‘o’, like for examples, ‘follow’ is pronouced as (fol-o) instead of (fal-ow); ‘blood (blod) instead of (blad); ‘box (boks) instead of (baks). As a result, some of them wrote the words in reffrence to the way how they pronounced them.

Analyzing the situation, my input appeared to be another kind of English to the students and that the students’ feedback, on the other hand, seemed to be another kind of English to me though I already had knowledge about the difference of British English and American English.

As a researcher, I described it as the encounter of two Englishes experiencing difficulty in trying to meet half-way. As a result of the observation I made, the comprehension of both parties was affected. Either I or the students experienced trouble in dealing with the English language.

Conclusion

My research employed quantitative and qualitative approaches in analyzing the data gathered and observed. In the eight written and two oral quizzes I gave, 27 out 30 students were found to be consistent in their errors in writing the spellings of the words with final and middle ‘r’ by dropping them out of the words resulting to inaccuracy in spellings. Five of the written quizzes I designed were to allow the participants to write words with middle and final ‘r’ to complete the sentences. The other three, were to instruct them to write the unknown words with middle or final ‘r’ based on the context clues given. I conducted the two oral quizzes by reading the instructions aloud to let them write the words with middle or final ‘r’. However, similar results were obtained. There were errors in spellings even if I pronounced the words the way how American do it.

Based on these facts, my study proved that pronunciation had a significant effect on spellings of some words, though my study was only focused in determining the words with middle and final ‘r’. My study also found out that pronunciation affected comprehension in learning a new English for the students who were exposed to another kind of English of which reduction of the final sound is practiced . This is the idea confirmed based on this study.

However, the problem raised in the study was not focused directly on the difference of American English and British English but to determine and discuss some common errors committed by the learners as influenced by their pronunciation. This was the reason why the participants of this study performed differently than what I expected as a teacher in trying to teach English using American English.

General Reference : American Speech, Vol. 77, No. 2, Summer 2002
Copyright © 2002 by the American Dialect Society

Oher Reference (cited in Gick’s Study)

Ash, Sharon. 1982a. “The Vocalization of /l/ in Philadelphia.” Ph.D. diss., Univ. of Pennsylvania.
———. 1982b. “The Vocalization of Intervocalic /l/ in Philadelphia.” SECOL Review 6: 162–75.
Bloom?eld, Leonard. 1935. Language. London: Allen and Unwin.
Broadbent, Judith. 1991. “Linking and Intrusive r in English.” UCL Working Papers in Linguistics 3: 281–302.
Browman, Catherine P., and Louis Goldstein. 1995. “Gestural Syllable Position Effects in American English.” In Producing Speech: Contemporary Issues. For Katherine Safford Harris, ed. Fredericka Bell-Berti and Lawrence J. Raphael, 1934. New York: American Institute of Physics Press.
Costa, Paul, and Ignatius G. Mattingly. 1981. “Production and Perception of Phonetic Contrast during Phonetic Change.” Journal of the Acoustical Society of America 69: S67.
Delattre, Pierre C., and Donald C. Freeman. 1968. “A Dialect Study of American r’s by X-ray Motion Picture.” Linguistics 44: 29–68.
Fasold, R. W. 1981. “The Relation between Black and White Speech in the South.” American Speech 56: 163–89.
Fowler, J. 1986. “The Social Strati?cation of (r) in New York City Department Stores, 24 Years after Labov.” Unpublished MS.
Gick, Bryan. 1991. “A Phonologically Motivated Theory of Consonantal Intrusion and Related Phenomena in English.” Unpublished MS.
———. 1997. “The Intrusive L.” Paper presented at the annual meeting of the American Dialect Society, Chicago, 2–4 Jan.
———. 1999. “A Gesture-Based Account of Intrusive Consonants in English.” Phonology 16.1: 29–54.
———. Forthcoming a. “Articulatory Correlates of Ambisyllabicity in English Glides and Liquids.” In Papers in Laboratory Phonology VI: Constraints on Phonetic
a m e r i c a n s p e e c h 77.2 (2002) 182 Interpretation, ed. J. Local, R. Ogden, and R. Temple. Cambridge: Cambridge Univ. Press.
———. Forthcoming b. “An X-ray Investigation of Pharyngeal Constriction in American English Schwa.” Phonetica.
Gick, Bryan, A. Min Kang, and D. H. Whalen. Forthcoming. “MRI Evidence for Commonality in the Post-oral Articulations of English Vowels and Liquids.”
Journal of Phonetics.
Giegerich, Heinz. 1997. “The Phonology of ‘/O:/’ and ‘/A:/’ in RP English: Henry Sweet and After.” English Language and Linguistics 1: 25–47.
Giles, Stephen B., and Kenneth L. Moll. 1975. “Cine?uorographic Study of Selected Allophones of English /l/.” Phonetica 31: 206–27.
Halle, Morris, and William Idsardi. 1997. “r, Hypercorrection and the Elsewhere Condition.” In Derivations and Constraints in Phonology , ed. Iggy Roca, 331–48.
Oxford: Clarendon.
Hardcastle, William, and William Barry. 1989. “Articulatory and Perceptual Factors in /l/ Vocalisations in English.” Journal of the International Phonetic Association 15.2: 3–17.
Harris, John. 1994. English Sound Structure. Cambridge, Mass.: Blackwell.
Jones, Charles. 1989. A History of English Phonology. London: Longman.
Jones, Daniel. 1917. An English Pronouncing Dictionary. London: Dent.
Kahn, Daniel. 1976. Syllable-based Generalizations in English Phonology. New York: Garland.
Kurath, Hans. 1964. A Phonology and Prosody of Modern English. Heidelberg: Winter.
Kurath, Hans, and Raven I. McDavid, Jr. 1961. The Pronunciation of English in the Atlantic States. Ann Arbor: Univ. of Michigan Press.
Labov, William. 1963. “The Social Motivation of a Sound Change.” Word 19: 273309.
———. 1966. The Social Strati?cation of English in New York City. Washington, D.C.: Center for Applied Linguistics.
———. 1994. Principles of Linguistic Change. Vol. 1, Internal Factors. Language in Society 20. Cambridge, Mass.: Blackwell.
———. 1996. “The Organization of Dialect Diversity in North America.” Paper presented at ICSLP4, Philadelphia, 6 Oct. Data published in The Phonological
Atlas of North America (Web site). Available from http://www.ling.upenn.eduphono_atlas/ICSLP4.html.
Labov, William, Malcah Yaeger, and Richard Steiner. 1972. A Quantitative Study of Sound Change in Progress. Philadelphia: U.S. Regional Survey.
Lanham, L. W., and C. A. MacDonald. 1979. The Standard in South African English and Its Social History. Heidelberg: Groos.
Lutz, John. 1984. “A Study of a Midwestern Dialect Using a Computational Model for Linguistic Variation.” Undergraduate senior thesis, Harvard Univ.
McCarthy, John. 1991. “Synchronic Rule Inversion.” In Proceedings of the 17th Annual Meeting of the Berkeley Linguistics Society, February 15–18, 1991, vol. 1,
General Session and Parasession on the Grammar of Event Structure, ed. Laure

Brazing is an effective thermal joining process commonly used in engineering. It is often preferred over other process like welding. Brazing can join almost all the metals and alloys. In this process, a molten brazing alloy is drawn into a capillary gap between the metals being joined. Many forms of brazing alloys are used for fulfilling this requirement. Brazing rods are perhaps the most popular forms of brazing alloys used world over by professionals.

What is a Brazing Rod?

Brazing rod is a piece of metal in the shape of a rod. It melts during the brazing process and attaches to the separate pieces of metals in order to join them together once cooled.

What are the Metals Used for Making Brazing Rods?

Brazing process has the ability to join different metals and components of dissimilar size and mass. However, for this, the perfect form of brazing alloy (filler metal which melts above 450˚C but below the temperatures at which metals being joined melt) has to be present. Therefore, brazing rods have to be made from different metals like aluminum, silver, steel, bronze etc.

What is Flux Coated Brazing Rod?

There are many types of brazing processes which are conducted in different atmospheres. In the one which is not contained within an inert or reducing atmosphere environment (for example a furnace,) flux is needed to prevent oxides from forming when the metal is heated. Not only this, flux also cleans up any contamination that is left on the brazing surfaces. Flux too comes in various forms like flux paste, liquid, powder or pre-made brazing pastes that combine flux with filler metal powder. Sometimes, flux is applied to brazing rods either in the form of a coating of flux or a flux core. This flux flows into the joint when the brazing rod is applied to the heated joint and is displaced by the molten filler metal entering the joint.

To know more about brazing rods as well as other forms of brazing alloys, read Brazing Rod

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Wyoming construction jobs are crucial to the state’s development. Construction is not as important to the rest of United States as it is to this particular region. This is because this activity plays a more important role in the state’s economy than in the rest of United States. About 20,000 jobs were provided in this field in Wyoming in 2002.

This was about 8.1% of the total employment of non farm laborers in the state. Compared to this only around 5.2% of the total non farm laborers of US were engaged in construction.

Construction jobs in Wyoming have increased down the years right from 1990. In the years 1990 to 2002, construction jobs have increased by about 60%. The best part about construction employment in Wyoming is that while other states pay around 3 every week for construction work, this state pays around 2.

Employment Season

Wyoming construction jobs are highly seasonal in nature. The late summer (around August) is the time when jobs are usually the highest. Around the time of February, the jobs decline in nature. In present years, opportunities have increased by about 5000 jobs.

Components

There are three main components of Wyoming construction work. These are: Building Construction, Civil and Heavy Engineering Construction and Specialty Trade Contractors.

Building Construction

This is the most general category of construction. This kind of construction has two parts- residential and non-residential. Residential construction work in this field includes construction of houses for single families, residential remodeling and construction of apartment buildings.

While non-residential construction includes institutional, commercial and industrial buildings. General contractors are employed in this industry. This field provided around 4000 jobs in 2002. However it is still the smallest field when it comes to construction job opportunities in Wyoming.

Civil and Heavy Engineering Construction

This includes all the heavy public engineering construction jobs that require special training. This kind of job includes the construction of utility systems like pipelines, bridges, streets and highways. This is the second largest field in the construction arena accounting for about 5400 jobs in the year 2002.

Specialty Trade Contractors

This is the largest field of construction in the state. In 2002, this field accounted for about 9800 jobs. This kind of construction work revolves around special trades. Special trade involves electrical work, roofing, flooring, painting, plumbing and framing contractors. Most often personnel of this field are seen to make contracts with the general contractors involved in the work of the first kind.

Opportunities

How many jobs are found in a year is dependent upon construction of power plants and pipelines and federal highway spending. It is difficult to make an estimate of how many jobs will be provided by heavy civil engineering as this kind of project is very irregular. Several factors like population and growth of income also affect construction jobs in Wyoming.

With growth of both these factors, arrives an intense demand of construction work. But it can be said without doubt, that Wyoming construction work will increase in the future to come due to the high demand for construction and new companies venturing into the state. The economy in Wyoming is growing rapidly due to construction jobs.

Wyoming construction jobs are thus a great prospect for money and respect.

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