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By Hal H. Engel

This publication was written in response to numerous requests for information about the Federal Bureau of Mines' "Demonstrated Lecture on Flame Propagation and Permissible and Explosion-Proof Electrical Equipment." The requests came principally from: (1) Persons wanting to know more about the demonstration before requesting it for groups they represented; (2) persons wishing advance information to help publicize a meeting where the demonstration was to be given; and (3) members of audiences desiring something to help them remember the salient points, facts, and figures presented during the lecture and demonstration. The purpose of the demonstration that accompanies the lecture is to show: (1) Variations in flame speed and pressure at various percentages of flammable gas within the flammable range; (2) effect of flame speed on the "pressure piling" within the area confining the mixture; and (3) the application of flame speed and pressure piling to the combustion of surrounding gas and to the design and maintenance of electrical equipment used in hazardous locations.

Jan 1, 1960

By James H. Scott

A technique of seismic refraction data analysis has been developed in which a digital computer is used to generate a two-dimensional model representing a layered-earth depth interpretation. Travel times are picked on seismic records by the human interpreter. These times, together with shot point and geophone locations and refraction layer control information, are submitted to the computer on punched cards. A first approximation delineation of each refraction horizon is obtained by a computer adaptation of the delay-time method. The approximation is then tested and improved by the computer through the use of a ray-tracing procedure in which ray travel times computed for the model are compared against field-measured travel times. The model is subsequently adjusted in an iterative manner so as to minimize the discrepancy between computed and measured travel times. The Fortran program is listed in the appendix of the report together with instructions for preparing data cards and examples of results.

Jan 1, 1972

By J. O. Jones

[Willis Mountain in southeastern Buckingham County is one of several kyanite deposits its central Virginia. It is composed principally of kyanite resulting from metamorphism of siliceous sedimentary beds rich in alumina. The mountain, which trends north-south, is 2 miles long and is topped by a narrow ridge with sleep rugged sides rising to an altitude of 1,160 feet and projecting 500 fast shove the surrounding countryside. Bureau Mines engineers examiner Willis Mountain early in 1949, when bonded concentrations of coarsely crystalline kyanite were observed in the kyanite-quartzite on the northern end of the mountain and in loose boulders on the eastern slope. Commencing in late July 1949, the investigations continued on the Long Mountain segment for 11 months, ended in June 1950. A total of 600 samples from 32 diamond-drill holes, aggregating 3,876 feet of drilling, and from 255 feet of sampling in 3 trenches was assayed for kyanite and ferric oxide.]

Jan 1, 1954

By Ernest L. Corp

The natural marine environment can be divided into four basic categories: the air-sea interface, the water zone, the seafloor, and the subbottom. Efforts are being made to accumulate data to delineate the conditions in each of these areas and to conduct engineering studies which will determine how these environmental parameters affect the mining process. Laboratory facilities have been constructed and equipment and techniques for scientific data collection and laboratory research have been developed. Major emphasis is being placed on studying the subbottom material. The objective of this emphasis is to study the engineering properties of marine placer deposits in order to assess their influence on the design and performance of the various mining subsystems involving penetration, excavation, transportation, and disposal. Presented are the results of engineering properties tests on a placer simulant which is currently being used for model and prototype testing of coring tools. The effect of these engineering properties on penetrability, core recovery, and sample recovery is discussed.

Jan 1, 1970

By Edward A. Barrett, Lynn L. Rethi

From 1987 through 1996, 13 fatalities occurred at underground operations in the U.S. stone mining industry. A review of the underground limestone mine industry data for this 10 year period indicated a high fatality concentration in one area: ground failures.

By Charles Anema

The Mancarried and Helicopter Receivers were developed under the contract I for trapped miner location. This program was a five phase program with 15 mancarried and 5 helicopter production receivers delivered under Phase IV and equipment documentation required under Phase V.

Jan 11, 1976

By Maust. E. J., W. R. Crane

"IntroductionIn the study of mine drainage in the red iron ore mines of the Birmingham district of Alabama, an extensive series of measurements were made in order to determine the drainage from the area overlying and adjacent to the mines. Gaging rods were generally used in measuring streams, and weirs in ditches and sometimes as a check on rod work. These tests in turn were checked by current meter tests. In all, 725 separate stream gagings and 97 weir measurements were made. Certain relationships were worked out, particularly between rod and weir tests, which permitted obtaining results that are much more accurate 'under the existing conditions, than any available formula would give. The large number of weir measurements and the period covered by the tests made it impracticable to construct a weir for each observation so portable, adjustable weirs were built. The methods used are described here for the benefit of those interested in measurement of streams in connection with a study of mine drainage or otherwise. The Drainage AreaThe area draining the mining district lies between the crest of Red Mountain and Little Shades Creek, and for convenience was divided into sub-districts adjacent to certain groups of mines. Gaging stations were established on Little Shades Creek at the upper and lower boundaries of each sub-district, also at points on the tributaries near their junction with the creek. The difference between the volumes of water flowing in Little Shades Creek as it entered and left the sub-districts represents the flow from the tributaries on both sides of the creek. Since the flow coming from the sub-districts was measured direct, the inflow from the tributaries on the opposite side of the creek can be computed from the three volumes determined."

Oct 1, 1926

"Correlatina Lung Crackle Usina Holographic lnterf erometryAli Afshari, MS, West Virginia University, 1989The Effect or Surfactants on Suppression of Non-Wettable ParticlesAli Alaboyun, MS, Mineral Engineering, The Pennsylvania State University, 1989Geochemical Characterization of Kerogem, ShaJes, and Coal .Refme ~ted with Allegheny Fonnationof Cases of Northern West VirginiaDick Andre, MS, West Virginia University, 1987Particle Concentrations in a Hazelton Inhalation ChamberShahram Bavani, MS, West Virginia University, 1985Use and Potential of Luer Holographic Interferometry and Subsidence Model Study of an Underground.Room and Pillar MineRichard Begley, MS, West Virginia University, 1984Development of a Mechanistic Model for Prediction of Subsidence in a Longwall MineRichard Begley, PhD, West Virginia University, 1990.Redesign of Micro-Orifice Unifonn Deposit ImpactorSteve Behm, MS, University of Minnesota, 1991A Fracture Mechanics Study of Crack Propagation Mechanism in Coal: The Mechanics of Fine FragmentFonnationZ. T. Bieniawski and R. Karl Zipf, Jr., Mining Engineering Department, The Pennsylvania State University,University Park, PA. Final Report, October 1, 1988A Mathematical Model for the Prediction of Ambient Dust Concentrations in Mine AtmospheresR. Bhaskar, MS, Mining Engineering and Operations Research, The Pennsylvania State University, 1984Spatial and Temporal Behavior of Dust in Mines-Theoretical and Experimental StudiesR. Bhaskar, PhD, Mining Engineering, The Pennsylvania State University, 1987Experimental Studies of Dispersion and Deposition of Fane Particles in a Wind Tunnel and Mine AirwayKlaus Bode, MS, Mining Engineering, The Pennsylvania State University, 1991Perf'onnance of the High Yield Technology PM - 100 - Particle 11ux MonitorRobert Caldow, MS, University of Minnesota, 1987Development of Improved Methods for Monitoring and Control of Diesel Particulate in an Underground CoalMineD. H. Carlson, B. C. Cornilsen, P. L. Loyselk, X. Shan and J. H. Johnson, Michigan Technological University,Houghton, Ml. Final Report, June 15, 1991"

Mar 1, 1992

By H. H. Schrenk

[A colorimetric method5/ for the determination of benzene in amounts as low as 0.001 mg has been developed recently at the U.S. Bureau of Mines Pittsburgh Experiment Station by the authors, with the assistance of chemical personnel fro a the Allegheny County (Pa.) Relief Works Division. The method is based on the direct nitration of either liquid - or gas - phase benzene, followed by neutralization, extraction with butanone, and final treatment with sodium hydroxide which produces a violet color. The color is matched with color standards of known values. Although the method is adaptable to many conditions the primary objective was a procedure that would be suitable for hygienic investigations. The development worth included a study of possible interference by chemicals that be present in those situations in which the method. would be employed. In this study it was found that a specimen of hexane prepared by the Gulf Research Laboratory, Pittsburgh, by fractionation of West Virginia natural gas gave positive result for benzene, whereas a specimen of pentane prepared in the same manner showed only a trace, and specimens of n -heptane and octane (2,2,4 trimethylpentane) supplied by Eastman Kodak Co. save a negative result. According to information obtained from the Eastman Kodak Co. the latter two compounds were highly purified, the n-heptene being prepared from line and the octane synthesized in the laboratory. On nitration of a larger amount of tae natural hexane a visible quantity, of needlelike crystals which resembled those of m-dinitrobenzene was obtained. The hexane from this nitration was recovered by distillation and again nitrated, but no crystals or colorimetric indication of benzene was obtained. This imitated that the specimen of natural hexane contained a substance which at least had the chemical behavior of benzene.]

Jan 1, 1935

By C. V. Davis

In the lnvestlg::ìt1on of mAthods for aSS8.7ing platin",. conducted by the Bureau ot MinAs, reoent experiments have d~velopad tha~ with ce..tain orei, especially when thr, quantity Of platinum 1s eonlidarablfl, nit'!le acid w111 not etfßct a iepard-Han of platinum and pa11adium. 'lhe following m;lthod has been found to be accurate and to reiu1 t in a complete S''lun''ation of' th~3:l metals. It is therefo 1" '!eeommei:ed that 1 t ba followed rath::r- than the method of separation with nitrio acid, givèn in Technical Pape'! 270.* At line 22, pagi 14, of that paper, bAglnnlng with ~tarm th,~ metals '.'ith dilute¡ nitrio acid," strikE out the rest of the paragraph, and substttutt~ the pro_t cedure g1 ven below. ?lunder and Thuringer.. have developed mnt¡iods for th"i sflparation of palladium from all the platinum metals exoept platinum bj m ,ans of dlmethy- 19lyoxlme. They state that the~ is no action for several hours if an excess of dimeth¡lglyoxime is added to an aqueous solution of ohloroplatinic acid in the cold, alio that only on boiling is the platinum pTecipi ated ¡~d than only PST't of the platinum i srenoved from the sUut1on. They found that palladium 1s p~ecipi tated quati tat! vely in the oold as (CaH 4N40 Pd) which is insoluble tn water, dilute hydroohlorio acid, dilute acetIc aofd or in 50~ ethyl alcbhol. All of their pT'90ipi tations we~p Carl". ied out ~hile the solutions were being heated. This caused a pal"tia~recipltation of the platinum along wi th the

May 1, 1922

By V. P. Bhavanandan, S. B. Dubbs

The mucus secreted in the respiratory tract provides the first barrier against inhaled particulate and gaseous toxicants. The major component of mucus which is responsible for the physical properties and protective functions of the respiratory mucus is mucin. We have initiated investigations to determine the effects of coal mine dust on the synthesis of respiratory mucin by rat trachea under in vitro and in vivo conditions. In this study we have established optimum conditions-:ro-r~ the asceptic growth and mucin secretion of rat tracheal explants in culture. The best outgrowth of ciliated epithelial cells and maximum mucin production was obtained in CMRL 1066 medium containing 10% fetal calf serum. The explants continued to secrete mucin even after three weeks in culture. For the estimation and characterization of mucins the tracheae were cultured in the presence of [3H] glucosamine and [35S] sulfate or [14C]leucine. The mucins were isolated from the medium by gel filtration, treatment with hyaluronidase, ion exchange chromatography and CsBr density gradient centrifugation. Precipitation of polyanionic material in the culture media with cetyl pyridinium chloride and fractional extraction with NaCl also yielded mucin free of glycosaminoglycans, but in low yields. The tritium label in the purified mucin was distributed in sialic acid (50%) galactosamine (37%) and glucosamaine (13%). The density of purified mucin as determined by CsBr gradient centrifugation was about l.43g per ml in comparison to l.46g per ml for human respiratory mucin with a carbohydrate content of about 80% by weight. Alkaline borohydride treatment released saccharides which contained about 80% of the radioactivity. The effect of adding varying amounts of coal dust to the culture medium is under investigation. (Supported by U.S. Bureau of Mines Grant G1135142, Project 4210).

Jan 1, 1989

By H. H. Storch

Methane is the chief constituent of natural gas, and large quantities of it are also obtained in coke-oven gas and in the off-gases from cracking higher hydrocarbons. Perhaps the most important potential chemical use of methane is in the production of higher hydro- carbons, both aliphatic and aromatic. The results of a relatively large number of researches have been published in the technical and patent literature on the thermal decomposition of methane, the objective being an industrial process for the production of "antiknock" motor fuel. No industrially feasible process has, however, been developed. An inspection of the literature on this subject indicates that the chief difficulty in the way of accomplishing this object lies in controlling the decomposition so that undesirable products are eliminated. A considerable number of quantitative experiments have been reported, the results of which provide only a vague and confusing picture of the various steps in the thermal decomposition of methane. The reaction mechanism has not been subjected to rigorous fundamental study, and the necessity for such a study is obvious if further progress is to be made. The thermal decomposition is only one of the reactions of methane which are of potential industrial importance and which require further fundamental investigation. The oxidation, hydrolysis, and halogenation of methane are other reactions which must be studied further. In view of the importance of methane as a raw material for various industrially desirable products, it is appropriate that a survey be made of the important facts concerning the physical and chemical properties of methane which will serve as an aid in subsequent experi- mental work. No attempt will be made to present a complete chronological review, but rather a condensed critical description of the important literature will be presented.

Jan 1, 1932

By D. S. Colby, E. M. SEELEY

The total production capacity of the natural-gasoline industry increased to 27,212,000 gallons (647,905 barrels) daily on January 1, 1950, from 21,322,000 gallons (507,670 barrels) daily on January 1, 1948. The rate of growth during these 2 years averaged 13 percent per year, compared with 9 percent per year from 1946 to 1948 and 6 percent from 1944 to 1946. The total number of operable plants on January 1, 1950, was 554, 5 more than at the beginning of 1948. The number of absorption plants increased by 12, the number of cycling plants by 7, and the number of combination plants by 4. The number of compression plants and charcoal plants continued to decrease. Absorption plants accounted for 67 percent of the total capacity on January 1, 1950, compared with 62 percent 2 years previous. Eighty-two per- cent of the expansion in these 2 years was in absorption-plant capacity. Cycle plants accounted for 24 percent of the total industry capacity at the beginning of 1950, compared with 27 percent on January 1, 1948. The average daily capacity of absorption plants increased from 38,400 gallons at the beginning of 1948 to 50,600 gallons at the beginning of 1950. During the same period, the average daily capacity of cycle plants decreased from 150,200 gallons to 144,100 gallons. Texas showed the largest gain in number of plants 13 absorption, 4 compression, and 4 cycling plants. The State accounted for 67 percent of the gain in capacity and on January 1, 1950 had 50 percent total national capacity. Louisiana followed with 7 additional plants. Pennsylvania reported 14 and West Virginia reported 13 fewer plants than in 1948. Most of these reductions were in the number of compression plants.

Jul 1, 1950

By Thomas V. Falkie, R. Venkataramani

Hand portable truck axle scales were purchased from the Martin¬Decker Company, Santa Ana, California, for weighing the rubber-tired mine shuttle cars. The scales consisted of two hydraulic load-pads, measuring 4" thick, and 21" long by 13" wide at the pad surface and one totallizer-dial indicator unit. The development of a technique to install the scales effectively for shuttle car-weighing followed an evolutionary process. The setup which finally proved to be effective entailed countersinking and level¬ling the load pads in the floor on the shuttle car trackway such that the tops of the pads were three inches below the floor level. A plat¬form consisting of two braced side-by-side 3" x 8" lumber planks was made. The platform was placed across the load pads with six inches of overlap on each side to provide room for imperfect tracking of the shuttle car. Additionally, 3" x 8" lumber planks were imbedded across the runway immediately behind and ahead of the platform. These auxili¬ary planks were firmly braced into the floor by vertical posts or jacks set against the roof; the planks constituted a stable approach platform to enable the shuttle car to roll unimpeded onto the scale platform in either direction of travel. Figure 22 shows this arrangement in detail. The setup of the scales was done during non-production hours prior to the first working shift of the week. This task took seven to twelve hours with two men. During the actual weighing experiment, the following limitations were realized. 1. Delays will be introduced into the cycle of operations because the shuttle cars must be stopped and positioned on the platform. However, these delays can be held to a minimum, time wise, as the

Jan 1, 1972

By Bruce K. Cantrell, Winthrop F. Watts

The U.S. Bureau of Mines and others have conducted a number of occupational exposure surveys since the publication of the International Agency for Research on Cancer report of 1989(1), which labeled diesel exhaust as a probable human carcinogen. These surveys have assessed diesel exhaust exposure using measurement of diesel aerosol and/or specific polycyclic aromatic hydrocarbons as indicators of exposure. This report reviews, available diesel exhaust aerosol and gas measurement techniques. Measurement of human exposure to toxic agents is the first step in determining the exposure-dose-response relationship. It is a fundamental step in risk assessment. Measuring exposure to diesel exhaust pollutants is particularly challenging due to the complexity and variability of exhaust components. This paper reviews current occupational health standards for diesel emissions and available diesel exhaust gas and aerosol measurement techniques. Although surveys in mines have primarily assessed diesel exhaust exposure using diesel particulate matter (DPM) some exhaust gas measurements have been used as indicators of exposure. DPM is emphasized because it is a major component of diesel exhaust, is suspected to make a major contribution to the health hazard, and is measurable. OCCUPATIONAL HEALTH STANDARDS Occupational exposure surveys of diesel exhaust frequently measure regulated pollutants, or pollutants that are suspected carcinogens, even if no permissible exposure limits (PELs) have been established. In the United States, various organizations recommend a range of allowable values for diesel exhaust gaseous constituents, including carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO.), nitrogen dioxide (NO2), nitric oxide (NO), and formaldehyde (HCHO). Table I summarizes these recommended levels, showing 8-hour or 10-hour time-weighted-average values where available; where these are not available, 15-minute short-term [ ]

By J. D. Davis

Coke Since the beginning of manufacturing of metallurgical coke in the United States, which dates from about 1859, Pennsylvania has main tamed supremacy in coke production Available statistics for the year 1880 show an output of 3,338,300 short tons, which was neatly trebled by the end of the succeeding 10 years. From this time on the increase was steady, though not rapid, and in 1922 the total production was 13,991,892 tons, which is approximately 37 per cent of the total coke production of the United States. The main reason for the rapid development of the coke industry in Pennsylvania lies in the abundance of coals particularly adapted to beehive coking, for which purpose the Pittsburgh bed in the Connellsville district has long been looked upon as standard At first practically all metallurgical coke was made in beehive ovens, the only exception being the short lived and wasteful method of coking in piles, byproduct owns did not make then appearance until after 1893 The suitability of a beehive coking coal cannot be accurately predicted from its chemical analysis, but it can be said, perhaps, that the volatile matter should be about 32 per cent, and that the oxygen content should not be mole than 10 pet cent or less than 4 per cent The sulphur and phosphorus content should be small-not over 1 25 per cent sulphur and under 0 02 pen cent phosphorus-and the ash content should not be over 7 per cent The Pittsburgh bed at Connellsvnlle fills these requirements well, as may be seen from the following representative analysis. Analysts of coal from Pittsburgh bed Moisture 1 70 Volatile matter 31 10 Fixed carbon 59 80 Ash 7 40 Sulphur 0 85 B t u 13,990

Jan 1, 1928

By R. J. Matetic

The National Institute for Occupational Safety and Health (NIOSH) has recognized that Noise-Induced Hearing Loss (NIHL) is the most common occupational illness in the United States. The use of heavy equipment, the drilling of rock, and the confined work environment are some of the factors that contribute to high levels of noise exposure to workers in the mining industry. Every day 80% of the nation’s miners go to work in an environment where the time weighted average (TWA) exceeds 85 dBA. Moreover, 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the Permissible Exposure Limit (PEL). Furthermore, a NIOSH analysis of a large sample of audiograms showed that at age 50 approximately 90% of coal miners and 49% of metal/non-metal miners have a hearing impairment. By contrast, only 10% of the non-occupational-noise exposed population has a hearing impairment at age 50 (Franks, 1997) (Stephenson, 1998). Simply stated, the majority of miners have a hearing loss by the time they retire. While NIHL is the most common occupational disease in this country, this problem is especially acute among workers in the mining industry. There are several barriers to reducing NIHL in the mining industry. These include: gaps in knowledge of noise dose/source relationships, the unavailability of effective noise controls, and needs for worker education and worker empowerment. A related issue is the difficulty of communication in noisy workplaces by both hearing impaired and normal hearing workers. The Pittsburgh Research Laboratory (PRL) at NIOSH has strategically developed a hearing loss prevention program for overcoming these respective barriers in an attempt to reduce NIHL in the mining industry. This paper provides an overview of the research program being conducted at the PRL.

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

1. Introduction This document represents Part II of our final report on the development of a "Remote Sealing System for Extinguishing Coal Mine Fires. " It is a technical report which summarizes the results of system development and field demonstration. Part I of this two - part final report is an Operator's Manual for the application of the Remote Sealing System to a coal mine fire. 1.1 Background When coal mine fires go out of control and can no longer be fought directly, the standard fire fighting technique is to construct air-tight seals in the mine passages leading to the fire area so'--,that the oxygen supply to the fire is". cut off. Ultimately, it is desirable to isolate the fire zone in such a way that normal operations can resume in the remainder of the mine. The construction of seals in the- mine causes the atmosphere to pass through a toxic and explosive phase. Explosions, if they occur, are not only hazardous to the men working at the sealing operation, but can also undo much of the sealing work which has already been accomplished. Sealing of passageways surrounding the fire zone from within the mine is extremely difficult and dangerous. Methods for direct sealing are detailed in "Control of Mine Fires'. 1 An alternative to this approach is the technique of remote sealing. This involves drilling boreholes which intersect the mine passages at the locations where the desired seals are to be constructed. The seals are then constructed by pouring material down the borehole and filling a segment of the passage from bottom to top. During this operation, there are no personnel in the mine, all operations taking place on the ground surface.

Jan 1, 1973

By Kathleen Kowalski-Trakofler, Edward Barrett

Problem: It is estimated that 5 to 10 arc flash explosions occur in electric equipment every day in the United States. In the mining industry the largest single injury category of electrical injuries are caused by non-contact electrical arcs. Method: This investigation progressed in two phases: (a) 836 Mine Safety and Health Administration (MSHA) reports of electric arcing incidents that occurred over a period of 11 years were reviewed, and (b) personal interviews were conducted with 32 individuals. A theoretical Safe Job Performance Model guided the study. Results: Behavioral dimensions were identified and included the effect of worker experience, judgment and decision-making ability, behavioral and organizational controls, and safety culture. Summary: The National Institute for Occupational Safety and Health (NIOSH) conducted an investigation of behavioral components associated with arc flash incidents and developed recommendations for interventions based on findings. Impact on Industry: This study fills a vacuum in electrical training with a focus on the organizational and behavioral aspects of arc flash incidents. There search is cross-cutting in its scope, in that the results apply not only to mining and construction, but many other industries employing electricians. Although the majority of mine electrical injuries are the results of burns from electrical arcs, few miners are aware that such a hazard exists. A safety training program, which includes a video and an instructor's discussion guide, was developed for electricians based on this study's findings. “Arc Flash Awareness” was released in 2007 (DHHS NIOSH PublicationNo.2007-116D) and is available through1-800 CDC-INFO. Phone:1-800232-4636 or email cdcinfo@cdc.gov. It is also available from MSHA at MSHADistribution@dol.gov or 304-256-3257 (DVD-576). Private industry is producing Portuguese and Spanish language translations.

By Lloyd A. Morley, Robert Stefanko

1 Abaibanel, S , "Deflection of Confining Walls by Explosive Loads," Israel Jour. Technology, vol. 4, n. 1, Feb 1966. 2 Albertoni, S and others, "Numerical Computation Methods for Implosion Processes," EURATOM Proc. of the Conf. on Megagauss Magnetic Field Generation by Explosives and Related Experiments, Milan (Italy), July, 1966. 3 Alexander, S. J , and Hambly, E. C., "Design of Structures to Withstand Gaseous Explosions," Concrete, vol. 4, n 2, Feb. and March, 1970. 4 Anonymous (Belgium Institute of Extractive Industries), "Report for 1968 (covering approved equipment for Belgiums gassy coal mines)," (in French and Flemish), Amales des Mines de Belgigue, n. 6, June, 1969. 5. Anonymous (Ghent Univ., Belgium), "The Welding of Very Thick Steels. Margin of Uncertainty of the Robertson Test," EURATOM Contract 042-61-9-RDB, May 20, 1965. 6. Anonymous, "Inportance of the Nature and Size of Weld Defects with Regard to the Mechanical Strength of Pressure Vessels, (in Flemish), A. Sys. Rev. Soudure, vol. 27, n. 3, 1971. 7. Anonymous (Raentgen Technische Dienst N V., Rotterdam), "Non¬Destructive Welding," Quarterly Report No 13, EURAEC - 1342, March 30, 1965. 8. Anonymous (Staff, USBM Safety Research Center), "Research and Technologic Work on Explosives, Explosions, and Flames: Fiscal year 1969," USBM IC8492, 1970. 9. Anonymous, "Symposium on Flameproofing Intrinsic Safety and Other Safeguards in Electrical Instrument Practice, April 27, 1962," IEEE Conf. Report Ser. 3, 1963. 10. Anonymous, "Unfired Pressure Vessels," ASME Pressure Vessel Code, Sec. 8, 1965. 11. Anonymous, "Unusual Pressure Relief Devices," Industrial and Engineering Chemistry, vol 54, n. 1, Jan., 1962. 12. Archer, G. L., "Design to Avoid Brittle Fracture in Welded Structures," Paper No. 4, Improving Welded Prod Design, vol. 1, Welding Inst., Cambridge, England, 1971. 13. Bailey, F. C., "Buckling and Failure Strength of Plating Panels Loaded in Shear," Final Report NASA Contract NObs-72290, Lessels and Assoc., Inc., Waltham, Mass., Sept. 20, 1963.

Jan 1, 1974