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By AIME AIME

MONDAY evening a reception, supper and bridge in honor of the guests of the Woman's Auxiliary was given by the New York Section in the Engineering Woman's Club. After supper, tables were made up for bridge. Some tried jig-saw puzzles, while others merely visited. On Tuesday morning the annual business meeting was called to order by President Bassett. Mrs. Bassett read a note from Mrs. Hoover regretting her inability to be present, and then gave her welcome and message: It gives me much pleasure to welcome you in this annual meeting, and I hope you will be able to come next year, and those who are not able to come this year I hope will be here next year.

Jan 1, 1933

Industrial minerals enjoyed a fairly successful year in 1978, despite the sluggish economy, inflation, and environmental restrictions. A glance at US Bureau of Mines statistics shows that, in general, production of industrial minerals increased from + 1% (salt) to as much as 26% (sulfur, other than Frasch or recovered). A few industrial minerals showed a decline; fluorspar production, for example, registered a 23% decrease in 1978 from 1977 due to the closing of three domestic mines. Bromine, natural sodium sulfate, Frasch sulfur, and vermiculite also had production decreases of 2-6% in 1978.

Jan 5, 1979

By Jordan Romero, Jimmy Nettles, Daniel Sprunk

The Venture Global Plaquemines LNG Project in Port Sulphur, Louisiana, stands as a great achievement in the world of liquefied natural gas (LNG) infrastructure. Encompassing a 632 acre (255 ha) site, 20 miles (32 km) south of New Orleans along the Mississippi River, it's designed to be one of the largest LNG export facilities in the U.S., with the capacity to handle up to 20 million metric tons (22 T) of LNG per year. The project's scope includes multiple LNG trains, storage tanks and large marine terminal infrastructure. The construction involves significant civil works, including deep foundation and flood protection systems. Given the scale and complexity of the project, the construction process is highly intricate, involving a multitude of deep foundation disciplines and coordination among various contractors and stakeholders. Cajun Industries was tasked with several critical components of the piling and civil construction phase, including the development of hurricane protection systems and the execution of extensive deep foundation scopes through the life cycle of the project. This involvement in the project began with a small-scale precast concrete test pile program using just one pile driving rig in 2020. By May 2024, operations had expanded significantly, with a peak workforce of 200 employees, 30 piling rigs and 15 different piling scopes. These scopes included a design-build flood protection system for the project's laydown yard and construction support facilities, single-piece pipe piles up to 145 ft (44 m) long, precast concrete piles up to 120 ft (37 m) long, 41 cofferdams with sheet piles up to 80 ft (24 m) Jong, as well as 140 ft (43 m) long H-piles. The scope also encompassed a comprehensive test pile program featuring more than 150 load tests. Over the course of the project, the team executed more than 575,000 safe man-hours, installing 18,300 piles of various types and sizes. These efforts equated to the installation of more than 1,965,9001ft (600,000 m) of piling or 372 mi (600 km), weighing a staggering 312 million lb (142 million kg). For perspective, one could travel three round trips to outer space when comparing the linear footage of piling.

Sep 1, 2024

By V Rajakumar, S Trang

Titanium has the potential to become the third wave of light metals used in high volume applications, following on from aluminium and magnesium. These light metals have functional attributes that can meet many of the goals needed for societyÆs transition to sustainable development. CSIRO has initiated a Light Metals Flagship to focus additional R&D efforts in support of the light metals industry. The vision of the Light Metal Flagship is for Australia to lead the Light Metals Age by reducing the costs and environmental impacts through innovative technologies for these metals. Life cycle principles will be used to identify novel technology pathways for metal production and product manufacture that are more energy efficient, less capital intensive and incorporating eco-efficient material flow chains.Under the auspices of the Light Metal Flagship, a Life Cycle Assessment (LCA) of titanium metal production was carried out with mineral sands mining of ilmenite as the starting point. Upgrading of the ilmenite to synthetic rutile by the Becher process and titanium metal production by the conventional Kroll process were the processing routes considered. Two alternative processes for titanium metal production, the FFC Cambridge process involving direct electrochemical deoxygenation of titanium dioxide, and a plasma process for producing titanium powder from titanium tetrachloride were also examined using LCA methodology and compared to the Kroll process. The environmental impacts included in the LCA were greenhouse gas emissions (Global Warming Potential, GWP) and acid rain gas emissions (Acidification Potential, AP). The Gross Energy Requirement (GER) of each process was also determined.These results for titanium, along with those from previous LCA studies by CSIRO on aluminium, magnesium, steel and stainless steel production, were used to show that despite the relatively large amounts of primary energy required for the production of these light metals, their special properties (eg corrosion resistance, strength and light weight) mean that these metals offer potential GER and GWP reductions compared to other competing materials in a number of applications, when viewed on a life cycle basis. Two applications considered in the paper are the lightweighting of motor vehicles and chemical plant equipment manufacture.

Jan 1, 2004

By S. K. Kawatra, T. C. Eisele

"Coal-fired electrical power generation plants produce 56% of all the electricity in the U. S., burning approximately 860 million tons of coal annually. This results in production of 58 million tons of fly ash; 19 million tons of bottom ash and boiler slag, and 23 million tons of desulfurization sludges. These are a considerable disposal problem, and it would therefore be very valuable to be able to sell these residues and byproducts as useful materials, rather than paying to dispose of them in landfills. However, utilization rates are currently very low, below 32% even for the most thoroughly commercialized combustion byproduct (fly-ash). This poor utilization rate is a result of the high impurity content of combustion byproducts, which make them unsuitable for existing markets. The experiments described in this paper were therefore carried out to study the application of mineral processing techniques to upgrading combustion byproducts.Experiments were conducted to upgrade and purify low-grade combustion products to produce highgrade, readily saleable materials. A process was developed for removing unburned carbon from coal fly-ash by froth flotation, using reagents originally developed for flotation of oxidized coals. This technique could reduce the carbon content of fly-ashes containing up to 11.1% carbon to less than 2%. The froth product was sufficiently carbon-rich that the recovered carbon has value as fuel, or as low-grade activated charcoal.Fly ash was also examined as a binder for producing iron ore pellets, primarily as a substitute for bentonite. It was found that Class F fly ash in combination with an activator (calcium hydroxide) was an effective pellet binder at dosages comparable to the currently-used dosages of bentonite clay. While the flyash worked very well alone, tests in combination with bentonite showed that fly-ash/bentonite mixtures had significantly worse binding performance than either pure bentonite or pure fly-ash-based binder. This was determined to be due to the fact that bentonite and fly ash have profoundly different binding mechanisms, with fly-ash undergoing a pozzolanic chemical reaction while bentonite binds through a physical attachment process."

Jan 1, 2003

By Charles C. Rodd

Prior to 1938, proration procedure in Kansas required the physical testing of wells in order to set up a basis for allocating production. Subsequently the use of liquid-level data and bottom-hole pressure data was authorized on certain types of wells as a basis for calculating well capacities, thereby permitting wells to be tested at low rates and with small volumes of production. This paper gives some attention to the equipment used for obtaining liquid-level data but in general it is devoted to the theoretical and physical factors involved in well testing by drawdown methods. These tests are divided into two classifications: (I) liquid-level data used directly to calculate capacities, and (2) liquid-level data and liquid-level measuring equipment used in connection with other data to determine bottom-hole pressure. Equations and calculations for both types are shown. Well capacities calculated from fill-up data have not been used generally but offer a simple means of testing some wells. Theoretical factors and calculations for such tests are shown. In the state of Kansas, proration laws required that the "ability of a well to produce" be given consideration in state allocation orders and for many years this was the only factor used in prorating the allowed oil. The "ability of a well to produce", was the quantity of oil that could be obtained from a well in a prescribed period, usually 24 hr. Early in the history of State-regulated proration, Kansas operators realized that, unless some restriction were placed upon equip- ment, the competition between producers to obtain large well "potentials" might result in a race to install the largest pumping equipment. Consequently, restrictions were placed upon the size of tubing and length of pump stroke that could be used in pumping wells during potential tests. Later, restrictions were placed also upon the size of tubing and chokes that could be used in flowing walls. Despite the restriction setup, better pumping equipment was designed and installed, pumps were improved, and various devices were invoked to obtain high rates of production for short periods of time. By 1937 pumping cycles of forty to forty-five 54-in. strokes per minute were not uncommon, and numerous wells had produced at the rate of 3500 bbl. per day for short periods. Such production was far beyond any rate that could be long sustained. Equipment necessary to take "potentials" was several times larger than that needed for normal producing purposes, and repairs and replacements required by the high pumping speeds were excessive. Also, many operators suspected that the high rates of production main tained during '"potential" tests were conducivc to early water encroachment. By 1938 large-scale physical testing of wells in Kansas ended, the use of the bottom-hole pressure gauge had become common, engineers and operators were becoming familiar with the term ''productivity index," and bottom-hole pressure was being used as a factor in allocation in many areas. There were many drawbacks, however, to large-scale use of

Jan 1, 1943

By Charles C. Rodd

Prior to 1938, proration procedure in Kansas required the physical testing of wells in order to set up a basis for allocating production. Subsequently the use of liquid-level data and bottom-hole pressure data was authorized on certain types of wells as a basis for calculating well capacities, thereby permitting wells to be tested at low rates and with small volumes of production. This paper gives some attention to the equipment used for obtaining liquid-level data but in general it is devoted to the theoretical and physical factors involved in well testing by drawdown methods. These tests are divided into two classifications: (I) liquid-level data used directly to calculate capacities, and (2) liquid-level data and liquid-level measuring equipment used in connection with other data to determine bottom-hole pressure. Equations and calculations for both types are shown. Well capacities calculated from fill-up data have not been used generally but offer a simple means of testing some wells. Theoretical factors and calculations for such tests are shown. In the state of Kansas, proration laws required that the "ability of a well to produce" be given consideration in state allocation orders and for many years this was the only factor used in prorating the allowed oil. The "ability of a well to produce", was the quantity of oil that could be obtained from a well in a prescribed period, usually 24 hr. Early in the history of State-regulated proration, Kansas operators realized that, unless some restriction were placed upon equip- ment, the competition between producers to obtain large well "potentials" might result in a race to install the largest pumping equipment. Consequently, restrictions were placed upon the size of tubing and length of pump stroke that could be used in pumping wells during potential tests. Later, restrictions were placed also upon the size of tubing and chokes that could be used in flowing walls. Despite the restriction setup, better pumping equipment was designed and installed, pumps were improved, and various devices were invoked to obtain high rates of production for short periods of time. By 1937 pumping cycles of forty to forty-five 54-in. strokes per minute were not uncommon, and numerous wells had produced at the rate of 3500 bbl. per day for short periods. Such production was far beyond any rate that could be long sustained. Equipment necessary to take "potentials" was several times larger than that needed for normal producing purposes, and repairs and replacements required by the high pumping speeds were excessive. Also, many operators suspected that the high rates of production main tained during '"potential" tests were conducivc to early water encroachment. By 1938 large-scale physical testing of wells in Kansas ended, the use of the bottom-hole pressure gauge had become common, engineers and operators were becoming familiar with the term ''productivity index," and bottom-hole pressure was being used as a factor in allocation in many areas. There were many drawbacks, however, to large-scale use of

Jan 1, 1943

By I. R. M. Chatson

Radial layout's guiding principle is the grouping under one roof of the operating processes which require continuous supervision. Separate treatment sections are isolated by outside stockpiles fed with radiating conveyors. Hence the name "radial" layout. Many plants are designed with "linear" layout where successive operating stages are dotted like beads along a string of conveyors.

Jan 11, 1978

By Y. H. Chia, P. Somasundaran

Carrier flotation of anatase from clay using coarse calcite is investigated, together with relevant basic properties of the system including aggregation and zeta potential, under different chemical and hydrodynamic conditions The roles of carrier sue and amount also are considered Mechanisms responsible for selective aggregation and flotation are reviewed

Jan 1, 1983

By R. V. Ramani

In this report, the application and limitation of the various equipment available for surface coal mining are discussed. The correction factors for adjusting equipment performance arising from machine design, material characteristics, and modes of operation are presented. Engineering design, pit layout and equipment selection are discussed with mathematical derivations. Two computer programs (SMCALC and SMRES) have been written to aid in pit design and equipment selection. The Strip Mine Calculation Program (SMCALC) can be used to select the bucket size and reach of shovels and draglines for various pit widths. It will also calculate the number of drills, loading shovels, trucks and bulldozers needed to achieve a production target. The Surface Mine Reclamation Equipment Selector (SMRES) can be used to select the number of bulldozers, scrapers and front-end loaders needed to achieve the desired production.

Jan 1, 1976

By Donald S. Colby

CARBON-BLACK shipments, which had declined in the latter art of 1953, remained low in 1954 until after settlement of the labor strike that occurred in the rubber industry in July and August. The production of new model automobiles in the last quarter of the year spurred the demand for rubber tires and consequently the demand for carbon black. Total shipments of 1,498 million pounds for the year were 4 percent below 1953.

Jan 1, 1958

By Rudolf E. Greuer, Linneas W. Laage, Xinton Chang

UNIT OF MEASURE ABBREVIATIONS USED IN MFIRE FT foot FT3/MIN cubic foot per minute LBM•MIN2/FT4 pound mass times minutes squared over feet to the fourth FT2/HR square feet per hour BTU/HR*FT*F British thermal unit divided by hours times fimes feet times degree Fahrenheit IN W G inches water gage FT3/MIN cubic feet per minute FT2 square feet FT3 cubic feet LBM, pound mass F Fahrenheit IN W G /CFM2 inches water gage per cubic foot per minute squared PERCENTAGE percent BTU/MIN British thermal unit per minute MFIRE BAT PROGRAM cls echo off echo MFIRE activated mfire0 echo Wait a moment for loading the program if EXIST zheng chg mfirel if EXIST zheng chg mfire2 if EXIST zheng chg mfire1 if EXIST zheng chg erase zheng chg if EXIST hang chg erase hang chg if EXIST yunzhi fan copy yaodong.ion+yunzhi fan yaodong ion if EXIST yunzhi fan erase yunzhi fan if EXIST xintan chg copy yaodong xin+xintan chg yaodong ion if EXIST xintan chg erase xintan chg if EXIST yaodong xin copy yaodong.xin mfire out if EXIST yaodong.xin erase yaodong.xin if EXIST net erase net echo Your output is saved in file MFIRE OUT MFIRE0 FOR PROGRAM CHARACTER•50 A OPEN (10,FILE='NET',STATUS='UNKNOWN',FORM='UNFORMATTED') NETWW=0 WRITE (10) NETWW OPEN (21,FILE='ZHENG CHG',STATUS='UNKNOWN',FORM='UNFORMATTED') A=) ' B=0.0 WRITE (21) A WRITE (21) A,B

Jan 1, 1990

By L. T. Lloyd, H. H. Chiswik

The operative deformation elements in a-uranium single crystals under compression at room temperature have been determined as a function of the compression directions. The deformation mechanisms noted may be arranged with respect to their frequency of occurrence and ease of operation in the following order: 1 — (010)-[I001 slip, 2—{130} twinning, 3—{~172} twinning, and 4bunder special conditions of stress application, kinking, cross-slip, {.-176) twinning, and (011) slip. The composition planes of the (172) and (176) systems were found to be irrational. Cross-slip was shown to be associated with the major (010) slip system, coupled with localized interaction of slip on the (001) planes. The mechanism of kinking was found to be similar to that observed in other metals in that it occurred chiefly when the compression direction was, nearly parallel to the principal slip direction [loo] and was associated with a lattice rotation about an axis contained in the slip plane and normal to the slip direction: the [001] in the uranium lattice. The resolved critical shear stress for slip on the (010)-[100] system was found to be 0.34 kg per mm2 In a single test it was shown that under compression in suitable directions twinning on the (130) also occurs at 600°C. DEFORMATION mechanisms of large grained polycrystalline orthorhombic a-uranium have been studied by Cahn.1 A major slip system identified as the (010) with a probable [loo] slip direction and a minor slip system on the (110) planes were reported; the slip direction of the minor system was not determined. The twinning systems that were identified experimentally included the (130) and the irrational (172) composition planes; observations of other traces which were not as frequent and which did not lend themselves to positive experimental identification led Cahn to postulate on the basis of indirect evidence that twinning also occurred on (112) and (121) planes. In addition to the foregoing slip and twinning mechanisms, Cahn also observed kinking and cross-slip in conjunction with the major (010) system; the cooperative cross-slip plane was not identified. The availability of single crystals to the present authors has enabled them to check these results, particularly with reference to the doubtful mechanisms and the preference of operation of any one mechanism in relation to the direction of stress application. The tests were confined to compression only, primarily because of experimental limitations imposed by the size and shape of the available crystals. The tests were performed at room temperature except for one crystal compressed at 600°C. The compression directions were chosen to obtain a representative coverage of one quadrant of the stereo-graphic projection. To test the existence of some of the deformation elements that were reported by Cahn, but were not found in the present study, several additional crystals were compressed in specifically chosen directions considered most ideal for their operation. Experimental Techniques The single crystals were obtained by the grain coarsening technique described by Fisher? They grinding and polishing on rotating laps, with final surface preparation performed in a H3PO4-HNO3 electropolishing bath. A typical crystal readied for compression is shown in Fig. 1; their dimensions were rather small and depended upon the testing direction. Crystals isolated for compression in a direction close to the [010] axis, which lay roughly parallel to the longitudinal axis of the polycrystalline rod, were about 3 to 4 mm long and 5 mm2 in cross-section, while those prepared for compression in other directions were smaller. Most of the crystals were free from twin markings and showed no evidence of Laue asterism. Several crystals, however, contained twin traces prior to compression; these were identified prior to compression so as to clearly distinguish them from those initiated during deformation. The origin of the twin markings prior to deformation may be ascribed to two sources: thermal stresses and specimen handling during isolation and preparation. Two other types of imperfections in the crystals should be mentioned: inclusions, which were probably oxides or carbides. and three of the crystals contained a small number of spherical included grains (<0.01 mm diam), which were remnants of unabsorbed grains from the coarsening treatment. The volume represented by these imperfections was small, and their presence presented no difficulties in the interpretation of the macrodeformation processes during subsequent compression. Two compression fixtures were employed: crystals A, B, C, E, and G were compressed in a hand-operated screw-driven jig whose compression platens were designed to minimize axial rotation;

Jan 1, 1956

By E. C. W. Perryman

The recovery of X-ray line broadening, hardness, and electrical resistivity from cold worked AI-Mg alloys has been investigated. The results, together with those from density measurements, suggest that magnesium atoms freeze in the excess vacancies formed by cold working, and that this affects the climb of dislocations during the recovery process. PREVIOUS work1, " has shown that while 1 pct Mg increases the activation energy for recrystalliza-tion, it decreases the activation energy for the recovery of mechanical properties and decreases the subgrain size both after cold working and annealing. A similar result has been reported by Varley2 for an A1-2 pct Mg alloy. With plastic deformation at high temperatures, McLean and Farmer&apos; and Rachinger have found that magnesium appears to retard the motion of dislocations and, furthermore, they find little or no effect of magnesium on the size of subgrains formed during high temperature deformation. In view of the apparent contradictions as to the effect of magnesium on subgrain size, the recovery process in Al-Mg alloys has been investigated more thoroughly by studying the annealing out of X-ray line broadening, hardness, and electrical resistivity from alloys cold worked at room temperature. Material Used—The chemical analyses of the alloys are given in Table I. Fabrication—The material used was cold rolled 20 pct at room temperature, the grain size prior to the last cold rolling operation being similar to that used in previous work; i.e., 230. The experimental procedure for annealing, determination of X-rav half-veak breadth. hardness measurement, electEica1 resistivity, and density and metallographic examination was exactly the same as previously described." Variation of X-Ray Half-Peak Breadth with Annealing Time—Isothermal annealing curves at 100°, 200°, and 250°C were obtained for material cold worked 20 pct. The half-peak breadth of the (333) Ka, line directly after cold working is shown as a function of magnesium content in Fig. 1. Only with the 2.87 pct Mg alloy was overlapping of the a, and n.. reflections observed to any appreciable extent. To separate these, Rachinger&apos;s method&apos; was used. Typical isothermal annealing curves are shown in Figs. 2 and 3 for 100" and 200°C, respectively. These curves are similar to those obtained previously for super-purity aluminum except that the

Jan 1, 1957

The Archaeozoic Willyama Complex at Broken Hill has suffered several periods of deformation and metamorphism. New structural and petrological information together with that available from the literature gives a picture of the metamorphic evolution of the Barrier Ranges. Several epochs of metamorphism are recognized, and potassium-argon dating of minerals has been applied with limited success to the resolution of these epochs.INTRODUCTIONAdvancements in the mineral industry at Broken Hill over the past eighty years have been accompanied by a continual striving towards increased understanding of both the geological history of the Barrier Ranges and the environment of the Broken Hill ore deposits. However, although many detailed studies of selected localities and particular-aspects of Broken Hill geology have been carried out recently, the regional geology of the Barrier Ranges as a whole has received little attention from a petrological viewpoint since the pioneer investigations of Mawson (1912) and Browne (1922). There still remains a great need for regional surveys combining field studies of the habits, structures and outcrop relationships of the various rock types with laboratory investigations of their chemistry, mineralogy and microscopic ,fabrics. Recording observations arising from three brief visits to the Broken Hill area during 1959 and 1963 may stimulate further surveys.During one of these visits, the generosity of the Zinc Corporation Limited in providing field transport and geological guidance enabled the writer to collect material and study field relationships and appearance of the various rock types at numerous localities covering most of the Willyama outcrop. A complete study has not been conducted...

Jan 1, 1963

By M. S. Oudenhoven

The Bureau of Mines conducted an investigation to determine the theoretical stress distribution in the vicinity of explosively expanded rock bolt anchors independent of their bolts. Plane-strain solutions applicable to this problem were obtained by combining the field pressure with the uniform pressure that would be produced by vertically placed anchors having 2-, 3-, and 4-foot spacings. High rock stress which would be produced by an anchor was localized, as would be expected from St. Venant&apos;s effect, and increased as the field pressure decreased.

Jan 1, 1967

By R. M. Brick, M. A. Williamson

CERTAIN features of the response of copper and brass to deformation and recrystallization remain obscure. The textures obtained on rolled sheet are listed by Schmid and Boas1 as: No adequate explanation has been advanced for the presence of the secondary deformation texture of copper and its absence in brass or for the origin of the cubic recrystallization texture of copper.2 A recent publication3 attempted to rationalize the above empirically described annealing texture of brass on the basis of retention of the (110) [112] rolling orientation plus twinning about the central octahedral poles of the usual secondary (110) [115] orientation. The difference in the textures of annealed copper as compared to 70-30 brass is also shown by the difference in the position of ears for drawn copper, at o° and 90°, as compared with drawn brasses, at 45°, for all compositions between 90-10 and 70-30.4 Data on individual crystals are as yet too few to permit of an analysis of these textures comparable to that of mild steel as made by Barrett and Levenson.5 EXPERITMENTAL METHODS The materials studied included copper specimens cut from the central, equiaxed crystal portion of a tough-pitch wirebar; brass made from this copper and high-purity (99.99 per cent) zinc including alloys of 7 per. cent, 15 per cent, 24 per cent, 29 per cent and 36 per cent Zn and large single crystals of 70-30 brass. Sections ¼ in. thick of the cast polycrystalline copper and brasses were reduced 40 per cent by rolling, recrystallized to a common grain size of 0.045 mm. and then rolled directly to foil 0.002 in. thick. Hardness readings employing both the Vickers and Rockwell machines were taken at intervals during the reduction. For comparison, similar specimens were cross-rolled-i.e., turned through 90 for each pass-and comparable hardness data were secured. Finally sections from the single crystals of brass were cut to obtain the following initial orientations; these sections were rolled, hardness data secured and a complete micrographic record of structural changes obtained:

Jan 1, 1941

By R. M. Brick, M. A. Williamson

Certain features of the response of copper and brass to deformation and recrystallization remain obscure. The textures obtained on rolled sheet are listed by Schmid and Boas1 as: No adequate explanation has been advanced for the presence of the secondary deformation texture of copper and its absence in brass or for the origin of the cubic recrystallization texture of copper.2 A recent publication3 attempted to rationalize the above empirically described annealing texture of brass on the basis of retention of the (110) [112] rolling orientation plus twinning about the central octahedral poles of the usual secondary (110) [115] orientation. The difierence in the textures of annealed copper as compared to 70-30 brass is also shown by the difference in the position of ears for drawn copper, at o° and go", as compared with drawn brasses, at 45o, for all compositions between oo-10 and 70-30.4 Data on indi- vidual crystals are as yet too few to permit of an analysis of these textures comparable to that of mild steel as made by Barrett and Levenson.5 Experimental Methods The materials studied included copper specimens cut from the central, equiaxed crystal portion of a tough-pitch wirebar; brass made from this copper and high-purity (99.99 per cent) zinc including alloys of 7 per cent, 15 per cent, 24 per cent, 29 per cent and 36 per cent Zn and large single crystals of 70-30 bras. Sections 1/4 in. thick of the cast polycrystalline copper and brasses were reduced 40 per cent by rolling, recrystallized to a common grain size of 0.045 mm. and then rolled directly to foil 0.002 in. thick. Hardness readings employing both the Vickers and Rockwell machines were taken at intervals during the reduction. For comparison, similar specimens were cross-rolled—i.e., turned through 90° for each pass—and comparable hardness data were secured. Finally sections from the single crystals of brass were cut to obtain the following initial orientations; these sections were rolled, hardness data secured and a complete micrographic record of structural changes obtained.

Jan 1, 1941

By R. M. Brick, M. A. Williamson

Certain features of the response of copper and brass to deformation and recrystallization remain obscure. The textures obtained on rolled sheet are listed by Schmid and Boas1 as: No adequate explanation has been advanced for the presence of the secondary deformation texture of copper and its absence in brass or for the origin of the cubic recrystallization texture of copper.2 A recent publication3 attempted to rationalize the above empirically described annealing texture of brass on the basis of retention of the (110) [112] rolling orientation plus twinning about the central octahedral poles of the usual secondary (110) [115] orientation. The difierence in the textures of annealed copper as compared to 70-30 brass is also shown by the difference in the position of ears for drawn copper, at o° and go", as compared with drawn brasses, at 45o, for all compositions between oo-10 and 70-30.4 Data on indi- vidual crystals are as yet too few to permit of an analysis of these textures comparable to that of mild steel as made by Barrett and Levenson.5 Experimental Methods The materials studied included copper specimens cut from the central, equiaxed crystal portion of a tough-pitch wirebar; brass made from this copper and high-purity (99.99 per cent) zinc including alloys of 7 per cent, 15 per cent, 24 per cent, 29 per cent and 36 per cent Zn and large single crystals of 70-30 bras. Sections 1/4 in. thick of the cast polycrystalline copper and brasses were reduced 40 per cent by rolling, recrystallized to a common grain size of 0.045 mm. and then rolled directly to foil 0.002 in. thick. Hardness readings employing both the Vickers and Rockwell machines were taken at intervals during the reduction. For comparison, similar specimens were cross-rolled—i.e., turned through 90° for each pass—and comparable hardness data were secured. Finally sections from the single crystals of brass were cut to obtain the following initial orientations; these sections were rolled, hardness data secured and a complete micrographic record of structural changes obtained.

Jan 1, 1941

By Richard C. Repsher

Intermittent mining in the slope section at Dutch Creek No. 1 mine, Carbondale, Colo., of the Mid-Continent Coal and Coke Co. has resulted in erratic and minimal rock noise data, which, in turn, has necessitated a change in the method used to plot daily mine noise in order to be useful to the researchers at the mine. Daily and weekly cumulative plots of rock noise under these conditions have not shown significant stress changes as clearly as bimonthly or longer noise rate plots. Hence, longer term cumulative rock noise plots, as described in this Bureau of Mines report, have been added to the data analysis at Dutch Creek No. 1 mine, and have been shown to delineate unique areas of rock noise activity more clearly than shorter term plots. The longer term plots should aid in the detection and delineation of potential failure areas, when used in conjunction with other proven forms of data analysis.

Jan 1, 1979