Metal Trough Research Articles

Aspects of Searching some Possibilities to Diminish the Processing Errors at Stamping Process

Processing errors in the process of stamping, represent some of the most important aspect that requires attention when you want to process parts with a simple configuration. Reducing errors increase the quality of stamped parts, therefore the processing industry of blanks from metal sheets attaches great importance to them. Given the international quality standards it is required to study in detail the problem of eliminating these errors. As a result the results of researches on the establishment of a special portable device to eliminate the clearance between the sheet metal and the guidance rulers of the material in die in order to reduce the deformations of the sheet metal trough successive actions dies. Are presented the proposed constructive solution, its advantages and experimental measurements at stamping with the use of the proposed solution.

Theory of Half-Space Light Absorption Enhancement for Leaky Mode Resonant Nanowires.

Semiconductor nanowires supporting leaky mode resonances have been used to increase light absorption in optoelectronic applications from solar cell to photodetector and sensor. The light conventionally illuminates these devices with a wide range of different incident angles from half space. Currently, most of the investigated nanowires have centrosymmetric geometry cross section, such as circle, hexagon, and rectangle. Here we show that the absorption capability of these symmetrical nanowires has an upper limit under the half-space illumination. Based on the temporal coupled-mode equation, we develop a reciprocity theory for leaky mode resonances in order to connect the angle-dependent absorption cross section and the radiation pattern. We show that in order to exceed such a half-space limit the radiation pattern should be noncentrosymmetric and dominate in the direction reciprocal to the illumination. As an example, we design a metal trough structure to achieve the desired radiation pattern for an embedded nanowire. In comparison to a single nanowire case the trough structure indeed overcomes the half-space limit and leads to 39% and 64% absorption enhancement in TM and TE polarizations, respectively. Also the trough structure enables the enhancement over a broad wavelength range.

Two-Stage Superplastic Forming of a V-Shaped Aluminum Sheet into a Trough with Deep and Irregular Contour

A sheet metal trough of aluminum alloy is manufactured by a two-stage gas forming process at 500 °C. The product with sloped side walls is of ~1.2 m length and ~260 mm opening width, comprising two near-conical-shaped sinks at two ends. The depth of one sink apex is ~350 mm, which results in the depth/width ratio reaching 1.4. To form such a deep and irregular trough, a superplastic aluminum alloy 5083 initially bent into a V-shaped groove was prepared prior to the gas forming work. Within a single die, gas pressure is used to form the V-shaped blank into a preform die cavity prior to the pressure being reversed to form the sheet into the final component cavity. The preforming of the V blank creates a uniform length of line in order to improve the thickness profile of the final part. In this work, a preform has been designed to improve the forming of a complex component by providing a superior thickness profile as compared to a conventional single-stage forming cycle. However, a serious wrinkling situation was encountered, the cause of which has been analyzed using basic mechanics as well as numerical simulation.

Gas Forming a V-Shape Aluminum Sheet into a Trough of Saddle-Contour

A sheet metal trough of aluminum alloys is manufactured by gas-forming process at 500 °C. The product with slope walls is of ~1.2 m long and ~260 mm opening width, comprising two conical sinks at two ends. The depth of one sink apex is ~350 mm, which results in the depth/width ratio reaching 1.4. To form such a complex shape with high aspect ratio, a pre-form of V-shape groove is prepared prior to the gas-forming work. When this double concave trough is turned upside down, the convex contour resembles the back of a twin hump camel. The formability of this configuration depends on the gas pressurization rate profile, the working temperature, material’s micro-structure, as well as pre-form design. The latter point is demonstrated by comparing two aluminum alloys, AA5182 and SP5083, with nearly same compositions but very different grain sizes.

Characteristic Analysis of Metal Trough Faces Cut by Pre-Mixed Abrasive Waterjet

In order to improve the cutting efficiency of abrasive waterjet (AWJ), the relationship between pre-mixed AWJ cutting depth and pressure was experimentally studied. Then, through analysis of the cutting results, the topographic characteristics and formation mechanism of the cut trough faces were investigated. Moreover, through comparing the effects of different jet pressures on the topographic characteristics of AWJ cut trough faces and the SEM analysis of the cut trough faces at different pressures and depths, the effects of pre-mixed AWJ cutting mechanism on the characteristics of cut trough faces were investigated, and the characteristics of the trough faces of metals cut by pre-mixed AWJ were analyzed.

The stability of amoxicillin trihydrate and potassium clavulanate combination in aqueous solutions

The effect of various environmental factors on the stability of aqueous solutions of amoxicillin-clavulanic acid combination in a veterinary water-soluble powder product was investigated. In the swine industry, the combination is administered via the drinking water, where both substances are quickly decomposed depending on several environmental factors. The degradation rate of the substances was determined in solutions of different water hardness levels (German hardness of 2, 6 and 10) and pH values (3.0, 7.0 and 10.0), and in troughs made of different materials (metal or plastic). Increasing the water hardness decreased the stability of both substances, amoxicillin being more stable at each hardness value than clavulanate. Amoxicillin trihydrate proved to be most stable at an acidic pH, while increasing the pH decreased its stability (P < 0.05). Maximum stability of potassium clavulanate was experienced at neutral pH, while its decomposition rate was significantly higher at acidic and alkaline pH values (P < 0.01). The stability of the amoxicillin-clavulanic acid combination depends mainly on the less stable clavulanate, although the effect of metallic ions significantly increased the decomposition rate of amoxicillin, rendering it less stable in metal troughs than clavulanate (P < 0.05). Therefore, the amoxicillin-clavulanic acid combination should be administered to the animals in soft water, at neutral pH and in plastic troughs.

A Vertical‐Lift Incubator (the “Seesaw”) Designed for Channel Catfish Egg Masses

AbstractEgg masses of channel catfish Ictalurus punctatus are typically incubated in mesh baskets suspended in metal troughs with rotating paddles fitted between the baskets that move the water to agitate the eggs. This system is widely used, but stress caused by low dissolved oxygen resulting from poor water circulation through the egg masses at higher egg loading rates can cause reduced hatch. We designed and tested a vertical‐lift incubator to improve hatch with higher egg loading rates. Angle‐aluminum racks were placed inside standard hatchery troughs. Three baskets with hinged lids were placed in each rack and the egg masses were placed in the baskets. The racks in a pair of troughs were connected to overhead bars that oscillated at six cycles per minute, raising the rack in one while lowering the rack in the adjacent trough. Egg masses were incubated at a mean ± SE loading rate of 33.4 ± 4.7 lb per trough, which is nearly twice the recommended rate, with no supplemental oxygen. Survival from egg through the swim‐up stage averaged 84.9%, higher than the reported industry average hatch rate. We produced 153,000 fry · gal−1 · min−1 at the highest egg loading rate tested (47.4 lb per trough). The vertical‐lift incubator may allow hatcheries to hatch more eggs using fewer troughs and less water than with traditional paddle agitation.

Interaction of H, O2, and H2O with 3C-SiC surfaces

Infrared absorption spectroscopy studies of Si-dimer-terminated 3C-SiC(100) 3×2 and c4×2 surfaces reveal marked differences between their atomic scale reactivity with H, O2, and H2O and that of Si(100) surfaces. While atomic hydrogen is well known to passivate dangling bonds on all Si surfaces, H exposure on both 3C-SiC(100) 3×2 and c(4×2) surfaces induces a metallic state instead. Furthermore, hydrogenated 3C-SiC(100) 3×2 surfaces exposed to O2 clearly show that oxygen atoms are inserted below the top surface without any loss in the H coverage at room temperature. Finally, while H2O decomposes into H and OH on both Si(100) 2×1 and 3C-SiC(100) 3×2, subsequent atomic H exposure induces a metallic state on the latter only, creating a thin oxide strip on the top surface separated by a metallic trough.

NANOSCALE ENGINEERING OF ALUMINIUM SURFACES

The development of regular, finely spaced, arrays of metal ridges and troughs, i.e. nanotex tures, by surface treatment of aluminium has been probed by atomic force microscopy (AFM) and transmission electron microscopy (TEM), assisted by radio frequency glow discharge optical emission spectrometry (rf GDOES). AFM reveals the grain orientation dependence of the tex ture and its increased dimensions with increased metal purity. TEM reveals atomic number contrast effects at the centres of metal ridges comprising the boundaries of the cells, thus implicating the composition and structure of the substrate. Enrichment of copper in the alloy immediately beneath the residual alumina film is evident in rf GDOES depth profiles; conversely, iron and silicon, present at similar levels as copper, are not detected. This suggests strongly that crucial impurities, i.e. silicon, are present as fine segregates in the alloy with a grain orientation dependent distribution originating from casting. The distribution of segregates controls the dissolution of the adjacent aluminium matrix in surface pretreatment, thus generating nanotex tures of regular arrangements of metal ridges and troughs with an amorphous alumina film developed over the macroscopic aluminium surface.

Comparison of Cabbage Seedling Growth in Four Transplant Production Systems

“Float-bed” (FB) is a simple hydroponic system used by the tobacco industry for transplant production. “Ebb-and-flood” (EF) is a modified FB system with periodic draining of the bed to limit water availability and control plant growth. Field-bed cabbage (Brassica oleracea L. gp. Capitata) transplant production was compared with FB, EF, and overhead-irrigated plug-tray greenhouse systems. Plants were produced in May and June and transplanted in a field near Blacksburg, Va., in June and July of 1994 and 1995, respectively. Beds for FB and EF production consisted of galvanized metal troughs (3.3 × 0.8 × 0.3 m) lined with a double layer of 0.075-mm-thick black plastic film. In 1994, both EF and FB seedlings were not hardened before transplanting, were severely stressed after transplanting, and had higher seedling mortality compared with plants from other systems. Plug-tray transplants showed the greatest increase in leaf area following transplanting and matured earlier than seedlings produced in other systems. In 1995, EF- and FB-grown cabbage plants were hardened by withholding water before transplanting, and seedlings had greater fresh mass and leaf area than plug-tray or field-bed seedlings 3.5 weeks after transplanting. Less succulent cabbage transplants were grown in EF and FB systems containing 66 mg·L-1 N (40% by nitrate) and 83 mg·L-1 K. Compared with the FB system, the EF system allowed control of water availability, which slowed plant growth, and increased oxygen concentration in the root zone. Both EF and FB systems are suitable for cabbage transplant production.

Nerve conduction studies in experimental non‐freezing cold injury: I. Local nerve cooling

In rabbits, the tibial nerve was exposed in the lower thigh under general anesthesia and cooled in a metal trough at 1 to 2 degrees C or 5 degrees C for 2, 3, or 4 hours. Nerve conduction studies showed local failure of conduction at the site of cooling which persisted after rewarming, and which was followed by distal degeneration of affected fibers. No persistent conduction block was seen. Changes in maximal velocity indicated that the fastest-conducting motor and afferent axons had been preferentially affected. Histological findings in nerves examined at different intervals after cooling confirmed the physiological evidence of primary axonal damage, affecting particularly large diameter fibers. Paranodal demyelination was inconspicuous and restricted to regions just proximal to sites of axonal degeneration. No segmental demyelination was seen. These results clarify previous uncertainties as to the time-course and distribution of nerve damage after local cooling at temperatures just above freezing point.

Advanced melting and casting plants with the high power electron and plasma beam

In the last three years, cold hearth melting and casting equipment with a total melting capacity of about 15 MW were procured or put in operation in USA and Japan. Further definitive projects of such plants will provide in the near future an additional melting power of the same magnitude. The plants are operating with the so-called ‘continuous flow’ or ‘cold hearth’ melting process, where the liquid metal is flowing from a water-cooled metallic trough into the casting metallic crucible. As heat sources, high power electron beam or plasma guns are used. This paper tries to introduce the present state of the art in this field from the view of a contributing equipment supplier.

Drying powdered coal with the aid of ultrasound

The results of introducing ultrasound into three different drying processes has been discussed. The processes included: (1) static drying of a layer of powdered coal with airborne ultrasound, (2) rotary kiln drying with airborne ultrasound, and (3) drying of powdered coal on a sloping, ultrasonically vibrated metal trough. In all three processes, the introduction of ultrasound increased the drying rate. The frequency of ultrasound used was 20 kHz with sound intensities up to 165 dB. The pulverized coal used had a size range from 400 μm to less than 2 smm, with 65% being less than 150 μm in size. Air temperatures used varied from 65 to 300 °C. The most energy-efficient drying process with ultrasound was found to be the sloping, ultrasonically vibrated trough. However, this process was limited to the use of an initial coal powder feed containing less than 10% moisture. For moisture contents above 10%, a dual drying system could be used. For example, the rotary kiln drier could be used ahead of the trough drier. Both the static airborne ultrasound drying process and the ultrasonically vibrated trough drying process work best with a relatively thin layer of powdered coal. However, the residence time for the powdered coal being dried is measured in seconds for the sloping trough process in contrast to minutes for the static drying process. The static drying of a layer of powdered coal is also a batch-drying process while the rotary kiln and sloping trough are continuous processes. The advantages of the static airborne ultrasonic drying process would be: (1) closer control of the drying process, and (2) smaller quantities of powder can be used.

Improved trough for ultramicrotomy.

Troughs made of metal or tape have been used to provide liquid reservoirs for ultrathin sectioning with glass knives (Hayat 1970). However, these types of trough have certain limitations. the metal trough is difficult to use and its paraffin seal is easily broken, causing leaks. Hayat(1970) has even suggested that fumes from heating this paraffin may be carcinogenic. the tape trough is easier to seal but deforms easily while sections are being collected and does not always provide an even surface for the observation of interference colors. This report describes a method of making inexpensive plastic troughs that can provide a reservoir comparable to those used with diamond knives.

A Review of Techniques Used to Hatch and Rear Channel Catfish in Kansas and Proposed Restrictions on Nutritional Requirements of Fingerlings

Problems encountered in incubating channel catfish embryos (Ictalurus punctatus) were solved at the Kansas Forestry, Fish and Game Commission hatchery by several ingenious developments in the 1920's. Spawns were collected from containers placed in spawning ponds and masses of embryos were placed into wire cages set in metal troughs housed in the hatchery building. Over each cage a metal plate was caused to move back and forth to force water through the mass of embryos. The movement of the plates simulated the fanning action of male fish over the embryos and excellent hatching success was obtained. Considerable difficulty was encountered in attempts to feed small fish. Supplemental feeding of dried buttermilk and meat scraps produced only fair growth. Numerous investigations on various phases of channel catfish nutrition were discussed. The authors proposed certain restrictions on nutritional requirements of fingerling channel catfish.

A method for the introduction of samples of long chain fatty acid methyl esters on to gas chromatography columns

A new method of introducing samples on to gas chromatography columns has been developed. A dilute solution of the sample in a volatile solvent is evaporated to dryness in a metal trough attached to a special manipulating device. The trough is introduced into the chromatograph without interrupting the flow of gas through the column or admitting air and is brought into contact with the hot packing phase of the column. This causes rapid volatilization of the sample which is then carried into the column by the gas stream. The performance of the new procedure with long chain fatty acid methyl esters is discussed and compared with that of a capillary micropipette.

Effect of Water Space Upon Chick Performance

ABSTRACT In order to compare the effect of water space upon chick growth and feed efficiency, two trails have been conducted at the Oregon Agricultural Experiment Station. The first trial involved seven pens with 250 New Hampshire chicks with equal numbers of each sex per pen. The second trial involved eight groups of 150 Crossbred broiler chicks with equal numbers of male and female chicks in each pen. Trial 1 was conducted during the winter months and Trial 2 was carried out during the summer season. In Trial 1, the watering equipment in six pens consisted of “V” shaped metal troughs with a constant flow of water. The water space allowances were .22, .43 and .77 inch per chick in duplicate pens. The seventh pen contained a circular pan type waterer that furnished .22 inch of space per chick. In one-half of the pens using the “V” troughs, the waterer was . . .

Window Flight Traps for Insects

During the past spring and summer glass barrier traps have been used as a means of sampling the flying populations of an ambrosia beetle, Trypodendron sp., and other scolytid beetles. The “window” trap has functioned well enough to warrant its brief description. A piece of window glass (2 × 2 ft.) is set in a three-sided wooden frame from which a sheet metal trough is hung. The trough is filled with fuel oil or water to which a wetting agent is added. Screened outlets provide for drainage of excess rain water in the laner case and when oil is present an inverted “L” tube drains this water from beneath the oil. Insects are collected by removing the trough and pouring its contents through a strainer. Traps are hung from various types of pole framework depending on their location, and guy wires are used to keep them from swinging.

Effects of Traces of Metallic Ions on Monolayers

IN a recent issue of NATURE, Myers and Harkins1 directed attention to the possibility of considerable errors arising in experiments on monomolecular films where small quantities of ions are introduced from the glass vessel or the metal trough. Experiments which we have carried out recently at University College, London2, show that corresponding errors may arise in the measurement of interfacial tensions as a result of the presence of minute quantities of ions in the distilled water. Thus when using ordinary laboratory distilled water, minima were obtained in the interfacial tension-concentration curves for sodium cetyl sulphate against various oils, the interfacial tension with 0.05 per cent sodium cetyl sulphate being several hundred per cent higher than the minimum which occurred at about 0.015 per cent. Similar results were obtained with sodium salts of other long-chain acids. On using very good conductivity water (specific conductivity 0.l × 106 ohm.1 cm.1 or less) these minima were no longer found. The ordinary distilled water evidently contained small quantities of a cation which strongly depresses the interfacial tension of such systems, its effect being greater in the lower concentrations of long-chain salt.

Polarisation of the Light of Rainbows

IT is quite well known that the failure of Brewster's law in the case of several substances is due to unavoidable imperfections in the polish of the surfaces. Several years ago the late Lord Rayleigh showed, by mechanical separation of surface impurities of water kept in a long metal trough, that Brewster's law did hold good in the case of water treated in this way.