Acrylic Cylinder Research Articles

Ammonia volatilization from surface-applied, fresh and composted poultry litter

Poultry litter is a mixture of excreta, bedding material, and waste feed, which is generated in large amounts by the poultry industry. This material is usually applied to pastures as fertilizer. Application of poultry litter on the soil surface can lead to high NH3 volatilization losses due in part to a high rate of N mineralization. Composted poultry litter has a lower rate of N mineralization than fresh poultry litter and, therefore, should show lower NH3 losses. The first objective of this work was to compare N mineralized and NH3 volatilized from fresh and composted poultry litter applied on the soil surface. When poultry litter is applied to pastures, a fraction of the material falls on top of a thatch layer, which prevents direct contact with the soil and may, therefore, affect NH3 volatilization. The second objective of this work was to evaluate the effect of a thatch layer on N mineralized and NH3 volatilized from surface-applied, fresh poultry litter. Moist samples from two soils were packed in acrylic cylinders to achieve 55% water-filled-porosity. Two composted litters were applied on the soil surface and fresh poultry litter was applied either directly on the soil surface or on a thatch layer. All samples were incubated at 25°C for 56 days, with NH3 volatilized measured during the first 21 days. Cumulative NH3 losses in 21 days ranged form 17 to 31% of the applied N for fresh poultry litter, and from 0 to 0.24% of the applied N for composted poultry litter. Application of fresh poultry litter on fescue thatch reduced the initial rate of NH3 volatilization but did not affect the total amount of NH3 volatilized in 21 days.

Nitrous oxide and carbon dioxide emissions from pelletized and nonpelletized poultry litter incorporated into soil

While several studies have shown that the addition of animal manures to soil can increase N2O and CO2 emissions, limited information is available on the effect that manure physical characteristics can have on these emissions. This study compared N2O and CO2 emissions from poultry litter incorporated as pellets (5.5 mm OD, 7 mm long) or fine particles (<0.83 mm) into Cecil soil samples. The soil-litter mixture was packed in acrylic plastic cylinders and adjusted to 55 or 90 % water-filled porosity (WFP). The cylinders were placed inside jars that were sealed and placed in an incubator at 25°C for 35 d, with periodic air samplings conducted for N2O and CO2 analyses. At 55% WFP, cumulative emission of CO2 was similar for both litter types, but cumulative emission of N2O was slightly higher for pelletized (6.8 % of applied N) than for fine-particle litter (5.5 %). In contrast, at 90 % WFP, cumulative emission of N2O was larger for fine-particle litter (3.4 % of applied N) than for pelletized litter (1.5 %). These results indicate that the effect of poultry litter physical characteristics on N2O emissions from incorporated applications can be expected to vary depending on the soil water regime.

Pelletizing and Soil Water Effects on Gaseous Emissions from Surface‐Applied Poultry Litter

AbstractSeveral studies have shown that the application of animal manures to soil can increase N2O and CO2 emissions. Little information is available, however, on the effect that physical characteristics of the manure can have on these emissions. The objective of this work was to evaluate the effects of physical characteristics of poultry litter (fine particles or pellets) and soil water‐filled porosity (WFP, 58 or 90%) on rates and total amounts of N2O and CO2 emissions from surface applications of poultry litter to soil. Poultry litter at 30.7 g N m−2 was surface applied to samples of Cecil loamy sand (clayey, kaolinitic, thermic, Typic Kanhapludult) that were packed in acrylic plastic cylinders. Each cylinder was placed inside a jar that was closed with a screw‐cap lid fitted with a rubber septum, and all jars were placed in an incubator at 25°C for 28d. Periodic air samplings were conducted for N2O and CO2 analyses. Maximum rates of N2O and CO2 emission occurred within the first 4 d and were highest for fine‐particle litter at 90% WFP. Cumulative CO2 emission did not differ between treatments, but cumulative N2O emission was significantly lower for fine‐particle litter at 58% WFP than for the other treatments. Expressed as a percentage of the applied N, the N2O lost represented 0.2% for fine‐particle litter at 58% WFP, and an average of 2.8% for the other treatments. These results suggest that for surface applications under the conditions of this study, pelletized litter may produce similar CO2 emission as fine‐particle litter, and may cause equal or larger emissions of N2O than fine‐particle litter.

Esthetic inserts for implant prostheses

A technique is described that uses preformed light-cured resin or acrylic resin cylinders for “permanent” placement i n the screw access holes of implant prostheses for better esthetics.

Relative humidity as an environmental factor determining the microhabitat of the nymphs of the rice brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

SummaryMicrohabitat of the nymphs and the adults of the rice brown, planthopper, Nilaparvata lugens is known to be the lower parts of rice plants. In this study, possible environmental factors determining the range of the microhabitat were experimentally analyzed by using the nymphs under laboratory conditions. Thirty individuals of the 1st or the 3rd instar nymphs were released to a potted rice plant covered with a transparent acrylic cylinder. When the top of the cylinder was kept opening (open condition), the temperatures in the cylinder were almost constant, and relative humidities in the cylinder decreased with the increase of the height from the water surface of the pot. In the open condition, most nymphs and all exuviae were found on the basal parts of rice plants where the humidity was more than ca. 90% r.h. When the top of the cylinder was kept closing with parafilm (closed condition), the temperatures in the cylinder were almost constant, and relative humidities in the cylinder were more than 95% r.h. In the closed condition, the nymphs and the exuviae were distributed sparsely to the whole parts of rice plants. In both of the open and the closed conditions, patterns of nymphal distributions on rice plants during the dark regime were the same as those during the light regime under 25±2°C and 16L∶8D. Four different temperatures ranging from 20°C to 35°C did not influence on the microhabitat in the open condition. It was concluded from the results that relative humidity is the important environmental factor to determine the microhabitat of the nymphs of N. lugens which showed to prefer very humid condition more than ca. 90% r.h.

Shear bond of resin cement to post-cured hybrid composites

Various surface treatments affected the shear bond strength of a dual-cured resin cement to a post-cured composite. Disks of post-cured composite inlay 2.0 mm thick by 10.0 mm in diameter, were mounted in acrylic cylinders. Various surface treatments were tested including: 1) smooth material; 2) treated by sandblasting (air abrasion); 3) sandblasting and etching with hydrofluoric acid (HF); 4) sandblasting and silane priming; 5) sandblasting, HF etching and silane priming; 6) HF etching alone; 7) HF etching and silane priming; and 8) silane priming alone. Specimens of dual-cured cement, 4.0 mm in diameter, were light-cured onto the prepared surfaces. The samples were stored in water at 37°C for 7d before shear bond testing. The highest mean shear bond strengths were achieved for specimens with the following surface treatments: 1) by a combination of sandblasting, HF etching and silane priming; 2) sandblasting and HF etching; and 3) sandblasting and silane priming. Most bond failures in these groups were cohesive within the post-cured composite inlay disks. The bond strengths of the specimen in other groups were significantly lower and bond failures were mainly adhesive at the interface between the disk of post-cured composite and dual-cured resin cement.

Analysis of axisymmetric waves propagating along a hollow cylindrical ultrasonic transmission line

A new ultrasonic device for feeding powder with the use of a hollow acrylic cylinder, on which an axisymmetric progressive elastic wave is excited, has previously been proposed. Its characteristics have also been reported. To find vibrational behaviors of the hollow cylinder for feeding powder, the elliptic particle movement on the inside surface was analyzed. The authors have found many forms of elliptic motion. Some of them can move objects inside the cylinder toward the vibration source, as expected, but, on the contrary, the others move in the wave propagation direction.

Beta dosimetry at surfaces of cylindrical containers

Beta dose rates on the surfaces of cylindrical vessels containing radioactive solutions are calculated using an empirically based Monte Carlo method. Interior source random path length distributions are derived for the container, and energy deposition in a thin surface layer is determined from empirical formulae used by Charlton and Cormack and others. Calculated results for the method are compared with experimentally determined results for 32P in acrylic cylinders of varying wall thickness; these show good agreement if one assumes that the ratio of projected particle range to the continuous slowing down approximation range is 0.8. Using this ratio theoretical results are derived for 90Y, 32P, 198Au, 153Sm and 131I in containers of varying diameters and wall thicknesses with wall materials of acrylic, Pyrex glass, polycarbonate and polypropylene. These results could be used to objectively derive guidelines for the handling of vessels containing beta emitting radionuclides.

Ultrasonic Measurement of Cylindrical Objects Making Use of Ray Tracing

This paper discusses an improvement of the time-of-flight method to measure the acoustic velocity in bone. As the first step we consider the thighbone and assume it to be isotropic coaxial cylinder. The measurement of the outer and inner radii of the cylinder as well as the acoustic velocity are studied. These parameters are obtained by finding the ray-path which fulfills the time-of-flight measured. In the experiment we examined two acrylic cylinders first and then a thighbone of cattle. The results seem to be reasonable, though there are some problems left.

Differentiation of Abnormal Blood Flow Patterns in Coronary Arteries Based on Doppler Catheter Recordings

Abnormal arterial blood flow patterns have been implicated as etiologic factors in thrombosis and atherosclerosis. Intravascular pulsed Doppler ultrasound techniques with fast-Fourier transform analysis offer the opportunity to measure these abnormalities. The authors hypothesized that statistical analysis of radial-directed beam spectra could be used to distinguish disturbed from non-disturbed flow and that analysis of conventional axial-directed beam spectra could then be used to distinguish laminar high-shear from laminar low-shear flow. They developed a scaled-up in-vitro model of coronary flow consisting of a glycerol/H2O test fluid flowing through an acrylic cylinder at Reynolds numbers spanning the typical physiologic range within the coronary arteries. A scaled-up Doppler catheter with the capacity for 90 degrees reflection of the beam was placed centrally. Disturbed flow was created by introducing a flow screen, and altered shear rates were produced by changing the Reynolds number. For the radial-directed beam studies, the coefficients of variation of the Doppler spectra for the disturbed flow states were significantly greater than for the nondisturbed flow states (p less than 0.01). For the axial-directed beam studies, the coefficients of variation of the Doppler spectra for the laminar high-shear flow states were significantly greater than for the laminar low-shear flow states (p less than 0.01). They conclude that abnormal blood flow patterns can be differentiated by the selective use of radial-directed and axial-directed Doppler catheter recordings.

The Provision of a Uniform Vaginal Surface Dose Rate by a Novel Afterloading Cylinder

The administration of a uniform dose rate to the vaginal surface is important in the management of endometrial, cervical, and vaginal malignancies. Unfortunately, conventional vaginal cylinders fail to provide this uniformity, and although dome cylinders do so, they require specialized 137Cs sources. Thus, a new acrylic vaginal cylinder has been developed to use with standard 137Cs sources and provides a uniform dose rate independent of vaginal size. Each contoured cylinder follows a particular isodose line. A metal ring is used to secure the device to minimize vulvar trauma associated with other vaginal cylinders. The construction and use of a set of these cylinders has allowed determination of their utility and limitations, which will be discussed in detail. Although these applicators do not completely replace conventional cylinders, they do offer a useful addition to the brachytherapeutic armamentarium.

Condensation heat transfer in a rotating horizontal cylinder with a scraper

A dryer used in the drying process of paper production is usually a rotating horizontal cylinder in which steam condenses. This study concerns some experiments and analyses of condensate flow and heat transfer in a dryer with a scraper. A laminar film model and a solid film model are introduced for the theoretical analyses. In the former the condensate flow is assumed to be laminar. In the latter the condensate film is assumed to adhere to the cylinder wall. In the analysis with the laminar film model, the film thickness diverges at relatively slow rotations. A criterion for the critical condition at which the divergence commences is proposed. From the solid film model, analytical expressions can be derived for the film thickness and the heat transmission coefficient through the condensate film and the cylinder wall. The experiments are conducted with an acrylic resin cylinder and a stainless steel cylinder. The experimental result on heat transmission agrees with the analytical result for the solid film model if a condensate film about 25 μm thick remains in spite of scraping.

Condensation heat transfer in a rotating horizontal cylinder with a scraper. (Case of thin condensate film).

This study concerns experiments and analyses of the condensate flow and heat transfer in a dryer with a scraper in the case where the condensate film is thin. In the analysis using a model, the film thickness diverges at relatively slow rotations. A criterion for the critical condition on which the divergence commences is proposed. The analysis of the heat transfer is possible with a simpler model termed the solid film model, unless the divergence occurs. The experiments of the heat transmission are conducted with an acrylic resin cylinder and a stainless steel cylinder, and the flow patterns are observed. The experimental results on heat transmission agrees with the analytical one if about a 25 μm thick condensate film remains in spite of scraping.

液―液直接接触式熱交換器に関する実験研究

Liquid-liquid direct contact heat exchangers have many advantages over conventional multi-tubular type exchangers from the point of view of area of heat exchange and scaling. However, the mechanism of liquid-liquid direct contact heat exchange is so complicated that many experimental researches are going on.Hot water and n-Pentane are mixed and exchanged each other in a acrylic cylinder, 40 mm dia. and 220 mm height, of our experimental apparatus.It is the main object of our research to observe flooding phenomenon of n-Pentane from the cylinder since research reports about the flooding phenomenon are very rare and a portion of liquid n-Pentane still exists in hot water at higher temperature than its boiling point. The evaporation rate of n-Pentane is an important scale of exchanged heat flux between hot water and n-Pentane.We have found evaporation rate of n-Pentane (evaporated n-Pentane/injected n-Pentane) from the measurement of flooding n-Pentane. From the measurement results, the evaporation rate (λ) is expressed by superheated temperature (ΔTW) of hot water and the mass flow rate (φ=n-Pentane/hot water) . Equation of the rate is obtained as follow;λ=1-exp{-[ΔTw-(10∅+2.0)/16∅0.6]} where ΔTW = Tl-TbTl: Inlet hot water temperature (K) . Tb : Boiling temperature of water and n-Pentane mixture (K) . φ : Mass flow rate (n-Pentane/hot water) .The equation is in accord with the experimental results in all superheated temperature region at hot water flow of 8.33×10-6 (m3/s) . And it differs about 5-10% at hot water flow of 16.7×10-6 (m3/s) . The experimental equation can be adopted to estimate evaporation rate, and the experimental process is acceptable to observe the flooding phenomenon in Liquid-Liquid Direct Contanct Heat Exchange.

Removal of dimethyl sulfide, methyl mercaptan, and hydrogen sulfide by immobilized Thiobacillus thioparus TK-m

Cells of Thiobacillus thioparus TK-m were immobilized on cylindrical porous polypropylene pellets (5 mmφ × 5 mm) which were packed in an acrylic cylinder of 50 mm inner diameter up to the height of 800 mm. When a sulfur-containing malodorous gas was charged to this packed tower at the superficial velocity of 0.1 m/s, maximum loading capacity (mmol/ l·d) for a malodorous gas to attain the removal rate of 95% or more was: 3.65 for dimethyl sulfide, 8.74 for methyl mercaptan, and 17.36 for hydrogen sulfide. At this time, the inlet concentration (μl/ l) of the malodorous compound was: 7.44 for dimethyl sulfide, 17.8 for methyl mercaptan, and 35.4 for hydrogen sulfide. For every compound, higher loading resulted in greater removal quantities. The removal rate of dimethyl sulfide was not overly affected by the presence of a large amount of easily decomposable hydrogen sulfide.

Drop Impact Energy‐Soil Exchangeable Sodium Percentage Interactions in Seal Formation

AbstractConstant intensity rain (40 mm h−1) with 3.2‐mm drops falling from 0.25‐, 0.90‐, and 2.63‐m heights and impact energies of 1.8, 7.6, and 18.6 kJ m−3, respectively, was used to produce seals on two soils in 55‐mm deep by 82‐mm diam acrylic cylinders. Soil exchangeable sodium percentage (ESP) was altered to ESP 0 (Casaturated soil), 5, and 10 before rain was applied. Infiltration rate (IR) and hydraulic conductivity (HC) of A horizon material from the Wyman (fine loamy, mixed, thermic Typic Haploxeralfs) and Wyo (fine loamy, mixed, thermic Mollic Haploxeralfs) soils decreased due to formation of soil seals as raindrop energy and ESP increased. The Wyo was more susceptible to sealing than Wyman despite its higher organic C content because of its higher (17 vs. 9%) clay content. Seal formation on Ca‐soils (ESP 0) increased gradually with increasing drop impact energy. Soils with ESP 5 and 10 were more susceptible to sealing at low energy rain than were ESP 0 soils. Relative HC and final IR (FIR) decreased with increasing ESP with all rainfall energies and with the no rain treatment on both soils. Aggregate dispersion by raindrop impact and chemical dispersion by sodicity are two complementary processes leading to seal formation. A 5‐Mg‐ha−1 phosphogypsum treatment applied to the Wyman surface reduced seal formation and maintained HC and FIR near the unrained‐on values for the 1.8 and 7.6 kJ m−3 treatments. The 18.6 kJ m−3 raindrop energy produced a seal on the gypsum treated soil with relative HC and FIR more than four times as high as the untreated Wyman.

Bonding orthodontic acrylic resin to enamel

Bonded acrylic orthodontic appliances are a recent alternative to banded methods. However, the physical properties demonstrated by bonding adhesives at the acrylic-enamel interphase have not been well documented. The purpose of this study was to use a laboratory testing model to evaluate the ultimate shear and tensile strengths and fracture sites of five bonding adhesives: unfilled (Bracketbond and Genie); filled (Unite, Excel, and Concise). One hundred bovine mandibular incisors were embedded in dental stone, labial surfaces ground flat for uniform acrylic-enamel adaptation, and stored in modified Fusyama's artificial saliva. Twenty 7-mm diameter acrylic cylinders were bonded in each group. Ten samples from each group were tested for shear strength and ten for tensile strength with an Instron testing machine. Bonding adhesive retained on the cylinder was measured by means of a Bioquant digitizer. Scanning electron microscopy was used to analyze fracture sites. The results showed that the percentage of bonding adhesive that remains on the acrylic surface after fracture is decreased by the addition of inorganic fillers to the adhesive and the use of separate liquid resin sealants, and is increased by the use of plastic bracket primers and bonding adhesives that are chemically similar to methylmethacrylate. Few significant differences in shear and tensile strengths were found among the bonding adhesives. Unfilled bonding adhesives cause less enamel damage and are indicated for clinical bonding of acrylic orthodontic appliances to enamel.

Absolute calibration and intercalibration of photomultipliers for the measurement of Cherenkov light intensities

We describe a technique for the absolute calibration of photomultipliers for the detection of lighthaving a Cherenkov spectrum. This technique utilizes the Chernekov light generated by single vertical cosmic ray muons in a horizontal ultraviolet transmitting glass plate. For use at a field station, a similar, but less time consuming, technique employing the ungated spectrum from a perspex (acrylic) cylinder is described. We discuss the use of temperature-stabilized LEDs for continuous monitoring of gain changes due to factors such as photomultiplier fatigue or temperature variations.

手抄き多層シートの調製法

An attachment to the standard laboratory sheet machine which enables easy and quick formation of multi-layered handsheet was designed and constructed in our laboratory. The divice named JPRI Multi-head consists of an acrylic cylinder with 4 perforated plates. It should be fixed on top of handsheet machine cylinder.Multi-head attachment enables easy control of number of layers and basis weight of each layer. Multi-layered papers made by using this device give good formation and strong plybonding. Multi-head is useful for simulating and predicting some properties of machine made multi-layered papers using a single headbox of multi-layer capability.

Bony Ankylosis of the Temporomandibular Joint

This paper presents the author's experience with interpositional arthroplasty using an acrylic cylinder in 70 cases of bony ankylosis of the temporomandibular joint. Ankylosis followed trauma in all but one patient. The diagnosis was established when restriction of mouth opening was associated with roentgenologic evidence of deformation of the condyle, obliteration of the joint space, and abnormal bone formation in and around the joint. The pathologic changes were classified into four types depending on severity, and each type influenced the treatment. Surgical treatment included creation of a transversely elliptical gap between the two bony components of the joint using a neurosurgical burr and perforator and a chisel through a preauricular approach and interposition of an acrylic cylinder. This maintained the gap, facilitated movement, and encouraged nonunion. The results following a long follow-up of 2 to 10 years showed uniformly good results with a range of mouth opening varying from 2 to 5 cm. Only three bilateral cases recurred and two others had a limited range of mouth opening, with interincisor distance varying from 2 to 2.5 cm.