Knife Applications Research Articles

Application of replaceable cutting plates in the design of knives of rotary crushers

The problems of application of knives with a replaceable cutting plate for the disposal of polymer structural materials in rotary crushers, as well as the use of high-speed steel as a cutting material, are considered. Calculations of knives strength and results of ultrajet water-polymer diagnostics of cutting materials are presented. Keywords: rotary crusher, polymer composite material, prefabricated knives, disposal, ultrajet diagnostics. kravchenko-in71@yandex.ru

Analysis of magnetic resonance image quality using an in-house phantom: Gamma knife application

Magnetic Resonance Imaging (MRI) is increasingly used for purposes of radiosurgery and radiotherapy planning. This imaging modality can explore the physical properties of tissue with great details, especially for the brain. However, the geometric distortion is reasonably occurred and can make significant differences in certain MR application such as, localization in Gamma Knife Radiosurgery. Therefore, the geometric distortion measurement and correction should be applied. In this study, an in-house phantom was developed to measure not only geometric distortion, but also uniformity and high contrast spatial resolution of MR image. The phantom attached to Leksell stereotactic frame was scanned using 1.5T MRI GE. T1-Bravo and T2-Fiesta scan protocol were applied. Standard MRI phantom, Magphan SMR100, was used as data comparison. The result shows that geometric distortion could not be found either in Magphan SMR 100 or in-house phantom images. PIU of the in-house phantom image generated by T1-Bravo and T2-Fiesta scan protocol was around of 79.57% and 56.39%, respectively. Furthermore, the high contrast spatial resolution of the in-house phantom images was 1.0 lp/cm lower compared to Magphan SMR100 phantom images. For this study, it was concluded that the in-house phantom could be employed to analyze MR image quality, yet still needs some improvements, especially for uniformity module.

The efficiency of radiowave technology in out-patient eye surgery

Purpose: to analyze the technique of outpatient operations using radiowave surgery.Material and methods. The clinical group of 691 patients (691 eyes; 315 men and 376 women aged 39.7 ± 4.2 years), with various pathologies of the eye and adnexa, in particular papilloma, eyelid cyst, abscess, chalazion, contagious mollusk, pterygium, pinguecula, conjunctival cyst, trichiasis, xanthelasma were observed for 2 years. Surgical treatment of adnexa neoplasms was performed using a Surgitron radiowave apparatus (USA) in three modes.Results. Multiple techniques of radiowave surgery targeting specific eye and adnexa pathologies are presented. Using electrodes of varied configurations enables the application of radio knives practically in all ophthalmoplastic surgeries belonging to “minor surgery”. The presence of flexible microwires on electrodes with changeable shapes contributes to improved surgery results.Conclusion. Radiowave technique of cutting and coagulation with the help of a radio knife not only reduces the time required for surgery but increases the convenience for the surgeon performing individual stages of the operation, or the whole operation. The disinfecting properties of the tips emerging due to the action of radiowaves help prevent the relapses of diseases and reduce the time of wound rehabilitation, thereby improving the cosmetic effect of the intervention.

Nitrogen Management to Improve Nutritive Value of Endophyte‐Free Tall Fescue Grown on Claypan Soil

Core Ideas Nitrogen management affected nutritive value of endophyte‐free tall fescue R4 and stubble hays. Increases in crude protein of hays across N rates were maximized with late winter and knife application. Fiber contents of R4 hay increased with N rate to 100 lb/acre when applied in late fall. Fiber contents of stubble hay were greater with late‐fall N fertilization.

Nitrogen Management for Forage Production from Endophyte‐Free Tall Fescue Grown on Claypan Soil

Core Ideas Better N management may be required for endophyte‐free fescue forage production. Knifed N may result in greater fescue yield and N uptake, especially when fall applied. Tall fescue yield increases were diminished as N rate approached 150 lb/acre. Average N uptake by fescue was linear to N rate, with ∼25% apparent recovery. Nitrogen fertilizer management affects forage production of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.], but data are limited regarding yield and N uptake of endophyte‐free tall fescue on claypan soil of the eastern Great Plains. A 3‐yr study was conducted to determine the effects of N fertilizer timing (late fall or late winter), N placement (surface broadcast, spoke [point injection at 3‐inch depth], and knife [subsurface band at 4‐inch depth]), and N rate (0, 50, 100, 150, and 200 lb/acre) on endophyte‐free tall fescue yield and N uptake. Each harvest (E2, R4, and stubble hay) was taken from individual, nonoverlapping subareas in each plot. In Year 1, subsurface placement (knife or spoke) increased yield by up to 34% above N broadcast. In Year 2, applying N in late winter instead of late fall resulted in greater E2 and R4 yields. In Year 3, broadcasting N in late winter or knifing N in late fall improved R4 hay yield, whereas stubble hay yield was >10% greater with knifing because average agronomic N use efficiency was >30% greater. Forage yield increased with low N rates, but the response diminished or plateaued as rates approached 150 lb N/acre. Nitrogen uptake in the R4 and stubble hay harvests, however, increased linearly with N rate, averaging 26 and 23% apparent N recovery, respectively. Nitrogen management for endophyte‐free tall fescue may be complex and variable by year, but yield and N uptake may be increased with knife applications, especially when fall applied.

One-step deposition by slot-die coating of mixed lead halide perovskite for photovoltaic applications

Recent advances in the performance and stability of lead halide perovskite solar cells announce a promising future for this technology. As the understanding of lab scale device fabrication progresses technology developments in the area of up-scaling are required to demonstrate their viability on an industrial and pre-commercial scale. These developments include replacing slow spin coated deposition techniques with continuous roll to roll compatible slot-die methods. In this work we demonstrate the suitability of a one-step slot-die coating method for the deposition of lead halide perovskite layers, in particular for infiltration into a mesoporous titania scaffold. Appropriate crystallisation dynamics of the perovskite are achieved by careful control of the substrate temperature in combination with a post-processed rapid air knife application. We show that devices fully processed in air using this method deliver a photovoltaic conversion efficiency up to 9.2%, this is comparable to those manufactured using a spin coating process.

Geometric, DVH and plan quality differences induced from different patient image registration methods used in gamma knife applications

Introduction In gamma knife (GK) radiosurgery, target and organs at risk (OARs) delineation is performed directly in MR images after they have been registered to the Leksell coordinate system (LCS). This registration can be performed either using the fiducial markers generated in the MR images by the N-shaped rods on the Leksell MR localization or through anatomical-based co-registration to corresponding registered (using the fiducial markers) CT images. Purpose To compare the two different methods used in GK radiosurgery for MR image registration and assess geometric differences and differences induced in plan quality and DVH-indices clinically used for plan evaluation and acceptance. Materials and methods A plan cohort formed by 20 patients with acoustic neuroma and pituitary adenoma treated using GK radiosurgery was used. Anonymized patient images, structures and dose distributions derived using the two different registration methods were imported to an independent software for dose distribution, DVH analysis and comparison. Results Geometric differences of the order of 1mm (mean value: 0.9 ± 0.4 mm) between the two different registration methods were observed. These differences can considerably influence plan evaluation indices of both target and OARs leading to dose differences of the order of 10% in D95% values of target volume (mean value: 8 ± 6%). Dose differences of similar degree were observed in Dmax and D 30 mm 3 values of OARs. Conclusion Despite being relatively small (of the order of 1 mm), geometric differences between the two registration methods used in GK radiosurgery may affect considerably plan quality due to high dose gradients encountered in such applications.

Seeding Rates and Fertilizer Placement to Improve Strip-Till and No-Till Corn

In 2013, late planting resulted in corn yields that were less than 110 bu/a. Yields were not increased with seeding rates above 26,000/a, but a small increase in yield was obtained with knife applications of fertilizer nitrogen (N) compared with dribble.

A comparative quality appraisal of finely comminuted batters produced using three types of knives

The aim of this study was to compare the work efficiency of three types of knives mounted successively on a knife roll of a cutter by evaluating the quality and structure of produced finely comminuted batters as well as power consumption and electric energy consumption during chopping. Experimental material comprised finely comminuted meat batters produced under commercial scale production conditions using smooth knives, knives with riffles and knives with holes. Parameters measured in batter included temperature, water, fat, free water, apparent viscosity, thermal drip and batter structure using computer image analysis.Computer image analysis showed that the best comminution and dispersion of fat globules in the protein matrix together with very good comminution of collagen fibres were observed at the application of knives with holes. Among the three types of knives used in the production of finely comminuted meat batters the best batter in terms of its quality and structure was produced using knives with holes.

On the use of polymer gels for assessing the total geometrical accuracy in clinical Gamma Knife radiosurgery applications

The nearly tissue equivalent MRI properties and the unique ability of registering 3D dose distributions of polymer gels were exploited to assess the total geometrical accuracy in clinical Gamma Knife applications, taking into account the combined effect of the unit's mechanical accuracy, dose delivery precision and the geometrical distortions inherent in MR images used for irradiation planning. Comparison between planned and experimental data suggests that the MR-related distortions due to susceptibility effects dominate the total clinical geometrical accuracy which was found within 1 mm. The dosimetric effect of the observed sub-millimetre uncertainties on single shot GK irradiation plans was assessed using the target percentage coverage criterion, and a considerable target dose underestimation was found.

Fertilizer Management for Short-season Corn Grown in Reduced, Strip-till, and No-till Systems on Claypan Soil

Strip-till is an alternative conservation tillage system that may overcome the yield depression often seen with corn (Zea mays L.) grown with no-till on the claypan soils of the eastern Great Plains. The objective of this research was to determine the effect of conservation tillage systems and fertilizer N-P management on short-season corn. Continuous corn yields with no-till, strip-till in the fall, or strip-till in the spring declined with year compared with corn grown with reduced tillage. By the third year, corn yields with reduced tillage exceeded 45 bu/acre more than with the other tillage systems. In part, this can be attributed to a reduced plant stand in no-till and strip-till systems. Average corn yield was about 10% greater when N-P applications were made in the spring than in the fall. Similarly, knife (subsurface band) applications of N-P resulted in about 12% greater yield than dribble (surface band). Yield differences due to fertilizer timing or placement were related to similar increases in the number of kernels per ear. Strip-till done either in the fall or spring for corn grown in claypan soil did not improve yield compared with no-till and may be less than yields with reduced tillage. Knife applications of N-P fertilizer done in the spring may help mitigate this deficit if the producer prefers the conservation aspects of strip- or no-till systems.

Experimental and computational studies on Coanda nozzle flow for the air knife application

To control the film thickness of zinc in the process of continuous hot-dip galvanizing, it is known from the early days that the gas wiping through an air knife is the most effective one. The gas wiping using in galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. So, in the present study, the effects of the deflection angle of Coanda nozzle on jet structure and the distribution of impinging pressure at the plate surface are investigated numerically and experimentally. In numerical analysis, the governing equations consisted of three-dimensional time dependent full Navier-Stokes equations, standard k-ɛ turbulence model to solve turbulent stress and so on are employed. In experiment, 16 channel pressure scanning valve and 3-axis auto traversing unit are used to measure the impinging pressure at the strip surface. As a result, it is found that the smaller the deflection angle for the same nozzle slit of air knife is, the larger the impinging pressure is. To reduce the size of separation bubble and to enhance the cutting ability, it is recommendable to use an air knife with the Coanda nozzle.

SANDVIK 12C27

Abstract Sandvik 12C27 is a martensitic stainless steel for knife applications. It is supplied in both the annealed or cold-rolled condition. This datasheet provides information on composition, microstructure, hardness, and tensile properties. It also includes information on forming and heat treating. Filing Code: SS-954. Producer or source: Sandvik Steel Company.

Three-dimensional dose verification of the clinical application of gamma knife stereotactic radiosurgery using polymer gel and MRI

This work seeks to verify multi-shot clinical applications of stereotactic radiosurgery with a Leksell Gamma Knife model C unit employing a polymer gel–MRI based experimental procedure, which has already been shown to be capable of verifying the precision and accuracy of dose delivery in single-shot gamma knife applications. The treatment plan studied in the present work resembles a clinical treatment case of pituitary adenoma using four 8 mm and one 14 mm collimator helmet shots to deliver a prescription dose of 15 Gy to the 50% isodose line (30 Gy maximum dose). For the experimental dose verification of the treatment plan, the same criteria as those used in the clinical treatment planning evaluation were employed. These included comparison of measured and GammaPlan calculated data, in terms of percentage isodose contours on axial, coronal and sagittal planes, as well as 3D plan evaluation criteria such as dose–volume histograms for the target volume, target coverage and conformity indices. Measured percentage isodose contours compared favourably with calculated ones despite individual point fluctuations at low dose contours (e.g., 20%) mainly due to the effect of T2 measurement uncertainty on dose resolution. Dose–volume histogram data were also found in a good agreement while the experimental results for the percentage target coverage and conformity index were 94% and 1.17 relative to corresponding GammaPlan calculations of 96% and 1.12, respectively. Overall, polymer gel results verified the planned dose distribution within experimental uncertainties and uncertainty related to the digitization process of selected GammaPlan output data.

Dose verification of single shot gamma knife applications using VIPAR polymer gel and MRI

This work describes an experimental procedure with potential to assess the overall accuracy associated with gamma knife clinical applications, from patient imaging and dosimetry planning to patient positioning and dose delivery using the automated positioning system of a Leksell Gamma Knife model C. The VIPAR polymer gel–MRI dosimetry method is employed due to its inherent three-dimensional feature and linear dose response over the range of gamma knife applications. Different polymer gel vials were irradiated with single shot gamma knife treatment plans using each of the four available collimator helmets to deliver a maximum dose of 30 Gy. Percentage relative dose results are presented not only in the form of one-dimensional profiles but also planar isocontours and isosurfaces in three dimensions. Experimental results are compared with corresponding Gammaplan treatment planning system calculations as well as acceptance test radiochromic film measurements. A good agreement, within the experimental uncertainty, is observed between measured and expected dose distributions. This experimental uncertainty is of the order of one imaging pixel in the MRI gel readout session (<1 mm) and allows for the verification of single shot gamma knife applications in terms of acceptance specifications for precision in beam alignment and accuracy. Averaging net R2 results in the dose plateau of the 4 mm and 18 mm collimator irradiated gel vials, which were MR scanned in the same session, provides a crude estimate of the 4 mm output factor which agrees within errors with the default value of 0.870.

Manufacture of diamond blades via microsystem technology

The application of diamond knives has steadily increased in ophthalmic surgery. However, the geometry of the blade, its thickness and the sharpness of the cutting edge are limited by the abrasive diamond polishing process, e. g. the crystalline morphology of the bulk material and the grinding powder used. A new generation of diamond blades is presented herewith allowing free choice of blade shape and thickness and possessing excellent sharpness due to a new polishing process. The new production method is based on a high-quality CVD (chemical vapour deposition) diamond film of some tenths of microns thickness, deposited on a silicon wafer as microchip technology. The mechanical properties of this synthetic diamond film are almost equal to those of a natural diamond and the surface of this film is mirror-like after deposition without requiring post-polishing. The shape of the blade can be freely defined and is transferred into the diamond film by a plasma polishing process adopted from microsystem technology. The new production method results in highly reproducible diamond blades. Concave blades and round shapes can now be realised without the restrictions of the conventional production process. The force-free fabrication method even allows realisation of miniaturized blades (e. g. width < 0.125 mm, thickness < 50 microm) far beyond the possibilities of conventional diamond blade production. Plasma polishing by means of gas atoms results in extreme sharpness with the cutting edge radius in the range of approx. 3 nm. Utilising microsystem technology we were able to manufacture reproducible artificial diamond blades. The new process offers for the first time surgeons a possibility of designing blades with a geometry close to their personal needs. Furthermore, the potential of facet-free ergonomically shaped diamond blades may stimulate further improvements towards novel surgical techniques.

Enhancing No‐Tillage Systems for Corn with Starter Fertilizers, Row Cleaners, and Nitrogen Placement Methods

No‐till production of corn (Zea mays L.) often gives slower early plant growth, lower yields, and reduced profitability in the northern Corn Belt. The objective of this field experiment was to determine if N source/placement method and row cleaner and starter fertilizer use on high‐phosphorus testing soils would enhance no‐till production of continuous corn (CC) and corn after soybean [Glycine max (L.) Merr.] (CSb). Experiments were conducted for each cropping system on a tile‐drained Nicollet–Webster clay loam complex (fine‐loamy, mixed, superactive, mesic Aquic Hapludoll and fine loamy, mixed, superactive, mesic Typic Endoaquoll, respectively) from 1996 to 1998. A 23 factorial design included combinations of with or without row cleaners, 0.0 or 93.5 L ha−1 (0 or 10 gal acre−1) of 10–15–0 starter fertilizer, and N sources anhydrous ammonia (AA) or spoke‐injected urea‐ammonium nitrate (UAN). A preplant broadcast application of UAN plus N‐(n‐butyl)thiophosphoric triamide (NBPT) also was compared with spoke‐injected UAN. Averaged across 3 yr, surface residue coverage during the growing season remained &gt;60% for CC and &gt;40% for CSb for all treatments, but was about 8% lower with knife application of AA compared with spoke‐injecting UAN. Grain yields were not affected by N source. Yield response to starter fertilizer depended on N source and row cleaners. Continuous corn responded to starter fertilizer (0.5 Mg ha−1 or 7 bu acre−1) when AA was used, but not when UAN was used. Yields of CSb were increased 0.5 Mg ha−1 (8 bu acre−1) by starter fertilizer when row cleaners were not used, but by only 0.2 Mg ha−1 (3 bu acre−1) when row cleaners were used. Injecting UAN increased CC and CSb yields 0.7 Mg ha−1 (10 bu acre−1) and 0.4 Mg ha−1 (6 bu acre−1), respectively, compared with preplant broadcasting of UAN plus NBPT. The data suggest that no‐till corn yields on fine‐textured, high P testing soils can be enhanced most consistently by using starter fertilizer and by injecting N below the soil surface.

Effects of phosphorus application method and rate on furrow‐irrigated ridge‐tilled grain sorghum

Conservation tillage systems, including ridge‐tillage, have become increasing popular with producers in the central Great Plains because of their effectiveness in controlling soil erosion and conserving water. A major disadvantage of the ridge system is that nutrient placement options are limited by lack of any primary tillage options. The objective of this research was to investigate the effects of method of phosphorus (P) placement and rate on irrigated grain sorghum [Sorghum bicolor (L.) Moench] grown in a ridge‐tillage system on a soil low in available P. This experiment was conducted from 1993 to 1995 on a producer's field near the North Central Kansas Experiment Field at Scandia, Kansas on a Carr sandy loam soil (course, loamy, mixed, calcareous, mesic, Typic Udifuvents). Treatments consisted of fertilizer application methods, surface broadcast, single band starter (5 cm to the side and 5 cm below seed), dual band starter (one band on each side of the row), and knifed in the center of the row middle (38 cm from each adjacent row). Each of these treatments was made at either 22 or 44 kg P2O5 ha‐1, and nitrogen (N) also was included at the rate of 13 kg ha‐1. Additional treatments were, a combination of 13 kg N and 44 kg P2O5 ha‐1 applied half broadcast and half as a single band starter, a 1:1 N:P2O5 ratio (44 kg N and 44 kg P2O5 ha‐1) applied as a single band starter, and a 3:1 ratio (134 kg N and 44 kg P2O5 ha‐1) applied as a single band starter. A no‐P check plot also was included. Broadcast and center‐of‐row middle knife applications were made approximately 1 week before planting. After planting, N was balanced on all plots to give a total of 180 kg ha‐1. Applied P treatments improved grain yield and nutrient uptake and consistently shortened the time from emergence to mid‐bloom in all 3 years of the experiment. On this low soil test P soil, treatments that subsurface banded P increased grain yield by 1.27 Mg ha‐1 compared to broadcast treatments. Placing N and P in a single starter band 5 cm to the side and 5 cm below the seed was as effective as placing a band on each side of the row. Knife applying N and P in the center of the row was not as effective as placement beside the row. Single band starter application of N and P in a 1:1 and or 3:1 N:P2O5 ratio consistently increased yields and nutrient uptake and shortened the time to mid‐bloom as compared to the single band starter treatment that provided only 13 kg N ha‐1. Over the 3 years of the study, these 1:1 and 3:1 N:P2O5 ratio starters were clearly superior to an other treatments.

Nitrogen Management in Furrow Irrigated, Ridge-Tilled Corn

Use of conservation tillage methods, including ridge-tillage increases crop residue cover which can increase loss of urea-based fertilizers. Objectives of this study were to evaluate N sources, rates, methods, and times of application for ridge-tilled, furrow-irrigared corn (Zea mays L.) on a Crete silt loam soil (fine, montmorillionic, mesic Pachic, Argiustoll) near Scandia, KS. When averaged over 5-yr, grain yields were less with urea-ammonium nitrate (UAN) broadcast and dribbled treatments than with anhydrous ammonia (AA) preplant knifed, 28% UAN solution preplant knifed, and split applications of UAN knifed or dribbled. Surface dribbled UAN proved to be no more effective than surface broadcasting [...]

Tall Fescue Response to Placement of Urea/Ammonium Nitrate Solution

AbstractSeveral studies have shown that cool‐season grasses may respond more to subsurface (knife) applications of fluid fertilizer than to surface applications. However, optimum depth of knife application has not been clearly identified. A field study was conducted from 1984 to 1986 to determine the effects of 5‐, 10‐, and 15‐cm knife and surface band (dribble) and broadcast applications of urea/NH4NO3 solution at 84 and 168 kg N ha−1 on forage yield and N use of tall fescue (Festuca arundinacea Schreb.), and on soil N levels. The soil is a Parsons silt loam (fine, mixed, thermic Mollic Albaqualf). In 1985 and 1986, 168 kg N ha−1 resulted in higher final forage yields than 84 kg N ha−1. Knife applications at 10 cm generally resulted in the highest forage yield, though not always significantly higher than other placements. Knife placement at 15 cm resulted in lower N uptake in early grass clippings (intermediate harvests), compared with surface and shallower knife applications. The N concentration, N uptake in the final spring harvest, and apparent fertilizer‐N recovery by the forage were usually increased by 10‐cm placement. Knife applications of N at or below 10 cm resulted in higher inorganic soil N concentrations at intermediate harvests than did surface applications.