A Study on New Surface Textured Tools for Inhibition of Derivative Cutting

Author(s):  
Ran Duan ◽  
Jianxin Deng ◽  
Shuting Lei ◽  
Dongliang Ge ◽  
Yayun Liu ◽  
...  

Abstract Derivative cutting is a texture-edge cutting of chip bottom side, which happens all the time in machining with textured tools. Two new types of textured tools are developed and fabricated: a micro-textured tool with chamfered texture edge (CTE) tool and a multiscale textured (MSTT) tool with the texture surface below the rake face. The effectiveness of the tools on inhibiting derivative cutting is investigated at different cutting velocities. For the CTE tool, the inhibiting effect is more pronounced with the increase in the chamfer angle, but the severe rake face wear eventually leads to the occurrence of derivative cutting. Compared with the CTE tool, the multiscale textures of the MSTT tool provide more sustainable effectiveness in inhibiting derivative cutting. The inhibition mechanisms of the two types of textured tools are discussed.

Author(s):  
J. Temple Black

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.


Author(s):  
J. Temple Black ◽  
William G. Boldosser

Ultramicrotomy produces plastic deformation in the surfaces of microtomed TEM specimens which can not generally be observed unless special preparations are made. In this study, a typical biological composite of tissue (infundibular thoracic attachment) infiltrated in the normal manner with an embedding epoxy resin (Epon 812 in a 60/40 mixture) was microtomed with glass and diamond knives, both with 45 degree body angle. Sectioning was done in Portor Blum Mt-2 and Mt-1 microtomes. Sections were collected on formvar coated grids so that both the top side and the bottom side of the sections could be examined. Sections were then placed in a vacuum evaporator and self-shadowed with carbon. Some were chromium shadowed at a 30 degree angle. The sections were then examined in a Phillips 300 TEM at 60kv.Carbon coating (C) or carbon coating with chrom shadowing (C-Ch) makes in effect, single stage replicas of the surfaces of the sections and thus allows the damage in the surfaces to be observable in the TEM. Figure 1 (see key to figures) shows the bottom side of a diamond knife section, carbon self-shadowed and chrom shadowed perpendicular to the cutting direction. Very fine knife marks and surface damage can be observed.


1967 ◽  
Vol 18 (03/04) ◽  
pp. 404-415 ◽  
Author(s):  
G. J. H den Ottolander ◽  
B Leijnse ◽  
H. M. J Cremer-Elfrink

SummaryDirect antiplasmin and anti-urokinase can be measured with artificial clots to which plasma, serum or platelet suspension is added incubated in plasmin or urokinase respectively. Whilst only 3% of the total antiplasmin in the blood is present in the platelets, there is 40% of the total antiurokinase present in the platelets. The properties of this thrombocytic anti-urokinase are discussed. Only 60% is soluble in water. By heating this solution the inhibiting effect increases. Platelet anti-activator is also active against other activators but has not the same properties as anti-urokinase. Implications of these findings are discussed.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.


1962 ◽  
Vol 41 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Björn Tengroth ◽  
Uno Zackrisson

ABSTRACT The general change in the connective tissues which occurs in animals with experimentally produced exophthalmos, consists in an increase in the amount of hyaluronic acid, which binds the water in the connective tissue. Many regard this process as a stimulation of the mucinous system in the connective tissues, and consider this an explanation of the phenomenon of exophthalmos. When the experimental animals are injected with thyroxine or thyroid extract, the reaction observed is opposite to that seen following the injection of the anterior lobe of the pituitary gland. In the former case, there is a reduction in the amount of hyaluronic acid and consequently a decrease in the water content in the connective tissues. In the experiments in question, Na-d-thyroxine and Na-l-thyroxine), in crystalline form, were tested for their inhibiting effect on the development of exophthalmos in experimental animals. The animals used were male albino guinea-pigs. An extract of the anterior lobe of the pituitary gland (TSH Organon)) was used to produce exophthalmos. In previous work (Tengroth 1961), it was shown, using an X-ray measuring technique, that d-thyroxine, despite its poor caloric effect, like l-thyroxine had an exophthalmos-inhibiting effect. When comparing the dose-response curves of the exophthalmos-inhibiting properties of both these optical isomers, it appears that d-thyroxine has an inhibiting effect which is significantly greater than that of l-thyroxine. The significance of this observation is discussed.


1996 ◽  
Vol 33 (6) ◽  
pp. 181-187 ◽  
Author(s):  
Jana Zagorc-Koncan

In recent years many waterways in Slovenia have been subjected to an increased loading with pesticides due to intensification of agriculture. The most widely used herbicides are atrazine and alachlor and they were detected in some rivers and even in ground water. Therefore the effects of atrazine and alachlor on selfpurification processes were investigated. The basic selfpurification processes studied were biodegradation of organic substances and photosynthesis and growth of algae. The inhibiting effect of pesticides on the process of biodegradation of organic pollutants was evaluated by the use of laboratory river model and mathematical modelling. The harmful impacts of pesticides on aquatic autotrophic organisms were assessed by measurement of net assimilation inhibition (24-h acute toxicity test) as well as growth inhibition - chlorophyll- a content (72-h chronic toxicity test) of algae Scenedesmus subspicatus. The results obtained demonstrate that atrazine and alachlor in concentrations found in our rivers have practically no effect on biodegrading heterotrophic organisms, while their adverse effect on algae is quite considerable.


1971 ◽  
Vol 24 ◽  
Author(s):  
W. H. Verstraete

Some  factors affecting the L-asparaginase activity of E.  aroideae were investigated. Increasing  concentrations of glucose in the culture medium had an inhibiting effect on  the production of L-asparaginase by this microorganism. Buffering of the  culture medium in order to stabilize the pH during growth resulted in a decrease  of the L-asparaginase activity. From the different nitrogen sources examined,  tryptone, proteose peptone nr 2 and nr 3 stimulated the L-asparaginase  production. Toluene treatment of the cells practically destroyed the  L-asparaginase. Acetone dried cells showed an L-asparaginase activity  comparable with the activity of living cells.


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