1. Ultrasonic cleaning (cleaning method)
Old Answer ( better)
This cleaning process is very different from those
so far described, and an understanding of its operating principle is
essential if its many potential uses are to be fully appreciated.The
operating principle is as follows. If a low-viscosity liquid such as
water is subjected to high-frequency (25–40 kHz) ultrasonic wave energy,
or ultrasound as it is called, intense cavitation is generated within
thefluid. Cavitation is the generation and growth of vast quantities of
gaseous bubbles within the fluid which,upon reaching a certain size,
typically 0.15 mm diameter, implode (collapse inwards). As each bubble
collapses , a microscopic inward moving jet of fluid is created at an
astonishing 250 mph, and it is this jet that blasts away the
contamination from the dirty surface.The sustained generation, growth
and implosion of huge numbers of bubbles throughout the ultrasonic
bath,and on all surfaces of the submerged component to be cleaned, is
referred to as the cavitation effect. Commercial ultrasonic cleaning
units usually consist of a bath of fluid specially selected to suit both
the material to be cleaned and the type of contaminant to be removed,
plus an electrical transducer unit for generating the required
ultrasound. The transducer(s) may be attached to the bath in a number of
ways but is frequently externally bonded to the bottom of the fluid
tank. Portable units can also be obtained for fitting into existing
tanks, transducer power required being approximately 10W per liter of
tank capacity. Cleaning times are typically 2–5 minutes depending upon
the level of contamination and component geometric complexity. Cleaning
speeds are generally quicker and more thorough than is achievable with
most other methods, and both intricate and delicate components can be
cleaned without risk of damage
(Waters F., Fundamentals of Manufacturing for Engineers, p. 146).
(Waters F., Fundamentals of Manufacturing for Engineers, p. 146).
New
(Developments in surface contamination and cleaning, Kohli R. ,Mittal K., p. 226)
2. Weighted failure rate (quality control)
Old Answer(better)
All the failure rates associated with a system are collected. These are then weighted, depending on the deviation from the system being assessed and other factors thought to be significant. A best estimate is then produced by combining all the available information and applying expert judgement. A good example of this is the failure rates used within the HSE risk assessment tool RISKAT. The pipework failure frequency was derived by a review of 22 references.
(Calow P.,Handbook of environmental risk assessment and management, page106)
New
When the quantity ln(100-%F) is plotted vs. the soak time, a line is obtained. In princible, one can plot the failure rates for each sample as a function of the soak time and fit the curves to equation. A somewhat simpler assessment of k can be made by weighting the failure rates inversely with their respective soak times and averaging the weighted rates as in equation (2) below:
When the quantity ln(100-%F) is plotted vs. the soak time, a line is obtained. In princible, one can plot the failure rates for each sample as a function of the soak time and fit the curves to equation. A somewhat simpler assessment of k can be made by weighting the failure rates inversely with their respective soak times and averaging the weighted rates as in equation (2) below:
(Adhesion measurement of films and coatings , L. Mittal, p, 428)
3. Junction Growth (material science)
Old Answer
Junction Growth (28.04 16:05)
Although the nature of the contact , whether it is elastic or plastic,does not affect the true area of contact under the action of a normal load,it may give rise to variations in behaviour when a load is applied which is to the tangetial interface.
(Cherry B.W.,Polymer Surface,p.110)
New ( better )
Another possible cause of this effect is the creep of the interfacial contact caused by the gradual squashing of roughnesses. When two solids are placed in contact, the true atomic contact area tends to grow slowly with time because the material is not perfectly elastic. So, even when the atomic adhesion remains constant, more extended contact can occur from this junction growth. This has been measured particularly for polymers.
(Tribology: a systems approach to the science and technology of friction, Horst Czichos, p. 72)
4. Vertical Integration (management)
Old Answer
Vertical Integration:
(Economic, Walter J. Wessels, p. 469)
5. Product-Focused Production System (management)
Old Answer
Product-Focused Production System:
The term product-focused is used to describe a form of production processing organization in which production departments are organized according to the type of product being produced. In other words, all of the production operations required to produce a produt are ordinarily grouped into one production department.
Product-focused production is also sometimes called line flow production or continious production. Both of these terms describe the nature of the routes that products follow through production. In line flow production, products tend to follow along direct linear paths without backtracking or sidetracking. In continious production, products tend to proceed through production without stopping.
(Production and Operations Management, Norman Gaither, Page 130)
New ( better )
(Production and Operation Managemen, Rastogi, p. 23)
3. Junction Growth (material science)
Old Answer
Junction Growth (28.04 16:05)
Although the nature of the contact , whether it is elastic or plastic,does not affect the true area of contact under the action of a normal load,it may give rise to variations in behaviour when a load is applied which is to the tangetial interface.
(Cherry B.W.,Polymer Surface,p.110)
New ( better )
Another possible cause of this effect is the creep of the interfacial contact caused by the gradual squashing of roughnesses. When two solids are placed in contact, the true atomic contact area tends to grow slowly with time because the material is not perfectly elastic. So, even when the atomic adhesion remains constant, more extended contact can occur from this junction growth. This has been measured particularly for polymers.
(Tribology: a systems approach to the science and technology of friction, Horst Czichos, p. 72)
4. Vertical Integration (management)
Old Answer
Vertical Integration:
Firms may find opportunities for exparison in existing product lines, in vertical integration or in diversification. They can achieve this expansion either by internal growth or by acquisition. Before turning to a detailed consideration of these issues it is useful to summarise some of the main factors that help shape the outcome
Vertical Integration may be considered either as a static dimension of market structure or as a dynamic process which alters market structure and possibly business behviour and performance.
As a static measure of the extent to which vertically related activities take place within a firm there is no difficulty in identifying individual industries where vertical integration is extremely important and those where it is not. The petroleum industry clearly falls into the first category since the largest firms carry out all the activities from exploration, through refining to the final marketing of the products. On the other hand retailing is largely unintegrated, with most retailing giants doing very little manufacturing.
Although clear-cut cases are not difficult to identify there are problems in devising quantitive measures that allow systematic comparisons across industries. A measure of integration that would appear suitable and which can be computed from available data is the ratia of value added to sales. However this will give misleading comparisons when firms are located at different stages in the vertical chain.
(Kenneth Desmond George, Caroline Joll, E. L. Lynk, Industrial organisation: competition, growth and structural change, 4th Edition, p.63-64)
New ( better )
(Economic, Walter J. Wessels, p. 469)
5. Product-Focused Production System (management)
Old Answer
Product-Focused Production System:
The term product-focused is used to describe a form of production processing organization in which production departments are organized according to the type of product being produced. In other words, all of the production operations required to produce a produt are ordinarily grouped into one production department.
Product-focused production is also sometimes called line flow production or continious production. Both of these terms describe the nature of the routes that products follow through production. In line flow production, products tend to follow along direct linear paths without backtracking or sidetracking. In continious production, products tend to proceed through production without stopping.
(Production and Operations Management, Norman Gaither, Page 130)
New ( better )
(Production and Operation Managemen, Rastogi, p. 23)
No comments:
Post a Comment