When a root tip encounters an obstacle that resists penetration, the root cap becomes less pointed
and the surface cells may slough off (Souty, 1987). Mechanical impedance decreases the rate of root
elongation because of both a decrease in the rate of cell division in the meristem, and a decrease in
cell length (rather than volume). Eavis (1967) found a decrease of 40% in the cell division rate at a
root penetration resistance (0.34 MPa) sufficient to decrease the root elongation rate by 70%. Cell
length is decreased and the volume of the inner cortical cells may...
This book is intended for both mechanical and electronics engineers (researchers and graduate students) who wish to get some training in smart electronics devices embedded in mechanical systems. The book is partly a textbook and partly a monograph. It is a textbook as it provides a focused interdisciplinary experience for undergraduates that encompass important elements from traditional courses as well as contemporary developments in Mechtronics.
The first edition of the Shock and Vibration Handbook in 1961 brought together for
the first time a comprehensive survey of classical shock and vibration theory and
current applications of that theory to contemporary engineering practice. Edited by
Cyril M. Harris and the late Charles E. Crede, the book was translated into several
languages and became the standard reference work throughout the world.The Second
Edition appeared in 1976, the Third Edition in 1988, and the Fourth Edition in
In argentina many pregnant women do not visit health centres
until late in their pregnancy. There is no gender-specific HIV strategy
within the government’s HIV prevention program, and most cases of
HIV infection among infants stem from the lack of antenatal care and
insufficient information and counselling provided to women on HIV/
AIDS and sexual and reproductive rights. Health care access varies
widely across the country, and stigma and discrimination from health
care workers impedes service utilization.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Bedside measurement of changes in lung impedance to monitor alveolar ventilation in dependent and non-dependent parts by electrical impedance tomography during a positive end-expiratory pressure trial in mechanically ventilated intensive care unit patients...
Corrosion is expensive and can be hazardous. It is costly to replace and repair
equipment, structures, and other industrial items that have been damaged as a result
of corrosion. In order to understand the mechanisms of corrosion, solve the corrosion
problems, and improve the corrosion resistance of materials, the use of modern
evaluation and protection techniques is essential. Therefore no significant progress can
be achieved in this area without the use of modern evaluation methods combined with
Fire escapes provide both a ladder down for the building occupant during an
emergency and a ladder up to a less secure upper floor for a burglar. Occupants
should not do anything that impedes access to a fire escape but there are things
that can be done to make it less attractive to the burglar. If an apartment building
uses a fire escape, there are a number of battery operated alarms for less than
$40.00 that can be installed to detect the opening of a door or window and sound
a loud alarm to alert the occupants. If the fire escape ladder is a pull down...
Mechanical impedance is experienced to varying degrees by virtually all roots growing through
soil. If continuous pores of sufficiently large diameter do not already exist, a root tip must exert a
force to deform the soil. This process may considerably decrease root elongation rates, increase the
root diameter and change the pattern of lateral root initiation (Russell, 1977).
In this paper, the effects of mechanical impedance on root morphology are reviewed and some
direct comparisons between soil resistance to root growth and resistance to a penetrometer are
It may not seem strange to us today that there is a thing
called energy that is conserved in all physical interactions.
Energy is a concept we have all grown up with. A hundred
and fifty years ago it was not so evident that there should be
an intimate, quantitative relationship between such appar-
ently unrelated phenomena as motion and heat. The
discovery that heat and motion can be seen as different
forms of the same thing—namely energy—was the first and
biggest step toward understanding the concept of energy
and its conservation.
Electromechanical mobility analogies  Mechanical parameter Electrical parameter Voltage Current Conductance Inductance Capacitance Inductance per unit length Capacitance per unit length Characteristic impedance Impedance Admittance Short circuit Open circuit Current Voltage
Variable Lumped network elements
Velocity, angular velocity Force, torque Damping Compliance Mass, mass moment of inertia Compliance per unit length Mass per unit length Characteristic mobility Mobility Impedance Clamped point Free point Force Velocity
A planar antenna with a broadband feeding structure is presented
and analyzed for ultrawideband applications. The proposed antenna
consists of a suspended radiator fed by an n-shape microstrip feed. Study
shows that this antenna achieves an impedance bandwidth from 3.1–5.1
GHz (48%) for a reflection of coefficient and an
average gain of 7.7 dBi. Stable boresight radiation patterns are achieved
across the entire operating frequency band, by suppressing the high order
mode resonances. This design exhibits good mechanical tolerance and manufacturability....
COMBINED ORAL CONTRACEPTIVES Mechanism of action
The combined oral contraceptive (COC) pills currently available in the UK are shown in Table 2. They combine an estrogen (ethinylestradiol (EE) in all cases but one) with one of seven progestogens. Aside from secondary contraceptive effects on the cervical mucus and to impede implantation, COCs primarily prevent ovulation. This makes the method highly effective in ‘perfect’ use (Table 1), but it removes the normal menstrual cyle and replaces it with a cycle that is user-produced and based only on the end-organ, i.e. the endometrium.
Distributed transactions have historically been implemented by
the database community in the manner pioneered by the architects
of System R*  in the 1980s. The primary mechanism by which
System R*-style distributed transactions impede throughput and
extend latency is the requirement of an agreement protocol between
all participating machines at commit time to ensure atomicity and
durability. To ensure isolation, all of a transaction’s locks must be
held for the full duration of this agreement protocol, which is typi-
cally two-phase commit.
The apical meristem and zone of cell extension of impeded roots is shorter (Barley, 1962; Souty,
1987), and root hairs develop closer to the tip of impeded roots (Goss & Russell, 1980). Lateral
initiation occurs nearer the tip and laterals occur together along the impeded axis (Goss & Russell,
1980; Barley, 1962). Where mechanical deflection causes roots to curve around an obstacle, the
initiation of laterals generally occurs on the convex side of the root (Goss & Russell, 1980). Root hair
development is greater on the opposite (concave) side and, in...