1,954 research outputs found
Temperature scaling in a dense vibro-fluidised granular material
The leading order "temperature" of a dense two dimensional granular material
fluidised by external vibrations is determined. An asymptotic solution is
obtained where the particles are considered to be elastic in the leading
approximation. The velocity distribution is a Maxwell-Boltzmann distribution in
the leading approximation. The density profile is determined by solving the
momentum balance equation in the vertical direction, where the relation between
the pressure and density is provided by the virial equation of state. The
predictions of the present analysis show good agreement with simulation results
at higher densities where theories for a dilute vibrated granular material,
with the pressure-density relation provided by the ideal gas law, are in error.
The theory also predicts the scaling relations of the total dissipation in the
bed reported by McNamara and Luding (PRE v 58, p 813).Comment: ReVTeX (psfrag), 5 pages, 5 figures, Submitted to PR
Distribution of larval tuna collected by the Carlsberg foundation's Dana expedition (1928-30) from the Indian Ocean
The geographical and seasonal distribution of larvae of five species
of tuna (Katsuwonus elamis, Neothunnus macropterus, Euthynnus affinis
affinis, Auxis thynnoides and Auxis thazard in the Indian Ocean based
mainy on the collections made by the 1928-30 Dana Oceanographical Expedition
are dealt with
Notes on eggs, larvae and juveniles of fishes from Indian waters XV Pegasus volitans Linnaeus. XVI Dactyloptena orientalis (Cuvier and Valenciennes) and XVII Ddactyloptena macracanthus (Sleeker)
Three species of pegasids viz., Pegasus volitans Linnaeus, P. laternarim Cuvier
and P. draconis Linnaeus have been recorded from the seas around India. Of these,
Pegasus draconis is distinct from the other two by the presence of 8 tail rings
and 2 pits on occiput. P. volitans differs from P. laternarius mainly in having 12
tail rings as against 11 tail rings in the latter. P. natans is considered synonym of
P. volitans (vide De Beaufort, 1962) and hence the larval and juvenile specimens
collected from the Orissa coast (Jones and Pantulu, 1958) and the postlarva collected
from Porto Novo (Krishnamurthy, 1962) should be known under P. volitans
The fishing industry of Minicoy Island with special reference to the tuna fishery
The coral island of Minicoy (Fig. 1 a and b) in the Indian Ocean (Latitude
8° 7' N., Longitude 73° 18' E.) is the most important tuna fishing centre in
the Indian Union (Fig. 1). Situated between the two main groups of islands
of the Laccadive and the Maldive Archipelagoes, it is about 10 km. long
and 820 m. broad in the centre and has an area of about 455
hectares and population of about 4,000 who speak the same Mahl dialect as
the Maldivians to whom they are related ethnically. The main port of
trade in India for the islanders is Cannanore about 420 km. away on the
Malabar coast and specially built sailing vessels known as odams are used
for carrying men and cargo to the mainland and back. Tuna fishery is the
most important industry of the island and the chief product of export is
the mas min or the cured and dried meat of tuna the value of which has
recently risen to the record figure of over half a million rupees a year. Export
of cured tuna meat contributes about two-thirds of the total income of the
islanders while next in order of importance comes the money remitted by
those serving as lascars in merchant vessels. The only other source of
income is from the sale of produce like copra, jaggery, coir and vinegar
from coconuts. There is practically no other source of revenue and the
inhabitants have to depend entirely on the mainland for all essential items
and necessities of daily life such as rice and other commodities. In view
of this, a barter system of trade prevails there and the necessary goods are
supplied by certain merchants at Cannanore directly or through their
agents stationed in the island
Non-Gaussian velocity distributions in excited granular matter in the absence of clustering
The velocity distribution of spheres rolling on a slightly tilted rectangular
two dimensional surface is obtained by high speed imaging. The particles are
excited by periodic forcing of one of the side walls. Our data suggests that
strongly non-Gaussian velocity distributions can occur in dilute granular
materials even in the absence of significant density correlations or
clustering. When the surface on which the particles roll is tilted further to
introduce stronger gravitation, the collision frequency with the driving wall
increases and the velocity component distributions approach Gaussian
distributions of different widths.Comment: 4 pages, 5 figures. Additional information at
http://physics.clarku.edu/~akudrolli/nls.htm
A CONCEPTUAL UNDERSTANDING OF THE CRITICAL FACTORS THAT INDUCE WOMEN ENTREPRENEURIAL SUCCESS IN THE KLANG VALLEY, MALAYSIA
Entrepreneurship has always been men’s realm, nevertheless women’s enthusiasm in business shows some intensification in Malaysia, but their success is still trivial. This stimulates doubts about the factors that induce their success as entrepreneurs. The objective of this research is to offer an understanding into the success factors of women entrepreneurs in the Klang Valley, Malaysia. Thus, this study focuses on the implication of five variables, which are financial capital, human capital, social capital, innovation and work-life balance that induces success to the women entrepreneurs. To attain the objective of this study, a survey technique is used. The primary data would provide an understanding of the factors that induces success to the women entrepreneur. This study used quantitative methods to produce empirical outcomes and validations to answer the research questions. The Resource-Based View Theory and Conflict Theory are the theoretical foundations that fill the gaps of the study. The findings of this study could perhaps be a benchmark to other women to rise against all tribulations faced in their pursuit to triumph and remain at the highest socio-economic level as well as attain a competitive edge in business. Article visualizations
A comparative study of ultrasound and x-ray in detection, of fracture callus in tibial shaft fractures, treated by unreamed interlocking nailing
Background: Trauma is a major health problem in young adults and adolescents. It is a major cause of disability with fracture being a leading contributor to hospital cost and lost productivity in the workplace. Comparative study of ultrasonography and radiography in the early detection of fracture callus in tibial shaft fracture treated by unreamed static interlocking nailing.Methods: All skeletally mature patients admitted to Krishna Kumar Orthopedic Hospital, Nagercoil were included in our study from 2007 to 2008. 21 patients totally, who had sustained an acute fracture of the tibial shaft and who were treated by statically locked unreamed interlocking nailing were candidates for the study.Results: The mean±standard deviation for ultrasound and X-ray method of detection fracture callus in fractures shaft of tibia treated with static interlocking nailing are 4.82±1.01 and 7.05±1.02 respectively which is statistically highly significant. This analysis reveals that ultrasound detects fracture callus much earlier than X-ray.Conclusions: Ultrasound was able to detect fracture callus in tibial shaft fracture treated by a static unreamed interlocking nail. There was a statistically high significance difference of 2.23 weeks between the two techniques Ultrasound was done using a 7.5 MHz linear transducer probe. Ultrasound could detect fracture callus at a mean period of 4.82 weeks. Whereas X-rays could d detect fracture callus only at a mean period of 7.05 weeks
A clinical study of axillary post burn scar contracture
INTRODUCTION:
Post burn axillary scar contracture are common after deep thermal burns
to the upper extremities. Because of poor positioning of the axilla during the
acute burns period or improper rehabilitation post burn axilla contracture
produces both functional and anatomic deformities. Surgical intervention is
still a challenge, because the axilla is a unique three dimensional pyramid. It
is often seen in our environment following poorly treated burn injuries
especially when the conservative approach is the method of achieving cover
for a burn wound around the shoulder joint. Post burn axillary contracture
almost always interferes with and limits abduction of the shoulder joint. This
interferes with the ability to feed and to perform other important upper
extremity function. A variety of therapeutic options such as skin grafting,
multiple Z plasties, and local flaps are reported in literature for the treatment
of axillary contracture. There are also many methods described for post
operative splinting of the axilla. A study of post burn axilla contracture was
done and analysis of axillary contracture was done based on age, sex, years of
post burn, classification of the axilla contracture based on anatomy distortion
and on severity of functional limitation, surgical option used and its
complications with follow up of patient and patient compliance.
AIMS AND OBJECTIVES:
The aims and objectives of the study are
• To analyze all cases of axillary post burn scar contracture in our
Department from August 2005 to Dec 2007.
• To analyze the age, sex, side distribution of axillary contracture.
• To classify axillary contracture based on type and severity.
• To study the various surgical options used for axillary contracture by
Duration of hospital stay,
Complication rate,
Re contracture,
Patient compliance.
MATERIALS AND METHODS
This study is a prospective analysis of all post burn axillary contractures
which were treated with contracture release with split thickness skin grafts
and by flaps in the Department of Plastic and Reconstructive Surgery,
Christian Medical College, Vellore from October 2005 to December 2007.
All patients who had axillary post burn scar contracture and who
underwent surgical management were included in the study.
Exclusion criteria:
1. Patients who had previous operative procedure for axillary contracture.
2. Patients who had burns of the elbow and hands.
3. Patients who had post burn axillary contracture less than 3 months.
Patient demographics:
The total number of post burn axillary contracture was 31. Out of this 21
had right side axilla involved and 10 had left side involvement (Fig 9). The
mean age of the patient with axilla contracture was 26.2.years (range 3 to 62
years) and there were 7 men (22.6 %) and 24 women (77.4 %).
RESULTS:
The compliance of the patients in our study was poor in 10 patients that is
patient who came for less than 2 visits and who did not do any physiotherapy
and did not use splint (32.6 %), moderate in 9 patients that is patient who
came for at least 3 visits and were using splint at least 12 hours per day and
doing some physiotherapy(29.0 %) and good in 12 patients that is patient who
came for 6 follow up visits and were regularly using splint and doing
physiotherapy (38.7 %) .
Compared between patients who underwent flap for contracture release
and patients who under went incision release and skin grafting there was no
statistical significance.
There were no major complications in the post operative period. In 5
patients who underwent incision release and split thickness skin grafting had
graft loss ranging from 2 % to 10% (Fig 14). For 3 patients who had between
5 to 10 % graft loss re grafting was carried out. Re grafting was done to
prevent healing by wound contracture and thus producing re contracture of
the axilla. For 2 patients who had 1 to 2 % graft loss graft loss conservative
management of regular dressings with hydrocoll moist dressings was carried
out and the wound healed in1 week. For these patients who had graft loss
active physiotherapy was delayed till the wound has completely epithelialised
or graft has taken well. Usually it took on the average 2 weeks before the
active physiotherapy was started. There were no complications in the
remaining 26 patients.
On comparison between patients who had incision release and split
thickness skin grafting and patient who underwent flap for contracture release
for complications there was a statistical significance of .042.
CONCLUSION:
Post burn axillary contracture release with flaps gives very good result in terms of
less hospitalization days, low re contracture rate and good patient compliance
although it requires skill and knowledge to choose the right flap for each
contracture type .Contracture release with split skin grafting although easy to
execute and can be done for any type of axillary contracture has more re
contracture rate and poor compliance because of long term splinting. In our study
the results of contracture release with flaps were good with no major complications
and it also does not require long term splinting when compared to split skin grafts.
In developing countries where patient has to go for work early it is always better to
do a contracture release with flap
Synthesis and Characterization of Mechanical Alloyed Mg-Ni-Ca and Mg-Cu-Ca Amorphous Alloys
AbstractMagnesium and its alloys are widely recommended for automotive, electronics and biomedical industries due to their strength to weight ratio. The mechanically alloyed magnesium with Ni, Cu and Ca alloys exhibits superior properties. In this work, the ternary Mg70Ni10Ca20 and Mg85Cu10Ca5 alloys were synthesized by mechanical alloying for 10h in SPEX mill with 10:1 ball to powder ratio under argon (Ar) atmosphere. Their structural and phase transformation with respect to milling time and composition were studied by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray spectroscopy. The XRD pattern showed the formation of amorphous with nano crystalline peaks. The Mg2Cu and CaCu intermetallic phases were identified in Mg85Cu10Ca5 alloy and Mg2Ni and MgNi2 intermetallic compounds were identified in Mg70Ni10Ca20 alloy. A crystallite size of 44.45nm was measured from the α-Mg XRD peak in Mg-Cu-Ca alloy, and 45.59nm was measured for the Mg2Ni phase in Mg-Ni-Ca alloy
A novel and sustainable method to develop non-equiatomic CoCrFeNiMox high entropy alloys via spark plasma sintering using commercial commodity powders and evaluation of its mechanical behaviour
A novel approach to developing high entropy alloys (HEAs) using spark plasma
sintering (SPS) was explored in this work where a mix of commercial commodity
powders like Ni625, CoCrF75, and 316L was used instead of pre-alloyed powders
avoiding the expensive pre-alloying steps like mechanical alloying or gas
atomizing. Three non-equiatomic HEAs, based on Co, Cr, Fe, Ni, and Mo were
designed and developed by blending the powders which were sintered via SPS and
resulted in a single FCC phase after homogenization. The HEAs were
microstructurally and mechanically characterized with tensile and hot
compression tests up to a temperature of 750oC showing excellent properties.
The maximum room temperature tensile strength and ductility demonstrated was
712 MPa and 62% respectively, by the alloy Co23.28Cr28.57Fe25.03Ni21.01Mo2.1.
Moreover, the same alloy exhibited a compression strength greater than 640 MPa
with a ductility above 45% at a temperature of 750oC. Also, this study paves
the way for a novel fabrication route that offers more flexibility to develop
new HEAs cost-effectively and efficiently which is crucial for the discovery of
new materials over high-throughput techniques. Using such commodity alloys also
opens the possibility of developing ingot casting from recycled scraps avoiding
the direct use of critical metals
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