82 research outputs found
Free Flow Traffic Noise in Three Malaysian Cities
This paper reports a study on free flow traffic noise in three cities in Peninsular Malaysia. It is
found that generally the noise level is high and correlates with the type of traffic. A few suggestions on
control measures are made
The satisfaction of the usage of electronic commerce applications among companies in Johor Bharu
This study examines the level of satisfaction of the usage of e-commerce applications among companies in Johor Bahru. To explore the issue, a set of questionnaires was distributed among the companies that have already implemented e-commerce.The finding shows that the majority of the companies are satisfied with the e-commerce applications.Almost all of the companies mentioned that e-commerce has the empathy, tangibility, responsiveness,reliability and assurance criteria with the last two criteria being the most profound. This significant finding will encourage other companies to use e-commerce applications in their business transactions
Determination of Effective Atomic Number of Rubber
This paper reports a simple technique to determine the effective atomic number of rubber materials.
The gamma ray attenuation coefficient of rubber was measured with high energy resolution Si(Li) detector
at low gamma ray energies and the effective atomic number was determined by the functional ratio of
attenuation coefficients at different energies. This study could provide a guide to an understanding of the
quality of rubber based on its composition
Gamma Ray Attenuation in Hevea Latex and its Application to DRC Measurement
This paper reports the measurement of the total solid content (TSC) of fresh Hevea latex by the
gamma ray attenuation technique. The component ratios of the total volume of water and solid
material in multiphase system of latex were determined by the measurement of attenuation coefficient
of latex with high energy resolution Si(Li) detector at low gamma ray energies. The result was compared
against the Standard Laboratory Method and the correlation coefficient was found to be 0.998.
Based on the behavior that the interaction of gamma ray with matter at a given energy depends upon
the atomic number of the material, the present technique may be able .to detect adulterants in the
latex, but investigations are needed to verify this
Enhancement of stack ventilation in hot and humid climate using a combination of roof solar collector and vertical stack
In the hot and humid climate, stack ventilation is inefficient due to small temperature difference between the inside and outside of naturally ventilated buildings. Hence, solar induced ventilation is a feasible alternative in enhancing the stack ventilation. This paper aims to investigate the effectiveness of a proposed solar induced ventilation strategy, which combines a roof solar collector and a vertical stack, in enhancing the stack ventilation performance in the hot and humid climate. The methodology selected for the investigation is physical experimental modelling which was carried out in the actual environment. The results are presented and discussed in terms of two performance variables: air temperature and air velocity. The findings indicate that the proposed strategy is able to enhance the stack ventilation, both in semi-clear sky and overcast sky conditions. The highest air temperature difference between the air inside the stack and the ambient air (Ti−To) is achieved in the semi-clear sky condition, which is about 9.9 °C (45.8 °C–35.9 °C). Meanwhile, in the overcast sky condition, the highest air temperature difference (Ti−To) is 6.2 °C (39.3 °C–33.1 °C). The experimental results also indicate good agreement with the theoretical results for the glass temperature, the air temperature in the roof solar collector’s channel and the absorber temperature. The findings also show that wind has significant effect to the induced air velocity by the proposed strategy
Finite Element Analysis of Proximal Cement Fixation in Total Hip Arthroplasty
Total hip arthroplasty (THA), or surgical replacement of
the hip joint with a prosthesis, is a reconstructive procedure that has
improved the management of hip joint diseases that have responded poorly to
conventional medical therapy. There are reasons to believe that the proximal
part of the cement withstands more stress than the distal part in THA.
Therefore, this study aims to determine whether it is possible to perform THA
by cementing only the proximal part of the hip prosthesis. The
polymethylmethacrylate cement has a Young’s modulus of 2GPa, a tensile strength
of 29 MPa, and a Poisson’s ratio of 0.3. This analysis was done using a
stainless steel stem model provided by the Department of Orthopaedic Surgery,
University of Malaya Medical Centre, using a Young’s modulus of 200 GPa and a
Poisson’s ratio of 0.28. The bone cement was modelled while the THA femur was
reconstructed by inserting stem prosthesis into the femoral canal. The effects
of different proximal cement lengths in THA were investigated by analyzing the
stress distribution and displacement of the THA model during walking and stair
climbing
Enceladus and Titan: Emerging Worlds of the Solar System (ESA Voyage 2050 White Paper)
Some of the major discoveries of the recent Cassini-Huygens mission have put Titan and Enceladus firmly on the Solar System map. The mission has revolutionised our view of Solar System satellites, arguably matching their scientific importance with that of their planet. While Cassini-Huygens has made big surprises in revealing Titan's organically rich environment and Enceladus' cryovolcanism, the mission's success naturally leads us to further probe these findings. We advocate the acknowledgement of Titan and Enceladus science as highly relevant to ESA's long-term roadmap, as logical follow-on to Cassini-Huygens. In this white paper, we will outline important science questions regarding these satellites and identify the pertinent science themes we recommend ESA cover during the Voyage 2050 planning cycle. Addressing these science themes would make major advancements to the present knowledge we have about the Solar System, its formation, evolution and likelihood that other habitable environments exist outside the Earth's biosphere
The case for studying other planetary magnetospheres and atmospheres in Heliophysics
Heliophysics is the field that "studies the nature of the Sun, and how it
influences the very nature of space - and, in turn, the atmospheres of
planetary bodies and the technology that exists there." However, NASA's
Heliophysics Division tends to limit study of planetary magnetospheres and
atmospheres to only those of Earth. This leaves exploration and understanding
of space plasma physics at other worlds to the purview of the Planetary Science
and Astrophysics Divisions. This is detrimental to the study of space plasma
physics in general since, although some cross-divisional funding opportunities
do exist, vital elements of space plasma physics can be best addressed by
extending the expertise of Heliophysics scientists to other stellar and
planetary magnetospheres. However, the diverse worlds within the solar system
provide crucial environmental conditions that are not replicated at Earth but
can provide deep insight into fundamental space plasma physics processes.
Studying planetary systems with Heliophysics objectives, comprehensive
instrumentation, and new grant opportunities for analysis and modeling would
enable a novel understanding of fundamental and universal processes of space
plasma physics. As such, the Heliophysics community should be prepared to
consider, prioritize, and fund dedicated Heliophysics efforts to planetary
targets to specifically study space physics and aeronomy objectives
Association between solar insolation and a history of suicide attempts in bipolar I disorder
In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p <0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.Peer reviewe
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