1,721,044 research outputs found
Effects of layer orientation of CFRP strengthened steel hollow members
No full textThis paper reveals the effects of layer orientation on structural behaviour of three layers configured (LHL, HHL, LLH) CFRP strengthened circular hollow section (CHS) members subjected to bending. The beams were loaded to failure under four-point bending. The structural behaviour of the CFRP strengthened tubular steel beams with various layer orientations were presented in terms of failure load, stiffness, composite beam action and modes of failure. The LHL and LLH layers oriented strengthened beams perform slightly better than HHL layers oriented strengthened beams. The LHL and LLH layers oriented treated beams showed very similar structural behaviour
Durability performance of carbon fibre-reinforced polymer strengthened circular hollow steel members under cold weather
No full textThe use of circular hollow steel members has attracted a great deal of attention during past few years because of having excellent structural properties, aesthetic appearance, corrosion and fire protection capability. However, no one can deny the structural deficiency of such structures due to reduction of strength when they are exposed to severe environmental conditions such as marine environment, cold and hot weather. Hence strengthening and retrofitting of structural steel members is now very imperative. This paper presents the findings of a research program that was conducted to study the bond durability of carbon fibre-reinforced polymer (CFRP) strengthened steel tubular members under cold weather and tested under four-point bending. Six number of CFRP-strengthened specimens and one unstrengthened specimen were considered in this program. The three specimens having sand blasted surface to be strengthened was pre-treated with MBrace primer and other three were remained untreated and then cured under ambient temperature at least four weeks and cold weather (3 C) for three and six months period of time. Quasi-static tests were then performed on beams to failure under four-point bending. The structural response of each specimen was predicted in terms of failure load, mid-span deflection, composite beam behaviour and failure mode. The research outcomes show that the cold weather immersion had an adverse effect on durability of CFRP-strengthened steel structures. Moreover, the epoxy based adhesion promoter was found to enhance the bond durability in plastic range. The analytical models presented in this study were found to be in good agreement in terms of predicting ultimate load and deflection. Finally, design factors are proposed to address the short-terms durability performance under cold weather
Durability of CFRP strengthened circular hollow steel members under cold weather: Experimental and numerical investigation
No full textThe durability of carbon fibre reinforced polymer (CFRP) strengthened steel circular hollow section (CHS) member under prolonged cold weather has not been explored sufficiently. Furthermore, various parameters that may affect the durability of such members have not been revealed yet. This paper presents an analytical and experimental study with a finite element (FE) approach to study the effects of prolonged cold weather (+3 OC) exposure on CFRP strengthened CHS member subjected bending. It was found that a prolonged exposure about 12 month cold weather immersion adversely affected the durability of strengthened beams by reducing strength and stiffness. Durability design factor has been recommended. The proposed analytical models and FE models were found in good agreement with the experimental results. The results of parametric studies showed that the durability design factors varied from section to section, CFRP with higher tensile modulus and higher number of CFRP layers performed better in cold weather
Durability of CFRP strengthened steel circular hollow section member exposed to sea water
No full textThis paper presents the results from a research program to investigate the durability of CFRP strengthened steel circular hollow section (CHS) members with and without embedded glass fibre reinforced polymer (GFRP) at ambient (24 OC ± 4 OC) and 50 OC temperatures under accelerated corrosion environment. The beams were tested to failure under four-point bending. It was found that the accelerated corrosion adversely affected the durability of the strengthened beams at both temperatures and the embedded GFRP enhanced the durability. Durability design factor has also been recommended. The proposed theoretical approach predicts ultimate loads reasonably compared to experimental value of ultimate loads
Structural performance of reinforced concrete beams\ud repairing from spalling
No full textThe effectiveness of a repair work for the restoration of spalled reinforced concrete\ud
(r.c.) structures depends to a great extent, on their ability to restore the structural integrity\ud
of the r.c. element, to restore its serviceability and to protect the reinforcements from\ud
further deterioration. This paper presents results of a study concocted to investigate the\ud
structural performance of eight spalled r.c. beams repaired using two advanced repair\ud
materials in various zones for comparison purposes, namely a free flowing self compacting\ud
mortar (FFSCM) and a polymer Modified cementitious mortar (PMCM). The repair\ud
technique adopted was that for the repair of spalled concrete in which the bond between the\ud
concrete and steel was completely lost due to reinforcement corrosion or the effect of fire\ud
or impact. The beams used for the experiment were first cast, then hacked at various zones\ud
before they were repaired except for the control beam. The beam specimens were then\ud
loaded to failure under four point loadings. The structural response of each beam was\ud
evaluated in terms of first crack load, cracking behavior, crack pattern, deflection, variation\ud
of strains in the concrete and steel, collapse load and the modes of failure. The results of\ud
the test showed that, the repair materials applied on the various zones of the beams were\ud
able to restore more than 100% of the beams’ capacity and that FFSCM gave a better\ud
overall performance
Socio-economic impacts of Gorai riverbank erosion on people: a case study of Kumarkhali, Kushtia
Full text linkThis thesis is submitted in partial fulfillment of the requirements for the degree of Masters of Arts in Governance and Development, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (page 54 - 56).The purpose of this research was to identify socio-economic impacts of riverbank
erosion on people of Kumarkhali. It was hypothesized that the socio-economic impacts
of riverbank erosion on affected people are quite significant and enormous. The findings
of the study reveal that affected people have experienced substantial socio-economic
impoverishment. At Kumarkhali point the erosion of Gorai solely started in the 40s of
the last century. But at that time the erosion was not so remarkable for the inhabitants. A
large number of people think that it took severe form specially when the river Kaliganga
and the Dakatia were blocked at the time of implementing GK Project in the 50s. Some
others believe that heavy siltation due to the lack of natural flow of Gorai as because of
the Farakka barrage is another important reason of continued erosion. Whatever might be
the reason all most 100% of the people on the bank line of Gorai had/have suffered due
to erosion. Loss of homesteads, cultivable lands, kitchen garden lands & home yard
lands have played vital role for the change of their livelihood pattern. Due to this they
have lost their familial and social ties, have got separated from their kith and kin, and
most painfully income erosion have turned them from well-off to poor overnight.
Irony is that several measures have been taken to control erosion from late 1960s to mid
1990s of the last century. But erosion continued as those measures were not taken at the
right time. Even no consultation has been made with the victims when groin or revetment
was made. 100% victims have said that, they are not consulted at the time of making
groin or revetment. In a third world country like Bangladesh policy planning and
implementation is almost a top-down approach. Moreover the policy is very often
political motive and personal interest driven. It does not fulfill the need of the people.
Hence governance is a very important issue for the effective planning and execution of
the policy. Bad governance works as a catalyst for increased vulnerability of the people.
Riverbank erosion at Kumarkhali is a classic example of this and that’s why the people
of the locality are suffering generation after generation.
Policy makers will have to learn from this experience and top down approach at the time
of policy planning should be avoided.
Lack of good governance always increases the vulnerability of the people. So without
good governance no development is real development. At the time of planning and
implementation the policymakers should keep it in mind otherwise development will not
be purposeful, sustainable and effective.A.T.M. Abdullahel BakiM. Governance and Developmen
FARMERS’ PERCEPTION TOWARDS HARMFUL EFFECTS OF SOIL SALINITY ON FOOD PRODUCTION
Full text linkA Thesis
Submitted to the Department of Agricultural Extension and Information System
Sher-e-Bangla Agricultural University, Dhaka
In partial fulfilment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
AGRICULTURAL EXTENSION AND INFORMATION SYSTEMSoil salinity seems to be one of the Important aspects of climate change that have
harmful consequence on crop production .The purpose of this study was to determine
farmers’ perception towards harmful effects of soil salinity on food production and to
explore the relationships between the characteristics of the farmers and their perception
towards harmful effects of soil salinity on food production. The study was conducted in 3
villages of Taltali upazila under Barguna district. The populations of the farmers in these
villages were 713 from where 106 samples were drawn by using random sampling
technique. An interview schedule was used for data collect ion. Perception towards
harmful effects of soil salinity on food production was measured by 5 point likert scale.
Descriptive statistics such as mean, standard deviation, range and percentage were used
to describe the variables under consideration. Pearson’s Product Moment Correlation Coefficient
test
was
used
to
ascertain
the
relationship
between
the
concerned
characteristics
and
focus variables. Majority (84.9 percent) of the farmers’ possessed favorable
perception and (15.1 percent) of the farmers had unfavorable perception towards harmful
effects of soil salinity on food production. Education, farm size, land under soil salinity,
knowledge on soil salinity effects, of the farmers had positive significant relationship
with their perception towards harmful effects of soil salinity on food production. The
policy makers may concentrate the significant factors while making policy to reduce the
harmful effects of soil salinity on food productio
Managing public private partnerships (PPPs) through collaborative governance structure: a tale of two infrastructure projects in Victoria, Australia
No full textIn recent decades, the use of Public Private Partnerships (PPPs) for infrastructure development has received significant scholarly attention. Much of this attention originates from recognition of the challenges inherent in this move towards greater collaboration between the public and the private sector in building large infrastructure projects as PPPs, especially in Australia. The adoption of this management model has come with much praise as well as some criticism, particularly concerning the ways in which the model is fundamentally different from traditional contractual arrangements. The purpose of this study is to examine the management practices of two Victorian PPP infrastructure projects: EastLink and the Southern Cross Station Redevelopment. The aim is to examine the operational aspects of these projects to show how management approaches can be instrumental in designing and implementing effective procedures for implementing large infrastructure projects. This study investigates how a collaborative governance structure provides better quality services through sharing of knowledge and information, managing risks, and involving stakeholders with an innovative engagement regime to complete the project on time and on budget. There has been little investigation into how management practices make a difference in large infrastructure projects to reduce costs and time. Understandably, the large number of stakeholders, often with conflicting interests, makes large infrastructure projects complicated to coordinate and manage. However, this study reveals that those complexities and challenges can be addressed through innovative management practices. Case study method is used for this study. Data were gathered through face-to-face interviews, using semi-structured questions, with 40 important participants, including senior policy makers from the Victorian Department of Treasury and Finance, project managers from the public and the private sector, local council officials and community groups. The questions were devised to elicit the key factors of collaborative governance and to identify a wide range of opinions about the management practices used in the two projects. Our findings reveal that PPPs require a better configured management approach, where factors such as mutual trust, risks and knowledge sharing between participating partners and, more importantly, stakeholders are incorporated into a collaborative governance structure. This study argues that the nexus between the state and market has significantly changed over recent decades and tilted from longterm contractual arrangements towards collaboration through PPPs, which provide operational flexibility for implementing infrastructure projects. We argue that the transparency of the process, continuous improvement of process-related actions, stakeholders' engagement and innovation in distribution of tasks and responsibilities in a segmented but well-synchronised manner strengthen partnership arrangements and help project teams identify and manage risks. We also conclude from these two cases that the success or failure of a PPP model depends on the management practices that the partner organisations use through a collaborative governance structure
Managing public private partnerships (PPPs) through collaborative governance structure: a tale of two infrastructure projects in Victoria, Australia
No full textIn recent decades, the use of Public Private Partnerships (PPPs) for infrastructure
development has received significant scholarly attention. Much of this attention
originates from recognition of the challenges inherent in this move towards greater
collaboration between the public and the private sector in building large
infrastructure projects as PPPs, especially in Australia. The adoption of this
management model has come with much praise as well as some criticism,
particularly concerning the ways in which the model is fundamentally different from
traditional contractual arrangements.
The purpose of this study is to examine the management practices of two Victorian
PPP infrastructure projects: EastLink and the Southern Cross Station Redevelopment.
The aim is to examine the operational aspects of these projects to show how
management approaches can be instrumental in designing and implementing
effective procedures for implementing large infrastructure projects. This study
investigates how a collaborative governance structure provides better quality
services through sharing of knowledge and information, managing risks, and
involving stakeholders with an innovative engagement regime to complete the
project on time and on budget. There has been little investigation into how
management practices make a difference in large infrastructure projects to reduce
costs and time. Understandably, the large number of stakeholders, often with
conflicting interests, makes large infrastructure projects complicated to coordinate
and manage. However, this study reveals that those complexities and challenges can
be addressed through innovative management practices.
Case study method is used for this study. Data were gathered through face-to-face
interviews, using semi-structured questions, with 40 important participants,
including senior policy makers from the Victorian Department of Treasury and
Finance, project managers from the public and the private sector, local council
officials and community groups. The questions were devised to elicit the key factors
of collaborative governance and to identify a wide range of opinions about the
management practices used in the two projects. Our findings reveal that PPPs require a better configured management approach,
where factors such as mutual trust, risks and knowledge sharing between
participating partners and, more importantly, stakeholders are incorporated into a
collaborative governance structure. This study argues that the nexus between the
state and market has significantly changed over recent decades and tilted from longterm
contractual arrangements towards collaboration through PPPs, which provide
operational flexibility for implementing infrastructure projects. We argue that the
transparency of the process, continuous improvement of process-related actions,
stakeholders' engagement and innovation in distribution of tasks and responsibilities
in a segmented but well-synchronised manner strengthen partnership arrangements
and help project teams identify and manage risks. We also conclude from these two
cases that the success or failure of a PPP model depends on the management
practices that the partner organisations use through a collaborative governance
structure
Somatic Embryogenesis in Musa Spp.
Full text linkEmbryogenesis competent material (scalp) was initiated from shoot tip of
Musa spp. cultivar Mas (AA), Berangan (AAA), Intan (AAA), Raja (AAB) and
Tanduk (AAB). Somatic embryogenesis were investigated from four explant sources
viz., scalps, male flower primordia, in vitro corm slices and immature ovules of
Musa acuminata cv. Mas. Scalp formation was optimal on Murashige and Skoog
(MS) medium with modified vitamins supplemented with 100 /lM BAP and 1.0 /lM
IAA. Among the cultivars investigated, cv. Mas was the most responsive for scalp
formation whereby 40% of the shoot tips formed scalps by the 7th month of culture.
Cultivar Mas was also the most responsive for meristematic globule formation from
scalps attaining 100% meristematic globule formation by week 7 of culture of scalps
in Z medium. Cells with embryogenic potential were released from the meristematic
globules of cv . Mas after 10 to 12 months of culture of the meristematic globules in
Z medium . The embryogenic cell suspension was transferred to liquid S medium and
formed globular embryos after 3 to 4 months in culture. Matured globular embryos
upon transfer to liquid S regeneration medium supplemented with 0, 1.0, 5.0, 10, 20,
40 and 80 /lM BAP germinated to form roots but without shoots
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