11 research outputs found
Thermophysical Properties of Gmelina Arborea Biodiesel
The depletion of petroleum reserves, rising cost of conventional fuels and the ill effect of emission from the use of fossil fuel on human health and environment have driven scientific research towards the development of alternative source of fuels such as biofuel and biodiesel. Biodiesel is a fuel from a renewable sources and it has the potential of being used as an alternative to fossil diesel in compression ignition engine. Some of the challenges encountered in the use of biodiesel in compression ignition engine are its availability, use of edible oil for its production, cost of biodiesel feedstock and unfavorable properties of biodiesel such as its high viscosity. Presently, there is a search for more inedible oil seeds since the available inedible feedstock are still not enough to replace more than 20 - 25% of the total transportation fuels. The thermophysical properties of the biodiesel which vary from feedstock have a significant impact on the combustion process thereby affecting the overall engine performance and emissions. The aim of this study is to test the compatibility of biodiesel from Gmelina arborea seed oil in the compression ignition engine through its thermophysical properties. The biodiesel was produced using transesterification method and the thermophysical properties tests were carried out. The results showed that the density and viscosity of Gmelina arborea seed oil was 868.8 kg/m2 (at 27.5°C) and 1.882(mm)2/s (at 40.0°C) respectively. It also showed that the biodiesel obtained had a density and viscosity value of 821.2 kg/m3 (at 27.5°C) and 0.794 9 (mm)2/s (at 40.0°C) respectively. Comparing these results with other biodiesel, it was observed that Gmelina arborea oil has a lower viscosity and density than other biodiesel from different feedstocks; therefore it has potential to perform better in the diesel engine in comparison to other biodiesel
Improved Drilling Efficiency via Enhanced Water Based Mud in the Niger Delta
This study focuses on latest advances in water based mud as a potential for the Niger Delta, its impact on drilling efficiencies and well productivity. Recently, New mud additives are been developed to enhance the rheology of water based mud to deliver the same characteristics and reliability of an oil based mud when considering the Niger Delta geology. Due to the challenges with Water Based Mud in respect to chemistry and suitability, Oil Based Mud (OBM) has become the main type of drilling fluid in deeper sections during drilling campaign in the Niger Delta. But the use of OBM as come with some challenges that has necessitated the further research and development of Water Based Mud rheology that can deliver the same results as OBM. Some of the challenges associated with the use of OBM include but not limited to high cost and management, contamination of OBM in the storage site during drilling activities, logistics complexity, environmental impact from spills and disposal, and impact on well productivity and reservoir management.
In countries such as Ghana, Columbia, Oman, Mexico, Enhanced WBM mud has been used and is still being used in drilling to deep depths (8000ft-10000ft)TVD in formations with similar geology with that of the Niger Delta. Sample wells will be reviewed from one of these regions for the project and they will be used to show the evolving new technologies and techniques in WBM rheology formulation.
This study is channeled to label the engineered properties of the mud, mud composition, its effects on drilling efficiency and well productivity, challenges encountered, the concept for an enhancement, added advantage in comparison to OBM, comparative cost advantage. It was discovered that Enhanced WBM has an added advantage hence leading to a reduction in pollution trends in the Niger Delta and cost effectiveness. Other advantages include addressing to an extent the challenges encountered with WBM such as (inhibition, hydration and solids control) leading to an enhanced well productivity and ultimately affects the overall cost of well delivery
Motorcyclists' reactions to safety helmet law: a qualitative study
<p>Abstract</p> <p>Background</p> <p>Extensive body of the literature reveals that proper use of helmets is an effective way to reduce the severity of injuries and fatalities among motorcyclists. However, many motorcyclists do not use safety helmet properly. This study aimed to empirically explore reactions of motorcyclists to the safety helmet laws, in Iran.</p> <p>Methods</p> <p>Qualitative data were collected via four focus groups and 11 in-depth interviews. Participants were 28 male motorcyclists who never used a safety helmet during rides, and 4 male police officers. All transcripts, codes and categories were read for several times to exhaust identifiable major themes. During this process data were reduced from text to codes and themes.</p> <p>Results</p> <p>Five major themes emerged from the data analyses, including themes related to the following: (1) circumventing or dodging police officers; (2) simulating a helmet wearing behavior; (3) accepting the probability of receiving a ticket; (4) taking advantage of the police neglect and carelessness; and (5) using a cheap or convenient helmet.</p> <p>Conclusion</p> <p>Our findings suggest certain levels of reckless driving among the participating motorcyclists in this study. They also point to a system of law enforcement that operates haphazardly and fails to consistently penalize those who deviate from it. Further studies are needed to investigate how "risks" are perceived and relate to "reactions", and how a 'culture of masculinity' may encourage risk tolerance and a disposition toward lawlessness and carelessness among male motorcyclists. Also, there is a need for the development and implementation of multidimensional interventions that would offer socio-culturally sensitive educational and motivational messages to the motorcyclists and the in-service traffic-enforcement officers in Iran.</p
Rationale and design of The Delphi Trial – I(RCT)(2): international randomized clinical trial of rheumatoid craniocervical treatment, an intervention-prognostic trial comparing 'early' surgery with conservative treatment [ISRCTN65076841]
BACKGROUND: Rheumatoid arthritis is a chronic inflammatory disease, which affects 1% of the population. Hands and feet are most commonly involved followed by the cervical spine. The spinal column consists of vertebrae stabilized by an intricate network of ligaments. Especially in the upper cervical spine, rheumatoid arthritis can cause degeneration of these ligaments, causing laxity, instability and subluxation of the vertebral bodies. Subsequent compression of the spinal cord and medulla oblongata can cause severe neurological deficits and even sudden death. Once neurological deficits occur, progression is inevitable although the rapidity of progression is highly variable. The first signs and symptoms are pain at the back of the head caused by compression of the major occipital nerve, followed by loss of strength of arms and legs. The severity of the subluxation can be observed with radiological investigations (MRI, CT) with a high sensitivity. The authors have sent a Delphi Questionnaire about the current treatment strategies of craniocervical involvement by rheumatoid arthritis to an international forum of expert rheumatologists and surgeons. The timing of surgery in patients with radiographic instability without evidence of neurological deficit is an area of considerable controversy. If signs and symptoms of myelopathy are present there is little chance of recovery to normal levels after surgery. DESIGN: In this international multicenter randomized clinical trial, early surgical atlantoaxial fixation in patients with rheumatoid arthritis and radiological abnormalities without neurological deficits will be compared with prolonged conservative treatment. The main research question is whether early surgery can prevent radiological and neurological progression. A cost-effectivity analysis will be performed. 250 patients are needed to answer the research question. DISCUSSION: Early surgery could prevent serious neurological deficits, but may have peri-operative morbidity and loss of rotation of the head and neck. The objective of this study is to identify the best timing of surgery for patients at risk for the development of neurological signs and symptoms
Thermophysical Properties of Gmelina Arborea Biodiesel
The depletion of petroleum reserves, rising cost of conventional fuels and the ill effect of emission from the use of fossil fuel on human health and environment have driven scientific research towards the development of alternative source of fuels such as biofuel and biodiesel. Biodiesel is a fuel from a renewable sources and it has the potential of being used as an alternative to fossil diesel in compression ignition engine. Some of the challenges encountered in the use of biodiesel in compression ignition engine are its availability, use of edible oil for its production, cost of biodiesel feedstock and unfavorable properties of biodiesel such as its high viscosity. Presently, there is a search for more inedible oil seeds since the available inedible feedstock are still not enough to replace more than 20 - 25% of the total transportation fuels. The thermophysical properties of the biodiesel which vary from feedstock have a significant impact on the combustion process thereby affecting the overall engine performance and emissions. The aim of this study is to test the compatibility of biodiesel from Gmelina arborea seed oil in the compression ignition engine through its thermophysical properties. The biodiesel was produced using transesterification method and the thermophysical properties tests were carried out. The results showed that the density and viscosity of Gmelina arborea seed oil was 868.8 kg/m2 (at 27.5°C) and 1.882(mm)2/s (at 40.0°C) respectively. It also showed that the biodiesel obtained had a density and viscosity value of 821.2 kg/m3 (at 27.5°C) and 0.794 9 (mm)2/s (at 40.0°C) respectively. Comparing these results with other biodiesel, it was observed that Gmelina arborea oil has a lower viscosity and density than other biodiesel from different feedstocks; therefore it has potential to perform better in the diesel engine in comparison to other biodiesel