81 research outputs found
Moderna (mRNA-1273) Covid-19 Vaccine, “A Systematic Review”
A Global pandemic, declared by WHO, caused due to a deadly virus known as a “SARS-Cov-2”, has resulted in 4.3 million deaths. Its RNA based genome and lack of proofreading ability has made this virus more prone to get the frequent mutations and results in the formation of new variants and increased pathogenicity. Scientists had been trying hard to develop the ways through which this lethal virus could be eradicated, from the day the genome of SARS CoV-2 was first reported. In order to prevent from this viral infection more than 90 vaccines were developed but few of them were approved by FDA for the human trials. Moderna Inc came up with “mRNA-1273” vaccine which was given EUA approval on 18th December, 2020 by the FDA. The vaccine is based on active mRNA, translated into spike proteins of virus, is developed by the help of nanotechnology. The clinical trials have proved an efficacy of 94.1%. Moreover, the vaccine is able to prevent disease caused by the alpha, beta, gamma and delta variant of SARS-Cov 2 in recent studies. In this review article the composition, technology, mode of action, immune responses, clinical trials and efficacy as well as the comparison of moderna vaccine with other available covid-19 vaccines has been discussed
A Commentary on Telerehabilitation Services in Pakistan: Current Trends and Future Possibilities
A 2014 World Health Organization (WHO) study reported that almost 27 million people with disability live in Pakistan with fewer than one allied rehabilitation professional per 10,000 people. The current study sought to determine the attitudes toward telerehabilitation via a survey administered to 329 Pakistani rehabilitation professionals. Study results indicate that rehabilitation professionals in Pakistan are knowledgeable about telerehabilitation and Information and Communication Technology (ICT), and are receptive to employing telerehabilitation programs and applications. Therefore, we can infer that the future of telerehabilitation can be bright in Pakistan but requires the attention of policy makers and non-government organizations to launch an appropriate program nationwide. The authors suggest that a range of telerehabilitation services (e.g., consultation, assessment, and therapy) could alleviate the shortage of rehabilitation personnel in Pakistan
Friction and wear performance evaluation of bio-lubricants and DLC coatings on cam/tappet interface of internal combustion engines
The environmental concerns associated with artificially formulated engine oils have forced a shift towards bio-based lubricants. The deposition of hard coatings on engine components and migrating to environmentally friendly green lubricants can help in this regard. Chemically modified forms of vegetable oils, with better low-temperature characteristics and enhanced thermo-oxidative stability, are suitable substitutes to conventional lubricant base oils. The research presented in this manuscript was undertaken to experimentally investigate the wear and friction performance of a possible future generation of an environmentally friendly bio-based lubricant as a potential replacement for conventional engine lubricants. In order to quantify the tribological benefits which can be gained by the deposition of DLC coatings, (an (a-C:H) hydrogenated DLC coating and an (a-C:H:W) tungsten-doped DLC coating) were applied on the cam/tappet interface of a direct acting valve train assembly of an internal combustion engine. The tribological correlation between DLC-coated engine components, lubricant base oils and lubricant additives have been thoroughly investigated in this study using actual engine operating conditions. Two additive-free base oils (polyalphaolefines (PAO) and chemically-modified palm oil (TMP)) and two multi-additive-containing lubricants were used in this investigation. Real-time drive torque was measured to determine the friction force, detailed post-test analysis was performed, which involved the use of a specialized jig to measure camlobe wear. An optical profilometer was used to measure the wear on the tappet, high-resolution scanning electron microscopy was employed to study the wear mechanism and energy-dispersive X-ray spectroscopy was performed on the tested samples to qualitatively access the degradation of the coating. When using additive-free TMP, a low friction coefficient was observed for the cam/tappet interface. The presence of additives further improved the friction characteristics of TMP, resulting in reduced average friction torque values. A tremendous enhancement in wear performance was recorded with a-C:H-coated parts and the coating was able to withstand the test conditions with little or no delamination
Friction and Wear Performance Evaluation of Bio-Lubricants and DLC Coatings on Cam/Tappet Interface of Internal Combustion Engines
The environmental concerns associated with artificially formulated engine oils have forced a shift towards bio-based lubricants. The deposition of hard coatings on engine components and migrating to environmentally friendly green lubricants can help in this regard. Chemically modified forms of vegetable oils, with better low-temperature characteristics and enhanced thermo-oxidative stability, are suitable substitutes to conventional lubricant base oils. The research presented in this manuscript was undertaken to experimentally investigate the wear and friction performance of a possible future generation of an environmentally friendly bio-based lubricant as a potential replacement for conventional engine lubricants. In order to quantify the tribological benefits which can be gained by the deposition of DLC coatings, (an (a-C:H) hydrogenated DLC coating and an (a-C:H:W) tungsten-doped DLC coating) were applied on the cam/tappet interface of a direct acting valve train assembly of an internal combustion engine. The tribological correlation between DLC-coated engine components, lubricant base oils and lubricant additives have been thoroughly investigated in this study using actual engine operating conditions. Two additive-free base oils (polyalphaolefines (PAO) and chemically-modified palm oil (TMP)) and two multi-additive-containing lubricants were used in this investigation. Real-time drive torque was measured to determine the friction force, detailed post-test analysis was performed, which involved the use of a specialized jig to measure camlobe wear. An optical profilometer was used to measure the wear on the tappet, high-resolution scanning electron microscopy was employed to study the wear mechanism and energy-dispersive X-ray spectroscopy was performed on the tested samples to qualitatively access the degradation of the coating. When using additive-free TMP, a low friction coefficient was observed for the cam/tappet interface. The presence of additives further improved the friction characteristics of TMP, resulting in reduced average friction torque values. A tremendous enhancement in wear performance was recorded with a-C:H-coated parts and the coating was able to withstand the test conditions with little or no delamination
Experimental investigation of engine valve train friction considering effects of operating conditions and WPC surface treatment
Reduction in friction ensures fuel economy, control on emissions and durability of components in internal combustion engines. A modern gasoline internal combustion engine was instrumented to determine the friction values at the cam–roller interface considering the effects of surface treatment and engine operating state. A series of tests under different operating speeds and lubricant inlet temperatures were undertaken using both an original surface roller and a Wonder Process Craft (WPC) surface-treated engine roller. The results clearly revealed a substantial reduction in friction magnitude for the WPC surface-treated engine roller in comparison to the original roller while operating under similar conditions, indicating their strong potential for employment in engines. An increase in friction with the rise in temperature was also observed for both types of rollers, whereas increased lubricant entraining velocity due to higher operating speed had the opposite impact. A considerable reduction in frictional drive torque ranging from 8% to 28% was observed by employing the WPC-treated roller in comparison to original/untreated roller at various operating conditions, which signifies the strong potential for employment of WPC surface treatment in the roller/follower valve train engines
Knowledge, attitudes and practices regarding dengue fever among adults of high and low socioeconomic groups
OBJECTIVE: To ascertain the knowledge, attitudes and practices of selected adult population in Pakistan regarding Dengue Fever.METHODS: A cross sectional survey was conducted among selected communities with different socio-economic backgrounds in Karachi, Pakistan. A sample size of 440 adults (aged 18 years and above) were interviewed using a pre-tested questionnaire regarding their knowledge, attitude and practices about dengue fever. A composite scoring system, based on the answers given in the questionnaire, was used to establish the level of awareness in the population. The division of the higher and lower socio-economic groups was based on their income and locality; both these variables were determined as a part of our survey.RESULTS: Data from 400 respondents (244 males, 156 females) was used for primary analysis. About thirty five percent of the sample had adequate knowledge about dengue fever and its vector. Knowledge had significant associations with education (p = 0.004) and socioeconomic status (p = 0.02). The high socioeconomic group showed better preventive practices.CONCLUSION: Knowledge of dengue is inadequate in the low socioeconomic class. Better preventive practices against the vector are prevalent in the high socioeconomic group. Hence, a greater focus should be accorded to the low socioeconomic areas in future health campaigns
Tribological characteristics comparison of formulated palm trimethylolpropane ester and polyalphaolefin for cam/tappet interface of direct acting valve train system
Purpose
There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives.
Design/methodology/approach
In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior.
Findings
In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil.
Originality/value
In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version
Application of Geospatial Techniques in Agricultural Resource Management
Although technological advancements have sparked the beginning of the fourth agricultural revolution, human beings are still facing severe problems such as shrinking croplands, dwindling water supplies, negative consequences of climate change, and so on in achieving agricultural resilience to meet the demands of the growing population over the globe. Geospatial techniques involving the integrated use of geographic information system (GIS), remote sensing (RS), and artificial intelligence (AI) provide a strong basis for sustainable management of agricultural resources aimed at increased agricultural production. In recent times, these advanced tools have been increasingly used in agricultural production at local, regional, and global levels. This chapter focuses on the widespread application of geospatial techniques for agricultural resource management by monitoring crop growth and yield forecasting, crop disease and pest infestation, land use and land cover mapping, flood monitoring, and water resource management. Moreover, we also discuss various methodologies involved in monitoring and mapping abovementioned agricultural resources. This chapter will provide deep insight into the available literature on the use of geospatial techniques in the monitoring and management of agricultural resources. Moreover, it will be helpful for scientists to develop integrated methodologies focused on exploring satellite data for sustainable management of agricultural resources
Recent developments in textile based polymeric smart sensor for human health monitoring: A review
In the modern age, the most important and prevailing issue is the monitoring of human health. To address this, several devices have been developed and a need new materials investigated. The idea of textile-based smart sensors is emerging rapidly. In this regard, ICPs and ECPs have attracted the attention of researchers due to their mechanical adaptability to suit the characteristics of textile fabric. The lighter weight, stretchability and wearability, etc. are considered an advantage while selecting the material for developing sensors not only in health monitoring but also in biomedical, sports, and military fields. The idea behind wearable sensing devices is to enable easy integration of the sensor device into daily life routines. Such wearable sensors also have the potential for real time and online monitoring of human health and integrate with smart monitoring devices. The purpose of this review is to discuss the recent developments in smart monitoring sensors.Open Access funding for this article is provided by the Qatar National Library, Al Luqta Street, Al-Rayyan P.O Box 5825 Doha, Qatar” The authors acknowledge the funding received for this work from Higher Education Commission (HEC) Pakistan under the Technology Development Fund (TDF) for grant number TDF-03-103
Tribological characteristics comparison of formulated palm trimethylolpropane ester and polyalphaolefin for cam/tappet interface of direct acting valve train system
Purpose: There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives. Design/methodology/approach: In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior. Findings: In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil. Originality/value: In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version
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