143 research outputs found
Development of a New Concept for Fire Fighting Robot Propulsion System
An additional cost to human loss and property destruction during fire disaster is fire fighters injuries and death. The recent statistics of 63,350 fire fighters injuries that occurred during the year 2014 confirms that firefighting still presents great risks of personal injury to the fire fighters [1]. The lack of details on information about the victims trapped in fire and situation in the fire zone increase the risk to fire fighters [2, 3]. To reduce these fatalities fire fighting robots (FFRs) emerged as possible solutions therefore they are developed and researched on. The FFRs are designed for either prevention or emergency (same as intervention) tasks of fire and are applied indoor or outdoor. However, the prime movers of the majority of the FFRs are electrically powered [4] which made them to be suitable for preventive task alone and inappropriate for the emergency task. Their inappropriateness is due to the vulnerability in high temperature environment that characterised fire emergency. Thus, alternative propulsion systems for the mobility of fire fighting robots in emergency setting are evolving.
Furthermore, literature survey reveals that water powered hydraulic propulsion system has been the only alternative to the drawbacks of dc motors in the hot environment. The mechanism was implemented on snake fire fighting robot for tunnel fire application [5]. In the mechanism, hydraulic motor was used to actuate the snake joints for mobility while water provides power for the hydraulic motors. However, the snake robot was designed for outdoor application. Consequently, the need for an autonomous fire fighting robot with a novel propulsion system becomes imminent
Prediction of dry ice mass for firefighting robot actuation
The limitation in the performance of electric actuated firefighting robots in hightemperature fire environment has led to research on the alternative propulsion system for the
mobility of firefighting robots in such environment. Capitalizing on the limitations of these
electric actuators we suggested a gas-actuated propulsion system in our earlier study. The
propulsion system is made up of a pneumatic motor as the actuator (for the robot) and carbon
dioxide gas (self-generated from dry ice) as the power source. To satisfy the consumption
requirement (9cfm) of the motor for efficient actuation of the robot in the fire environment, the
volume of carbon dioxide gas, as well as the corresponding mass of the dry ice that will
produce the required volume for powering and actuation of the robot, must be determined. This
article, therefore, presents the computational analysis to predict the volumetric requirement and
the dry ice mass sufficient to power a carbon dioxide gas propelled autonomous firefighting
robot in a high-temperature environment. The governing equation of the sublimation of dry ice
to carbon dioxide is established. An operating time of 2105.53s and operating pressure ranges
from 137.9kPa to 482.65kPa were achieved following the consumption rate of the motor. Thus,
8.85m3 is computed as the volume requirement of the CAFFR while the corresponding dry ice
mass for the CAFFR actuation ranges from 21.67kg to 75.83kg depending on the operating
pressure
SUSTAINABLE ENERGY ANALYSIS OF NIGERIAN ROAD TRANSPORTATION SECTOR: EFFECTS OF INFLUENCED FUEL DEMAND PATTERNS
Petrol and diesel utilisations in the Nigerian road transportation sector have been assessed, using exergy efficiency and improvement potential as parameters. The mean petrol engine exergy efficiency was 13.05%, while that of diesel engines was 10.79%. The average improvement potential of petrol engines was 2.07×1011 MJ, which was 75.6% of average input exergy. Diesel engines had an average improvement potential of 5.15×1010 MJ, which was 69.2% of average input exergy. Practical constancy of the exergy efficiencies of the engines left input exergy values as the sole determining factors of improvement potentials of the systems. Petrol fuel was found to be utilised, away from sustainable path, more than diesel fuel. This observation was found attributable to subsidisation of petrol downstream sector and simultaneous deregulation of the diesel downstream sector as well as the preponderance of petrol engines in the road transportation sector. In conclusion, it was recommended that a mechanism be put in place to check the unsustainable petrol fuel utilisation in the transport sector
Development of a Solar-Powered Integrated Wireless Soil Moisture Meter
In this study, we developed a solar-powered integrated wireless soil moisture meter that can easily measure in situ soil moisture, soil temperature, and hydrogen potential (pH) using nature\u27s solar energy. Knowledge of soil moisture content and other relevant soil-specific parameters is essential for irrigation scheduling, fertilizer selection, and fertigation. Also, considering that the electricity supply in some developing countries is either erratic or unavailable, this research aims to bridge the gap in electricity availability and ease of measurement and integrate more soil-specific parameters. The sensor system was developed using the frequency domain (FD) technique for fast response. These parameters were measured sequentially at an interval of about 5 seconds, with the readings displayed simultaneously on a Bluetooth-connected device (e.g., an Android phone) located about 50 meters away from the developed system. The different sensors are classified and adequately labeled to identify the parameter to be measured. The performance evaluation carried out indicated a reasonably functioning device that is cost-effective. The results obtained showed that the system was resourceful as it not only measured the parameters of interest (soil moisture, temperature, and pH) but also gave a prompt response in measurement and transmission. Overall, the developed wireless soil moisture meter provides instantaneous data on pH, moisture, and temperature circulation across soil layers. The system is promising as it can be integrated into large-scale automated irrigation systems for agricultural lands
Drivers of transformation of the maize sector in Nigeria
Open Access ArticleMaize is widely used for food, animal feed, and industrial raw material in Nigeria. This paper documents the
important changes that characterize Nigeria’s maize production and area expansion along with contributing
factors that have transformed maize from a backyard food crop to a dominant food security and commercial crop. Using both secondary and primary data on maize production and varietal adoption over the last six decades, we found that Nigeria now produces ten times more maize than it did in 1960 and four times more maize than it did in 2005. Our findings further suggested that government policies and institutional arrangements that promoted access to and use of modern inputs and increased demand of maize grain for food, feed, and other industrial uses have played major roles in transforming maize from a backyard crop to a dominant staple and commercial crop in Nigeria. Considering the impeding climate change threats to food security in Nigeria, policy interventions should be tailored towards further scaling-up of stress resilient and climate-smart maize varieties to improve the productivity, income, and resilience of smallholder farmers. This requires strong support not only to get recently released superior improved varieties into the hands of smallholder farmers but also to accelerate varietal turnover
Improving mechanical and thermal properties of graphite–aluminium composite using Si, SiC and eggshell particles
Abstract: Please refer to full text to view abstract
Perspectives on Effectiveness of Gypsum Board over Sandcrete Block as Walling Material
Alternative material for construction of walls is gradually coming to stay in view of the scarce
nature of traditional concrete material that is often being used. In the choice of suitable
alternative walling material such as Gypsum board presented in this study, parameter such as
cost, durability, shelf live among others need to be considered. It is based on this premises that
perspectives on effectiveness of Gypsum board over sandcrete blocks as walling material.
The analysis of the primary data received through the administered questionnaires was done
using the Statistical Package for Social Sciences (SPSS), a software package developed for data
analysis. Ninety-five (95) questionnaires were distributed to various construction organizations.
· The data was analyzed using the Mean Index Score (MIS) method of ranking. the research
showed that the use of gypsum wallboard will be beneficial in terms of time, ease of construction
and handling; it is not yet manufactured in Nigeria and will require some special training for
manufacture and installation by local technicians or artisans. the research showed that the board
is durable especially for construction of non-load bearing walls as it is not subjected to too much
stress so it can last for very long periods.Nine, the research proved that the effect of the Nigerian
weather on the board is minimal. The board panels are used for internal walling and are not
affected by the sun or rain or extreme temperatures and therefore are not damaged easily. The
board however is affected by the foundation on which it stands: therefore, if the foundation is
stable, failure free and water free, the gypsum panel wall also remains stable and damage fre
Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015
SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation
Systematic review assessing the effectiveness of dietary intervention on gut microbiota in adults with type 2 diabetes
Can medical therapy mimic the clinical efficacy or physiological effects of bariatric surgery?
The number of bariatric surgical procedures performed has increased dramatically. This review discusses the clinical and physiological changes, and in particular, the mechanisms behind weight loss and glycaemic improvements, observed following the gastric bypass, sleeve gastrectomy and gastric banding bariatric procedures. The review then examines how close we are to mimicking the clinical or physiological effects of surgery through less invasive and safer modern interventions that are currently available for clinical use. These include dietary interventions, orlistat, lorcaserin, phentermine/topiramate, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, pramlintide, dapagliflozin, the duodenal–jejunal bypass liner, gastric pacemakers and gastric balloons. We conclude that, based on the most recent trials, we cannot fully mimic the clinical or physiological effects of surgery; however, we are getting closer. A ‘medical bypass' may not be as far in the future as we previously thought, as the physician's armamentarium against obesity and type 2 diabetes has recently got stronger through the use of specific dietary modifications, novel medical devices and pharmacotherapy. Novel therapeutic targets include not only appetite but also taste/food preferences, energy expenditure, gut microbiota, bile acid signalling, inflammation, preservation of β-cell function and hepatic glucose output, among others. Although there are no magic bullets, an integrated multimodal approach may yield success. Non-surgical interventions that mimic the metabolic benefits of bariatric surgery, with a reduced morbidity and mortality burden, remain tenable alternatives for patients and health-care professionals
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