American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)
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Fibre Characteristics of Delonix regia (Hook.) Raf. Wood as Indices of its Suitability for Papermaking
Get PDFThe fibre characteristics of Delonix regia, a fast and deciduous tropical tree with form like leaves that is considered one of the most beautiful trees in the world was evaluated to assess its potential for pulp and paper making. Three trees of D. regia were used for the study, they were obtained at different locations within University of Ibadan main campus, Ibadan, Oyo State, Nigeria. Samples were collected at base (10%), middle (50%) and top (90%) portion of the merchantable height. At each sampling height, strips of 2.5cm were removed from the centre of the discs and divided into 3 zones namely: corewood, middlewood and outerwood based on the relative distance from the pith. Slivers were obtained from each of the zones and macerated in equal volume of glacial aceticacid and 30% hydrogen peroxide at 80oC in an oven. Data were subjected to statistical analysis of 3×3×3 factorial experiment in a completely randomized design (CRD) and Mean±SEM. However, a follow-up test was carried out using the least significant difference test (LSD) at 5% level of probability. A total of twenty whole fibres were measured in swollen conditions with a calibrated eye piece microscope from each sampling zone for fibre characteristics evaluation viz: fibre length (FL), fibre diameter (FD), lumen width (LW), cell wall thickness (WT), runkel ratio (RR), Coefficient of rigidity (CR), Slenderness ratio (SR), Flexibility ratio (FR), F-factor (FF) and solid factor (SF). The results obtained show that Delonix regia has the following mean value: FL (1.34mm), FD (39.42µM), LW (26.83µM), WT (6.49µM), RR (0.55%), CR (16.95%), SR (36.03%), FR (68.45%), FF (236.33) and SL (1390408.51). Based on the derived value such as the Runkel ratio of 0.55 which is less than 1 compared favourably with other known species for pulp and paper making. The values indicate the suitability of the specie for pulp and paper production in a place where there is shortage of wood material for this purpose
Children and Mothers\u27 Preferences of Dentists’ Attire in Public Daycare Centers
Get PDFAccording to the environment and appearance of the professional in the dental office, the child may have different emotional reactions. New designs and styles of clothing are emerging in the market and offered to health professionals. This study aimed to verify the preference of mothers and children from 3 to 6 years of age concerning dental attire. Material and Method. The sample had 621 preschoolers of both genders, age randomly selected in public daycare centers in 6 cities, covering the Brazil states of Tocantins, Goiás, Pará, and Bahia. The study was conducted with a child playful projective test and an interview questionnaire for the mothers. The results among children\u27s preferences of dental attire from daycare centers in different cities showed a statistically significant correlation at the level of 5% (P < 0.0001). The mother’s preferences for attire showed a significant correlation at the level of 5 % (P = 0.0004). The children\u27s preferences were for colorful attires, and their respective mothers prefer blue color. This selection has no cultural character nor for the family environment, as demonstrated in the various places the non-predominance of a single preference they mothers and their children. Preschool children were able to select their game options with this infant test
Structural, Electronic and Optical Properties of CsMI3(M=Ge,Sn,Pb) Perovskite from First Principles
Get PDFThe all-inorganic lead halide perovskites has received wide attention in optoelectronic applications such as solar cells and light-emitting diodes due to its high photoabsorption, suitable bandgap and good stability. Based on the first principles, the electronic structure and optical properties of the structure are studied by substituting all the lead elements in CsPbI3 with Ge and Sn.We found that the structural stability of all the substituted materials was enhanced. The tolerance factors of CsGeI3 and CsSnI3 were 0.934 and 0.874, respectively. The most important point is to replace the toxic Pb element, which not only reduces environmental pollution but also can be more suitable for commercial production. By analyzing the imaginary part of the dielectric function and absorption coefficient, it is found that the blue shift occurs in all the materials which replace Pb element, and the absorption ability of sun light is stronger in the visible light range, which proves the foundation for lead free perovskite solar cells
MRI Image Segmentation System of Uterine Fibroids Based on AR-Unet Network
Get PDFUterine fibroids are the most common benign tumors in female reproductive organs. The segmentation of uterine fibroids is crucial for accurate treatment. This paper proposes a new uterine fibroids MRI T2W image segmentation network AR-Unet (Attention Resnet101-Unet), which uses the deep neural network ResNet101 as the front end of feature extraction, extracts image semantic information, and combines U-net design ideas to build a network structure. The attention gate module is added before the upsampling and downsampling feature maps are spliced. We tested a total of 123 uterine fibroids MRI T2W images from 13 patients. The segmentation results were verified with expert-defined manual segmentation results. The average Dice coefficient, IOU value, sensitivity and specificity of all segmented images were 0.9044, 0.8443, 88.55% and 94.56%, the performance is better than ResNet101-Unet and Attention-Unet models, and finally the network is encapsulated into an auxiliary diagnostic system
Relationship of Field Capacity with Geotechnical Parameters in an Urban Solid Waste Landfill
Get PDFOne of the main environmental problems of landfills of urban solid waste is the release of leachate which can result in soil and water contamination. Leachate represents one of several risk factors for the environment, since it has high concentrations of polluting agents. The possibility of knowledge about the leachate generation is important for the evaluation of the efficiency of a treatment system, as well as the knowledge of the soil and waste field capacity is also essential to implement a control of the total moisture content in the landfill that influences biodegradation and methane production. The objective of this work was to evaluate the use of an efficient method of obtaining the field capacity for the layer of grounded solid waste cover, relating them to several geotechnical parameters. The obtaining of the field capacity of the soil and the residues consisted of driving the sampling cylinder through a backhoe, statically driving the small Shelbys (10.4 to 11.8 cm in diameter by 20 cm in height) to obtain the samples. In the laboratory, the samples had their ends sawn to remove excess waste, where they were then placed in a large bucket with a gravel mat, approximately 15 cm, to facilitate the saturation of the sample by the hydrostatic process of vessels communicants, where, after reaching saturation, they were placed in free drainage conditions in order to reach field capacity. The tests indicated that the average field capacity for the soils was 35%; for new wastes values ??varying from 43 to 56% and for old wastes values ??of volumetric field capacity ranging from 30 to 44%. Thus, it was observed that many empirical models used in dimensioning leachate treatment plants do not take into account a variable that directly influences leachate production
Design of Flight Control Systems for a Hypersonic Aircraft Using sliding-PID Control
Get PDFThe paper presents the application of sliding-PID control to the design of robust flight control system for a hypersonic aircraft. The proposed controller uses an approach that combines the high-order PID controller with high-order sliding mode (HOSM) control. The PID uses high-order time-derivative (HOTD) function of the sliding mode variable while the HOSM uses the signum function of the HOTD function. HOTD is built using the relative degree nonlinear dynamics of multivariable systems driven by affine control inputs. A displacement autopilot is designed for pitch control of an air-breathing hypersonic vehicle model. Numerical simulation demonstrates the effectiveness of the proposed controller and shows its advantages as compared to the quasi-homogenous HOSM controller
Malaria Hazard and Risk Analysis Using GIS and Remote Sensing in Korahey Zone of Somali Regional State, Eastern Ethiopia
Get PDFMalaria is one of the killer human diseases caused by protozoan parasites from plasmodium family which foremost transmitted by the bite of the female Anopheles species of Mosquito. Ethiopian lowland areas are favorable for mosquito breeding and malaria transmission due to their tropical location and environmental factors. The current study was aimed to analyze the malaria hazard and risk areas in the case of Kebridahar and Sheykosh districts of Korahey zone by using GIS and RS technique. In order to achieve the study objective, different data’s such as satellite images, soil map, digital elevation, topographic map, study area shape files and the environmental factors like temperature, elevation, slope, soil, land use land cover and proximity to pond water site were used as an input data for the analysis. Weight was assigned for these parameters by pairwise comparison method and weighted overlay was used in Arc GIS spatial analyst tools to produce the final malaria hard and risk map of the study area. The hazard, malaria prevalence was mapped based on the environmental factors, computed using Multi Criteria Decision Evaluation technique (MCDE).
The result of this study revealed that, from the total areas of both districts, 41.4%, 42.2% is mapped as very high and high hazard zone, whereas, the remaining 16.2% is mapped as low level of malaria hazard. The result of the malaria risk map also shows that about, 4095 km2 (23.7%), 12169.2 km2 (70.5%) and 1010 km2 (5.8%) of the study area were subjected to very high, high and moderate malaria risk level respectively. Generally, the result of this study revealed that large area (94.2%) is located in very high and high risk area toward the malaria hazards in Kebridahar and Sheykosh districts of Korahey Zone in Somali region. Therefore, it is recommended that all stakeholders especially health offices at district, zonal, regional and federal levels as well as NGOs should make awareness creation towards malaria prevention in the study area as special and in lowland areas as general
Waterlogging in the Southwest Coastal Areas of Bangladesh: Local Adaptation Techniques and Challenges
Get PDFWaterlogging is a critical environmental problem in the southwest coast of Bangladesh predominantly in some parts of Jashore, Satkhira and Khulna districts which create substantial impacts on livelihood. Therefore, this research aims to analyze how the coastal society deals with the increasing pressure on livelihood that emerged during and after waterlogging episodes. This research is dependent on empirically gathered data using both quantitative and qualitative approaches. A total 210 in-depth interviews from six unions, two unions from each of the three districts were conducted using a semi-structured questionnaire. In addition, six focus group discussion sessions and six key informant interviews were organized. For statistical analysis of collected data, SPSS was used. The study identifies some critical impacts of waterlogging on livelihood which include physical and mental illness, crop failure and damage, disruption in cropping mechanism, loss of income, and increasing level of debt. The adaptation techniques practiced by the local people have been identified to be short term and insufficient to permanently improve livelihoods in the face of recurrent waterlogging
Exhaust Flue Gas Concentration of Engines Running on Ethanol, Gasoline and Bio-oil - a Theoretical Estimate
Get PDFThe creation of new technologies over the last 100 years has improved the quality of human life, but the necessary chemical and industrial transformations have caused significant changes in the environment. The production of new inputs depends on the chemical processes employed and, as a consequence, must be in line with water and air treatments that are undoubtedly undermined by world technological development. Thus, the principles of physics and chemistry apply to the prediction and understanding of the release of gaseous pollutants into the environment, which come from the burning of fuels in automobiles. It also discusses the influence of aspects related to the air content fed to the engine, as well as the effect of temperature and pressure on the concentration of these pollutants
The Analysis of Traffic Flow on the Three-leg Intersection – Case Study Cazin
Get PDFThis paper deals with the analysis of traffic on the three-leg intersection in the city Cazin, at the junction of the three-leg intersection. The main issue of this research refers to the left-turn of vehicles coming from the merging road of the given intersection. The extensive analysis covered the current state of traffic flow by using the software tool, SIDRA INTERSECTION program. Within the suggested measures of improvement, the construction of a unsignalised roundabout was proposed. Implementation of the construction of a unsingalised roundabout would increase the level of traffic safety, reduce time losses while taking a left turn and therefore improve the Level of Service (LOS) as a qualitative indicator of traffic flow.