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Design and implementation of internet of things based irrigation system
Get PDFThis work considered the design and implementation of an Internet of things (IoT) based irrigation system that encourages efficient and optimal use of water management practice. The proposed IoT based irrigation system promotes user acknowledgment practice on farmlands by monitoring the soil moisture value and other environmental parameters. This system, which is based on IoT, stores the sensor data, and the water pump can be monitored via the internet using a ThingSpeak channel. Using a micro-controller which coordinates system activities, a wireless fidelity (WIFI) module which transmits the sensed data to the cloud, a motor driver which controls the pump, a digital temperature and humidity (DHT)11 sensor which monitors environmental parameters, and a YL-69 soil moisture sensor, an IoT based irrigation system is implemented. Results obtained showed that the system irrigates the soil based on the defined threshold value of the soil moisture in order to promote efficient and optimal utilization of water management practice. Additionally, farmers can monitor the irrigation processes remotely from a ThingSpeak channel, which gives a graphical representation of the soil moisture value, pump status, temperature and humidity value as well as the flow rate within the environment
Parametric optimization and determination of a suitable welding process for stainless steel-mild steel dissimilar metals weld
No full textDifficulties associated with dissimilar metals welding differ remarkably and can be minimized with the selection of a suitable joining process, modification of the joining technique, and the adoption of optimal process parameters. This study investigates the suitability of three fusion welding processes (gas tungsten arc welding (GTAW), gas metal arc weld (GMAW), and shielded metal arc welding (SMAW)) in the welding of stainless steel to mild steel plates based on their mechanical properties and observed weld defects. Gas tungsten arc welding (GTAW) process which turned out to be the most suitable of the three, recording the least imperfections, an efficiency in mechanical properties of 8% higher compared to the other processes, furthermore analyzed using the response surface methodology (RSM) to obtain a models of the input and output relationship, as well as the optimal process parameters was conducted. An optimal parameters of 461.88N/mm2 for the tensile strength and 31.65% for the Elongation was observed at the combined input parameters of 200 amp, 15 volt, 20 l/min, and 2.4mm for the weld current, arc voltage, gas flow rate and filler rod respectively. Therefore, the application of optimal process parameters along with a compatible weld process is recommended in the welding of dissimilar metals to guarantee excellent weld qualities.
 
Structural efficiency of concrete containing crushed bone aggregates
No full textThe indiscriminate dumping of animal waste, especially cow bones in abattoir has brought about the need for adequate safe disposal and recycling of such waste. This study investigated the use of crushed bones as a partial substitute for fine aggregate and its efficiency in concrete structures. Sieve analysis test was conducted on the crushed bone and used as partial replacement of fine aggregate in concrete at 0, 25, 50, 75, and 100% by weight. Slump test on the fresh concrete was investigated, while the density, compressive strength test and structural efficiency of the hardened concrete were also determined. The sieve analysis result revealed that the crushed bone was poorly graded, and the slump test showed that the 25% of crushed bone concrete has a low slump. The density was 2370 kg/m3, the compressive strength was 17.10N/mm2 at 28 days, while the structural efficiency was 7.22. The 50, 75 and 100% samples has compressive strength of 16 N/mm2, 6.10N/mm2 and 4 N/mm2 at 28 days respectively and these values are far below expectations. The work concluded that crushed bones could partially replace fine aggregate in lightweight concrete at not more than 25% by weight. This test is limited to a short-term test of 28 days
Application of microbial induced calcite precipitation (MICP) technology in geotechnical and geo-environmental engineering: A review
No full textOne of the most recent areas of research in geotechnical and geo-environmental engineering is bio-mineralization, a natural process in living organisms, also known as Microbial Induced Calcite Precipitation. It is the formation of calcium carbonate from a supersaturated solution due to the presence of microbial cells and bio-chemical activities. In the process, microbes secrete metabolic products that reacts with ion in the medium to precipitate minerals. Through this process, soil improvement/remediation have been investigated and proven reliable with minute carbon print as compared to conventional binders. This paper presents an overview on the wide application of Microbial Induced Calcite Precipitation in the areas of geotechnical and geo-environmental engineering with the mechanisms and factors influencing its performance explained. The work has also considered both laboratory and field scale researches conducted in these areas. The key contribution of this work is the compilation of different approaches in soil stabilization and remediation, via urease producing microbes, in single source. It also outlined different treatment dosages based on environmental conditions suitable to soil types.
 
Infiltration capacity of compacted lime treated black cotton soil as hydraulic barrier material
No full textStudies have shown the effect of hydraulic barriers in the reduction in movement of leachates, that have the potential of contaminating groundwater. Laboratory tests were conducted on black cotton soil treated with up to 5% lime by dry weight to assess its suitability in waste containment facilities. The test samples were subjected to particle size distribution analysis, consistency limit tests, compaction and hydraulic conductivity. The compaction energy of British Standard Light (BSL) was employed. The study showed decrease in liquid limit from 65.20% to 56.30% and plasticity index from 41.50% to 28.58% while plastic limit increased from 23.70% to 27.72% with the increase lime content. Maximum Dry Density (MDD) increases with increased in lime from 1.78 to 1.88 g/cm3 whereas the Optimum Moisture Content (OMC) decreased from 19.79% to 15.39%. Hydraulic conductivity of black cotton soil treated with percentage of lime content 0%, 1%, 3% and 5% of the soil weight examined for a period of 28days. The hydraulic conductivity value of natural soil was 1.65E-08 and decreased to 3.71 E-09 m/s at 5% lime content. Therefore, it is clear that hydraulic conductivity decreases with percentage increase in lime content. It is recommended that volumetric shrinkage, free swell and unconfined compressive strength should be carried out
Rainfall-runoff modeling for Challawa and Jakara catchment areas of Kano City, Nigeria
No full textFor the past decade, the magnitude and frequency of rainfall that resulted into flooding of Kano city have been relatively high and there is need to manage the flood in order to safe life and properties. This research aimed at generating Challawa and Jakara catchment areas runoff for hydrological applications. The two catchments were first delineated and their basic physical properties were extracted from processed 30 m x 30 m Digital Elevation Models (DEMs) of the respective watershed. Basin models of the watersheds were imported from ArcGIS 10.7 to Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS) environment, the meteorological models were developed in HEC-HMS with rainfall data and control specifications assigned which defined the period and time step of the simulation run. SCS-Curve Number, Unit Hydrograph and Muskingum methods were used for estimation of loss, runoff and flow routing respectively. The rainfall-runoff simulations were carried out for 31 years of maximum daily rainfall record (1988 – 2018). The simulated flow rate obtained can be used for further hydrological analysis such as flood frequency analysis and in design of safe and economical drainage and flood control facilities or in maintenance of culverts, sewers, bridges and roads for Jakara and Challawa catchment areas. It is recommended that; the catchment areas be gauged while further research should be conducted on the quality of the simulated flow obtained
Basic Constitutive Equations in Elasto-Plasticity – A Review
No full textThe present paper reviews the constitutive equations of engineering materials in the elasto-plastic regime. Here the plastic flow rules, strain rate, yield function, overstress function as well as evolution equations for the internal parameters are discussed. Similarly, the implementation of the elasto-viscoplastic constitutive model in a standard finite element code is also discussed and it has been concluded that an appropriate choice of material model is key in accurately simulating the behaviour of an engineering material to applied loading. It is also recommended that the appropriateness of the selected constitutive response is crucial for mimicking precise the material behaviour
Length of stay of pneumonia patients associated with comorbid and complications factors in referral National Infectious Diseases Hospital
Get PDFIntroduction: The length of stay for hospitalized pneumonia patients is influenced by various factors. The study aims to describe the relationship between factors that can cause prolonged hospital stays, complications such as metabolic disorders and electrolyte imbalance and comorbidities.
Method: This study is a cross-sectional study, using total sampling with purposive sampling methods to meet the inclusion criteria. The data was taken from the medical record of adult hospitalized pneumonia patients from 1 January 2015 to 31 December 2017 in the Referral Infectious Diseases Hospital Prof. Dr Sulianti Saroso Jakarta.
Results: There were 316 hospitalized pneumonia patients enrolled in the study, most patients were 56-65 years old (29.4%). There 228 of 316 (72.2%) had comorbid and 118 of 316 (37.3%) had a complication. The most common complication was metabolic disorders of plasma proteins (31%) and electrolyte imbalance (46%). Meanwhile, patients who had comorbid complications were 95 of 316 (30.1%). The number of patients treated ≤ 10 days, with comorbid 178 of 228 patients (78.1%) and without comorbidities 82 of 88 patients (93.2%) (p-value = 0.003). There were 175 out of 198 patients (88.4%) patients without complications and treated ≤ 10 days. While pneumonia patients with complications, 85 of 118 patients (72.0%) were treated for 10 days (p-value = 0,000). 65 of 95 (68.4%) patients with both comorbid and complications, were treated for ≤ 10 days. Whereas patients with one comorbidity or complications or none, 195 of 221 (88.2%) patients were treated ≤ 10 days (p-value = 000).
Conclusion: The most common comorbid found in this study was hypertension (15.3%). The most common complication found was metabolic disorders such as electrolyte imbalance (46%). The length of stay for patients without comorbid and or complications was ≤ 10 days or less
Household socio-economic status and the risk of HIV infection among under five-year children in Muheza district, north-eastern Tanzania
Get PDFBackground: There are pieces of evidence of the association between socioeconomic factors and HIV prevalence in sub-Saharan Africa. However, there is a dearth of information on such a relationship in Tanzania.
Objective: To determine the relationship between household socioeconomic factors and HIV prevalence among under five-year children in Muheza district, Tanzania.
Methods: A facility-based study among HIV-exposed children with their respective mothers/guardians was conducted from June 2015 to June 2016. Information on the HIV status of the child and household socio-demographic characteristics were analyzed in the STATA version 13.0.
Results: A total of 576 child-mother/guardian pairs were interviewed. Sixty-one (10.6%) children were confirmed to be HIV positive. The odds of HIV infection were found to be lower among children belonging to the heads of households with secondary and high levels of education (AOR = 0.5, 95% CI 0.2-0.9); P=0.04, those living in wealthier households (AOR = 0.5, 95% CI 0.3-0.9; P=0.03) and those whose mothers/guardians had good knowledge of HIV (AOR = 0.2, 95% CI 0.1-0.3; P<0.001) compared to their counterparts.
Conclusion: Children with heads of households having high educational levels and those from wealthier households were associated with reduced odds of acquiring HIV infection in Muheza district
Community-based HIV services during Differentiated Service Delivery Models: a cross-sectional survey from nine regions in Tanzania
Get PDFIntroduction: To combat the HIV epidemic and reach the 90-90-90 goals, community-based HIV/AIDS services (CHBS) plays a great role. However, how well CHBS works in the era of adopting differentiated service delivery models for care and treatment has not been adequately evaluated. We hence assessed CBHS programs implemented by various partners with a focus on the coverage; program needs; linkage and referral process; consistent use of guidelines and training curricula and challenges faced by providers and clients.
Methods: It was a cross-sectional study conducted in July 2020 in 9 regions using both quantitative and qualitative methods. Quantitative data were analyzed using STATA version 12 and qualitative data were managed using Thematic Content Analysis.
Results: 26 implementing partners were offering CBHS in biomedical, behavioral, and structural areas. Their focus was on PLHIV, orphans, and key and vulnerable populations. The majority of PLHIV had a positive perception of different CBHS. Key factors in the perceived effectiveness of community HIV services were the consistent use and availability of guidelines and training curricula, standard operating procedures, and readiness of essential commodities and supplies. Out of 1391 PLHIV who were involved, 67.4% and 25.0% were tested at the health facility and communities respectively. About 69.8% were referred after confirming their seropositivity and forms were not given to about 57.5% when referred from health facilities to communities for CBHS. There was a deficit of 45% in health workers across different cadres, a deficit in all categories of supplies and equipment example the HIV test kit by 53.8%. Challenges for CBHS included financial hindrances, HIV-related stigma, and discrimination, distance to health facilities, and poor incentives for community health workers.
Conclusion: it is important to address HIV-related stigma hence accelerating efforts to limit the spread of the HIV epidemic in the respective communities