172 research outputs found

    Performance of No-Filter Smooth Drain Pipe on Clayey Loam

    Get PDF
    The performance of smooth drainage pipes fitted with no-filter material as against those with nylon, rice husks and cowpea chaffs were investigated. The study was conducted on a clayey loam during the 2005, 2006 and 2007 rainy seasons.  The experimental design was completely randomized design replicated three times.  The treatments applied include drains installed with cowpea chaff, rice husks, no-filter and nylon drainage filter materials.  The filter materials were compressed using locally available materials and installed manually to a soil depth of 25 cm using ASABE Standards (2006). The drainage area was about 180 m2 (0.432 ha) with a buffer zone of 1m allowed in between the plots.  The slope along the length was 3.90 % and across the length was 1.63 %.  The soil physical characteristics like the texture, moisture content, field capacity and bulk density were determined.  Properties such as load at peak, strain at peak, energy at peak, load at yield and energy at yield were highest for sand samples collected from no-filter treated pipes with recorded average values of 958.5 N, 36.53 Nm, 22.45 %, 195.63 N, and 0.93 Nm respectively.  Nylon filter pipes gave the highest strain at yield recording an average value of 8.54 mm.  Rice filter samples recorded the highest deformation at yield value of 9.29 mm. Results of the drainage yield showed that during the 2005 rainy season, plots treated with no-filter material gave the highest discharge of 56.3 l/day, while plots with rice husk gave a discharge of 44.8 l/day. For the 2006 rainy season, plots treated with no-filter material gave the highest discharge of 500.4 l/day, while plots with bean chaff gave the lowest discharge of 60 l/day.  For the 2007 rainy season, for first 11 days plots treated with no-filter recorded the highest amount of discharge recording the highest value of 110.8 l/day while plots treated with rice husk gave the highest drainage yield for the remaining 19 days recording the highest amount of 120.9l/day. The results showed that for the same rainfall amount and pattern, plot with rice husk gave the highest drainage yield of 148.9l/day, while plot with control (no-envelope) gave the lowest drainage yield of 99.4 l/day. The plots treated with nylon-synthetic material produced the best water quality because it was free of debris, smell and the discharge was clear, while that of the others were loaded with debris and discharge has a foul smell.  The study shows that drainpipes can be installed successfully in the area under study without using filter material because of the high drainage discharge and also because there is no decay of material with time

    Relative Effectiveness of Water Hyacinth, Bacteria and Fungi in Purifying Sewage

    Get PDF
    The relative effectiveness of water hyacinth (Eichhornia Crassipes) (phytoremedian), bacteria and fungi (bioremedians) used for the purification of domestic sewage was carried out using Completely Randomised Design (CRD) replicated three times. Treatments imposed include: no treatment (control), 1kg and 2kg water hyacinth, bacteria and fungi cultures. Physical, bacteriological and chemical properties of domestic sewage were investigated before and after purification. The results show that for suspended solids, cultured tanks treated with 2kg water hyacinth reduced the sewage concentration from 73mg/l to 37.5mg/l, dissolved solids was reduced from 312mg/l to 266mg/l, Biological Oxygen Demand (BOD) was reduced from 11.2mg/l to 4.37mg/l, Chemical Oxygen Demand (COD) was reduced from 7.6mg/l to 2.7mg/l. Dissolved Oxygen increased from 6.8mg/l to 7.17mg/l for 2kg hyacinth treatment due to photosynthesis but reduced to 3.7 for fungi. The cultured tanks treated with bacteria performed best in reducing turbidity and bacteriological properties of sewage. Turbidity was reduced from 5.8NTU to 1.2NTU for tanks cultured with bacteria. During the first three weeks, the hyacinth's growth was very rapid. It effectively depleted the nutrients present in the sewage, by the 4th week, gradual wilting of water hyacinth was noticed and by the end of the 5th week, serious wilting occurred due to deficiency in essential nutrients. The 2kg water hyacinth tanks wilted permanently due to total consumption of sewage. The results show that purification potential of water hyacinth is related to plants population with the 2kg hyacinth's tanks purifying better than the 1kg hyacinth density and also that bacteria purifies sewage better than fungi. Generally the 2kg water hyacinth was best in reducing the physio-chemical properties of the sewage better than the other treatments applied while the tanks treated with bacteria performed best in reducing bacteriological properties of sewage. Keywords:-Purification, sewage, phytoremediation, water hyacinth, bioremediation, bacteria and fungi.

    Influence of Land Use Types on Physical and Chemical Properties in Oba Hill Forest Reserve, Iwo, South-western Nigeria

    Get PDF
    Ecosystems have been affected by series of activities that occurred on lands. The effects of land use change on the physical and chemical properties of the soil in Oba Hill Forest Reserve have been studied using standard instrumentation techniques. Results obtained showed that the texture of the soils ranged from loam to sandy loam while the pH of the soils from the four land use types ranged from 4.92 (acidic) to 7.80 (alkaline).The bulk densities in soils from the four land use types are natural forest (1.01 g/m3), teak plantation (1.21 g/m3), farmland (1.55 g/cm3) and residential (1.66 g/m3). Concentration of Mn in soils are higher than Zn, Cu and Fe from the all the studied land use types. Higher mean concentration values of Mn is recorded in soils from natural land (98.12±0.99 mg/kg) followed by plantation land with mean value of 74.32±0.52 while soils from residential land had lowest mean value of 19.59±0.13mg/kg. Soils from the natural land also have the highest mean concentrations value of Fe (69.04±0.26 mg/kg), Zn (21.48±0.11mg/kg) and Cu (15.43±0.04 mg/kg) while least mean concentration values of Fe (25.46±0.03 mg/kg), Zn (8.59±0.01mg/kg) and Cu (3.55±0.01mg/kg) are recorded in residential land. The results revealed that changing in land use types from natural forest to residential land decrease the organic matter, available nitrogen, soil moisture, porosity exchangeable cations, micronutrients and increased the bulk density in the soils. This study has shown that land use types can affect soil properties and existence of essential nutrients in the soils. &nbsp

    Integrated Marketing Communications and Customer Loyalty in Nigeria’s Telecommunications Industry

    Get PDF
    This study focused on integrated marketing communications and customer loyalty in the telecommunications industry in Nigeria. Lagos State, Nigeria constitutes the scope of the study being that it is the commercial hub of Nigeria and there resides a huge population of telecoms subscribers. Survey design was adopted for the study. Cross-sectional data were collected across the twenty local government areas in Lagos State with the aid of a structured questionnaire. The questionnaire administered on 600 telecommunications subscribers yielded 82.3% response rate. Using descriptive statistics, Kaiser-Meyer-Olkin measure of sampling adequacy and Bartlett’s test of sphericity, the data collected were analyzed. The findings reveal that integrated marketing communications (IMC) has a significant positive effect on customer loyalty. The result further shows that each of the proxies of IMC studied influenced customer loyalty at varying degrees, ranging from high to weak extent. It can therefore be inferred that implementation of IMC in the telecommunications industry in Nigeria enhances customer loyalty. Some recommendations were made and the managerial implications highlighted.

    Purification, characterization and toxicity of a mannose-binding lectin from the seeds of Treculia africana plant

    Get PDF
    In this study, a mannose-specific, homodimeric lectin from the seeds of Treculia africana was purified, characterized and its adverse effects were investigated in mice. The purification protocol involved anionic exchange chromatography on DEAE-Cellulose followed by gel filtration on Sephadex G-100. The hemagglutinating activity of lectin towards human erythrocytes was sensitive to inhibition by D-mannose. Treatment of the protein with EDTA exerted no inhibitory effect; however, analysis of metal content by atomic absorption spectroscopy revealed the presence of Cu2+, Fe3+, and Mg2+. The results obtained showed that the lectin possesses maximum hemagglutinating activity towards human erythrocytes activity over the pH range 3–7.2 and is relatively thermostable up to 50°C. Periodic acid Schiff's (PAS) reagent staining showed that the protein was non-glycosylated while its amino acid composition analysis revealed that the protein contained 155 residues per subunit. The subunit had a minimal molecular weight of 22,139 Daltons, while the native molecular weight was estimated to be 41,000 Daltons. The lectin was found to be moderately toxic to mice with an LD50 of 47.21 µg g−1 body weight while, histopathological analysis showed no treatment related effects in any of the organs examined

    In silico investigation of a KCNQ1 mutation associated with short QT syndrome

    Get PDF
    Short QT syndrome (SQTS) is a rare condition characterized by abnormally ‘short’ QT intervals on the ECG and increased susceptibility to cardiac arrhythmias and sudden death. This simulation study investigated arrhythmia dynamics in multi-scale human ventricle models associated with the SQT2-related V307L KCNQ1 ‘gain-of-function’ mutation, which increases slow-delayed rectifier potassium current (IKs). A Markov chain (MC) model recapitulating wild type (WT) and V307L mutant IKs kinetics was incorporated into a model of the human ventricular action potential (AP) for investigation of QT interval changes and arrhythmia substrates. In addition, the degree of simulated IKs inhibition necessary to normalize the QT interval and terminate re-entry in SQT2 conditions was quantified. The developed MC model accurately reproduced AP shortening and reduced effective refractory period associated with altered IKs kinetics in homozygous (V307L) and heterozygous (WT-V307L) mutation conditions, which increased the lifespan and dominant frequency of re-entry in 3D human ventricle models. IKs reductions of 58% and 65% were sufficient to terminate re-entry in WT-V307L and V307L conditions, respectively. This study further substantiates a causal link between the V307L KCNQ1 mutation and pro-arrhythmia in human ventricles, and establishes partial inhibition of IKs as a potential anti-arrhythmic strategy in SQT2

    Night nursing – staff's working experiences

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Although the duties and working conditions of registered, and enrolled nurses have previously been described from different perspectives, they have not been examined from the night nursing aspect. The aim of the study was to describe the night nursing staff's working experiences.</p> <p>Methods</p> <p>The design of the study is qualitative and descriptive. Interviews were conducted with 10 registered and 10 enrolled nurses working as night staff at a Swedish University Hospital. The interview guide was thematic and concerned the content of their tasks, as well as the working conditions that constitute night nursing. In addition, the interviews were transcribed verbatim and analyzed using content analysis.</p> <p>Results</p> <p>The night duties have to be performed under difficult conditions that include working silently in dimmed lighting, and making decisions when fatigue threatens. According to the night staff, its main goals are to provide the patients with rest and simultaneously ensure qualified care. Furthermore, the night nursing staff must prepare the ward for the daytime activities.</p> <p>Conclusion</p> <p>The most important point is the team work, which developed between the registered and enrolled nurses and how necessary this team work is when working at night. In order for nurses working at night to be fully appreciated, the communication between day and night staff in health care organizations needs to be developed. Furthermore, it is important to give the night staff opportunities to use its whole field of competence.</p

    Global Perspectives on Task Shifting and Task Sharing in Neurosurgery.

    Get PDF
    BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit. METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018-January 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores. RESULTS: Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low- and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine). CONCLUSIONS: Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs
    • …
    corecore