Spacing effects on planted pines of four species

Pine seedlings of four species were planted in two acre split plots at the Highland Rim Forest Experiment Station in 1965 using four spacings. At the end of the first growing season, all the dead trees were replanted. After five growing seasons survival count and height of living trees were taken. At the end of ten growing seasons, survival, height, diameter and pruning height of the living trees were recorded. Chi-Square contingency table tests indicated that survival, species, except for white pine, and spacings were dependent at the 5 percent level of probability. The same test at the same level indicated that self pruning is dependent on the species and the spacings used. The analysis of variance indicated that there were differences due to species for height to live crown, total height, diameter, basal area and volume. Spacing has a significant effect on the branch mortality, diameter, basal area and volume. The interactions between species and spacing was also significant for height to live crown and for volume. The result of this study could offer immediate guidance to the private, state and corporate land owners in choosing a spacing for planting any of the four species to meet their specific production needs

Conceptual and Simulated Semi-Automatic Urban Waste Management System using Global Systems for Mobile Communication and Customer Reliability Indices

: Municipal Solid Waste Management (MSWM) poses great challenges to many cities around the world. The challenges are fuelled by population explosions all over the world, especially in the major urban centres, against the backdrop of limited resources to manage wastes efficiently. In this paper, a conceptual and simulated semi-automatic approach to MSWM is considered using the prevalent Global Systems for Mobile Communication (GSM) technology to engage both the waste generators and collectors. This system connects users into a central database where data about their waste bin levels are harnessed. Users are prompted via GSM handsets daily for the level of the waste bin. Waste Collection Vehicles are routed based on the responses while an updatable Reporting Reliability Index (RRI) is computed for each user based on estimate of actual level of waste collected as against the reported level to factor future reporting. With history of collection volume at a location known, forecast is made as to the generated waste level when a customer’s response to prompt is not available. The system is tested on a simulated 30-node housing estate and two dump sites with vehicles routed to optimize distance covered and volume of waste collected. Customers report when prompted with 0, 1, 2, 3, 4 for waste levels ranging from empty to full bin fills. Vehicles are routed to collect wastes at locations with a minimum threshold level of 2. Results obtained showed statistically insignificant differences in distribution of means of collection distance covered weekly but 13.31 volume units/km collected with this method compared with 3.08 volume units/km run of fixed routing scheme, at = 0.05. The cost saving potential and environmental benefits of timely waste disposal of this scheme is thus demonstrable.Keywords: Municipal Solid Waste, Waste Management, SMS Gateway, GSM, Reporting Reliability Index

Corrosion resistance of surface-conditioned 301 and 304 stainless steels by salt spray test

The corrosion rate of surface-conditioned 301 and 304 stainless steels (SS) was determined by salt spray test in a controlled accelerated corrosive medium (9.5 L of pure distilled water + 500 g NaCl). Surface conditioning via mechanical attrition treatment was firstly carried out before the salt spray test. The corrosion rate was determined by weight loss method before and after the salt spray test. Compared to the untreated 301 SS sample with a weight loss of 0.15 g, the surface-conditioned 301 SS samples treated for 300 s and 1200 s experienced a lower weight loss of 0.04 and 0.02 g, respectively. A similar reduction in weight loss was achieved for 304 SS sample when treated for 300, 600, and 1200 s

Additive manufacturing in the oil and gas industries

Additive manufacturing (AM), also known as 3D printing, is a process for creating prototypes and functional components achieved by consolidation of material layer upon layer. Applications of AM technologies have been witnessed in the healthcare, automotive, architecture, power generation, electronics and aviation industries. Some of the main benefits of AM include effective material utilisation, new design possibilities, improved functionality of the products and flexible production. The opportunities for the applications of additive manufacturing in the oil and gas industries are only just being explored. In this study, a review of the potential opportunities of AM technologies in oil and gas industries was reported. The adoption of the AM technologies necessitated the need for a rethink on design for manufacture and assembly of oil and gas component parts such as high-tech end burners, metal fuel nozzles, and submersible pump components amongst others. The possibility of employing AM technologies on-site for the production of spare parts for replacement of damage components in oil and gas equipment and facilities is commendable, as this brings about reduction in production downtime and replacement cost. The future of AM in the oil and gas industries is highly promising, however before AM can actualize its full-fledged potentials in these industries, further research is required in the area of new materials development and processing, improved surface finish of AM fabricated parts, enhanced fabrication speed and parametric optimisation to improve the mechanical properties of the fabricated components

Corrosion resistance of surface-conditioned 301 and 304 stainless steels by salt spray test

The corrosion rate of surface-conditioned 301 and 304 stainless steels (SS) was determined by salt spray test in a controlled accelerated corrosive medium (9.5 L of pure distilled water + 500 g NaCl). By surface conditioning via mechanical attrition treatment, a gradient-structured layer was firstly generated on the surface of the samples before the salt spray test. The corrosion rate was determined by the weight loss before and after the salt spray test. Compared to the untreated 301 SS sample with a weight loss of 0.15 g, the surface-conditioned samples treated for 300 s and 1200 s experienced a lower weight loss of 0.04 and 0.02 g, respectively. A similar reduction in weight loss was achieved for 304 SS sample when treated for 5, 10, and 20 mins

Primary Carcinoid Tumour of the Kidney: A Review of the Literature

Context. Primary renal carcinoid tumours are rare. Their pathogenesis is unknown and the clinical presentation is similar to other renal tumours thus posing diagnostic dilemmas for clinicians. Objectives. To review the literature for case reports of primary renal carcinoids. Methods. Literature was extensively searched for case reports for primary renal carcinoids. Reports of metastatic carcinoids to the kidneys were excluded. Results. Approximately less than 90 cases of primary carcinoid tumours of the kidney have been reported in the literature. A total of 29 cases of primary renal carcinoids were reviewed. The mean age of presentation was 48 years (range 29–75) with both right kidney (48.3%) and left kidney (44.8%) being equally affected. 28.6% of the cases reviewed were diagnosed as an incidental finding. The mean followup time was 20 months with 73.1% of patients without evidence of disease after surgical treatment (radical or partial nephrectomy). Primary carcinoid tumours of the kidney are often well differentiated tumours. They are often misdiagnosed because of their rarity and similar presentation with other renal tumours. Conclusions. Primary carcinoid tumours of the kidney are rare tumours with an indolent course with frequent metastasis. Metastatic work up and followup is required in their management

Assessment of Home-Based Nigerian Engineers on Risk Management Approach during Project Implementation

The objectives of this paper are to identify possible gaps in identification, evaluation, analysis, implementation and effectiveness of risk management approaches among home-based consulting Engineers in Nigeria vis-à-vis the implementation of such practices. Structured Questionnaire method was adopted as the survey instrument to collect data centred on issues on the subject matters. Out of 80 questionnaires distributed, 61 were returned and 6 of the returned responses rendered invalid leaving 55 valid questionnaires. The Analysis of Variance (ANOVA) and Correlation methods were adopted for statistical analysis with respect to which four hypotheses based on the subject matter were formulated and evaluated using the F-and Correlation statistics. The first premised on risk identification resulted in comparative F-statistics of Fcat = 0.057592 < Fcrit = 2.866081, the second on risk evaluation yielded Fcat = 0.194683 < Fcrit = 2.866081 while the third based on risk management implementation resulted in Fcat = 0.093474 < Fcrit = 2.866081. The results of the first three hypothesis indicted the home-based Consulting Engineers of not identifying, analysing/evaluating and implementing risk management approaches in project execution respectively. The fourth hypothesis premised on correlation between management approach and policy implementation yielded a correlation statistics of 0.501642 establishing a positive correlation between the two among the home-based Consulting Engineers. The study thus establishes risk management practices as key to successful project management and its neglect as major causal factor for project failures in Nigeria

Simulation-based analytical design for aluminium recycling processing plant

Indiscriminate disposal of beverage cans as waste poses a great threat to the environment, causing flooding, landfill, and blockage of drainages, leading to land pollution and sometimes accident. Hence, there is a need to design a system capable of converting these wastes into usable products. In this study, a simulation-based analytical design for aluminium recycling processing plant was carried out to ascertain the efficiency and reliability of the design before fabrication using finite element analysis (FEA) approach. The simulation results revealed a lesser maximum stress of 6.323 MPa for the furnace outer casing under the action of load with a displacement of 0.0795 mm. The stress of the machine components is less than the yield strength of the selected materials, making the machine fit and workable. The analytical results agree with the numerical analysis; hence the conceptual design is fit for fabrication based on the design analysis and evaluation. After the design analysis and simulation, the designed recycling process plant parts are found to be under negligible deflection and stress which is far below the yield strength of chosen materials

DEVELOPMENT OF A FUSED DEPOSITION MODELLING MACHINE FOR PLASTIC-BASED ADDITIVE MANUFACTURING PURPOSES

In this work, the development of a Fused Deposition Modelling (FDM) machine was successfully carried out and reported. The machine was designed to boost local manufacturing capabilities in Nigeria by promoting the use of additive manufacturing techniques for the production of plastic-based prototypes, functional components and casting patterns. The machine consists of a heater bed, hot-end extruder, machine frame, controller and electrical circuitry and it was designed to have a working envelope with a maximum build volume of 200 x 200 x 200 mm3. The design of each machine component parts was analyzed and the structural capacity was assessed using finite element analysis (FEA) tool in Autodesk Inventor and COMSOL Multi-physics applications. The simulation result showed that maximum stress of 3.669 MPa was attained in one of the machine stands when a component aggregate load of 301.29 N was exerted on the frame structure. The machine component with a maximum resultant displacement of 0.04 mm was also observed while the minimum factor of safety was 12.5. This result shows that the design of the machine is satisfactory for its development since the yield strengths of the selected materials for the individual components were not surpassed by the stresses obtained from the FE analysis. Upon the machine development, it was able to produce prototypes of some vehicle logos which confirms its capability to perform the intention of its vehicle logos which confirms its capability to perform the intention of its development

Simulation-based analytical design for aluminium recycling processing plant

Indiscriminate disposal of beverage cans as waste poses a great threat to the environment, causing flooding, landfill, and blockage of drainages, leading to land pollution and sometimes accident. Hence, there is a need to design a system capable of converting these wastes into usable products. In this study, a simulation-based analytical design for aluminum recycling processing plant was carried out to ascertain the efficiency and reliability of the design before fabrication using finite element analysis (FEA) approach. The simulation results revealed a lesser maximum stress of 6.323 MPa for the furnace outer casing under the action of load with a displacement of 0.0795 mm. The stress of the machine components is less than the yield strength of the selected materials, making the machine fit and workable. The analytical results agree with the numerical analysis; hence the conceptual design is fit for fabrication based on the design analysis and evaluation. After the design analysis and simulation, the designed recycling process plant parts are found to be under negligible deflection and stress which is far below the yield strength of chosen materials