Open Access Case study

The Effect of Sodium Silicate on the Behaviour of Shotcretes for Tunnel Lining

Luigi Coppola, Alessandra Buoso, Denny Coffetti, Patricia Kara, Sergio Lorenzi, Franco D’Alessandro

Journal of Scientific Research and Reports, Page 1-8
DOI: 10.9734/JSRR/2017/33641

Present case study investigates the rheological, mechanical and in-placing performances of fiber-reinforced shotcrete manufactured with different fibers (steel, glass and polypropylene) and with sodium silicate based set-accelerating admixture for tunnel linings. The study compares the performances of concretes manufactured and fully compacted with those shotcretes which are manufactured directly on the job-site. The influence of sodium silicate accelerator on mechanical and rheological properties of fiber-reinforced shotcretes with respect to reference concrete were evaluated. It was observed that: The addition of fibers does not influence slump and workability retention with respect to reference concrete, independent of type and dosage of fibers; Spraying and set accelerator dosage determined a decrease about of 10-30% in compressive strength compared to that of concrete placed and vibrated without sodium silicate accelerator; The set-accelerating admixture has negative effect on compressive strength of fiber-reinforced shotcrete (15%).

Open Access Original Research Article

The Obstacles and Gains of Green Construction Development in China

Mohammed Shareef M. S. Hasan, Mohannad Husain Alsherrawi

Journal of Scientific Research and Reports, Page 1-10
DOI: 10.9734/JSRR/2017/33513

The research embraced the utilization of an irregular overview technique to gather master feelings from green improvement specialists in China. A particular concentration was given to development specialists who have at least 5 years in green improvement, either locally or abroad. The group of stars of the green specialists included yet was not limited to engineers, scene designers, tree huggers, amount surveyors, and temporary workers, to identify the difficulties and advantages of green development compared to traditional buildings.

Open Access Original Research Article

A Study on Trends and Variability in Monthly Temperatures in Antalya Province between the Years 1960 and 2015

Emre Duman, Fatih Kara

Journal of Scientific Research and Reports, Page 1-16
DOI: 10.9734/JSRR/2017/33038

The purpose of this study is to measure statistically the change in the monthly mean temperatures within the boundaries of Antalya province between the years 1960 and 2015. For this purpose, temperature observation values, obtained from 12 meteorological stations within the boundaries of Antalya province, were analysed using the Mann-Kendall Test and Sen’s Slope Estimator. In addition to the values from stations, the mean monthly time series data, generated for all of the boundaries of Antalya province by the Thiessen Polygons method, was also analysed by the methods in question. Antalya province was seen to reflect the typical features of the Mediterranean climate when monthly and seasonal mean temperatures were analysed. The highest temperatures measured in Antalya were 12.5 °C (Kas station) in January and 28.5 °C (Kale) in July. The lowest temperatures were 2.3 °C (Elmali station) in January and 23.8 °C (Korkuteli station) in July. The stations, which best represent Antalya province, were Manavgat and Kemer stations in winter and Kale station in summer, according to correlation and Root Mean Square Error (RMSE) test results. Seasonal trend analysis results showed an increase in 10 out of 12 stations in the summer. Furthermore 7 of 12 stations showed increasing trends in annual mean temperatures. Negative trends were identified in the Kumluca and Kas stations. There were trends of increase throughout Antalya province only in the months of summer, and no trends in other months, according to the trend test applied to the mean values obtained by the Thiessen method.

Open Access Original Research Article

Evaluation of Methods for Determination of Dispersion Coefficient for Utu Etim-Ekpo River, Nigeria

Ify L. Nwaogazie, Henry A. Akpan, Oghenefejiri Bovwe

Journal of Scientific Research and Reports, Page 1-9
DOI: 10.9734/JSRR/2017/33645

This study was conducted to evaluate methods for the determination of the longitudinal dispersion coefficient of Utu Etim-Ekpo River. Rihodamine-B was used in the tracer dye study. The variable distance – variable time method of sample collection was adopted. The samples collected were immediately transferred to the laboratory for analysis. Three approaches were adopted for the computation of dispersion coefficient with respect to this study, namely: Leverspiel & Smith method; Agunwamba’s method; and Ojiako’s method, respectively. The first two methods are analytical while the third is numerical. The dispersion coefficients obtained were 16.24, 19.679 and 14.68 m2/s with respect to Leverspiel & Smith method, Agunwamba’s method and Ojiako’s method, respectively. Agunwamba gave a higher value than the other methods due to the fact that the model is best suited for when tracer experiments are done using variable distance – variable time method which was not the case in Utu Etim-Ekpo tracer dye study.

Open Access Original Research Article

Phosphor Removal from Waste Water Using Hydrodynamic Cavitation

K. Dölle, M. Van Bargen

Journal of Scientific Research and Reports, Page 1-11
DOI: 10.9734/JSRR/2017/33285

Hydrodynamic cavitation principle was applied to phosphate containing water and waste water. A 20% Calcium hydroxide slurry was applied before hydrodynamic cavitation to precipitate calcium phosphate by reacting calcium hydroxide and phosphate in water. A 70% reduction of phosphate in waste water is observed compared to controls runs using orifice plate and jet nozzle designs to produce cavitation. The jet nozzle design showed best results of for phosphate reduction in waste water. After cavitation calcium hydroxide, rich treated waste water was settled and then naturalized with carbon dioxide gas.