Biomass based film materials have gained attention due to their carbon neutrality. Film materials which were designed for packaging of fresh produce require good water vapor transport control to extend the shelf life of the products. In this study the water vapor transmission rate was investigated and measured by a modified technique of wet cup method, according to ASTM E 96. Biomass based film materials presented higher value of water vapor transmission rate compared to the conventional polyethylene films. Loading of scallop-shell powder increased the ability of the film to absorb or immobilize water due to enhancement of the formation of pores when the film was stretched. In addition, the water vapor transmission rate increased with increasing temperature or relative humidity difference.
A novel method for the easy and detailed visualization of water pathways (i.e., xylem vessels) involving girdling after staining is proposed. This technique was applied to intact seedlings as well as seedlings whose vessels were intentionally damaged to evaluate the effectiveness of the procedure. The applicability of the technique to grafted fruit-vegetable seedlings was tested using tomato seedlings (Lycopersicon esculentum Mill. ‘Momotaro’). The vessels were stained with congo red via the roots prior to girdling. This technique is unique in that it allows the visualization of the vessel network by a simple procedure as well as the continuous and unambiguous observation of the vertical and horizontal networks of vessels. Using the technique, we can observe a complex network of vessels, including vessel branching and vessel regeneration after damage.
The swine wastewater from Sunchon swine farm was decomposed using a sequencing batch reactor (SBR). The reactor body was fabricated using a plexi glass cylinder and its total volume was 20L with 15L of working volume. Each operating cycle consisted of five phases (fill, react, settle, draw and idle) with a total cycle time of 8 hours, thus resulting in three cycles per day (with 5 days of hydraulic retention time and 41 days of solid retention time). The cycles of the SBR system were controlled by a designed on-site computer and custom software. The results showed removal efficiencies of 85.5%, 80.3% and 87.2% for BOD, COD and TP respectively. It was found however that there were some non-satisfactory results, only attaining removal efficiencies of 61.0%, 31.2% and 54.5% for TN, NH3-N and NO3--N respectively. This was possibly due to the lack of enough carbon source and the inadequate aeration rate. It was also observed that removal efficiencies of 61.4%, 62.8%, 77.6% and 73.2% could be obtained for TS, TVS, TSS and TVSS respectively. The study showed that the SBR system could be used to attain good removal efficiencies of BOD, COD and nutrients in swine wastewater treatment if it is supplied with sufficient carbon source for de-nitrification and optimum aeration for nitrification.
An experimental testbed and a data analysis procedure were developed to evaluate the dynamic performance of global positioning system (GPS) receivers. Receiver I — radio beacons differential correction based GPS receiver and Receiver II — satellite differential correction based GPS receiver were evaluated. Under dynamic conditions, the position errors were 1.39 and 1.71 m, the speed errors were 0.067 and 0.068 m/s, and the direction errors were 9.7° and 16.9° for the receivers I and II, respectively. The results indicated that the trends in the dynamic accuracy of GPS receivers were completely different from those for static accuracy. The study signifies the need for evaluating the GPS positioning errors under static as well as dynamic conditions to correct the errors.