Applied Mechanics and Materials Vol. 804

Abstract: The optimum ratios of auxin and cytokinin are necessary for callus induction and plant regeneration. This ratio is a key function involving in the promoting cell division and proliferation in tissue culture. The axillary buds of in vitro plantlets from Vetiveria nemoralis A. Camus cv. Roiet were used as explants for the callus induction experiment. These explants were cultured on Murashige & Skoog (MS) medium [1] supplemented with various combinations of auxins and cytokinins. Under this experimental study, the highest frequency of callus induction was found on MS medium supplemented with 2 mgL^-1 α-naphthalene acetic acid (NAA) and 1 mgL^-1 2-furanylmethyl-1H-purine-6-amine (kinetin) (62.5%). On the other hand the combination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 6-benzylaminopurine (BAP) was toxicity to this explants. All culturing explants were dead and no calli appearance. The calli derived from each medium were transferred into the same regeneration medium (MS with 1 mgL^-1 NAA and 2 mgL^-1 BAP). After culturing on regeneration medium, calli induced from the highest callus induction medium have shown high frequencies of regeneration and also shoot number per callus (58.33% and 7.1 shoots).

Abstract: The main reasons which caused the water pollution in canals, especially in Khlong Prem Prachakorn, are untreated, and improperly treated household, accumulation from flood situation in Bangkok. Soil sediment accumulation in canal contain many types of organic compounds. However, contaminant that causes an increase health risk is the mostly concern. This research was performed to investigate the organic compounds in household wastewater removal under biodegradation, and adsorption mechanisms by using soil sediment taken from Khlong Prem Prachakorn, Bangkok, Thailand. For the adsorption experiment, inactivated sludge was used for determining adsorption capacity of soil sediment. The samples were slowly mixed at 30 rpm and taken at constant time intervals for the determination of biological oxygen demand (BOD), and chemical oxygen demand (COD) reduction. The influent BOD, and COD concentration were found 63 mg/l, and 354 mg/l, respectively. The results indicated that the concentration of BOD, and COD were decreasing rapidly by both biodegradation and adsorption mechanisms within 12 h. In this research, the biological activity by microorganisms in soil sediment as an important role and helped to remove organic compound in household wastewater.

Abstract: This work studied fluid flow in the hydroponics systems to create 4 prototypes of the hydroponics systems; horizontal (traditional), inclined-flow, vertical-droplet and vertical-bowl systems, for a household application with initial conditions as low investment cost and easy installation. Red Oak was used to plant in all prototypes to investigate the prototype productivity. Fluid in the experimental investigation was the plant nutrient solution. All variables; fluid and ambient temperatures, fluid pH and sunlight intensity were measured 2 times a day from 4 systems placed in the same area and environment during 15 days of the experimental period in July 2013,. From results, the solution temperatures affected the productivity less than the fluid flow patterns did. The vertical-droplet system could not be used to grow Red Oak because the plants died during the experiment period. The vertical-bowl system could provide the highest productivity. We noticed that the fluid in the vertical-bowl system flowed transitionally while the flow in the other systems was laminar. Therefore, the fluid flow patterns could affect the productivity in the hydroponics systems.

Abstract: Waste pollution is environmental problem on an international level that is particularly important to an island which is limited area, as well as where is little management capacity to carry the number of future wastes. This article aims to present the reviewed relevant documents about waste management education; a kind of tool in which to reach the environmental education objectives. These are an increasing of knowledge, awareness, attitude, skills, and participation for all stakeholders in order to reduce the number of waste volume. Two keywords were used to search from the secondary data which are environmental education (EE.) and waste management. The waste management was mainly focused to the education process only on island. The results found that waste management education conducted in all educational systems promoted both children and adults in different processes and settings. For example; educational set, waste management program, learning activities, and waste training manual. Moreover, the designed contents were varieties; such as, waste issues, effects from wastes, waste management, waste disposal, and waste separation by practice. However; not all of them reached the EE objectives. Consequently, this information will be useful for the future research about waste management education in island context.

Abstract: This article aims to investigate the potential of using effluent wastewater (called raw wastewater) from wastewater treatment plant as a recirculation liquid in a wet scrubber to remove volatile fatty acid (VFA). This research was conducted in 2 steps. Firstly, surveys and interviews were carried out at STR 20 factory in order to obtain information about STR 20 production and odor control process. Secondly, a study of the potential of using the raw wastewater in a wet scrubber to absorb the VFAs was conducted. The exhausted gas with high VFAs causes malodor in Standard Thai Rubber 20 (STR20) industry. The wet scrubber with counter-current mode runs for 7 operational days. Pall ring is used as packing media without bacterial attachment. The study demonstrates that in these 7 operational days, the raw wastewater has the potential to absorb the VFA. This is indicated by higher VFA concentration 4,372.5 mg/l as acetic acid of a recirculation liquid compared to raw wastewater 75.38 mg/l as acetic acid fed. It increases efficiency of absorbing volatile fatty acid approximately by 24%. VFA concentration in effluent wastewater was found 1,734 mg/L as acetic acid compared to influent wastewater was found 1,395 mg/l as acetic acid fed. In addition, bacterial growth on packing media was observed with volatile solid (VS) and total bacteria count present due to biodegradation of VFA. This information will be useful for further research in the future about biodegradation of VFA by bacterial attachment in packing media.

Abstract: The variation of water vapor can be detected from the Global Positioning System (GPS) data. The GPS signal was delayed when propagated through the wet atmosphere. The delayed signal can be retrieved into Precipitation Water Vapor (PWV) data. The GPS data of CUSV station from 2009 to 2012 were used in this research. The results showed that the PWV varied during the summer of Thailand. The PWV were slightly increased from 20 mm at the beginning of the season to 40 mm at the end of season. The increased PWV data were shown as linear line. A slope of the linear line may relate with the amount of the cumulative rain in the season. The steeper line might relate to the great number of raining in the end of the season, otherwise, the fairly gradual line might relate to the raining at any time in the season. The high level of PWV up to around 33 mm could induce the rain in the summer of Thailand.

Abstract: We study the heating energy of briquettes from cashew nut shell (CNS), cultivated in south Thailand. CNS briquettes (CNSB) were produced by mixing CNS powder with the cassava starch ratio 5:1w/w. A chemical component analysis of the CNSB was performed, and the heat utilization efficiency was compared with firewood charcoal. CNSB were found to have a fixed carbon content of 49.2%, ash content of 4.2% (750°C°C at 6 hours), and moisture content of 6.6% (105°C for 24 hours). It was observed that CNSB consists of energy consumption at 0.440-0.456 KW/kg and high compressive strength of 60.2 kg/cm².The value of heat utilization efficiency obtained inside the fuel briquette of 18.01%, attributed to the burn rate average at 11.90 g/min. CNSB could be used to replace firewood and reduce cost for heating manufacturing processes.

Abstract: Data assimilation is used in numerical weather prediction to improve weather forecasts by incorporating observation data into the model forecast. The Ensemble Kalman Filter (EnKF) is a method of data assimilation which updates an ensemble of states to provide a state estimate and associated error at each step. The atmospheric model that is used in this research is a one-dimensional linear advection model. This model describes the motion of a scalar field as it is advected by a known speed field. The result shows that by selecting appropriate initial ensemble, model noise and measurement perturbations, it is possible to achieve a significant improvement in the EnKF results. The accuracy of the EnKF increases when the number of ensemble member grows. That is, the larger ensemble sizes perform better than those of smaller sizes.

Abstract: In this study, 2 wt% NiFe₂O₄/HAp composite ceramic was fabricated by the solid state reaction method to form a composite with the future potentiality to remove heavy metals. HAp powders were synthesized by precipitation using Ca (NO₃)₂ as Ca source, (NH₄)₂HPO₄ as the P source and ammonia as a pH adjuster. NiFe₂O₄ powders were prepared by mixing and milling NiO and Fe₂O₃ powders (using stoichiometry ratio) in ethanol and sequent dehydration and then calcination. 2 wt% of NiFe₂O₄ powders were milled with 98 wt% of HAp powders for 10 minutes before uniaxial pressing and sintering at 1200 °C for 3 hours to form 2 wt% NiFe₂O₄/HAp composite ceramic. The prepared ceramic was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). XRD result shown that 2 wt% NiFe₂O₄/HAp composite ceramic with only HAp and NiFe₂O₄ phases obtained. FT-IR results revealed vibration bands of standard HAp and indicated the interaction between ZnFe₂O₄ and HAp. For the SEM result, the morphology of the prepared ceramic revealed nanoand micro sized grains. These results could lead us to the development of a method for a NiFe₂O₄/HAp composite ceramic optimized for specific heavy metal removal applications.

Abstract: Linuron and atrazine as a kind of pesticides were used more widely in agriculture. The toxic effect in the environments, which accumulation in soil, water and human effect. Both of pesticides were adsorped using zeolites with batch method. Three difference types of zeolite were used for comparison. Those pesticides consisted of various Si/Al ratio which were 3.61 (Y), 8.61 (Y-10) and 111.35 (Y-100). The organo-zeolite, which modified with hexadecyltrimethyl ammonium (HDTMA) surfactant were used for comparison. It was found that the adsorption capacity of linuron more than atrazine 30 % for Y , 40 % for Y-10 and 10 % for Y-100. It can be explaned that the small molecules of linuron (thickness 6.12 Ao) could move onto pore size of zeolite (7.4 A^o). While the larger molecules of atrazine (thickness 9.6 A^o) could not do this. The maximum asorption capacities of all pesticides are Y-100 and MY-100 because they have most external area and hydrophobic properties which were form their most dealuminative potential. The comparison of MY-10 and Y-10 found that MY-10 has more adsorption capacities than Y-10 as follow 4 % for linuron and 20 % for atrazine since MY-10 has more increased hydrophobic force. Adsorption capacity of MY-100 is similar to Y-100. Adsorption capacities of MY is lower than Y since it has steric effect and pore blocked with surfactant. This results were identified by XRF, XRD, FT-IR, TGA and CHNS.