Extraction and characterization of coal derived humic acids as soil conditioner

Humic acids (HA) were extracted from young Mukah coal using alkaline extraction (NaOH and KOH solution). The humic acids precipitates were separated by centrifugation from its acidified solution. Samples were characterized by the yield, moisture content, ash content, total acidity, -COOH group, -OH group, nitrogen content and E./E6 ratio. The functional groups were identified by FTIR spectroscopy. The properties of the coal-derived humic acids were compared with the properties of humic acids extracted from the nitrated sample which produce through regenerated process

Characterization and heat transfer performance of quarternary nitrate based molten salts

The use of molten salts as heat transfer has become the preferable composition. It has excellent properties such as low melting points, high heat capacity, and a wide range of temperatures. This paper focuses on the characterization and heat transfer performance of quaternary nitrate based on molten salts whose composition has been reported by previous researchers. The quaternary molten salts (LiNO3, NaNO3, KNO3, Ca(NO3)2) were characterized to determine the melting point and heat capacity using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), respectively. The heat transfer performance was then tested on the test rig of the designated system to determine the heat transfer properties of molten salts. The composition of 10 wt% LiNO3, 10 wt% NaNO3, 40 wt% KNO3, 40 wt% Ca(NO3)2 has a low melting point of 97.7°C, high heat capacity which was 0.46J/g°C, and maximum thermal stability temperature was 439.04°C. The heat transfer performance test showed that this sample can be used as heat transfer fluid and can store energy in the system. In conclusion, quaternary nitrate�based molten salt is a promising candidate for heat transfer and energy storage in heat recovery applications

Characterization of the coal derived humic acids from Mukah, Sarawak as soil conditioner

In Malaysia, abundant coal resources were found in Sarawak and Sabah. The utilization of coal resources, to date, is emphasized on the energy productions. The non-energy utilization as soil conditioner is unexplored. Therefore, this study attempted to characterize the coal humic acids extracted from Mukah coal and to evaluate its properties as soil conditioner. The coal humic acids from the regenerated sample were also assessed. The results revealed that different extractants and concentrations influenced the properties of humic acids. The extraction with KOH at 0.5 mol L-1 produced humic acids with low ash content and high acidic functional groups, which are substantial as soil conditioner. However, the yield was low. Regeneration of coal sample with 10% nitric acids improved the yield to an average of 83.45%. The acidic functional groups of nitrohumic acids were improved with the ash content remained at a low level

Identification and expression profiles of amino acid biosynthesis genes from psychrophilic yeast, glaciozyma antarctica

The mechanism of amino acid uptake and synthesis in the psychrophilic microorganism lives and proliferate in the extreme low-temperature environment is still not well understood. The aim of this study was to identify genes involved in amino acid generation for psychrophilic yeast, Glaciozyma antarctica and to determine their expression profiles when cells grow in media rich in amino acids or with limited amount of amino acids. The identification of genes was carried out by generating expressed sequence tags (EST) from two cDNA libraries generated from cells grown in complex growth medium and minimal growth medium without amino acids. A total of 3552 cDNA clones from each library was randomly picked and sequenced, generating 1492 unique transcripts (complex medium) and 1928 unique transcripts (minimal medium). Homology analyses have identified genes encoding proteins required for free amino acid uptake, biosynthesis of amino acids and recycling of amino acids based on the pathway used in the model yeast, Saccharomyces cerevisiae. Gene expression analysis by RT-qPCR showed that genes required for free amino acid uptake showed a higher expression profile in the complex medium, whereas the expression of most genes encode for proteins essential for biosynthesis and recycling of amino acids are higher in the minimal medium. In summary, genes that are involved in the generation and the uptake of amino acids for psychrophilic microorganism are conserved as in their mesophilic counterparts and the expression of these genes are regulated in the presence or absent of free amino acids in the surrounding

Pengenalpastian dan profil pengekspresan gen biosintesis asid amino yis psikrofil, Glaciozyma antarctica

Mekanisme pengambilan dan penghasilan asid amino bagi mikroorganisma psikrofil yang bermandiri dan berpoliferasi pada persekitaran sejuk melampau masih belum difahami sepenuhnya. Objektif kajian ini ialah untuk mengenal pasti gen yang terlibat dalam penjanaan asid amino bagi yis psikrofil, Glaciozyma antarctica serta menentukan pengekspresan gen tersebut semasa kehadiran dan kekurangan asid amino dalam medium pertumbuhan. Pengenalpastian gen telah dilakukan melalui penjanaan penanda jujukan terekspres (ESTs) daripada dua perpustakaan cDNA yang dibina daripada sel yang dikultur dalam medium pertumbuhan kompleks dan medium pertumbuhan minimum tanpa asid amino. Sebanyak 3552 klon cDNA daripada setiap perpustakaan dipilih secara rawak untuk dijujuk menghasilkan 1492 transkrip unik (medium kompleks) dan 1928 transkrip unik (medium minimum). Analisis pemadanan telah mengenl pasti gen mengekod protein yang terlibat di dalam pengambilan asid amino bebas, biosintesis asid amino serta gen yang terlibat dengan kitar semula asid amino berdasarkan tapak jalan yang digunakan oleh yis model, Saccharomyces cerevisiae. Analisis pengekspresan gen menggunakan kaedah RT-qPCR menunjukkan pengekspresan gen mengekod protein yang terlibat di dalam pengambilan asid amino bebas iaitu permease adalah tinggi pada medium kompleks manakala pengekspresan kebanyakan gen mengekod protein yang terlibat dalam kitar semula dan biosintesis asid amino adalah tinggi di dalam medium minimum. Kesimpulannya, gen yang terlibat dalam penjanaan dan pengambilan asid amino bagi mikroorganisma psikrofil adalah terpulihara seperti mikroorganisma mesofil dan pengekspresan gen-gen ini adalah diaruh oleh kehadiran atau ketiadaan asid amino bebas pada persekitaran

Heat Transfer Performance of Quaternary Molten Nitrate Salt Mixture for Heat Transfer Application

Previous, study has shown that synthetic oil and water are the best medium that can act as heat transfer fluid in heat transfer application. However, in the context of transferring energy, these medium are insufficient for operating at high temperature range due to its characteristic such as low melting point. The use of high temperature molten salt mixture in various industries has resulting big changes in transferring of heat energy. It is proven that the molten salt mixture can carry more heat from one place to another. This study shows the effect of quaternary molten salts mixture consisting of four different salts which are Sodium Nitrate, (NaNO3), Potassium Nitrate, (KNO3), Lithium Nitrate, (LiNO3), and Calcium Nitrate, (Ca(NO3)2) that can enhance the heat transfer rate in heat transfer application. New line of quaternary nitrate salt mixtures (NaNO3 - KNO3- LiNO3 – Ca(NO3)2) were prepared through mixing process. Those mixtures were then heated inside the box furnace at 150oC for four hours and rose up the temperature to 400oC for eight hours to homogenize the mixtures. The temperature was then dropped for several hours until it reaches 115oC before removing the mixture from the furnace. After that, the quaternary molten salt has been placed inside the boiler for heat transfer performance test. The quaternary molten salt was heated inside the boiler and transferred the heat to the working fluid through the copper coil. The inlet and outlet temperatures were recorded by reading the measuring devices that installed at the inlet and outlet of the boiler. At the boiler temperature of 200oC, it is shown at time of 25 minutes, sample 5 with composition of 10wt% NaNO3, 60wt% KNO3, 10wt% LiNO3 and 20wt% Ca(NO3)2 gives the highest value of heat transfer rate which was 2.65kW, meanwhile at boiler temperature of 100oC, sample 2 with composition of 22wt%NaNO3, 40wt%KNO3, 23wt%LiNO3 and 15wt%Ca(NO3)2 gives the lowest value of heat transfer which was 0.37kW. In the nut shell, by replacing the previous heat transfer fluid to quaternary molten salt mixture can increase the heat transfer rate in heat transfer application

Thermal analysis of quaternary molten nitrate salts mixture for energy recovery system

Quaternary molten salt nitrate have been used very practically as medium for energy storage or heat transfer fluid in terms of energy recovery system. Quaternary molten salt nitrate is a mixture that can transfer heat to generate energy such as electricity. Mixed alkaline molten nitrate salt can act as a heat transfer fluid due to their advantageous in terms of heat recovery system due to high specific heat capacity, low vapour pressure, low cost and wide range of temperature in its application. This studies shows about determining the new composition of quaternary molten nitrate salts from different primary salts that can possibly give a high specific heat capacity with low melting point. The mixture of quaternary molten nitrate salts was then heated inside the box furnace at 150oC for four hours and rose up the temperature to 400oC for eight hours. Through heating process, the quaternary molten nitrate alkaline was completely homogenized. The temperature was then dropped to room temperature before removing the mixture from the furnace. The specific heat capacities of each sample were determined by using Differential Scanning Calorimeter, DSC. From the result of DSC testing, Sample 6 gives the highest point of specific heat capacity and low melting point which is 0.4648 J/goC and 97.71oC respectively. In the nut shell, Sample 6 was chosen as a good mixture with good thermal properties that has a low melting point which is below 100oC but high specific heat capacity that may be a helpful in the application energy recovery system

Stabilization of Soft Clay by Using Diapers Back Sheet Layer Wastes

This research focus on improving the weaknesses of soft clay soils by using proper recycled material as a stabilization agent for strengthening purpose. Therefore, Diaper’s Back Sheet Layer Wastes (DBSLW) were used as the agent of soil stabilization. In this study, series of laboratory test were conducted to evaluate the optimum size and content of DBSLW as a strip reinforcement to increase the strength of Batu Pahat Soft Clay (BPSC). Testing program involves obtaining the physical properties of BPSC followed by California Bearing Ratio (CBR) test to determine the strength of BPSC with and without the addition of DBSLW. Result shows that the optimum size for DBSLW is 10 mm x 30 mm while the optimum content is 0.5%. At 15 mm penetration, sample with diapers strip of 10 mm x 30 mm dimension record 4.10 kN CBR value compare to 1.64 kN CBR value of untreated soil, 2.5 times stronger than untreated soil. Results of CBR tests demonstrated that inclusion of DBSLW strips in soil with optimum amounts and size improved strength and deformation behavior of soils substantially. The proposed technique could be used to advantage in road construction, industrial yards, and building structure