http://hdl.handle.net/20.500.12228/20 2026-04-07T01:38:05Z http://hdl.handle.net/20.500.12228/906 Volumetric and Sound Velocity Studies on L-Lysine and L-Arginine in Aqueous Sodium Benzoate Solution at Different Temperature Mou, Iffat Ara In this study, a general volumetric and sound velocity method was used to analyze the effects of sodium benzoate (SB) on the structure of essential amino acids (L-lysine, L-arginine). Densities and sound velocities of L-lysine and L-arginine in aqueous and in aqueous 0.05 mol.kg-1, 0.2 mol.kg-1, 0.35 mol.kg-1 and 0.5 mol.kg-1 SB solutions have been studied at 293.15K to 313.15K with an interval of 5K. The density data have been used to calculate apparent molar volume (φv), limiting apparent molar volume (φv 0), limiting apparent molar volume transfer (Δtrφv 0), apparent molar expansibilities ( 0  E ) and Helper’s constant ( E / T) p 0    . The acoustic properties such as adiabatic compressibility (βs), apparent molar adiabatic compressibility (k), limiting apparent molar adiabatic compressibility (φk 0), apparent molar adiabatic compressibility transfer (Δtrφk 0), acoustic impedance (Z) and hydration number (nH) have been calculated by densities and sound velocities data. The densities increase with the increase of concentration of amino acids. Densities of amino acids in aqueous SB solutions are higher than that of amino acids in aqueous solution. The limiting apparent molar volumes (φv 0) and the values of experimental slope (Sv) are positive. The smaller values of Sv as compared to φv 0 values suggest the dominance of solute-solvent interaction over the solute-solute interaction. The limiting apparent molar volume transfer (Δtrφv 0) values of L-lysine and L-arginine in SB solutions are negative. This indicate that ion-hydrophobic and hydrophobichydrophobic group interaction are dominating over the hydrophilic-hydrophilic interaction. The values of limiting apparent molar expansion ( 0  E ) are positive. These trends in limiting apparent molar expansions for these amino acids in each concentration of SB solutions indicating the presence of solute-solvent interaction. The Hepler’s constant p ( E / T) 0    values of binary system are entirely positive for all studied amino acids suggest the studied systems act as structure makers. In ternary system some values are small negative and some values are positive. Hepler’s constant p ( E / T) 0    in ternary solutions indicating the structure making properties of amino acids in SB solutions. The values of partial molar volumes (V̅ 2) increase with increasing of concentration of L-lysine, L-arginine for the studied systems. As the concentration of amino acids increases, the adiabatic compressibility (βs) decreases. This indicates the water molecules around the amino acids are less compressible than the water molecules in the bulk solution. The negative apparent molar adiabatic compressibility (k) values indicate the greater loss of structural compressibility of water implying a greater ordering effect by the solute on the solvent. Δtrφk 0 values of L-lysine are positive whereas Δtrφk 0 of L-arginine are negative. This indicate that hydrophilichydrophilic and ion-hydrophilic interaction are dominating for L-lysine systems whereas hydrophobic-hydrophobic and ion-hydrophobic interactions are dominating for L-arginine systems. The small Sk values also indicates the solute-solvent interactions. The increase in acoustic impedance Z, indicates the presence of effective solvent-solvent interactions with the increase in solution concentration. The positive hydration number (nH) values indicate an admirable solubility of the solutes. Water molecules around amino acids have less shrinkage than water molecules in bulk solutions. The compressive strength of the ternary solution is less than that of the binary solution. This result suggests that the proteins or peptides generated from the studied amino acids will be denatured in ternary SB solutions. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, September 2018.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 133-140). 2018-09-01T00:00:00Z http://hdl.handle.net/20.500.12228/762 Volumetric and Viscometric Properties of N-Acetylcysteine in Dimethylformamide Containing Binary and Ternary Mixtures Pal, Gopal The density and viscosity of NAC (0.10 to 1.00) mol.L−1 in H2O, DMF and DMF– H2O mixed solutions were measured and studied over the entire molarity range with in the temperature range of 298.15 to 318.15 K at 5 K interval. The apparent molar volumes, were determined from density values experimented by Density and Sound Velocity Meter (DSA 5000M) Anton Paar, Austria. In the NAC–H2O and NAC in [1:4] and [2:3] [DMFH2O] solvent systems the apparent molar volumes of NAC were found to be increased, whereas in the NAC–DMF and NAC in [4:1] and [3:2] [DMFH2O] solvent systems apparent molar volumes of NAC were found to be decreased. Apparent molar volume at infinite dilution, 0 v  and Sv values were also computed according to the experimented density values. The apparent molar volume at infinite dilution provided an idea about the presence of solutesolvent interactions of the investigated systems. Sv, the experimental slopes which provided an idea about the prevailing solutesolute interactions in the mixtures. Both 0 v  and Sv values indicated that there both solute-solute and solute-solvent interactions present in the binary as well as in ternary solutions. The investigated systems showed hasty increase of viscosity values with the increased NAC concentration but the values of viscosity decreased with the increase of temperature. In binary and ternary systems showed the similar trend viscosity changes but in different order of magnitude. The order for binary and ternary systems are: NAC– DMF > NACH2O and NAC in [3:2] [DMF–H2O] > NAC in [4:1] [DMF–H2O] > NAC in [2:3] [DMF–H2O] > NAC in [1:4] [DMF–H2O] > NAC–DMF > NACH2O, respectively. The viscosity values were employed to determine the viscosity coefficients i.e., A and B-coefficients; change of free energy, G*; change of enthalpy, H* as well as change of entropy, S*. Negative values of A and positive values of B co-efficients suggesting that weak solute-solute but strong solute-solvent interaction present in the binary and ternary solution, respectively. From these thermodynamic parameters state of the spontaneity of the investigated systems were known. On the basis of this data, the predominant molecular interactions occurring between NAC–H2O and NAC in [1:4] and [2:3] [DMFH2O] solvent systems were found to be solute-solute interaction, where as in NAC–DMF and NAC in [4:1] and [3:2] [DMFH2O] solvent systems solute-solvent interaction were predominant. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, 29 June, 2019.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 74-80). 2019-06-29T00:00:00Z http://hdl.handle.net/20.500.12228/761 Analysis of Heavy Metal Concentration in Soils of a Waste Disposal Site in Khulna using Artificial Intelligence Techniques Sarkar, Shyamol Kumar The collection of soil samples is labored and time consuming as well as the determination of heavy metal concentrations in laboratory was expensive. To these attempts, artificial intelligence techniques (AI) such as adaptive neuro-fuzzy inference system (ANFIS), support vector machine (SVM) and artificial neural networks (ANN) were implemented for the analysis of heavy metal concentrations in soils of a selected waste disposal site at old Rajbandh, Khulna. The aim of this study was to fix the functions, algorithms, optimization methods for AI techniques based on their best performance and then select a best technique for the analysis of heavy metal concentrations in soils. In this study, soil samples were collected from eighty-five locations at a depth 0-30 cm from the existing ground surface from the selected disposal site. In the laboratory, the concentrations of heavy metals of Pb, Cu, Ni, Zn, Co, Cd, As, Sc, Hg, Mn, Cr, Ti, Sb, Sr, V and Ba in soils were measured. Result reveals the model with SCP, gaussmf, linear and hybrid was the best-fitted model of ANFIS for the prediction of heavy metal concentrations in soils. In addition, in SVM analysis, the model SVM-RBF with 15 folds was selected for the prediction of heavy metal concentrations in soils. In ANN, the model LT (Levenberg-marquardt and Tansig functions) with neuron structure 2-10-1 was selected. The accuracy of the predicted results were checked based on the acceptable limits of prediction parameters like R value, RMSE, MAPE, GRI and percentage recovery. Among all heavy metals analysis in ANFIS, the maximum R-value 0.999 was found with the minimum RMSE 0.12 for Sc indicating the best correlation in prediction of Sc in soils. The others value of prediction parameters (MAPE= 36.00, GRI=1.50, percentage recovery=123.43%) for Sc were found within the acceptable limits. In addition, in SVM analysis, maximum R-value 0.73 with RMSE 2.03 was found for Cu; while, maximum R-value 0.88 with the minimum RMSE 1.01 for As was found in ANN. The results demonstrated that ANFIS model was a reliable technique than that of other counterparts of SVM and ANN to analyse the heavy metal concentrations in soils with the acceptable degree of robustness and accuracy. Therefore, the performance of AI techniques may be expressed by the sequence of ANFIS > SVM > ANN. Here it can be noted that one can easily be computed the concentration of a particular heavy metal in soils by inserting GPS values (latitude and longitude) only in the developed rule viewer of ANFIS. Therefore, this newly developed model will further be helpful for other researchers in this line to analysis heavy metal concentration in soils of selected waste disposal sites. This thesis is submitted to the Department of Civil Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering, September 2019.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 154-160). 2019-09-01T00:00:00Z http://hdl.handle.net/20.500.12228/760 Micro-Characterization of Indoor Particulate Matter in Selected Areas of Jashore University of Science and Technology Patwary, Md. Helal Uddin Indoor air pollution has drawn considerable attention in recent years. Indoor air quality is very important for human health especially for vulnerable group of people (the asthmatic, the children and the elderly). The indoor environment can be subdivided into different micro-environments such as residents, transport, offices, educational institutions etc. and each may have a different source of indoor pollution. Indoor particulate matter has harmful impact on human health and environment. The finer the size of particles the higher the harmful impact. In this research work an attempt has been made for characterization of indoor particulate matter at three buildings named10-storied residential Tower, Administrative and Academic building of Jashore University of Science and Technology (JUST) campus. In the dust sample, presence of heavy metals (Ti,Fe,Cu,Zn,As,Pb,Zr) and criteria air pollutant(Pb)was found. The concentration of PM10 (μg/m3) and PM2.5 (μg/m3) measured by Tactical Air Sampler (TAS) was found highest value (PM10, 170μg/m3 and PM2.5,103μg/m3) in Academic building among the three buildings. The reason is that this building is situated near road side and construction work is going on adjacent the building. Again concentration of PM2.5 is found higher inside than outside the building in all cases. Concentration of PM10 (130μg/m3) is found higher inside than outside (76μg/m3) in Administrative Building. Concentration of PM10 and PM2.5 in all cases exceeds WHO guideline limit (WHO guideline for PM10 in 24 hour- 50μg/m3 and 1 year is 20μg/m3; For PM2.5 in 24 hour- 25μg/m3 and 1 year is 10μg/m3 ) and in academic building exceeds Bangladesh standard both in outdoor and indoor(Bangladesh standard for PM10 in 24 hour- 150μg/m3 and 1 year is 50μg/m3). Concentration of PM10 in administrative building both in outdoor and indoor and 10-storied residential tower building in outdoor is within Bangladesh 24 hour standard but exceeds Bangladesh 1 year standard. In academic building exceeds Bangladesh standard both in outdoor and indoor (Bangladesh standard for PM2.5 in 24 hour- 65μg/m3 and 1 year is 15μg/m3). Concentration of PM2.5 in administrative building exceeds Bangladesh standard in indoor but in outdoor within 24 hour standard but exceeds 1 year standard. Concentration in 10-storied residential tower in outdoor within the 24 hour standard but exceeds 1 year standard. In XRF analysis presence of Pb (667±0.19,ppm) and Ca (61340±919,ppm) was found highest in academic building PM. Inter elemental correlation was calculated. Strong correlation (R2 >0.90) was found Pb with Zr; Sr with Ca, Ti, Zn and As; Rb with K and Cu; As with Ca, Fe and Zn; Zn with Ti and Fe; Cu with K; Fe with Ca and Ti. Strongly correlated elements originated from same source such as re-suspended road dust, trace element of earth crust, cement, paint and other construction materials. Adequate control, management, housekeeping can minimize the exposure of indoor dust to occupants. This thesis is submitted to the Department of Civil Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering, July 2019.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 81-86). 2019-07-01T00:00:00Z