Water flooding is one of the most influential methods for pressure maintenance and enhanced oil recovery. However, water flooding is likely to develop the formation of oilfield scale. Scale formation in reservoirs, due to the mixing of injection water and formation water, could cause formation damage and production limit. Therefore, it is necessary to simulate the compatibility of brine and injection water. Scale prediction is performed using many thermodynamic and/or kinetic based models. In this study, simulations with speciation (ion pairing) are studied, which is a thermodynamic based tool. The utilization of reservoir conditions, formation water analysis, and sea water analysis as the inputs in this method resulted to the accurate prediction of potential scales. In this study, the factors impacting on the scale potential such as pH, Temperature, and mixing ratio were also investigated. The obtained results showed that calcite and aragonite were the major scale potential to precipitate. Finally, the results illustrated the important effect of pH and Temperature on different scales formation.

The effluent quality of a sewage treatment plant using activated sludge process and finally secondary treatment depends on the flocculation efficiency and settling of the flocs. The survey of various treatment processes in water and wastewater treatment shows that Temperature and pH are the important factors affecting efficiency of flocculation and settling properties. This study was performed to determine the effects of pH and Temperature on settling of the flocs in activated sludge process. It was carried out for three months in two phases, using mixed liquor suspended solids (MLSS), obtained from aeration tank from one of wastewater treatment plants in Tehran. In the primary phase, the Temperature of samples was increased from 15oC to 35oC. As a result, the sludge volume index (SVI) and effluent suspended solids increased and consequently, COD removal percent decreased.In the second phase, the pH was increased from 5.7 to 9. As a result, SVI and effluent suspended solids decreased and COD removal percent increased.

The production of secondary metabolites varies under the different environmental conditions. The aim of this study was to investigate the effects of pH and Temperature on the content of antioxidant compounds in a species of microscopic algae. First, the microalgal strain Monoraphidium sp. was cultured under the different Temperature and pH treatments. The biochemical assays were then performed on the compounds such as photosynthetic pigments, phenolic compounds, and total flavonoids. The total antioxidant activity was evaluated by FRAP and DPPH methods. The results of this study showed that the microalgae Monoraphidium sp. had the maximum growth and high content of antioxidant compounds at the acidic pH and Temperature 28°, C. The results indicated that the optimal conditions can be achieved for the high production of antioxidant compounds in microalgae by changing the environmental factors, which can be used in the pharmaceutical, medical, and production of nutritional supplements industries.

Objective (s): Nowadays hydrogels are one of the upcoming classes of polymer-based controlled-release drug delivery systems. Temperature and pH-responsive delivery systems have drawn much attention because some diseases reveal themselves by a change in Temperature and/or pH. The objective of this work is to prepare and characterize composite membrane using responsive nanoparticles into a polymer matrix.Materials and Methods: These nanoparticles were made of the copolymer poly (N-isopropyl acrylamide-comethaçrylic acid) by an aqueous dispersion polymerization process and are responsible for dual sensitivity to Temperature and pH. Morphology study with SEM, swelling behavior with Dynamic Light Scattering Technique, in vitro drug release behavior with side-by-side Diffusion Cells were also investigated in this paper. Doxorubicin hydrochloride was used as a model solute.Results: The study on the release of doxorubicin hydrochloride showed that the release rate was higher at pH 5 than pH 7.4, increased with the increase of Temperature. Nevertheless, ionic strength only poses a minor direct effect at higher pH.Conclusion: Such system may be potentially used as a tumor-targeting doxorubicin hydrochloride delivery in the body.

The rheological and filtration properties of drilling mud under down-hole conditions may be very different from those measured at ambient pressures and Temperatures at the surface. This paper presents the results of an experimental investigation into the Temperature and salinity and pH effects on drilling mud rheological and filtration properties. Results are given from tests on water base mud containing CMC polymer and XC polymer. Drilling fluid was investigated at three different Temperatures (21.1°C, 48.9°C, 80°C) containing 8.165Kg/bbl bentonite. The drilling mud salinities in this study were fresh water (Ahwaz water: ppm: 400, Hardness: 120), 2000 ppm, 4000 ppm, 8000 ppm and 40000 ppm. It was found that pH of drilling mud should be kept at range of 8-10, because increasing pH of drilling mud will increase its rheological properties. The salinity and Temperature effects show that as the salinity and Temperature of drilling mud are increased the effectiveness of polymers in drilling mud will decreased. Moreover, they have a negative effect on filtration properties of drilling mud. In suspensions of sodium montmorillonite that are well dispersed and have low gel strength, both plastic viscosity and yield point decrease with increasing Temperature.

Inabilities to attain adequate aqueous solubility and stability have made the preparation of a clinically suitable formulation of taxol difficult. Addition of nicotinamide (ND), 2-hydroxypropyl-b-cyclodextrin (HPßCD), polyethylene glycol, (PEG), bile salts (BS, 50:50 sodium cholate: deoxycholate), and cremophor EL can improve the solubility of taxol. Studies were undertaken to compare the stability of taxol in HPßCD (20%), ND (20%), PEG (20%), BS (20%), and cremophor EL (cremophor: ethanol 0.5% of each) solutions at 25, 37, 50, and 60oC. Taxol concentration was measured by HPLC method. The rate of degradation proceeded in a Log-linear fashion and increased progressively with the elevation of Temperature in all solutions except in HPbCD which taxol had negligible degradation. In the absence of added agents, taxol exhibited the lowest and highest stability at pH 1.2 and 4.5, respectively. Taxol was most stable in HPbCD followed by PEG and then ND. The stability of taxol increased linearly with the HPbCD concentration (0-5% w/v). Due to the observed improved stability and solubility, HPbCD may be considered for pharmaceutical studies as a suitable stabilizer for formulation of taxol.