Controlling the rate and behaviour of the biodegradable polymer matrix is important in the development of drug delivery systems. In this project, we succeeded to control the speed of degradation and changing the degradation site from the bulk to the surface by addition of excipients. Antiacid excipients, such as Mg (OH)2 have significant effects on rate and behaviour of biodegradation, by neutralization of the acidic microclimate pH in polymer. We synthesized high molecular weight poly (L-lactide) by using tin- 2-ethyl hexanoate as catalyst. The polymer has been characterized by GPC, DSC and SEM. Mixtures of the polymer with Mg (OH) 2 at 1, 3 and 5% w/w were prepared and the degradation of the samples, kept at in vitro condition after 3 and 6 months, were studied. The results of average molecular weight changes, thermal characteristics and morphology of samples after 3 and 6 months revealed that it is possible to redirect the bulk degradation towards surface degradation. It is found that the ratio of bulk degradation to surface degradation and speed of degradation has reverse relationship with the additives concentration and when Mg (OH)2 increases, the speed of degradation decreases as well. In samples with Mg(OH)2, the polymer degradation rates were reduced by 2-3 folds and the percentage of crystallinity increased by maximum 90% (3% Mg(OH)2) after 6  months.

Apparently all of the Jurists and lawyers have agreed that any sale contract transfers the ownership of the thing sold, in a way that this "transfer of ownership" is considered as inherent consequence of any sale contract. However, this clarity faces with serious doubts in case of analysis of all types of sale contracts as some lawyers deny the inherent description of transferring the ownership in some kinds of sale contracts, obviously.In this essay, we are going to elaborate on this point that the sale contracts are all transferor in terms of ownership of object matter and as soon as conclusion, they apply their effect. Therefore, the existing difference between these lawyers' opinion from one side and the implication of Civil Code rules-that are based on transferring of ownership in all types of sale contracts-on the other side, raised from difference between the majority's opinion in Shi'a Jurists with other legal systems in defining the concept of "ownership tie" that the Civil Code has accepted the former one and lawyers followed the later.

Introduction: Suitable fracture resistance is a main factor for long term success in restoration treatment. The purpose of this study was to evaluate the fracture resistance of Class II restoration with total-etch and self-etch adhesives along with various bulk-fill composites. Materials and Methods: In this in-vitro study, conventional class II cavities were prepared on the proximal surface of 40 sound human premolar teeth with almost same size and shape. Half of the cavities were restored with Sonic Fill nanohybrid bulk-fill composite with total-etch (Optibond Solo Plus, Kerr) and self-etch (Optibond XTR, Kerr) adhesives, and the other half were restored with Tetric N-Ceram, (Ivoclar vivadent) bulk fill composite with total-etch and self-etch adhesives. For fracture resistance evaluation, the specimens were put in Instron device. The amount of force was recorded at the moment of fracture for the evaluation of experimental groups. The data were analyzed by bivariate ANOVA. Results: The highest and lowest fracture resistance were observed in Tetric N-cream with total-etch adhesive and self-etch adhesive, respectively. There was no significant difference in fracture resistance between Tetric N-Ceram and Sonic fill with totaletch and self-etch adhesives (P>0. 05). Conclusion: Both of the bulk-fill composites with various adhesives had the same fracture resistance.

This research investigates the dynamics of excess return on vessels trip charter and time charter in travel leases and rental of the specified route in bulk dry market. Initially, using a weekly dataset between January 2003 and January 2016, a long-term co-integration relationship between temporary travel contracts and maritime-specific contracts was evaluated in the ship's temporary lease equations. Then, a new method was developed based on technical analysis to identify surplus return signals and the formation of a business strategy. Accordingly, our focus was on short-term deviations and we developed a leasing strategy for technical analysis. In particular, we designed the MMTM method and formed a rental strategy. Finally, we tested our strategy for a simple weekly entry into a specific lease. The results show that our method performs better than the benchmark strategy and reveals that a proper utilization of market price deviations will result in significant surplus returns.

The present study was conducted in two forests in Abha (Capital of Asir Region) and two forests in Al Namas (130 km north of Abha), south western Saudi Arabia (Asir region) to investigate the effect of terraces on rainwater harvesting and growth of Juniperus procera Hochst. ex Endlicher. Farmers grow their crops within Juniper forests and woodlots by constructing terraces from soil and stones to harvest rainwater. Juniper forests and woodlots present important watersheds and sources for water. Study plots were established in four forests, two of which contained maintained terraces and the other two have been covered by abandoned and damaged terraces. The results showed that maintained terraces served as important means for rainwater harvesting, whereas abandoning of terraces resulted in increased soil loss, surface runoff, and bulk density and reduced infiltration rates. Significant correlations and regression between soil loss, total runoff, and soil bulk density and infiltration rate were provided. Diameter at breast height, total height, basal area, volume, number of trees, crown coverage and regeneration/ha of J. procera were significantly (P < 0.0001) higher in forests with maintained terraces compared with abandoned terraces. Finally, maintained terraces improved rainwater harvesting and growth performance of J. procera.

Knowledge of resistance to airflow through agricultural products is an important consideration in the design of drying, cooling, or aeration systems and proper fan selection for these systems. Resistance to airflow of bulk chickpea seeds was studied at moisture contents in the range of 9.21 to 21.36 % (wet basis) for airflow rate range from 0.02 to 0.50 m3 s-1 m-2, using an experimental test column. The effects of airflow rate, bed depth (0.25 to 1 m) fill method (loose and dense) and moisture content on airflow resistance of chickpea samples were investigated. Results indicated that the airflow resistance of chickpea seeds increased with increase in airflow rate, bed depth, and decreased moisture content. One percent increase in moisture content decreased the pressure drop about 2.94%. The dense fill method resulted in an increase in resistance to airflow by about 33.17% more than that of the loose fill. Three models (Shedd’s, Hukill and Ives’s, and Ergun’s models) were fitted to the experimental data at each moisture level and were examined with two parameters. Shedd’s model that gave a higher value for the coefficient of determination and a lower value for the mean relative percentage error of pressure drop predication was found to be the best model to describe airflow resistance of chickpea seeds.

In polymerization, shortening of reaction time is always considered to be important. Although many methods can be used in order to decrease the reaction time but most of them have an adverse effect on product quality, for example, using too much initiator at high temperature, polymerization rate is increased but molecular weight decreases, so mechanical properties fall considerably. In this work, by using two initiators with different decomposition temperatures and selecting a proper heating rate a reduction in the length of time for polystyrene synthesis was observed while molecular weight remained constant.