Combustion in homogeneous charge compression ignition (HCCI) engine is controlled auto ignition of well-mixed fuel, air and residual gas. Since onset of HCCI combustion depends on the auto ignition of fuel/air mixture, there is no direct control on the start of combustion process. Therefore, HCCI combustion becomes unstable rather easily especially at lower and higher engine load. Charge strati...

Eastern black walnut (Juglans nigra L.) is used as a rootstock for the Persian walnut (Juglans regia L.) in some parts of the world and also has an important role in forestry and wood industry. Due to the deep physiological dormancy, the seed often shows an inconsistent or low germination percentage, making establishment difficult. This experiment was carried out as a completely randomized desi...

social stratification, formation of various classes and appearance of various layers in the society is a fact resulting from social conditions of public life and a wide variety of material, economic and subsistence factors as well as political situation, religious beliefs and public customs and thoughts; also ethnic divisions play an essential and undeniable role in this field. greed and coveto...

the dormancy characteristics and optimum conditions for seed germination of alstroemeria ligtu had not been explained. in vitro and in vivo alstroemeria (a. ligtu hybrid) seed germination tests were conducted in a randomized completely design at two different treatments (gibberellic acid (ga3) 0, 100, 200 and 400 mg/l with and without stratification in 5±1oc) in four replications. seeds were pl...

background: dams are one of the most important manmade buildings to provide of drinking water. in order to manage of water quality in dams reservoirs, the recognition of phenomena that occurred in it is essential. thermal stratification is one of the major problems that decrease the water quality of dam. the aim of this study was to investigate thermal stratification of ekbatan dam (hamadan) as...

The aim of this research is to study social factors influencing on social consensus. Sampling method was multi-process and included cluster and multistage sampling and sample size based on Cochran's Formula was 380 persons too. Data collection tools was questionnaire. In this research, the methods of data analysis were independent T-Test, Spearman Correlation Coefficient, Multivariate Regressio...

in this study, a one-dimensional model called dyresm was used to simulate the thermal structure and artificial destratification of 15-khordad reservoir over a period of one year. the simulation showed that the reservoir is warm monomictic and is stratified during 210 days of the simulation year. the model reproduced the temperature of the meta- and hypolimnion very close to the observed data, b...

No society is classes or without strata. Social stratification part and parcel of social life. Every defines a means categorizing each person into particular group. The placement individual in turn determines his value, as defined by the larger society: hence, greater role defining every person’s value. Differences values statuses engender society. If affected only such matters who gets elected...