The aim of this research is to study the factors affecting drag coefficient (C d ) in
non-Newtonian fluids which are the rheological properties ,concentrations of non-
Newtonian fluids, particle shape, size and the density difference between particle and
fluid .Also this study shows drag coefficient (C d ) and particle Reynolds' number (Re
P ) relationship and the effect of rheological properties on this relationship.
An experimental apparatus was designed and built, which consists of Perspex pipe
of length of 160 cm. and inside diameter of 7.8 cm. to calculate the settling velocity,
also electronic circuit was designed to calculate the falling time of particles through
fluid.
Two types of solid particles were used; glass spheres and crushed rocks as
irregularly shaped particles with different diameters and compared with each other.
The concept of equivalent spherical diameter (D S ) was used to calculate the
diameters of irregularly shaped particles.
The flow behavior for Non-Newtonian fluids was represented by Power-Law model.
Two types of polymers were used, Carboxy Methyl Cellulose CMC with
concentrations of (3.71, 5, 15 and 17.5) g/l and polyacrylamide with concentrations of
(2, 4 and 6) g/l.
The results showed that the drag coefficient decreased with increasing settling
velocity and particle diameters and sizes; and increased as fluid become far from
Newtonian behavior and concentrations and the density difference between particle
and fluid.
The results also showed that the rheological properties of Non-Newtonian fluids
have a great effect on the drag coefficient and particle Reynolds number relationship,
especially in laminar-slip regime and decreases or vanishes at transition and turbulentslip
regimes.
New correlations were obtained which relates drag coefficient with concentrations
of polymers and with flow behavior indices for spherical and irregular shaped
particles in Carboxy Methyl Cellulose CMC and polyacrylamide solutions.
Crop coefficient for cherries was evaluated by measure the water consumption in Michigan State to find its variation with time as the plant growth. Crop coefficients value (Kc) for cherries were predicated by Michigan State University (MSU) and also by Food and Agriculture Organization (FAO) according to consume of water through the season. In this paper crop coefficients for cherries are modified accordingly to the actual measurements of soil moisture content. Actual evapotranspiration (consumptive use) were measured by the soil moisture readings using Time Domain Reflectometers (TDR), and compared with the actual potential evapotranspiration that calculated by using modified Penman-Monteith equation which depends on metrological statio
... Show Mores The study aims to identify the fairness in the distribution of municipal services between municipal districts and areas, from point of view of municipal chamber staff and from the point of view of the citizen. It also aims to identify factors affecting the fairness of the distribution of municipal services. Municipal services were being studied : hygiene and waste, water supply, sewer, creating gardens, and street paving .Factors which examined its impact on municipal services are: resources available to municipal chamber, the managerial process at municipal chamber, and factors in the external environment surrounding municipal chamber.The results of the study showed that level of the e
... Show MoreThis research aims at studying each of the cold and hot thermal wavelengths affecting
Iraq for a minimum climatic course of 11 years beginning from 1992 till 2002. Three stations
were selected including the parts of Iraq surface: Mosul, Baghdad and Basrah.
The wave days were also connected with the related climatic elements represented by
the wind direction and speeds and the relative humidity. It was shown that Iraq is affected by
the rates of hot thermal wave lengths greatly compared to the rates of cold wavelengths. The
results suggested that the highest rate of hot and cold wavelengths recorded over Basra station
was (3.5) days for the cold and (5) days for the hot. While the lowest rates was at Mosul
station
have suffered from deteriorating residential neighborhoods, poor economic, social and urban living conditions of the population and deteriorating the infrastructural and superior services. These problems were the secretions of these cities' rapid urbanization. Based on the principles of sustainable urban planning and in order to achieve adequate opportunities for the lives of the population and provide them with sustainable livelihoods, policies have emerged to upgrade along the lines of community participation and programmes to reform and develop those neighbourhoods, raise their efficiency and make them livable. Thus, the problem of research was identified "The absence of a comprehensive cognitive perception of the most prominent facto
... Show MoreIn light of this, attention should be paid to tax reform as part of a comprehensive economic reform program. Therefore, the research started from the problem of the weak efficiency of the tax reform process in the General Authority for Taxation, as well as the need to know the addition of new taxes or increase taxes.The research aims study the relative importance of each disabled person, whether organizational, human, financial, legislative or technical. The research led to a number of conclusions, the most important of which were that the financial obstacles occupy the highest importance of the other obstacles and for the success of the tax reform, the material resources must be provided in order to provide the n
... Show MoreIt is estimated that over the next few decades, EOR will be used for the more than 50% of oil production in the US and worldwide. From these, in reservoir with viscositites ranging between 10 – 150 mPa.s, polymer flooding is suggsted as the EOR method. Therefore, there is an upper limit to the recommended range of reservoir oil viscosities for polymer flooding. To address the issue of this limitation of polymer injectivity and pumping efficiency, we propose a novel method. The method involves the use of Supramolecular Systems, which are composed of long-chain aminoacids and maleic acids post complexation. Their unique feature of resersible viscosities allows the operator to overcome
Introduction Periodontal diseases are ranked among the most common health problems affecting mankind. These conditions are initiated by bacterial biofilm, which is further modulated by several risk factors. Objectives To investigate the association of different risk factors with periodontal...