Electric lineation and tortuosity for assigning fracture porosity in Nukhul formation, north of the gulf of Suez, Egypt

An integrated interpretation of petrographical, petrophysical and anisotropic fabric studies has been carried out for assigning fracture porosity of Nukhul Formation in north of the Gulf of Suez. Petrographically, the available Nukhul core samples are composed mainly of clastic rocks as glauconitic and dolomitized quartz wacke, echinoidal and foraminiferal dolomitic quartz wacke, and calcareous quartz arenite. Beside to some microfacies, they could be assigned as sandy dolopackstone microfacies, sandy molluscan packstone microfacies and dolomitic packstone microfacies. The 2-D porosity determination in the thin section revealed negligible porosity values mainly dishanced by compaction and pressure solution, silicification and cementation by calcite. Some other diagenetic processes slightly/hardly enhanced porosity as dolomitization, dissolution, replacement and aggrading neomorphism. Petrophysically, porosity and permeability are poor due to the tight cementation mostly by silica, which obliterated the primary porosity and also the diagenetic porosity formed after the dolomitization process. Permeability values decrease with increasing the irreducible water saturation and the tortuosity values in perpendicular direction to the bedding plane, whereas it increases by increasing porosity. Both the petrographical and petrophysical studies showed the presence of some fracture and channel porosity in the field scale, assigned from the well-log data, and hardly assigned by using the traditional petrophysical and petrographical methods. Using the electric fabric parameters and measuring tortuosity in 3-D is a useful tool for assigning fracture and channel porosity at the upper and middle parts of the studied rock unit

Relationship between caries status, colony forming units (cfu) of Streptococcus mutans and Snyder caries activity test.

It is a well established fact that dental caries is caused by streptococcus mutans. For qualitative and quantitative analysis of streptococcus mutans, saliva samples are often preferred and are processed according to Kohler and Brathall method. In the present study an attempt is made to relate caries status (caries free, average caries, and rampant caries group) with cfu counts of streptococcus mutans and Snyder test. The streptococcus mutans were isolated using MSB agar and cfu were determined of each individual from different caries groups. The saliva of the same individual was drooled into a culture bottle containing Snyder test agar and extent of colour change was observed after 24, 48, and 72 hours incubated at 37 degrees C. The time and extent of colour change determined the conduciveness of diet. It has been observed that caries free individuals have low cfu count and their diet was mild or moderately conducive, while the individuals having average caries had medium cfu count and their diet was moderately-high conducive. In rampant caries, individuals however the cfu count were high and the diet was highly conducive. In caries free, average caries and rampant caries group 40, 60, and 80 per cent samples showed colour change, in Snyder test up to full length in 72 hours respectively. Thus a definite correlation exists between caries status, cfu count of streptococcus mutans and Snyder caries activity test.

Prevalence of dental caries in nursery school children of Akola city.

A study of prevalence and severity of dental caries was undertaken in seven nursery schools of Akola city in the age group of 5-6 years. A total of 508 children were examined out of which 288 were boys and 220 girls. The examination for dental caries and data collection was carried out as per W.H.O. (1987) criteria. Out of the total 508 children examined 61.41% were observed to be having caries with mean dmft/dmfs of 2.75+/-3.98 & 4.04+/-6.84 respectively. Total 17.91% school children were found to be having decay in either all upper or lower molars. In the high risk caries group 0.98% children were found to be affected with nursing caries and 0.2% children with rampant caries. Only a negligible proportion of filled teeth (1.42%) and missing due to caries (0.14%) was observed in the population. Occlusal surface caries was the most prevalent type of decay (44.71) and the mandibular deciduous second molars were the most affected by caries. Due to high prevalence of dental caries (61.41%) research must be carried out in the direction of identification of the children population at high risk of caries, so that a rigorous preventive programme be implemented.