This document discusses two studies: 1) A study that evaluated the sedimentation process in rectangular channels used for cassava starch production in Colombia. It found that particles greater than 10 μm were efficiently retained, while particles between 6.7-8.8 μm were discharged, causing environmental problems. 2) A study of Spanish adolescents that analyzed sexual practices and protection methods based on age of sexual debut. It found that those with early debut (before 15) reported more partners and less condom use, associated with increased health risks. Both studies examined processes and relationships to draw conclusions.

3.  Background:
Cassava Production Starch mainly In The
northern Region Of The Cauca a Colombian
Departament, In Small Agricultural Industrias
Know As “Rollanderías”.
 Purpose And Focus:
Evaluate The Sedimentation Process Performed
In Rectangular Channels (0.3m High; 0.4m Wide;
165m Long) Which Are generally Used In The
Region.

4.  Methods
Two main components were evaluated the
determination of the change in the concentration of the
slurry zone, entering the settling zone and the
determination of the particle size distribution in the
settling zone.
 Results
The Slurry Concentration During The Strainer Operation
was Between 0,1 to 6%.
The Settling Process Variation During The Process
Varied Between 0,82 to 1.44 L/S. With A Predominance
Of Laminar Flow And A Hydraulic Retention Time
Greater Than 150 Minutes.

5. Conclusion:
In The First 104m Of The Channels, Particles Greater
Than 10 μm in size were efficiently retained,
particles between 6.7 to 8.8 μm were not retained
and were discharged into local bodies of water,
generating a great environmental problem.

7.  Background:
In Spain young people have their first sexual
intercourse at an earlier age than in other
countries; however, little is known about the
relationship between age of sexual debut and
sexual behavior in this population.
 Purpose And Focus:
Sexual practices and methods of protection are
analyzed depending on the age of sexual debut
among Spanish adolescents who are sexually
experienced (N=351). The mean age was 15.9 years
(SD = .75, range: 14-18).

8.  Methods
Three groups were formed according to The age of sexual
debut reported: early sexual debut (earlier than 15 years),
average (15 years) and late (later than 15 years).
 Results
The early sexual debut group reported further mutual
masturbation, vaginal intercourse and oral sex with a higher
number of sexual partners than the rest.
Condom use at first intercourse, percentage of use and
consistent condom use was significantly lower in the early
sexual debut group compared to the others. Sexual debut
before 15 years old was associated with increased risk of
sexual infections, deficit in condom use and increased
sexual exposure.

9. Conclusions
The findings of this study suggest that the age
of sexual debut has implications for the sexual
health in young people.