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With the growing popularity of computers and the Internet, most teachers are taking advantage of Internet functions to assist in both teaching and student learning. However, students only login to the assisted learning system once or twice a week on average to surf for relevant references, participate in discussions, or hand in assignments, even though information and interaction are greatly enhanced by these online services. Therefore, increasing the transfer rate of useful information and interaction during the course period would help students learn. To this end, we designed an e-news delivery system that sends personalized e-mails to every student's mailbox to make information access and peer interaction more convenient and efficient. Through the daily habit of using e-mail, students can receive the latest information, new instructions or peer discussions early. To encourage usage of the system, a user friendly interface was designed. The e-news system takes advantage of webpage hyperlinks to allow students to click on interesting topics while reading e-news; doing so will cause another window to pop-up with detailed content retrieved from the web-based learning system. A mouse-click allows students to login to the web-based learning system and extract the details of the chosen topic. To enhance the efficiency of e-news, learners' needs and interests were taken into consideration when forming the e-news content. Students' learning status and reading preferences are assessed to determine which information or content to include in the e-news. Experiment results reveal that e-news and personalized information greatly promote the reading of new information and participation in online activities.

The 2003 flood of the Muda River reached 1,340 [m.sup.3]/s at Ladang Victoria and adversely impacted 45,000 people in Malaysia. A flood control remediation plan proposed a levee height based on a 50-year discharge of 1,815 [m.sup.3]/s obtained from hydrologic models. This design discharge falls outside the 95% confidence intervals of the flood frequency analysis based on field measurements. Instream sand and gravel mining operations also caused excessive riverbed degradation, which largely off sets apparent benefits for flood control. Pumping stations have been systematically required at irrigation canal intakes. Several bridge piers have also been severely undermined and emergency abutment protection works were needed in several places. Instream sand and gravel mining activities should be replaced with offstream mining in the future. DOI: 10.1061/(ASCE)HY.1943-7900.0000163 CE Database subject headings: Floods; Hydrologic models; Hydraulic engineering; Gravel; Mining; Malaysia. Author keywords: Flood mitigation; Flood control; Hydrologic models; Hydraulic engineering; Gravel mining.

A new preparatory method helps synthesize a ditopic porphyrin, which is designed to bind with two metals with a predicted geometry. This synthesis is relevant to the study of cytochrome oxidase a3-Cu site. X-ray crystallography and NMR studies help characterize a mu-acetate-bridged monozinc(II) complex and a dizinc complex.

The feasibility of using a sol-gel derived titanium carboxylate thin film, whic can be supported on glass, for the fabrication of optical test strips was investigated using a model probe/analyte combination. The porous films, being optically transparent and having the capability to host probe molecules, provided an excellent system to investigate the possibility of making optical test strips. A colorimetric reagent, an iron-(III) porpohyrin, was chosen as th probe molecule to detect free cyanide ion concentrations in aqueous solutions. Entrapment of the porphyrin in the film was accomplished by direct dissolution of the porphyrin in the sol-gel solutions. Chemically induced structural modifications of the polymer were carried out to stabilize the encapsulated metalloporphyrin within the sol-gel derived matrix. The syntheses of this model analyte detection system and its response are presented. An optical parameter reflective of the chemical changes that occur in the system was selected as the measurement tool; its response asymptotically increased over the cyanide ion concentration range of 40-25 000 ppm.

The iron-free derivative porphyrin o dimethyl ester derived from the reaction of iron(III) heme o clearly manifested the structure of the heme o prosthetic function of Escherichia coli quinol oxidase. Mass, vibrational, electronic absorption and nuclear magnetic resonance spectroscopies were applied to determine the structural conformation of the iron prophyrin macrocycles. The successful preparation of the acetylated and dehydrated forms of porphyrin o confirmed the derived structure of the prosthetic group.