Pyrolysis of polystyrene waste in the presence of activated carbon in conventional and microwave heating using modified thermocouple.

Pyrolysis process was experimented using two types of heating source, namely conventional and microwave. Polystyrene (PS) plastic waste was used as feedstock in a batch reactor for both the conventional (slow pyrolysis) and microwave pyrolysis. The effect of activated carbon to polystyrene ratio on (i) yield of oil, gas and residues (ii) reaction temperature (iii) reaction time were studied. Quality of oil from pyrolysis of polystyrene were assessed for the possible applicability in fuel production. Microwave power of 450 W and polymer to activated carbon ratio of 10:1, resulted in the highest oil yield of 93.04 wt.% with a higher heating value of 45 MJ kg-1 and a kinematic viscosity of 2.7 cSt. Microwave heating when compared to conventional heating method, exhibits a reaction temperature and time of 330 °C in 5.5 min, whereas in conventional heating system it was 418 °C in 60 min. The gas chromatography-mass spectrometry analysis of liquid oil from microwave pyrolysis predominantly yields alkenes of 8.44 wt.%, α-methyl styrene 0.96 wt.%, condensed ring aromatics 23.21 wt.% and benzene derivatives 26.77 wt.% when the polystyrene to activated carbon ratio was 10:1. Significant factor of using microwave heating is the amount of energy converted (kWh) is lesser than conventional heating.

Ophthalmic manifestations in Rothmund-Thomson syndrome: Case report and review of literature.

A 24-year-old male patient presented to us with diminution of vision in both eyes with watering and photophobia for the past 8 years. General physical examination showed short stature and poikiloderma. Ocular findings include photophobia with reflex tearing, dry eye, cicatricial ectropion, symblepharon approaching pupillary area of cornea, and multiple superficial punctuate erosions on the cornea. Both eyelids showed scanty meibomian glands on infrared meibography. The rest of the anterior and posterior segment was normal. The patient was treated with topical lubricants which reduced photophobia and corneal erosions. He then underwent symblepharon release with buccal mucosal grafting, which improved ectropion. Patient improved symptomatically with reduction of photophobia and improvement in vision as well.

An analysis of blood utilization for elective surgery in a tertiary medical centre in Malaysia.

BACKGROUND: The purpose of this study is to determine the efficiency of blood utilization for elective surgery at the University of Malaya Medical Centre (UMMC). A similar study conducted six years earlier in the same unit resulted in the introduction and implementation in December 1997 of the local Maximum Surgical Blood Order Schedule (MSBOS) and the Group Screen and Hold (GSH) procedure instead of a full crossmatch. This paper compares the findings of the current study with that conducted earlier. MATERIALS AND METHODS: A prospective survey of the blood ordering practice for elective surgery over a 3-month period, from February to April 2001 was conducted in the Transfusion Medicine Unit (TMU) of the UMMC. Outcome measures used in this study were (a) decision on whether to perform a full cross match or a GSH procedure using the MSBOS guidelines, (b) the crossmatch transfusion ratio (CT), (c) the transfusion index (TI) and (d) the degree of over transfusion calculated from the pre and postoperative hemoglobin levels. The CT ratio and the TI were calculated for each type of elective surgery performed during the study period. RESULTS: In the present study 31.2% of cases had blood crossmatched as against 40.6% in the earlier one The overall CT ratio was 5.0 and many procedures were found to have a high CT ratio and a low transfusion index. It was observed that 47.7% of patients were over transfused as compared to 45.5% in the earlier study. CONCLUSION: The introduction of MSBOS and GSH has led to a significant decrease in the percentage (p= < 0.05) of cases for which a full crossmatch is done. The conservation policies have led to a decreased crossmatch workload and reduced blood outdating. Although the CT ratio has improved for many individual procedures, the overall CT ratio in fact increased from 4.4 to 5.0. There remains therefore, a continuous opportunity to improve transfusion practices by reviewing the local MSBOS. The transfusion index (TI) calculated for each procedure in this study can be utilized to recommend a GSH for those procedures with low TI.

An audit of fresh frozen plasma usage in a tertiary referral centre in a developing country.

This paper evaluates the practice of fresh frozen plasma (FFP) transfusion at the University Hospital, Kuala Lumpur, and analyses its usage by the various clinical departments. The aim of this study is to identify where it is inappropriately used and the clinical indications in which such misuse is common. A retrospective analysis of the blood bank request forms and work sheets during a 6-month period between January 1998 and June 1998 formed the basis of this study. Overall, 40% of 2665 units transfused were considered appropriate. However, out of the 931 episodes of FFP transfusions only 31% were for appropriate indications. The average FFP requirement when used for appropriate indication was about 4 units per episode, whereas for inappropriate indication it was 2.5 units per episode. Inappropriate use in terms of the number of units was highest by the surgical services (68%) and Orthopaedics (64%), while the Department of Paediatrics had the lowest incidence of inappropriate use (40%). When Paediatrics was used as the benchmark, the incidence of inappropriate use by other departments was significantly higher (p < 0.01). As for FFP usage in common clinical indications, there was a high incidence of inappropriate use in burns (82%), perioperative period (73%), cardiac surgery (68%), massive bleeding (62%) and trauma (60%). The findings in this study, specifically the use of FFP for volume support in trauma, massive bleeding and burns, routine requests without identified indication in cardiac bypass surgery, and prophylactic use in the perioperative period can be the basis for recommendations to minimize the inappropriate use of FFP in the future.