Studies of Thermal Stability of Polymers by Thermal Volatilisation Analysis

A great deal of work has been carried out on the degradation of polystyrene in order to elucidate the mechanism of the reactions involved. Most of the workers have assumed that transfer reactions are taking place and included them as a factor in the theoretical treatments of the kinetics of degradation. Other workers have shown, by indirect experimental work, that transfer reactions to take part in the degradation process of this polymer. However, this work is a direct attempt to show that intermolecular transfer is a major factor taking part in the degradation process. The technique used was the TVA where the small pressure which exists in a continously evacuated system between a hot sample, decomposing to volatile products, and a cold trap placed some distance away is recorded continuously as the temperature of the sample is increased in a linear manner. The TVA curve indicates the variation of rate of volatilization of the sample with temperature. The degradation method used was that of comparing the thermal stability of very thin films of polymer with that of the thicker films. Degradation was carried out under conditions of temperature rise of 10 C/min. or at isothermal temperatures. Thin films of polystyrene were observed to be thermally more stable than the bulk material. The molecular weight dropped more sharply in the case of thick films when compared with thin films of the same sample weight. More styrene monomer was produced from degraded thin films than from the thicker films. Also, the shape of the curve of the rate of volatilization against percentage conversion in thin films resembled that of poly (a- methyl styrene) where the zip length is much greater than the chain length. This behaviour was considered to be due to the reduction of intermolecular transfer reactions in thin films of polystyrene. Polymers where transfer reactions are well established such as polypropylene, poly (isobutene) and some elastomers were also examined and showed an effect of thin film stability similar to that observed in polystyrene. Poly (methyl methacrylate) was also examined in the form of thin and thick films and in powder form. The results suggested that transfer reactions of the secondary hydrogen atoms might be taking place to some extent. Poly (methyl acrylate) which contains a tertiary hydrogen atom showed an effect similar to that observed in polystyrene; while there was no change in thermal stability of thin and thick films of poly (tert. butyl methacrylate). Very few useful conclusions could be drawn from results obtained from the degradation of thin and thick films of PVC, PVA and poly (vinyl alcohol)

Peperites: Insight into the Submarine Eruptions within Walash Volcanosedimentary Group, Mawat Area, Iraqi Kurdistan Region

Peperites are volcanosedimentary materials generated by the mingling of magma and unconsolidated wet sediments. They have unique insights into submarine volcanisms and the tectonic environments where they form. For the 1st time, the authors identified two types of peperites (blocky and fluidal) hosted by micritic limestone rocks in the Walash Volcanosedimentary Group of the Mawat area, Kurdistan Region-Iraq. They are designated as peperitic facies one and two (PF1 and PF2) and consist of black basaltic rocks mixed with chocolate-brown micritic limestone rocks. Their abundance demonstrates the contemporaneity of deep marine sediment deposition and submarine volcanism during Walash’s nascent arc. Despite hydrothermal alteration, the basaltic rocks retained their magmatic textures. Basaltic rocks comprise mainly albite, anorthite, diopside, hematite, and alkali-feldspar. Calcite dominates micritic limestone rocks, while quartz is minor. Based on geochemical data, igneous sections are basaltic rocks with tholeiitic series that are strongly enriched in Light Rare Earth Elements with low concentration ratios of (La/Yb) and (Sr/Y), indicating geochemical affinity to normal island arc basalt with a primitive arc signature. Furthermore, their formation is thought to be caused by partial melting of subducted slabs deep within 30 km and the associated derived fluids above the subducted slab. Thirteen species of planktonic foraminifera (Morozovella) are identified through paleontological research and biostratigraphy. Using these various tools lead the authors to illustrate the tectonic setting of the formation of peperitic rocks in arc fronts of the subducted Walash arc during the Middle to Late Paleocene (60 Ma)

Oxfendazole Resistance in Gastrointestinal Nematodes of Beetal Goats at Livestock Farms of Punjab (Pakistan)

This study was carried out to screen goat farms for anthelmintic resistance (AR) against oxfendazole (OXF) and to determine contributory factors for its development. For this purpose, Beetal goat farms (n = 18) were randomly selected, with natural mixed gastrointestinal nematodosis infection. In vivo (faecal egg count reduction test) and in vitro (egg hatch assay) tests were used to ascertain the presence of AR while a scorecard was used to determine the role of possible contributory factors for oxfendazole resistance. For in vivo test, the experimental animals were divided into two groups of 10 animals each; one group received OXF treatment, while the other served as control. Pre- and post-treatment coproculture was performed to identify the species and genera of nematodes. Egg hatch assay (EHA) was used to confirm the results of FECRT. Fecal egg count reduction test (FECRT) revealed the development of resistance on six farms and post-treatment larval cultures indicated Haemonchus contortus, Trichostrongylus colubriformis, Cooperia curticei, Teladorsagia circumcincta and Oesophagostomum spp. as dominant species with resistance. Furthermore, EHA confirmed the results of FECRT. Among the presumptive factors for AR, the highest composite score was for rotation of anthelmintics followed by treatment frequency, dose rate and nature of medication. The scorecard for the development of AR, used in this study, may be helpful for the assessment of contributory factors of AR

Standard of knowledge about their disease among patients with diabetes in Karachi, Pakistan

Objective: The aim of this study was to determine the standard of knowledge among people with diabetes.METHOD: Two hundred and thirty patients were randomly chosen from outpatient clinics and a 34-item multiple choice questionnaire administered to them. The questionnaire was structured to assess knowledge about the disease state, diagnostic tests, complications and management.Results: The average score of correct answers for the group was 40%. A significantly higher score correlated with younger age (16-30 years), educational status and regular follow-up with a diabetic clinic. There was no significant difference in the knowledge score between males and females or between those on oral hypoglycemic agents (OHA) and insulin. Fifty percent of the patients could correctly answers questions regarding food and nutrition and only 60% were aware of target blood glucose levels for optimal control. It was alarming to learn that 75% of those on insulin did not know that using U-40 or U-100 insulin does not change the dose required.CONCLUSION: The study emphasizes the need for diabetes education at all levels, both for the patients as well as the health care providers to counter the pandemic of diabetes-related complications globally

Aplikasi Metode Taguchi Analysis Dan Failure Mode and Effect Analysis (Fmea) Untuk Perbaikan Kualitas Produk Di PT. Xyz

PT. XYZ merupakan Perusahaan yang bergerak dibidang produksi lolly dan cup plastik. Produk lolly yang dihasilkan oleh Perusahaan ini sering mengalami kecacatan dan tidak sesuai dengan standar yang telah ditetapkan, bahkan jumlah produk cacat melebihi toleransi yang diberikan oleh Perusahaan. Ketatnya persaingan saat ini memaksa Perusahaan harus membuat suatu konsep rencana yang berorientasi kepada kualitas produk yang akan menjadi suatu keunggulan yang dapat dipergunakan untuk menghadapi persaingan. Pentingnya kualitas merupakan salah satu alasan melakukan penelitian terhadap kualitas produk yang dihasilkan oleh Perusahaan tersebut. Tujuan penelitian ini adalah untuk mengetahui sejauh mana produk lolly telah memenuhi spesifikasi yang telah distandarkan Perusahaan dan untuk mengetahui dan menganalisis faktor-faktor yang menyebabkan penyimpangan kualitas produk. Metode yang digunakan adalah Metode Taguchi Analysis dan Metode Failure Mode and Effect Analysis (FMEA) untuk memberikan rekomendasi tindakan perbaikan yang tepat. Hasil analisa taguchi diolah dengan menggunakan S/N Ratio dan analisis varians. Hasil penelitian menunjukan faktor-faktor yang berpengaruh secara signifikan terhadap kualitas produk lolly adalah suhu pendingin produk pada level 1 dengan suhu 140 C, kecepatan injeksi angin pada level 2 dengan kecepatan 25 m/s dan suhu injeksi bahan baku ke dalam cetakan pada level 1 dengan kecepatan 220 m/s. Hasil penerapan Failure Mode and Effect Analysis (FMEA) diperoleh faktor yang paling berpengaruh dan paling besar penyebab kegagalan proses produksi yaitu suhu pendingin produk yang terlalu tinggi dengan nilai RPN terbesar 192

Redesigning the 'choice architecture' of hospital prescription charts: a mixed methods study incorporating in situ simulation testing.

Objectives: To incorporate behavioural insights into the user-centred design of an inpatient prescription chart (Imperial Drug Chart Evaluation and Adoption Study, IDEAS chart) and to determine whether changes in the content and design of prescription charts could influence prescribing behaviour and reduce prescribing errors. Design: A mixed-methods approach was taken in the development phase of the project; in situ simulation was used to evaluate the effectiveness of the newly developed IDEAS prescription chart. Setting: A London teaching hospital. Interventions/methods: A multimodal approach comprising (1) an exploratory phase consisting of chart reviews, focus groups and user insight gathering (2) the iterative design of the IDEAS prescription chart and finally (3) testing of final chart with prescribers using in situ simulation. Results: Substantial variation was seen between existing inpatient prescription charts used across 15 different UK hospitals. Review of 40 completed prescription charts from one hospital demonstrated a number of frequent prescribing errors including illegibility, and difficulty in identifying prescribers. Insights from focus groups and direct observations were translated into the design of IDEAS chart. In situ simulation testing revealed significant improvements in prescribing on the IDEAS chart compared with the prescription chart currently in use in the study hospital. Medication orders on the IDEAS chart were significantly more likely to include correct dose entries (164/164 vs 166/174; p=0.0046) as well as prescriber's printed name (163/164 vs 0/174; p<0.0001) and contact number (137/164 vs 55/174; p<0.0001). Antiinfective indication (28/28 vs 17/29; p<0.0001) and duration (26/28 vs 15/29; p<0.0001) were more likely to be completed using the IDEAS chart. Conclusions: In a simulated context, the IDEAS prescription chart significantly reduced a number of common prescribing errors including dosing errors and illegibility. Positive behavioural change was seen without prior education or support, suggesting that some common prescription writing errors are potentially rectifiable simply through changes in the content and design of prescription charts