Fouling Mitigation Using Helixchanger Heat Exchangers

One of the major indeterminates in the design as well as operation of heat exchangers is the rate of fouling a select heat exchanger geometry would exhibit over the operation cycles. Gradual deterioration of heat exchanger performance due to the accumulation of fouling film on the heat transfer surface is often accounted for in the form of a fouling resistance, or commonly known as the fouling factor, while determining the heat transfer surface required for a specific heat duty. More often, the fouling mechanism responsible for the deterioration of heat exchanger performance is flow-velocity dependent. Maldistribution of flow, wakes and eddies caused by poor heat exchanger geometry can have detrimental effect on heat exchanger performance and reliability. Helixchanger heat exchangers have demonstrated significant improvements in the fouling behavior of heat exchangers in operation. In a Helixchanger heat exchanger, the quadrant shaped shellside baffle plates are arranged at an angle to the tube axis creating a helical flow pattern on the shellside. Uniform velocities and near plug flow conditions achieved in a Helixchanger heat exchanger, provide low fouling characteristics, offering longer heat exchanger run-lengths between scheduled cleaning of tube bundles. This article demonstrates the Helixchanger heat exchanger option in reducing the velocity-dependent fouling in heat exchangers

Evolution of substrate-specific gene expression and RNA editing in brown rot wood-decaying fungi.

Fungi that decay wood have characteristic associations with certain tree species, but the mechanistic bases for these associations are poorly understood. We studied substrate-specific gene expression and RNA editing in six species of wood-decaying fungi from the 'Antrodia clade' (Polyporales, Agaricomycetes) on three different wood substrates (pine, spruce, and aspen) in submerged cultures. We identified dozens to hundreds of substrate-biased genes (i.e., genes that are significantly upregulated in one substrate relative to the other two substrates) in each species, and these biased genes are correlated with their host ranges. Evolution of substrate-biased genes is associated with gene family expansion, gain and loss of genes, and variation in cis- and trans- regulatory elements, rather than changes in protein coding sequences. We also demonstrated widespread RNA editing events in the Antrodia clade, which differ from those observed in the Ascomycota in their distribution, substitution types, and the genomic environment. Moreover, we found that substrates could affect editing positions and frequency, including editing events occurring in mRNA transcribed from wood-decay-related genes. This work shows the extent to which gene expression and RNA editing differ among species and substrates, and provides clues into mechanisms by which wood-decaying fungi may adapt to different hosts

Analisis Hasil Pemeriksaan Spesimen Darah Penderita Demam Berdarah Dengue di Jakarta Tahun 1988

Dengue Haemorrhagic Fever is an endemic and important public health disease in Indonesia. Surveillance of hospitalized case usually reported 5.000 cases annually but 10.000 cases could be reported during an outbreak period. The case fatality rate had been decreasing to 4% at present. Studies to analyse the risk factors of an area, pathophysiology of shock or bleeding, prevention, eradication and surveillance were still needed. The important Dengue Haemorrhagic Fever factors were analysed in this tudy based on the 1756 specimens tested in the Communicable Disease Research Center during the period from January1988 to Desember 1988, sent by most of the hospitals in Jakarta. The overall difference between male and female was not significant, although on January, July, September and Desember 1988 females were almost 2 times higher then males.Theoverall difference of children and adult groups were also not significant, although on February, March, November and Decem­ber 1988 adults were higher 2-5 times then children. This findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren. These findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren then adults, although it was still lower then in Thailand

PHARMACOGNOSTIC AND PHYTOCHEMICAL EVALUATION OF TREMA ORIENTALIS LEAF

Trema orientalis (Ulmaceae) is native to India. This tree species has been of interest to researchers because it is a medicinal plant employed in the Indian indigenous system of medicine. Pharmacognostic standardization, physic-chemical evaluation of the leafs of Trema orientalis was carried out to determine its macro-and micro-scopical characters and also some insoluble ash and sulphated ash values, alcohol-and water-soluble extractive values were determined for phytochemical evaluations. Preliminary phytochemical screening was also done to detect different phytoconstituents. Microscopically, Leaf showed trichomes, Lamina, midrib regions, stomata and calcium oxalate crystals. Powder microscopy showed mesophyll region, abundant xylem vessels with annular thickenings and xylem vessels, Unicellular, multiseriate covering trichomes and glandular trichomes, Rosette and prism shape calcium oxalate crystals, Anomocytic stomata. Total ash was approximately two times and four times more than acid insoluble and water soluble as, respectively Ethanol soluble extractive was approximately two times higher than water soluble extractive. TLC of petroleum ether and ethanol extract showed five spots using Hexane: Ethyl acetate (12:4) and four spot using Choloroform: Ethyl acetate (5:4). Phytochemically, root exhibited phytosterols, Flavanoids, Tannin and phenolic compounds