Recovering coefficients in a system of semilinear Helmholtz equations from internal data

We study an inverse problem for a coupled system of semilinear Helmholtz equations where we are interested in reconstructing multiple coefficients in the system from internal data measured in applications such as thermoacoustic imaging. We derive results on the uniqueness and stability of the inverse problem in the case of small boundary data based on the technique of first- and higher-order linearization. Numerical simulations are provided to illustrate the quality of reconstructions that can be expected from noisy data

Photothermally enhanced drug release by kappa-carrageenan hydrogels reinforced with multi-walled carbon nanotubes

Temperature and near infrared (NIR) light responsive multi-walled carbon nanotube (MWCNT)-kappa-carrageenan hydrogel composites have been prepared. The effects of the MWCNTs on the microstructure, strength, swelling and release properties of the resultant materials were investigated. MWCNTs acted as reinforcing fillers and enhanced the mechanical properties of the hydrogels, the effect being mostly nanotube concentration dependent. Surface functionalization of nanotubes had a major influence on the swelling of the composites. The increased release of a model drug (methylene blue) in in vitro conditions, from kappa-carrageenan hydrogel composites due to the NIR photothermal effect of MWCNTs was demonstrated at the physiological temperature. Thus, these composites are promising materials for the development of carriers for remotely activated drug delivery

Rates and controls of the air-sea flux of bromoform (CHBr3): a review and synthesis

Bromoform (CHBr3) is the largest single source of atmospheric organic bromine and therefore of importance as a source of reactive halogens to the troposphere and lower stratosphere. The sea-to-air flux, originating with macroalgal and planktonic sources, is the main source for atmospheric bromoform. We review bromoform's contribution to atmospheric chemistry, its atmospheric and oceanic distributions and its oceanic sources and sinks. We have reassessed oceanic emissions, based on published aqueous and airborne concentration data, global climatological parameters, and information concerning coastal and biogenic sources. The goals are to attempt an estimate of the global source strength and partly to identify key regions that require further investigation. The sea-to-air flux is spatially and temporally variable with tropical, subtropical and shelf waters identified as potentially important source regions. We obtain an annual global flux of bromoform of ∼10 Gmol Br yr−1 (3–22 Gmol Br yr−1). This estimate is associated with significant uncertainty, arising from data precision and coverage, choice of air-sea exchange parameterizations and model assumptions. Anthropogenic sources of ∼0.3 (to 1.1) Gmol Br yr−1 (as CHBr3) can be locally significant, but are globally negligible. Our estimate of the global oceanic source is three to four times higher than recent estimates based on the modeling of atmospheric sinks. The reasons for this discrepancy could lie with the limited regional and temporal data available and the broad assumptions that underlie our flux calculations. Alternatively, atmospheric sink calculations, often made on the basis of background CHBr3 levels, may neglect the influence of strong but highly localized sources (e.g., from some coastal and shelf regions). The strongly variable and poorly characterized source of CHBr3, together with its short atmospheric lifetime, complicates model-based estimation of the distribution of reactive Br resulting from its atmospheric degradation. An integrated program of marine and atmospheric observations, atmospheric modeling and mechanistic studies of oceanic bromoform production is required to better constrain present and future Br delivery to the atmosphere

ENDOSKOPI THT FK UNAIR/RSUD DR SOETOMO MASA LALU, KINI, DAN YANG AKAN DATANG

Endoskopi diambil dari kata endos artinya dalam dan scopein yang berarti memeriksa1. Jadi seksi endoskopi memeriksa organ yang letaknya di dalam rongga dalam tubuh. Seksi endoskopi THT bertugas melihat/memeriksa dalam rangka membuat diagnosis penyakit-penyakit di laring, esofagus, dan bronkus. Tugas lain ialah melaksanakan terapi di organ tersebut dengan alat endoskopi, seperti eksterpasi bedah laring mikroskopis, aritenoidektomidll. Sekarang seksi endoskopi THT juga melihat nasofaring dan melakukan operasi sinus, dan semua tindakan ini memerlukan alat endoskopi (teleskop maupun mikroskop)

De fermentatieve bereiding van butanol

Document uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science

EFEK FARMAKOLOGIS DAUN MENIRAN (PHYLLANTHUS NIRURI LINN.) TERHADAP OTOT POLOS USUS HALUS SECARA TERPISAH PADA KELINCI

Kandungan meniran yang telah banyak diketahui adalah zat pahit (phillantine) yang telah dapat diisolasi, tergolong alkaloid, sebagaimana kandungan alkaloid pada spesies phyllanthus yang lain. Selain itu masih terdapat sejumlah zat inorganik serta beberapa zat lain yang belum diketahui. yang dibuktikan dengan adanya kadar abu yang sebagian larut dan sebagian tidak larut dalam asam.Penelitian ini bcrtujuan untuk mengetahui efek farmakologis daun meniran (Phyllanthus niruri Linn.) terhadap otot polos usus halus terpisah pada kelinci, dan dari hasil penelitian ini diharapkan dapat memberikan informasi kepada masyarakat tentang penggunaan daun meniran sebagai obat antidiare

EKSPLORASI TOKSISITAS AKUT INFUSUM BIJI KEDAWUNG

Dalam penelitian ini digunakan 40 mencit jantan bobot badan 20g-25g yang dibagi menjadi 4 kelompok, dan diberikan beberapa konsentrasi infus biji kedawung, berturut-turut larutan A: 20%, B: 40% dan C: 80%, kelompok D air digunakan sebagai kontrol. Setelah pemberia 1/2 jam, 1 jam, 2 jam, 3 jam, 4 jam, 5 jam, 6 jam, 24 jam dan 48 jam.Hasil menunjukkan tidak ada kematian, tidak ada pengaruh pada lakrimasi, salivasi, pilo ereksi, respirasi, dan konvulsi. Diare teramati secara jelas pada mencit kelompok C, 3 sampai 5 jam setelah pemberian. Diare tersebut berhent setelah 5-7 jam pada semua mencit