Destruction-free parameter extraction for a physics-based circuit simulator IGCT model

This paper presents a practical destruction-free parameter extraction methodology for a new physics-based circuit simulator buffer-layer Integrated Gate Commutated Thyristor (IGCT) model. Most key parameters needed for this model can be extracted by one simple clamped inductive-load switching experiment. To validate this extraction method, a clamped inductive load switching experiment was performed, and corresponding simulations were carried out by employing the IGCT model with parameters extracted through the presented methodology. Good agreement has been obtained between the experimental data and simulation results.

Improved chemical methods for extraction of fin rays from shark fins

A survey was undertaken of methods available for the extraction of fin rays from shark fins. The development of new, quicker and easier methods of processing is presented.

Extraction of fibre network architecture by X-ray tomography and prediction of elastic properties using an affine analytical model

This paper proposes a method for extracting reliable architectural characteristics from complex porous structures using micro-computed tomography (μCT) images. The work focuses on a highly porous material composed of a network of fibres bonded together. The segmentation process, allowing separation of the fibres from the remainder of the image, is the most critical step in constructing an accurate representation of the network architecture. Segmentation methods, based on local and global thresholding, were investigated and evaluated by a quantitative comparison of the architectural parameters they yielded, such as the fibre orientation and segment length (sections between joints) distributions and the number of inter-fibre crossings. To improve segmentation accuracy, a deconvolution algorithm was proposed to restore the original images. The efficacy of the proposed method was verified by comparing μCT network architectural characteristics with those obtained using high resolution CT scans (nanoCT). The results indicate that this approach resolves the architecture of these complex networks and produces results approaching the quality of nanoCT scans. The extracted architectural parameters were used in conjunction with an affine analytical model to predict the axial and transverse stiffnesses of the fibre network. Transverse stiffness predictions were compared with experimentally measured values obtained by vibration testing. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A new method for venom extraction from venomous fish, green scat

Scatophagus argus argus (Green Scat) is a pretty aquarium fish. Its hard spines are venomous and can cause painful injury. In this study 60 specimens of Green Scat were collected periodically from coastal waters of Boushehr (south of Iran) from May 2011 to April 2012. Anatomical features of venomous spines were investigated. Scat venom was extracted from the spines in a new manner for keeping the specimens alive. The nature of venom was tested by SDS-PAGE. Ethical issues and animal welfare principles such as rapid and instantaneous anesthetizing, post operation disinfection and fast recovery of the specimens was practiced in order to minimize the complications. This method enhanced the purity and quantity of venom as demonstrated by 12 separated proteins in electrophoresis. New ethical issues were developed to surviving the specimens and prolong viability as well.

Shark fin rays: technology of extraction

A simple process is described for extraction of rays from shark fins. The process consists in treating the rays with acetic acid to soften the tissue, separation of the rays by hand and drying. White fins yield almost double the quantity of rays compared to black fins.

Extraction, PCR amplification, and sequencing of mitochondrial DNA from scent mark and feces in the giant panda

To expand the feasibility of applying simple, efficient, non-invasive DNA preparation methods using samples that can be obtained from giant pandas living in the wild, we investigated the use of scent markings and fecal samples. Giant panda-specific oligonucleotide primers were used to amplify a portion of the mitochondrial DNA control region as well as a portion of the mitochondrial DNA cytochrome b gene and tRNA(Thr) gene region. A 196 base pair (bp) fragment in the control region and a 449 bp fragment in the cytochrome b gene and tRNA(Thr) gene were successfully amplified. Sequencing of polymerase chain reaction (PCR) products demonstrated that the two fragments are giant panda sequences. Furthermore, under simulated field conditions we found that DNA can be extracted from fecal samples aged as long as 3 months. Our results suggest that the scent mark and fecal samples are simple, efficient, and easily prepared DNA sources. (C) 1998 Wiley-Liss, Inc.

The extraction of mimosine from ipil-ipil (Leucaena leucocephala) by soaking in water

The study aimed to find a cheap and practical method of extracting mimosine from Leucaena leucocephala, otherwise known as ipil-ipil in the Philippines. L. leucocephala leaves are used in cattle, poultry and swine feed and have been tried as a food ingredient in some fish diets. While it contains relatively high amount of protein, its use as feed has been limited because of the presence of toxic substance, mimosine. Findings revealed that soaking the leaves in water was highly efficient for the extraction of mimosine, the longer the duration of soaking the more mimosine was extracted. On the other hand, 87 % of the juveniles Penaeus monodon fed with diets containing L. leucocephala leaves soaked for 24 hours survived, much higher compared to those that were fed with unsoaked leaves for eight weeks.

Extraction, purification and analysis of conotoxin of Conus textile captured from Persian Gulf and the investigation of analgesic effects of conotoxins in an animal model

Identification of venomous species of Persian Gulf cone snails and characterization of venom composition and their features is so important from the point of medical importance. Marine cone snails from the genus Conus are estimated to consist of up to 700 species. The venom of cone snails has yielded a rich source of novel neuroactive peptides or conotoxins. The present study was aimed to study the analgesic effect of Persian Gulf Conus textile and its comparison with morphine in mouse model. The specimens of Conus textile were collected of Larak Island from depth of 7 m. The collected samples were transferred to laboratory alive and were stored at -700 c. he veno s ducts were separated and ho ogenized with deionized water he ixture centrifuged at rp for inutes upernatant was considered as extracted veno and stored at - C after lyophylization. The protein profile of venom determined by using SDS-PAGE and HPLC used to investigate the extracted venom and to evaluate the analgesic activity, formalin test was carried out. SDS-PAGE indicated several bands ranged between 6 and 250 kDa. Chromatogram of the venom demonstrated more than 44 large and small fractions. The amount of 10 ng of Conus crude venom and analgesic peptide showed the best anti-pain activity in formalin test. No death observed up to 100 mg/kg, which is 250,000 times higher than the effective dose.Venom characterization of Persian Gulf Conus textile may be of medical importance and potential for new pharmaceutical drugs as well.

Venomics and biological analysis of Scatophagus argus argus (Spotted scat) venom isolated in Persian Gulf, extraction and purification of hemolytic protein

Green scat namely as Scatophagus argus argus is a venomous aquarium fish belonging to Scatophagidae family. It can induce painful wounds in injured hand with partial paralysis to whom that touch the spines. Dorsal and ventral rough spines contain cells that produce venom with toxic activities. According to unpublished data collected from local hospitals in southern coastal region of Iran, S. argus is reported as a venomous fish. Envenomation induces clinical symptoms such as local pain, partial paralysis, erythema and itching. In the present study green scat (spotted scat) was collected from Persian Gulf coastal waters. SDS-PAGE indicated 12 distinct bands in the venom ranged between 10-250 KDa. The crude venom had hemolytic activity on human erythrocytes (1%) with an LC100 (Lytic Concentration) of about 1.7 μg. The crude venom can release 813 μg proteins from 0.5% casein. Phospholipase C activity was recorded at 3.125 μg of total venom. Our findings showed that the edematic activity remained over 48 h after injection. The purification of the venom was done by HPLC and 30 peaks were obtained within 80 min but only one peak in 68 min retention time showed hemolytic activity at 90% acetonitril was isolated. The area percentage of the hemolytic protein showed that this hemolytic protein consist of 32 percent of total proteins and its molecular weight was 72 KDa in SDS_PAGE. The results demonstrated that crude venom extracted from Iranian coastal border has different toxic and enzymatic activities.

Extraction and structure elucidation of natural compounds of some gorgonians of the Persian Gulf and also physiological and pharmacological effects of gorgonian extract on some selected organisms

In the present research, investigations were carried out for structure elucidation of natural compounds and also for studing biological and teratogenical effects of two Genus of soft corals named as " Echinogorgia cf. indica" and "Sinularia erecta" in Persian Gulf. First, 350 gr Echinogorgia was extracted by Acetone, then, the extract was separated by ether from aqueos phase to give 4.5 gr oil. The oil eluted with Petrol - ether Et2 o (9:1) which was recovered Linderazulene and it's derivative as purple Cristals (350 mg/ca 0.1 %). In order to determine molecular structure, the Samples were used for spectroscopic method as: H1- NMR , C13- NMR and 2D NMR. Also, for extraction and structure elucidation of natural compounds, the soft coral " sinularia erecta " were used 1187/37 gr and extracted by Aceton. The extract was concentrated and resulting aqueous suspension and extracted by using ether to give 8.41 gr oil. The oil , was Chromatographed on a column of silica gel and some different fractions were gathered. Initial fraction (1-11) which were nonpolar compounds were seprated by GC/MS. Mass spectrum were prepared and much compounds were recognized.

Parameter extraction and calorimetric validation for a silicon carbide jfet pspice model

This paper focuses on the PSpice model of SiC-JFET element inside a SiCED cascode device. The device model parameters are extracted from the I-V and C-V characterization curves. In order to validate the model, an inductive test rig circuit is designed and tested. The switching loss is estimated both using oscilloscope and calorimeter. These results are found to be in good agreement with the simulated results.

Treatment of Phaeodactylum tricornutum cells with papain facilitates lipid extraction.

Triacylglycerols (TAGs) from microalgae have the potential to be used for biodiesel, but several technical and economic hurdles have to be overcome. A major challenge is efficient extraction of intracellular TAGs from algae. Here we investigate the use of enzymes to deconstruct algal cell walls/membranes. We describe a rapid and simple assay that can assess the efficacy of different enzyme treatments on TAG-containing algae. By this means crude papain and bromelain were found to be effective in releasing TAGs from the diatom Phaeodactylum tricornutum, most likely because of their cysteine protease activity. Pre-treating algal biomass with crude papain enabled complete extraction of TAGs using heptane/isopropyl alcohol. Heptane as a single solvent was also effective, although complete recovery of TAG was not obtained. Economic implications of these findings are discussed, with the aim to reduce the complexity of, and energy needed in, TAG extraction.

Sparsity-Inducing Optimization Algorithm for the Extraction of Planar Structures in Noisy Point-Cloud Data

Most of the manual labor needed to create the geometric building information model (BIM) of an existing facility is spent converting raw point cloud data (PCD) to a BIM description. Automating this process would drastically reduce the modeling cost. Surface extraction from PCD is a fundamental step in this process. Compact modeling of redundant points in PCD as a set of planes leads to smaller file size and fast interactive visualization on cheap hardware. Traditional approaches for smooth surface reconstruction do not explicitly model the sparse scene structure or significantly exploit the redundancy. This paper proposes a method based on sparsity-inducing optimization to address the planar surface extraction problem. Through sparse optimization, points in PCD are segmented according to their embedded linear subspaces. Within each segmented part, plane models can be estimated. Experimental results on a typical noisy PCD demonstrate the effectiveness of the algorithm.