7 research outputs found

    Impact damage on a thin glass plate with a thin polycarbonate backing

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    We present experimental and computational results for the impact of a spherical projectile on a thin glass plate with a thin polycarbonate backing plate, restrained in a metal frame, or in the absence of the frame. We analyze the dependence of the damage patterns in the glass plate on the increasing impact velocities, from 61 m/s to 200 m/s. Experimental results are compared with those from peridynamic simulations of a simplified model. The main fracture patterns observed experimentally are captured by the peridynamic model for each of the three projectile velocities tested. More accurate implementation of the actual boundary conditions present in the experiments will likely further improve modeling of brittle damage from impact on a multi-layered system. The peridynamic computational model sheds light into the early stages of the complex brittle damage evolution in the glass layer, and the influence of boundary conditions on the dynamic fracture process

    Study on the Chemical Modification Process of Jute Fiber

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    Degumming of pre-chlorite treated jute fiber was studied in this paper. The effects of sodium hydroxide concentration, treatment time, temperature, sodium silicate concentration, fiber-to-liquor ratio, penetrating agent TF-107B concentration and degumming agent TF-125A concentration were the process conditions examined. With respect to gum decomposition, fineness and mechanical properties, sodium hydroxide concentration, sodium silicate concentration and treatment time were found to be the most important parameters. An orthogonal L9(34) experiment designed to optimize the conditions for degumming resulted in the selection of the following procedure: sodium hydroxide of 12g/L, sodium silicate of 3g/L, TF-107B of 2g/L, TF-125A of 2g/L, treatment time of 105 min, temperature of 100℃ and fiber to liquor ratio of 1:20. The effect of the above degumming process on the removal of impurities was also examined and the results showed that degumming was an effective method for removing impurities, especially hemicellulose

    Detection of cervical cancer and high grade neoplastic lesions by a combination of liquid-based sampling preparation and DNA measurements using automated image cytometry. Cellular Oncology 27

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    Abstract. Objective: To establish if measurements of DNA ploidy could be used to assist cytopathologists and cytotechnologists in population based cervical cancer screening programs in countries where manually reading the slides is impossible due to the lack of sufficient skilled cytotechnologists. The goal of such program is to identify only clinically significant lesions, i.e. those where a clinical intervention to remove the lesion is required immediately. Study design: A total of 9905 women were enrolled in the study. Cervical samples were taken with a cervix brush that was then placed into a fixative solution. The cells were separated from mucus by mechanical and chemical treatment and then deposited onto microscope slides by a cytocentrifuge. Two slides were prepared from each case; one slide was stained by Papanicolaou stain for manual cytology examination, while the other slide was stained by a DNA specific stain. The latter slide was used to determine the relative amount of DNA in the cell nuclei. Results: A total of 876 women were followed by colposcopy examination where biopsies were taken from the visible lesions or from suspicious areas and histopathology diagnosed 459 as normal or benign cases, 325 as CIN1, 36 as CIN2, 25 as CIN3/CIS, and 31 as invasive cancer. Of these 876 cases, manual cytology called 655 normal or ASCUS, 197 as LSIL, 16 cases as HSIL, and 8 as cancer. DNA measurements found 704 cases having no cells with DNA greater than 5c, 98 cases where there were 1 or 2 cells having DNA amount greater than 5c, and 74 cases where there were 3 or more cells having DNA amount greater than 5c. If manual cytology were to be used to refer all cases of HSIL and cancer to colposcopy and biopsy, 23 lesions that had to be removed would have been discovered (2 CIN2, 11 CIN3/CIS, and 10 cancers), for a sensitivity of 25.0 ± 5.2% at specificity of 99.9 ± 0.1%. If DNA assisted cytology were to be used instead, and all cases having 3 or more cells with DNA amount greater than 5c were to be referred to colposcopy and biopsy, then 50 lesions that had to be removed would have been discovered (10 CIN2, 15 CIN3/CIS and 25 cancers) for the sensitivity of 54.3 ± 6.2% at specificity of 96.9 ± 0.6%. Conclusions: The study suggests that screening for high grade cervical neoplastic lesions and cervical cancer by DNA assisted cytology could be implemented with minimal use of skilled cytotechnologists, at least in those countries where it would be difficult to introduce population based screening for cervical cancer due to the lack of availability of such skilled cytotechnologists

    Characteristic and surgical results of multisegment intramedullary cervical spinal cord tumors

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    Background: To evaluate the clinical characteristic, microsurgical treatment and outcomes of patients with multi-segment intramedullary cervical spinal cord tumors (MSICCT). Materials and methods: Prospective single center cohort study. 63 patients underwent microsurgery for MSICCT. Pre and postoperative function were assessed using the modified McCormick's grade, IJOA scoring system, and analyzed using the appropriate statistical tests. Results: 41 males, 22 females, three spinal segments were involved in 22(35%) cases, four or more in 41(65%) of cases. Majority of the tumors were ependymoma (54%), followed by astrocytoma (low grade 25%, high grade 8%). McCormick's grade: I&II in 40 patients (64%). There was no statistical difference between preoperative and three-month postoperative IJOA scores (P = 0.76), indicating no significant neurological deterioration after surgery. The extent of surgical resection was highly correlated to histological tumor type of MSICCT (χ2 = 34.82, P = 0.0001) and three-month postoperative IJOA scores (F = 2.62, P = 0.006). There is a high proportion of total resection in ependymomas, haemangioblastomas, cavernomas and schwannoma, whereas, we only achieved partial resection in most gliomas. With a mean follow up of 5.5 years (3 months–more than 12 years), clinical outcome improved or stabilized in 91% of cases (80% improved, 11% stabilized, 9% deteriorated). Conclusion: This series of MSICCT showed that high extent of surgical resection could be achieved in most ependymomas with good long-term outcome. Astrocytomas, in contrary remained challenging with 25% achieved gross total resection. Overall, compared to previous surgical series, we showed encouraging improvement in the clinical outcome of these patients managed surgically

    Graphenes as Potential Material for Electronics

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