31 research outputs found

    Solution to Secondary Sedimentation Problem by Spreadsheet and VBA

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    The sedimentation process is one of the most commonly used processes in environmental engineering. Modelling and simulation of secondary sedimentation units usually requires writing mass balance equations for each layer of the settler. Then, the set of ordinary differential equations (ODEs) is solved to obtain solids concentration in each layer of the sedimentation tank. This paper presents implementation of an MS Excel add-in for solving the secondary settling problem. The add-in contains a number of Visual Basic for Applications (VBA) functions, which can be used directly on the worksheet. It is capable of calculating steady-state solution by the multivariate Newton-Raphson method. Also, the add-in is equipped with a VBA function that integrates the set of ODEs until a certain time specified by the user, providing an option for dynamic simulation of the sedimentation tank. The author uses the add-in for teaching settling models in an environmental modelling course. Both students and teachers can benefit from the tool

    An Extraordinary Cause of the Sucking Difficulty: Ecthyma Gangrenosum

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    Ecthyma gangrenosum is a cutaneous lesion often associated with pseudomonas aeruginosa bacteremia, even though it may develop without bacteremia and may originate from other bacterial and fungal organisms. Pseudomonas aeruginosa bacteremia or sepsis, which mainly affects immunocompromised patients, frequently occurs in hospitals. This lesion typically occurs on the extremities and gluteal and perineal regions. In this report we present a case of ecthyma gangrenosum in a premature newborn occurring secondary to pseudomonas sepsis causing sucking dysfunction due to tissue loss in the lip, soft palate, and tongue

    An MS Excel Add-in for Calculating Darcy Friction Factor

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    An MS Excel add-in was prepared for calculating Darcy friction factor. The tool contains a function named “FFACTOR” and it calculates friction factor under laminar, transient, and turbulent conditions. Under turbulent conditions, the function employs a total of 25 friction factor models and the user can select one of these to calculate Darcy friction factor. Tip texts and pop-up help were also prepared and are available if open-source Excel-DNA Intellisense add-in is also added to MS Excel. The students can benefit from the MS Excel add-in. Also, professors can use it for teaching purpose

    New insight into anti-wrinkle treatment: Using nanoparticles as a controlled release system to increase acetyl octapeptide-3 efficiency

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    Botulinum neurotoxins represent a revolution in cosmetic science because of their extraordinary and long-term anti-wrinkle properties. Nevertheless, high neurotoxicity severely limits their usage. Therefore, design and validation of new non-toxic molecules which mimics the Botox are needed. Here, acetyl octapeptide-3 is used which mimics the effect mechanism of botulinum neurotoxin to reduces the depth of wrinkles, was chosen as an alternative molecule. Glutamic acid containing poly(2-hydroxyethyl methacrylate–methacryloylamidoglutamic acid) [p(HEMAG)] nanoparticles were synthesized for controlled release of acetyl octapeptide-3 to increase the efficiency on the related area. Scanning electron microscopy and atomic force microscopy were used to state the morphological characteristics of the synthesized nanoparticles, and the Fourier transform infrared was used to characterize chemical structures; additionally, the dimensional analysis was carried out by using a zeta-sizer device, and then, characterized nanoparticles were used for loading acetyl octapeptide-3. Time, pH, ionic strength, temperature and concentration experiments were performed to optimize the adsorption conditions of the acetyl octapeptide-3 to the nanoparticles. The maximum acetyl octapeptide-3 adsorption capacity onto nanoparticles was found 220.69 mg/g. The pH and temperature experiments were carried out to follow-up the release conditions of acetyl octapeptide-3-loaded nanoparticles. Lastly, cytotoxicity tests were done by using Alamar Blue method and Lactate Dehydrogenase (LDH) Assay. Our results imply that the developed nanocosmetic material is non-toxic, efficient and cost-effective and it is promising to use in anti-wrinkle treatment. Graphical abstract: [Figure not available: see fulltext.]

    Meteorological parameters as an important factor on the energy recovery of landfill gas in landfills

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    The effect of meteorological factors on the composition and the energy recovery of the landfill gas (LFG) were evaluated in this study. Landfill gas data consisting of methane, carbon dioxide, and oxygen content as well as LFG temperature were collected from April 2009 to March 2010 along with meteorological data. The data set were, first, used to visualize the similarity by using self-organizing maps and to calculate correlation factors. Then, the data was used with ANN to further analyze the impacts of meteorological factors. In both analysis, it is seen that the most important meteorological parameter effective on LFG energy content is soil temperatures. Furthermore, ANN was found to be successful in explaining variations of methane content and temperature of LFG with correlation coefficients of 0.706 and 0.984, respectively. ANN was proved itself to be a useful tool for estimating energy recovery of the landfill gas. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769202

    Associations between the standardized uptake value of F-18-FDG PET/CT and demographic, clinical, pathological, radiological factors in lung cancer

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    Objectives: F-18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is extensively used to diagnose and stage of lung cancer. The aim of the current study was to investigate the correlation of demographic, clinical, pathological and radiological factors with primer tumor FDG Uptake in patients with lung cancer. Materials and methods: This cross-sectional, clinical study was performed on a total of 57 lung cancer patients newly diagnosed that underwent FDG PET/CT. In addition to descriptive variables, histopathological diagnosis, tumor site and size, hemoglobin level, red cell distribution width, neutrophil to lymphocyte ratio were noted for each patient. The correlation of these variables to SUVmax values in FDG PET/CT was investigated. Results: A total of 57 patients (4 women, 53 men) with an average age of 60.8 +/- 9.4 (range: 33-89) participated in the study. Histopathological diagnoses were consistent with squamous cell carcinoma (28, 49.1%), adenocarcinoma (15, 26.3%) and small cell cancer (14, 24.6%). The SUVmax of primary tumor was positively correlated with tumor size (P<0.001). The tumor SUVmax of squamous cell carcinoma (SqCC) (17.49 +/- 8.37) was higher than that of adenocarcinoma (AC) (12.80 +/- 4.77) and small cell carcinoma (SCC) (12.40 +/- 5.80) (P=0.038). Conclusion: SUVmax value was significantly higher for squamous cell carcinoma and it SUVmax values in PET scans was found to be positively correlated with tumor size. This study suggests that, tumor size and histologic subtype had influences upon FDG uptake in lung cancer

    Case Report An Extraordinary Cause of the Sucking Difficulty: Ecthyma Gangrenosum

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    Ecthyma gangrenosum is a cutaneous lesion often associated with pseudomonas aeruginosa bacteremia, even though it may develop without bacteremia and may originate from other bacterial and fungal organisms. Pseudomonas aeruginosa bacteremia or sepsis, which mainly affects immunocompromised patients, frequently occurs in hospitals. This lesion typically occurs on the extremities and gluteal and perineal regions. In this report we present a case of ecthyma gangrenosum in a premature newborn occurring secondary to pseudomonas sepsis causing sucking dysfunction due to tissue loss in the lip, soft palate, and tongue

    Does Wide Excisional Biopsy in Skin Cancer Prevent Finding The Real Sentinel Lymph Node?

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    Purpose/Aim: The presence of nodal metastasis is an important prognostic factor for malignant melanoma and causes a 50% decrease in survival. Patients found not to have lymph node metastasis as a result of sentinel lymph node biopsy but develop regional lymph node metastasis in the follow-up period are called false negative sentinel. The hypothesis of this study was that excisional biopsy in patients with large lesions may change the lymphatic pathway and therefore cause false negative results. Materials & Methods: A total of 40 Sprague-Dawley rats were divided into 4 groups: the control group, Group 1 (10 mm excision), Group 2 (15 mm lesion excision), and Group 3 (20 mm excision). Sentinel lymph nodes were found via imaging with nanocolloidal albumin including 99mTc and indocyanine green (ICG) before the excision and at 3 weeks after the excision. Evaluations were performed to determine whether or not they were the same nodes. Results: The false sentinel node detection rate in Group 3 was significantly higher than in both the control group and Group 1 (p < 0.05). No significant difference was detected between Group 2 and 3 according to false sentinel node detection rate. There were differences between preoperative and postoperative detection of sentinel lymph nodes found by radioactive and ICG methods but no significant difference was detected in the Kappa agreement coefficient. Conclusion: It can be suggested that incisional biopsy is performed on large lesions initially, followed by wide excision combined with SLNB at the second stage. This can help to prevent changes in the lymphatic pathway and therefore to decrease false negativity rates caused by the previous surgery
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