77 research outputs found

    Impacts of nano-clay particles and heat-treating on out-of-phase thermo-mechanical fatigue characteristics in piston aluminum-silicon alloys

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    Abstract. In this article, the effect of nano-clay particles and heat-treating on thermo-mechanical fatigue (TMF) behaviors and failures of piston aluminum-silicon (AlSi) alloys was investigated. For this purpose, thermo-mechanical fatigue tests were conducted under out-of-phase (OP) loading conditions. Two loading conditions were checked based on different maximum temperatures (250, 300, and 350 °C) and various thermo-mechanical loading factors (100, 125, and 150%). The minimum temperature was constant in all tests at 50 °C under a heating/cooling rate of 10 °C/s and a dwell time of 5 s. Results showed that the nano-composites had a longer fatigue lifetime, at least 2 times higher, compared to the Al alloy, when the maximum temperature was 250 °C and the thermo-mechanical loading factor was 100%. However, no effective change was seen for the stress value and the plastic strain. At higher maximum temperatures, the change in the material behavior was lower. The fracture analysis by scanning electron microscopy (SEM) demonstrated that both materials had a brittle behavior due to cleavage and quasi-cleavage marks. The damage mechanism was also due to the Si-rich phase and intermetallics, respectively for the crack propagation and the micro-crack initiation

    Low Iris and Anterior Chamber Volume Associated with Deepening after Laser Peripheral Iridotomy in Primary Angle Closure Suspects

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    Purpose: To evaluate the association between baseline ocular variables and the opening of the anterior chamber angle by laser peripheral iridotomy (LPI) in primary angle closure suspects (PACS) using a new Fourier-domain swept-source anterior segment optical coherence tomography (FD-ASOCT). Method: Sixty-six PACS eyes of 41 individuals were included in this prospective interventional case series. An FD-ASOCT (Casia SS-1000 OCT; Tomey, Nagoya, Japan) was used to measure biometric baseline variables and at one month after the LPI. Paired t-test was used to compare the difference between pre-and post-LPI measurements. Multivariate regression analysis was used to test for an association between baseline iris thickness and volume, anterior chamber depth and volume, and lens vault with a widening of the angle after an LPI. Results: The mean age of participants was 58.6 ± 8.7 years, 682% of whom were female. The angle opening distance, recess area and trabecular iris surface area at 500 microns increased by 48 to 73% (all p<0.001). Lens vault and iris volume did not change. A low anterior chamber volume and low iris volume were associated with angle greater deepening by LPI. Conclusion: Eyes with a shallow anterior chamber and thinner irises are more likely to experience angle opening from an LPI

    Removal of styrene from waste gas stream using a biofilter

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    280 tyrene is produced in large quantities in the chemical industries and its monomer constitutes the building block for the production of polystyrene, styrene copolymers, polyester resins, and rubber. It is also used in the production of fiberglass boats, storage tanks, pipes, shower units and car parts. Besides the known industrial releases from the production and processing units, styrene is also generated in smaller quantities from other sources such as natural microbial and fungal metabolism, cigarette smoke, automobile exhaust, and the pyrolysis and cracking of petroleum and its derivatives S Original Article Removal of styrene from waste gas stream using a biofilter B. Bina*, R.Dehghanzadeh *, H. Pourmoghadas *, A.Kalantary *, A.Torkian** ABSTRACT Background: Styrene is produced in large quantities in the chemical industries and it has been listed among the 189 hazardous and toxic atmospheric contaminants under Clean Air Act Amendments, 1990, due to its adverse effects on human health. The biofiltration has been widely and efficiently applied during recent decades for the treatment of air streams contaminated by volatile organic compounds at low concentrations. Also this technology has been applied widely and efficiently in the removal of styrene from waste gas streams

    Association between depression, anxiety, and insomnia with musculoskeletal pain source: a multi-center study

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    Background: Musculoskeletal pain syndrome (MPS) is one of the modern diseases. Musculoskeletal pain (MP) may develop at any age and impact physical and mental health. This study aimed to evaluate the association between anxiety, depression, and insomnia with musculoskeletal pain source. This cross-sectional study was conducted on 450 patients with musculoskeletal pain. Goldberg depression (GB), Beck Anxiety Inventory (BAI), and Morin Insomnia Severity Index (ISI) questionnaires were used to collect data. Participants have divided into two groups: individuals with unknown musculoskeletal pain sources and individuals with known musculoskeletal pain sources. Anxiety, depression, and insomnia scores were compared between the two groups. For statistical analysis of data mean (SD), frequency (), Chi-square, Mann-Whitney test, and Logistic regression models were used. All analysis was performed using SPSS 26. Results: In this study, 39.4 of the participants were in severe depression, 31.1 in severe anxiety, 34.7 in the no clinically significant, and 32.9 in the sub-threshold insomnia group. There was a significant difference between the severity of anxiety and insomnia in the two groups with the known and unknown pain sources (p < 0.05). However, the score of depression (OR = 1.00, 95 CI 0.99�1.01), anxiety (OR = 1.00, 95 CI 0.99�1.02), and insomnia (OR = 1.01, 95 CI 0.98�1.03) was not related to the pain source. Conclusion: There was a statistically significant relationship between anxiety and insomnia severity with musculoskeletal pain source. According to the high prevalence of depression, anxiety, and depression in both groups with known and unknown musculoskeletal pain sources, the cooperation of orthopedists, rheumatologists, and physical therapists with psychiatrist can be useful in improving the condition of patients. © 2021, The Author(s)

    Diagnostic pitfalls in fine needle aspiration of solitary pulmonary nodules: two cases with radio-cyto-histological correlation

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    BACKGROUND: Fine needle aspiration is an important tool for diagnosis and preoperative evaluation of solitary nodules of the lung. It provides a definitive diagnosis in most patients at low cost with minimal trauma. However, because of the nature of the study and the presentation of the cells in a more distorted and incomplete tissue structure than a histological slide, false positive results can occur. Prior detailed clinical knowledge about the patient, procedures and methods of radiology in obtaining the aspirate specimen is extremely useful in the accurate interpretation of fine needle cytological specimens. CASE PRESENTATION: We report two cases of solitary pulmonary nodules in two elderly females, which were initially diagnosed as malignant by fine needle aspiration biopsy. Both cases subsequently underwent pulmonary lobectomy in which, one turned out to be a pulmonary hamartoma and the other appeared to be a middle lobe syndrome of the right lung with liver tissue contamination at the time of fine needle aspiration of the lung. CONCLUSIONS: We are now strong believers that much care must be taken in the interpretation of fine needle aspiration of solitary nodules of the lung. Complete study of the entire specimen, including the cell block, is warranted, since what one interprets as malignant, could have different features in another part of the sample. Last but not the least, prior knowledge of the complete clinical history of the patient together with the salient radiological findings would greatly facilitate the cytopathologist to reach an accurate diagnosis

    Impacts of nano-clay particles and heat-treating on out-of-phase thermo-mechanical fatigue characteristics in piston aluminum-silicon alloys

    Get PDF
    Abstract. In this article, the effect of nano-clay particles and heat-treating on thermo-mechanical fatigue (TMF) behaviors and failures of piston aluminum-silicon (AlSi) alloys was investigated. For this purpose, thermo-mechanical fatigue tests were conducted under out-of-phase (OP) loading conditions. Two loading conditions were checked based on different maximum temperatures (250, 300, and 350 °C) and various thermo-mechanical loading factors (100, 125, and 150%). The minimum temperature was constant in all tests at 50 °C under a heating/cooling rate of 10 °C/s and a dwell time of 5 s. Results showed that the nano-composites had a longer fatigue lifetime, at least 2 times higher, compared to the Al alloy, when the maximum temperature was 250 °C and the thermo-mechanical loading factor was 100%. However, no effective change was seen for the stress value and the plastic strain. At higher maximum temperatures, the change in the material behavior was lower. The fracture analysis by scanning electron microscopy (SEM) demonstrated that both materials had a brittle behavior due to cleavage and quasi-cleavage marks. The damage mechanism was also due to the Si-rich phase and intermetallics, respectively for the crack propagation and the micro-crack initiation

    Impact of Same-Session Trabectome Surgery on Ahmed Glaucoma Valve Outcomes

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    Purpose: To evaluate the efficacy and survival rates of same session ab interno trabeculectomy with the trabectome and Ahmed glaucoma valve implant (AT) in comparison to the Ahmed glaucoma valve alone (A). Method: A total of 107 eyes undergoing primary glaucoma surgery were enrolled in this retrospective comparative case series, including 48 eyes which underwent AT and 59 eyes which received A alone. Participants were identified using the procedural terminology codes, and their medical records were reviewed. The primary outcome measure was surgical success, defined as intraocular pressure (IOP) > 5 mmHg, ≤ 21 mmHg, and IOP reduction ≥ 20% from baseline at two consecutive visits after three months, no reoperation for glaucoma. Secondary outcome measures were IOP, the number of glaucoma medications, incidence of a hypertensive phase, and best corrected visual acuity (BCVA). Results: The cumulative probability of success at one year was 70% in AT, and 65% in A (p=0.85). IOP decreased significantly from 26.6 ± 10.1 mmHg at baseline to 14.7 ± 3.3 mmHg at the final follow-up in AT (p= 0.001). The corresponding numbers for A were 28.8 ± 10.2 and 16.7 ± 4.9, respectively (p= 0.001). The final IOP was significantly lower in AT (p= 0.022). The number of medications at baseline was comparable in both groups (2.6 ± 1.2 in AT and 2.5 ± 1.3 in A, p=0.851). Corresponding number at 1 year visit was 1.2±2 in AT and 2.8±1.8 in A (p=0.001). The incidence of a hypertensive phase was 18.7% in AT and 35.5% in A (p=0.05). HP resolved in only 30% of eyes. The criteria for HP resolution were fulfilled in 9 eyes (30%). There was no difference in the rate of resolution of the hypertensive phase between AT and A (33.3% and 28.5%, respectively, p=0.67). Conclusion: Ahmed glaucoma valve implant with same session trabectome surgery significantly decreased the rate of the hypertensive phase and postoperative IOP as well as the number of glaucoma medications

    Primary de novo malignant giant cell tumor of kidney: a case report

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    BACKGROUND: Osteoclast-like giant cell tumors are usually observed in osseous tissue or as tumors of tendon sheath, characterized by the presence of multinucleated giant cells and mononuclear stromal cells. It has been reported in various extraosseous sites including breast, skin, soft tissue, salivary glands, lung, pancreas, female genital tract, thyroid, larynx and heart. However, extraosseus occurrence of such giant cell tumors in the kidney is extremely rare and is usually found in combination with a conventional malignancy. De-novo primary malignant giant cell tumors of the kidney are unusual lesions and to our knowledge this is the second such case. CASE PRESENTATION: We report a rare case of extraosseous primary denovo malignant giant cell tumor of the renal parenchyma in a 39-year-old Caucasian female to determine the histogenesis of this neoplasm with a detailed literature review. CONCLUSION: Primary denovo malignant giant cell tumor of the kidney is extremely rare. The cellular origin of this tumor is favored to be a pluripotential mesenchymal stromal cell of the mononuclear/phagocytic cellular lineage. Awareness of this neoplasm is important in the pathological interpretation of unusual findings at either fine needle aspiration or frozen section of solid renal masses

    Rotating biological contactors : a review on main factors affecting performance

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    Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a Ciência e a Tecnologia (FCT

    Slaughterhouse Wastewater Treatment by Combined Chemical Coagulation and Electrocoagulation Process

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    Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater
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