57 research outputs found
Modeling and Checking the Power Quality of High Pressure Sodium Vapor Lamp
High pressure sodium Vapor lamps due to long service life High Light, as the most comprehensive street lighting and industrial lighting Whose use is increasing day by day. One of the major drawbacks to these lamps is producing a lot of current harmonic. Therefore, check the Power Quality of these lamps becomes necessary. To check the quality of our lamps, it's necessary to express the exact model of these lamps. In this paper, we simulate a high-pressure lamp based on plasma physics equations. With this exact model, the power consumption of these lamps is considered by using THD and the results are compared with the standard values. In this paper, taking into account the magnetic ballast for a high-pressure sodium Vapor lamp, a precise simulation of these lamps was performed using the MATLAB / Simulink software
Printable Organic Thermoelectric Energy Harvesting Devices For Applications In Wearable Biomedical Devices
Thermal energy as an alternative renewable source of electricity can be used in a wide range of applications. Over the past decade, thermoelectric (TE) devices have emerged as potential candidates to convert thermal energy to electrical power. Due to the advantages of using organic TE materials over conventional TE generators, including light weight, low thermal conductivity, cost effectiveness, flexibility, and processability, they have become the subject of universal research in recent years.
Poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) is a promising candidate among other polymers to be used in TE modules due to its unique characteristics. Therefore, the focus on this thesis was to design and develop a thermoelectric energy harvesting module using only PEDOT: PSS as the active component. In addition, in order to test the performance of the module, a test setup was designed and developed particularly for the purpose of this work.
The performance of the TE device was evaluated by examining an induced voltage resulting from establishing a temperature difference across the two sides of the modules. It was observed that by increasing the temperature difference across the module, the generated voltage will also increase linearly reaching a maximum value of 280 μV for a 40 °C temperature difference.
The TE device developed in this work can be used as a power source in a wide range of applications from electronic devices to power supplies for distributed sensor networks in the Internet of Things. However, the main application is wearable medical devices in which the electricity is generated by thermoelectric conversion of body heat
Intratympanic Dexamethasone Delivery versus Placebo in Intractable Meniere Disease
Background: Numerous treatments strategies were used for Meniere disease (MD). In this study, we aimed to compare the efficacy of intratympanic dexamethasone versus intratympanic placebo in intractable MD.Methods: This was a single-blinded randomized clinical trial. All patients with Intractable MD underwent ventilation tube insertion into tympanic membrane and were randomly allocated to two groups of 18-patients. The patients of the first group used dexamethasone base drop (placebo) every other day, the second group used dexamethasone drop for 3 months, and all patients were followed for 12 months.Results: Control of vertigo and tinnitus with dexamethasone was more than the placebo, but there was no statistically significance difference between two groups (P > 0.05). Hearing function improvement and aural fullness resolution were higher in the placebo group, but there was no statistically significance difference, too (P > 0.05). Vertigo control in dexamethasone group in our study ranged from 72.2% to 83.3% of patients at different intervals. These figures ranged from 66.6% to 83.3% in placebo group. The highest rate of hearing function improvement in our study was 27.7% in placebo group. Tinnitus also followed the same pattern as hearing function.Conclusions: Intratympanic dexamethasone for MD is very satisfactory if medical treatment fails with good vertigo control and no risk to hearing
Relationship between Phosphatase and Tensin Gene Expression and Clinicopathologic Features of Breast Cancer in Patients who Underwent Biopsy or Breast Surgery
Background: Phosphatase and tensin (PTEN) gene is a tumor suppressor gene on chromosome 10q23 that is composed of 11 exons. Several studies have shown that loss of PTEN function is a common occurrence in breast cancer in particular in triple negative type, and it is significantly associated with age and higher stage of cancer. In this study, the expression of this gene in malignant breast cancer tissue samples and their correlation with clinicopathologic parameters was studied.Methods: In this retrospective study, 65 malignant tissue samples were chosen for immunohistochemistry (IHC) test. Other information about clinicopathologic features were collected from pathology reports and patients’ medical records. IHC on the selected paraffin blocks was performed, and the collected data were analyzed using SPSS software and chi-square test. P < 0.0500 was considered statistically significant.Results: PTEN expression rate in malignant breast tissue was 50.8% of the cases (33 out of 65 samples). Lack of PTEN expression had significant correlation with involvement of the lymph node sent by the sample, vascular or perineural invasion, metastasis and chemotherapy background, spontaneous malignancy presence, familial history, negative progesterone receptor, negative estrogen receptor, and positive her2/neu. No relationship was observed between the expression of PTEN with patients’ age, tumor size, age group of the patients after categorization into two groups of under 50 years and over 50 years, lesion location (left or right breast), and tumor grade.Conclusions: The results showed PTEN loss as a frequent event in breast cancer that is closely associated with progression and poor prognosis. PTEN loss might predict more aggressive behavior and worse outcomes in patients with breast cancer
Comparison between ideal and estimated pv parameters using evolutionary algorithms to save the economic costs
Micro grids are now emerging from lab modules sites into commercial markets, driven by technological improvements, falling costs, a proven track record, and growing recognition of their benefits. Their main contribution is to improve reliability and resilience of electrical grids, to manage the addition of distributed clean energy resources like wind and solar photovoltaic (PV) generation to reduce fossil fuel emissions, and to provide electricity in areas not served by centralized electrical infrastructure. In between, the popularity of photovoltaic panel is not deniable. In this paper, the ideal and practical electrical model of PV is being discussed. Due to significant role of the PV parameters, they are assessed by several heuristic methods and the results are compared. Hence an optimal method for parameter estimation is discussed that can be used in micro grid simulations to reach to an optimal quiescent working condition
Comparison between ideal and estimated pv parameters using evolutionary algorithms to save the economic costs
Micro grids are now emerging from lab modules sites into commercial markets, driven by technological improvements, falling costs, a proven track record, and growing recognition of their benefits. Their main contribution is to improve reliability and resilience of electrical grids, to manage the addition of distributed clean energy resources like wind and solar photovoltaic (PV) generation to reduce fossil fuel emissions, and to provide electricity in areas not served by centralized electrical infrastructure. In between, the popularity of photovoltaic panel is not deniable. In this paper, the ideal and practical electrical model of PV is being discussed. Due to significant role of the PV parameters, they are assessed by several heuristic methods and the results are compared. Hence an optimal method for parameter estimation is discussed that can be used in micro grid simulations to reach to an optimal quiescent working condition
3D-printed calcium phosphate-based scaffolds: The role of pore geometry on the in vitro biological behavior
editorial reviewe
Coronary Artery Bypass Grafting: Simultaneous Head and Neck Mass Surgery
Background: Coronary artery disease (CAD) and cancer have common risk factors. According to the necessity of mass resection in patients with CAD at the same time, we decided to do neck and head mass resection and coronary artery bypass grafting (CABG) simultaneously and assess the results.Methods: The current study was done on patients who were candidates for simultaneous head and neck mass resection and CABG. The patients’ files were extracted, the information and complications were recorded in a questionnaire, and then necessary data were extracted.Results: Totally 9 patients (3 females and 6 males) with a mean age of 69.11 ± 6.67 standard deviation years were studied. The most common site of squamous cell carcinoma in this study was tongue. Infection occurred in three patients, two of which (66.66%) died. Side effects occurred in four patients.Conclusions: It seems that, according to the anatomical position of neck mass, proximity to the airways and large blood supply in that area, and also because of inappropriate access to the anatomical zones, the survival rate and complications in this surgical setting (simultaneous surgeries) are different from that of other studies. It seems that further studies are needed to be done with the subject of concomitant head and neck mass surgery and CABG this time with a larger number of patients
The effect of pore architecture in calcium phosphate additively manufactured scaffolds
The effect of pore architecture on Cell-ECM formation in hydroxyapatite bone scaffolds in 3D perfusion culture
editorial reviewe
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