255 research outputs found
Suitability of viscosity measurement methods for liquid food variety and applicability in food industry - A review.
Although there are several approaches to measure viscosity of liquid foods in the literature, the successful selected technique depends on the specific product and the functional characteristics that need to be analyzed. Accordingly, it is not an easy task for food technologists to determine the suitable approach to be used. Therefore briefing the existing methods, working principles, advantages, limitations and their successful applications for well known published articles, may enable the researchers to choose the optimum approach. The intensive review revealed that the most commonly used viscosity measurement devices are capillary flow viscometers, orifice type viscometers, falling ball viscometers, and rotational viscometers. Glass capillary viscometers are widely used for measuring low to medium viscosity of Newtonian fluids. In order to measure the viscosity of difficult fluids like those having large particles non-conventional geometries such as mixer viscometry method is used. Tube viscometer method which might be considered as a wide-bore capillary viscometer with a special capability to handle suspensions is currently used to determine rheological behaviour of a product after a thermal treatment. Scraped surface heat exchangers (SSHE) are widely used in food industry for thermal treatment of very viscous food products. Mass detecting capillary viscometer is a new technique to measure the viscosity of milk and soymilk products. In order to measure the viscosity of food stabilizers coaxial viscometers are recommended. Also, possibly the best known of the orifice viscometers in the food industry is the dipping-type Zahn viscometer. Finally, it could be inferred that the viscosity ought to be independent on the instrument, so different instruments will yield the same results, but this is a theoretical concept and different instruments rarely yield identical results
Electrothermal Design of a GaN-Based Axially Stator Iron-Mounted Fully Integrated Modular Motor Drive
The concept of More Electric Aircraft (MEA) has gained a lot of attention from researchers recently. For such an application, two of the pivotal requirements are having a power dense and energy efficient propulsion system. To that end, in the design procedure of the electric motor and its drive system, high power density and efficiency over the entire operating range is the ultimate goal. Thus, the integration of the electric motor and drive system into a single unit has been introduced as an effective method to meet the design objectives. Therefore, this paper presents the design procedure of a module of an Integrated Modular Motor Drive (IMMD). Electrothermal design of the GaN single phase full bridge inverter module has been conducted and the results are discussed. The analysis includes the thermal investigation of the WBG semiconductors by sweeping the number of parallel devices in each switch position at different switching frequencies. Furthermore, a single drive PCB module is designed and evaluated in ANSYS Q3D for parasitic extraction. Finally, double pulse test (DPT) is performed to verify the optimal design of PCB busbar
Community seismic network and localized earthquake situational awareness
Community-hosted seismic networks are a solution to the need for large numbers of sensors to operate over a seismically active region in order to accurately measure the size and location of an earthquake, assess resulting damage, and provide alerts. The Community Seismic Network is one such strong-motion network, currently comprising hundreds of elements located in California. It consists of low-cost, three-component, MEMS accelerometers capable of recording accelerations up to twice the level of gravity. The primary product of the network is to produce measurements of shaking of the ground and multiple locations of every upper floor in buildings, in the seconds during and following a major earthquake. Each sensor uses a small, dedicated ARM processor computer running Linux, and analyzes time series data in real time at hundreds of samples per second. The network reports on shaking parameters that indicate intensity of the structural response levels such as maximum floor acceleration and velocity, displacement of a floor in a building, as well as data products that depend on the response time histories. To do this, Cloud computing has been expanded through the use of statically defined subsets of sensors called cloudlets. These are smaller subsets of similar sensors that carry out customized calculations for those locations. The measurements are reported as rapidly as possible following an earthquake so that they may be incorporated into structural diagnosis and prognosis applications that can be used by first responders to prioritize their initial disaster management efforts. The cloudlet displays are customized for specific buildings and they show in real time: instantaneous displacement, inter-story drift, and resonant frequency and mode shapes using system identification software tools. The real-time display products are useful for decision-making about whether the potential for damage exists, what level of damage may have occurred and where, and whether total business disruption is necessary. City-wide dense monitoring makes it possible for emergency response managers to prioritize the target locations requiring first response on a block-by-block scale based on reports of shaking intensity
Application of NRCS-curve number method for runoff estimation in a mountainous watershed
The major problem in the assessment of relationships between rainfall and runoff occurs when a study is
carried out in ungauged watersheds in the absence of hydro-climatic data. This study aims to evaluate the
applicability of Natural Resources Conservation Service-Curve Number (NRCS-CN) method together with
GIS in estimating runoff depth in a mountainous watershed. The study was carried out in the semi-arid
Kardeh watershed which lies between 36º 37´ 17˝ to 36º 58´ 25˝ N latitude and 59º 26´ 3˝ to 59º
37´ 17˝ E
longitude, about 42 km north of Mashhad, Khorasan Razavi Province, Iran. The hydrologic soil groups,
land use and slope maps were generated with GIS tools. The curve number values from NRCS Standard
Tables were assigned to the intersected hydrologic soil groups and land use maps to generate CN values
map. The curve number method was followed to estimate runoff depth for selected storm events in the
watershed. Nash-Sutcliffe efficiency, pair-wise comparison by the t-test, Pearson correlation and percent
error were used to assess the accuracy of estimated data and relationship between estimated and observed
runoff depth. The results showed relatively low Nash-Sutcliffe efficiency (E = – 0.835). There was no
significant difference between estimated and observed runoff depths (P > 0.05). Fair correlation was
detected between estimated and observed runoff depth (r = 0.56; P < 0.01). About 9% of the estimated
runoff values were within ±10% of the recorded values and 43% had error percent greater than ±50%. The
results indicated that the combined GIS and CN method can be used in semi-arid mountainous
watersheds with about 55% accuracy only for management and conservation purposes
The trend of changes in depression, anxiety and stress in men with lower limb trauma: A prospective study
Introduction: Activity restrictions can have potential impacts on the prevalence of mental disorders. However, in patients with lower limb traumas the problems and the physical disabilities are usually taken more into consideration than mental status, while they refer for further examinations. Therefore, this study is aimed to investigate the changes in the process of depression, anxiety and stress in men with lower limb traumas. Materials and Methods: In a prospective study the patients with lower limb traumas, who have been hospitalized in Amir Al-Mo�menin and Kowsar hospitals in Semnan since June 2012 to August 2015, were selected randomly and studied. The data was collected by demographic and incident questionnaire and depression, anxiety and stress questionnaire. At first the patients were asked to complete the questionnaires based on their psychological experience of one month prior to the trauma. Then same questionnaires were completed by the patients one and three months after the trauma. The data was analyzed using Friedman and Wilcoxon tests. Results: The data of 157 patients was analyzed. The results showed that there was a significant difference in the severity of depression disorders, anxiety and stress in three stages of the study (P0.05). Conclusion: The prevalence of depression, anxiety and stress is increased in people with lower limb traumas. Therefore it is recommended that the patients with lower limb traumas to be supported mentally, socially and economically. © 2016, Semnan University of Medical Sciences. All rights reserved
Investigating centering, scan length, and arm position impact on radiation dose across 4 countries from 4 continents during pandemic: mitigating key radioprotection issues
Purpose: Optimization of CT scan practices can help achieve and maintain optimal radiation protection. The aim was to assess centering, scan length, and positioning of patients undergoing chest CT for suspected or known COVID-19 pneumonia and to investigate their effect on associated radiation doses. Methods: With respective approvals from institutional review boards, we compiled CT imaging and radiation dose data from four hospitals belonging to four countries (Brazil, Iran, Italy, and USA) on 400 adult patients who underwent chest CT for suspected or known COVID-19 pneumonia between April 2020 and August 2020. We recorded patient demographics and volume CT dose index (CTDIvol) and dose length product (DLP). From thin-section CT images of each patient, we estimated the scan length and recorded the first and last vertebral bodies at the scan start and end locations. Patient mis-centering and arm position were recorded. Data were analyzed with analysis of variance (ANOVA). Results: The extent and frequency of patient mis-centering did not differ across the four CT facilities (>0.09). The frequency of patients scanned with arms by their side (11–40% relative to those with arms up) had greater mis-centering and higher CTDIvol and DLP at 2/4 facilities (p = 0.027–0.05). Despite lack of variations in effective diameters (p = 0.14), there were significantly variations in scan lengths, CTDIvol and DLP across the four facilities (p < 0.001). Conclusions: Mis-centering, over-scanning, and arms by the side are frequent issues with use of chest CT in COVID-19 pneumonia and are associated with higher radiation doses
Inter-sleep stage variations in corrected QT interval differ between obstructive sleep apnea patients with and without stroke history
Obstructive sleep apnea (OSA) is related to the progression of cardiovascular diseases (CVD); it is an independent risk factor for stroke and is also prevalent post-stroke. Furthermore, heart rate corrected QT (QTc) is an important predictor of the risk of arrhythmia and CVD. Thus, we aimed to investigate QTc interval variations in different sleep stages in OSA patients and whether nocturnal QTc intervals differ between OSA patients with and without stroke history. 18 OSA patients (apnea-hypopnea index (AHI)≥15) with previously diagnosed stroke and 18 OSA patients (AHI≥15) without stroke history were studied. Subjects underwent full polysomnography including an electrocardiogram measured by modified lead II configuration. RR, QT, and QTc intervals were calculated in all sleep stages. Regression analysis was utilized to investigate possible confounding effects of sleep stages and stroke history on QTc intervals. Compared to patients without previous stroke history, QTc intervals were significantly higher (β = 34, p<0.01) in patients with stroke history independent of age, sex, body mass index, and OSA severity. N3 sleep (β = 5.8, p<0.01) and REM sleep (β = 2.8, p<0.01) increased QTc intervals in both patient groups. In addition, QTc intervals increased progressively (p<0.05) towards deeper sleep in both groups; however, the magnitude of changes compared to the wake stage was significantly higher (p<0.05) in patients with stroke history. The findings of this study indicate that especially in deeper sleep, OSA patients with a previous stroke have an elevated risk for QTc prolongation further increasing the risk for ventricular arrhythmogenicity and sudden cardiac death.publishedVersionPeer reviewe
Community seismic network and localized earthquake situational awareness
Community-hosted seismic networks are a solution to the need for large numbers of sensors to operate over a seismically active region in order to accurately measure the size and location of an earthquake, assess resulting damage, and provide alerts. The Community Seismic Network is one such strong-motion network, currently comprising hundreds of elements located in California. It consists of low-cost, three-component, MEMS accelerometers capable of recording accelerations up to twice the level of gravity. The primary product of the network is to produce measurements of shaking of the ground and multiple locations of every upper floor in buildings, in the seconds during and following a major earthquake. Each sensor uses a small, dedicated ARM processor computer running Linux, and analyzes time series data in real time at hundreds of samples per second. The network reports on shaking parameters that indicate intensity of the structural response levels such as maximum floor acceleration and velocity, displacement of a floor in a building, as well as data products that depend on the response time histories. To do this, Cloud computing has been expanded through the use of statically defined subsets of sensors called cloudlets. These are smaller subsets of similar sensors that carry out customized calculations for those locations. The measurements are reported as rapidly as possible following an earthquake so that they may be incorporated into structural diagnosis and prognosis applications that can be used by first responders to prioritize their initial disaster management efforts. The cloudlet displays are customized for specific buildings and they show in real time: instantaneous displacement, inter-story drift, and resonant frequency and mode shapes using system identification software tools. The real-time display products are useful for decision-making about whether the potential for damage exists, what level of damage may have occurred and where, and whether total business disruption is necessary. City-wide dense monitoring makes it possible for emergency response managers to prioritize the target locations requiring first response on a block-by-block scale based on reports of shaking intensity
Autologous Adipocyte Derived Stem Cells Favour Healing in a Minipig Model of Cutaneous Radiation Syndrome
Cutaneous radiation syndrome (CRS) is the delayed consequence of localized skin exposure to high doses of ionizing radiation. Here we examined for the first time in a large animal model the therapeutic potential of autologous adipose tissue-derived stroma cells (ASCs). For experiments, Göttingen minipigs were locally gamma irradiated using a 60Co source at the dose of 50 Gy and grafted (n = 5) or not (n = 8). ASCs were cultured in MEM-alpha with 10% fetal calf serum and basic fibroblast growth factor (2 ng.mL−1) and post irradiation were intradermally injected on days 25, 46, 67 and finally between days 95 and 115 (50×106 ASCs each time) into the exposed area. All controls exhibited a clinical evolution with final necrosis (day 91). In grafted pigs an ultimate wound healing was observed in four out of five grafted animals (day 130 +/− 28). Immunohistological analysis of cytokeratin expression showed a complete epidermis recovery. Grafted ASCs accumulated at the dermis/subcutis barrier in which they attracted numerous immune cells, and even an increased vasculature in one pig. Globally this study suggests that local injection of ASCs may represent a useful strategy to mitigate CRS
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