12 research outputs found
Setting the Stage for Transformative Learning in MA TESOL Classrooms at a Saudi University
No full textThis article explores the impact of transformative theory on the learning outcomes of seven Saudi female student-teachers enrolled in a Master’s TESOL course at a Saudi university. They were actively engaged in designing learning materials for learners with special needs. In this intervention, transformative theory principles were used. They involved dialogue, authentic assessment, and structured reflection. Following the intervention, data were collected using focus group discussions and document analysis. The data were analysed using Mezirow’s transformative theory components: experience, critical reflection, reflective discourse, and action. The findings reveal the experience supported the participants’ autonomy, providing them with opportunities to reflect on their teaching practices, and improved their knowledge construction skills. Based on the results, the author makes a case for greater use of transformative theory approaches in designing and implementing teacher education
A simplified combined displacement and personalized ventilation model
No full textA multi-layer model has been developed to represent thermal transport in rooms equipped with combined displacement ventilation and personalized ventilation systems. The air movements and temperatures in the plumes and the rest of the room are represented separately at each air layer in a room of seven layers. The personalized ventilation is included in the layer containing the trunk and head of the human body and is considered to affect the heat source plume temperature and flow rate. The temperatures and flow rates of the plumes and the surrounding air at each layer are calculated by solving the heat and mass balance equations. The multi-layer model results were compared with results obtained from experimental measurements. Eight experimental cases were considered for the validation of the model at a displacement ventilation flow rate of 60 L-s (127 ft 3-min) and temperatures of 18C and 20C (64.4F and 68F) along with personalized ventilation flow rates of 4 L-s and 7 L-s (8.47 ft 3-min and 14.83 ft 3-min) and temperatures of 20C and 22C (68F and 71.6F). Measurements of the surrounding air temperature and the heat source plume centerline temperature were taken and compared to the predicted results of the model. The simplified model accurately predicted the surrounding air temperature at the higher levels, while it lightly underestimated by 6percent the lower level temperatures. At lower personalized ventilation flow rates and temperatures, the model was able to predict accurately the plume temperature directly above the human, but it underestimated the plume temperature when it gets closer to the ceiling or when the personalized ventilation flow rate and temperature are increased. © 2012 Copyright Taylor and Francis Group, LLC.ASHRAE, 2009, 6212009 ANSIASHRAE; Ayoub M, 2006, HVACandR RES, V12, P1005, DOI 10.1080-10789669.2006.10391448; Behne M, 1999, ENERG BUILDINGS, V30, P155, DOI 10.1016-S0378-7788(98)00083-8; Carrilho da Graca G, 2003, THESIS U CALIFORNIA; Eckert ERG, 1950, 1015 NACA; Etheridge D., 1996, BUILDING VENTILATION; Halvonova B, 2010, HVACandR RES, V16, P75, DOI 10.1080-10789669.2010.10390893; Jaluria Y., 1980, NATURAL CONVECTION H; JIANG Z, 1992, ASHRAE TRAN, V98, P33; Linden PF, 1990, J FLUID MECH, V212, P300; Min T.C., 1956, ASHRAE T, V62, P337; MORTON BR, 1956, PROC R SOC LON SER-A, V234, P1, DOI 10.1098-rspa.1956.0011; Mossolly M, 2008, ASHRAE TRAN, V114, P541; Mundt E., 1992, ROOMVENT 92 P 3 INT, V3, P69; Yuan X., 1998, ASHRAE T, V104, P7820
Comprehensive model of upper human body clothing ventilation in standing and walking conditions
Get PDFThe ventilation of the microclimate air of the clothed human body segment is a result of (1) the air flow from the environment through the clothing open apertures, (2) the penetration of the porous clothing, or (3) air flow originating in the microclimate of the other clothed body parts. The microclimate air flow at the connections of clothed segments is named the inter-segmental ventilation and constitutes a real physical boundary condition that leads to ventilation of connected segments. In this study, a simplified electric circuit model is developed to estimate clothing ventilation based on the analogy between the air flow in the microclimate air layer and an electric circuit composed of resistance and inductance elements. The model takes into account the inter-connection between the segments for the clothed human upper part driven by difference of pressure in the microclimate air of the trunk and the upper arms. The developed model is validated using the tracer gas method applied on a walking manikin placed in a climatic chamber under windy conditions. Good agreement was found between predicted segmental ventilation and the experimental values with a maximum error of 16%. It was found that the inter-segmental ventilation is significant at high relative velocity for permeable clothing and increased with the increase in the relative velocity constituting about 30% of the arm ventilation and 14% of the trunk ventilation. © The Author(s) 2018
Determination of segmental and overall ventilation of clothed walking human by means of electric circuit analogy
Get PDFA new simplified model has been developed to determine the ventilation induced by swinging motion and external wind for a fabric clothed cylinder representing a limb or a trunk. The simplified model is based on an analogy between air flow and an electric circuit. When a clothed body segment is subject to external wind, the microclimate air flow electric circuit is represented by resistances. When the clothed segment is subject to a swinging motion, the air flow electric circuit is composed of inductance and resistance elements. The model is validated by comparing the predicted ventilation rates to published experimental data in different conditions: varying permeability, wind speeds, swinging frequencies (for the clothed arm), walking conditions, and aperture configurations. The predictions of the simplified model lie within the standard deviation range of the published experiments. Moreover, although it is simplified, the relative error between the simplified model and the published experiment of an oscillating limb is considered acceptable (18%). © 2016, © The Author(s) 2016
Author Correction: Topological limits to the parallel processing capability of network architectures
No full textThermal comfort chamber study of Nordic elderly people with local cooling devices in warm conditions
Get PDFIn this study, we investigated the thermal response of Nordic elderly people before and after using local cooling devices in warm conditions. A climate chamber was used to simulate warm environments. We studied three types of local cooling devices: a table fan, an evaporative cooling device, and an air-cooled jacket. A total of 26 elderly participants were recruited for this study. During the experiments, votes of thermal and air movement perception were collected. The elderly voted for a neutral temperature of 26 °C, preferred temperature of 26.5 °C, and an acceptable temperature of 28 °C. Local thermal sensation in the torso areas of the elderly affected their overall thermal sensation more than local thermal sensation in the extremities under warm conditions. When the ambient temperature was risen to 1 °C and 4 °C higher than 26 °C, the behavior pattern of using local cooling devices for the elderly was: 1) with the small rise the use rate reached 50% with the lower speed modes mainly chosen; and 2) the higher rise caused more people to choose higher speed modes. Our findings show that the three local cooling devices can increase thermal acceptability under warm conditions. More than 80% of elderly accepted the 28 °C thermal environment, and less than 80% accepted 32 °C. The acceptance rate for air movement after using devices was decreased and less than 80% in most conditions. Moreover, all devices performed better under low-humidity conditions
Evaluating thermal response when elderly people using local cooling devices:Correlation among overall and local thermal sensation with skin temperature
No full textThe thermal comfort of elderly people in warm indoor environments is important because of their higher risk of heat stress. The use of local cooling devices may help alleviate heat stress. In this study, 26 elderly participants were recruited for climate chamber experiments in neutral (26 °C, 40 % relative humidity (RH)), slightly warm (29 °C, 40 % RH; 28 °C, 60 % RH), and warm (33 °C, 40 % RH; 32 °C, 50 % RH) environments. Three local cooling devices were tested: a table fan, evaporative cooling device, and air-cooled jacket. This study found, in different warm environments, the use of local cooling devices by the elderly results in an mean skin temperature decrease of no more than 0.5 °C. The thermal sensation in the head and torso has the most significant impact on overall thermal sensation. The mean skin temperature (MST) remains an effective physiological indicator for estimating overall thermal sensation after using local cooling devices. The skin temperature in the head, limbs, and extremities plays a substantial role in predicting overall thermal sensation. The thermosensory mean skin temperature (TMST) proposed based on the skin temperature of these parts can more accurately predict overall thermal sensation than MST. This study provides a reference for the development of future local cooling devices. This study has implications for guiding the selection of devices for nursing homes or residential environments for the elderly, and it can be utilized to formulate recommendations for improving device design
Constitutional Delay of Growth and Puberty: the Patient’s Perspective
No full textIntroduction: Constitutional delay of growth and puberty (CDGP) is a common cause of psychosocial upset among adolescents and their families. Concerns about reduced final height often urge patients to ask for urgent treatment rather than to wait for observation.Aim: The main objective is to evaluate the concerns, knowledge, understanding, and expectations of a group of children with CDGP and their families. Secondary objective is to study the auxological and socioeconomic characteristics of the patients.Patients and Methods: Forty nine patients with CDGP were included. Fifteen were followed for two years, and seven until final height. Patients and parents completed a designed question sheet to identify their concerns, knowledge, expectations from treatment, and willingness to follow up for observation. Socioeconomic standard scoring and anthropometric evaluation were performed.Results: 59.2% presented because of the concern of the whole family. There was a delay of 1.8 years between the time when patients were concerned about short stature and/or delayed puberty and presentation to clinic The delay was greatest in patients who stopped following up. Twenty seven patients (55.1%) were of low socioeconomic background, 17 (34.7%) were medium low, and 5 (10.2%) were medium high. 69.4% of patients were concerned about their height, not puberty. Two thirds were not convinced that shortness was not due to growth hormone deficiency and that treatment if needed would be sex hormones. 69.4% were not convinced to follow up without treatment.Conclusion: Short stature rather than late puberty is usually the reason for consultation in CDGP. Incomplete understanding of the condition among families and dissatisfaction with the treatment options available remains a problem even after detailed explanation. Extra effort is needed to raise the awareness and avoid the adverse psychosocial sequels in patients with CDGP
Author Correction: A multinational study on the factors influencing university students’ attitudes and usage of ChatGPT
No full textEffect of Phase Change Material Cooling Vests on Body Thermoregulation and Thermal Comfort of Patients With Paraplegia: A Human Subject Experimental Study
Get PDFStudy design: Randomized experimental study. Objective: Compared to able-bodied people, patients with paraplegia due to thoracic spinal cord injury (SCI) are at an increased risk of heat illnesses during exercise due to impaired thermoregulatory responses. To overcome this limitation, we investigated the performance of three phase change material (PCM) cooling vests of different melting temperatures (Eijsvogels, #49) and coverage area of the trunk. Methods: Sixteen participants were divided into three groups according to their injury level. All were tested for V20 full vest (20°C Tm, 75% coverage). Mid-thoracic and high-thoracic groups were tested for V14 vest (14°C Tm, 75% coverage). The mid-thoracic group was tested for V20 half vest (20°C Tm, 50% coverage). The participants performed a 30-min arm-crank exercise followed by a recovery period inside a controlled hot climatic chamber. The heart rate, segmental skin (Tskin), and core temperature (Tcore) values were recorded, and subjective questionnaires were taken. Results: Compared to no vest (NV) test, all the vests showed an effective decrease in Tskin values of the trunk. However, the decrease in Tskin was not enough to induce a significant decrease in Tcore in all three groups. Mid-thoracic and low-thoracic groups showed a reduction in the increasing Tcore by the end of the exercise and recovery period. Finally, the level of thermal comfort was enhanced for the three groups. Conclusion: The effectiveness of cooling vests for persons with paraplegia is dependent on injury level and thus the ratio of sensate to insensate skin. Future studies necessitate the investigation of the cooling effects of PCM vests at a lower Tm with a larger sample size. © The Author(s) 2021
