Development of an Experimental Facility for Measurement of Tangential Jet Flow in a Sudden Expansion Channel

This thesis describes the development of an experimental facility of a tangential jet flow in a sudden expansion channel. The present study is intended to clarify experimentally the relation between flow and geometrical variables on the thermal development using a point wise temperature measurements technique. The temperature measurements have been conducted on a flat plate inside a low speed open circuit wind tunnel. The mainstream flow has a maximum of temperature 50" C. The temperature was controlled by a 10 kVA/40 Ampere voltage regulator. A maximum velocity, (urnat) t he mainstream intake is 10 d s . The velocity on the coolant jet flow (u,)is between 2 m/s to 8 mls, the expansion ratio (ER) is 1.2 and the Reynolds numbers, ( ~ e , ) is, 1.3 x 1 o5 on the mainstream location. The coolant distribution system is fabricated into three type of geometry: a slot shape 20 mm2 1 mm , a square shape 10 mm x 10 rnm and a circular shape 10 mm of diameter. The surface temperature in the direction of the jet flow media is evaluated based on the measured temperatures, obtained through the thermocouples over the flat surfaces. The jet flow is tangentially injecting a jet of cooling air at an exit angle of 0" from the coolant distribution system to the plate surface. The test plate is made of plastic material (acrylonitrile butadiene stryrene) plate of 10 mm thick flat plate which is installed on the channel wall and instrumented with a stream wise row of Ttype thermocouples. The thermocouples are spaced 25.4 mm apart along the center line of the plate. The temperature ratio between the cooling air temperature (T,) and T the mainstream temperature (T,) is in the range of 0.77 5 1 0.87 while the T, velocity ratio between the cooling velocity (u,)an d mainstream velocity (u,) is in range of 0.2 5 35 0.7. From the observation made at the location XX -- 0.5, the cooling effectiveness (r) for tangential jet flow emanating from the slot, square and circular holes geometry, is to be at maximum value of 0.8, 0.6, and 0.5 respectively. The data presented here would be off interest to engineers to gain further understanding in the development of heat transfer due to tangential jet flow in a sudden expansion channel

Simulation and experimental design of thermoacoustic heat engine

Renewable energy is an important field in providing reliable and sustainable energy to the world. Wasted heat is found to be a good source of renewable energy. This wasted energy can be found almost in all types of production processes, including the heat exchanger. The heat energy dissipated from these processes is unutilized leading to inefficiency in the system. The need to harvest the wasted heat is essential in making sure the energy can be further utilized for other applications. Previous research works conducted on harvesting heat into sound in the system is still lacking and there is no specific standard can be employed. This research focused on analysing and developing a reference method of harvesting sound from a thermoacoustic heat engine system. A simulation approach was employed to investigate the performance of heat flow on the heat exchanger and related components. A standard test rig was designed to evaluate the performance of heat transfer experimentally. A comprehensive laboratory work was set-up to collect ample data to obtain the correlation of acoustic sound pressure-volume due to heat transfer performance by the oscillatory flow on the thermoacoustic system. The design of the developed thermoacoustic engine was able to produce waste heat in the range between 200°C and 700°C, and the harvested sound frequency ranged from 20Hz to 2kHz. From the experimental study, the sound level started at 4s to 8s and reaches a steady-state at 10s. The temperature gradient on stack performance was 8.45°C/mm with a temperature difference at the steady-state point of 300°C. The spectrum analysis amplitude reached 133.5dB with the frequency value of 397.5 Hz. The pressure volume analysis has proved the existence of both isochoric and isothermal process through the gas bucket brigade phenomenon as the lead compression and expansion happened at the stack wall between the sound pressures of 12.94Pa and 20.15Pa. The finding confirmed that the sound energy from the heat oscillation can be harvested and a standard method has been developed. This study also confirmed the presence of a thermoacoustic cycle on the stack wall. This finding is significant as it provides a new standard in harvesting sound from the thermoacoustic heat engine. The efficiency of the system was successfully improved by 40% and the wasted energy was successfully harvested for further applications

THE RELATIONSHIP STUDY BETWEEN COHESION AND PERFORMANCEOF PLAYERS OF HOCKEY, IN PAKISTAN

This paper represents the findings of a larger study which highlights the relationship between cohesion and the performance among hockey players of Pakistan in view of socio-interactional context. Pakistan won laurels in Field hockey with four World Cup and three Olympics titles to its credit but no effort has been made to find out the factors which have turned Pakistan (as a team) from the status of a giant into a pygmy during the last two decades. The foremost objective of this paper is to scrutinize the relationship between cohesion and players’ performance. A sample of 296 players from 14sport departments was chosen as respondents. Adopted questionnaire was used to collect the survey data. The findings highlighted the significant (p=.001) relationship between cohesion and players’ performance. It is concluded that the cohesiveness among players is to be developed and expanded regarding players’ performance to fulfil sport requirements. Recommendations have been made to raise the excellence, relevance, and legitimacy in team regarding cohesion with players’ performance

THE RELATIONSHIP STUDY BETWEEN COHESION AND PERFORMANCEOF PLAYERS OF HOCKEY, IN PAKISTAN

This paper represents the findings of a larger study which highlights the relationship between cohesion and the performance among hockey players of Pakistan in view of socio-interactional context. Pakistan won laurels in Field hockey with four World Cup and three Olympics titles to its credit but no effort has been made to find out the factors which have turned Pakistan (as a team) from the status of a giant into a pygmy during the last two decades. The foremost objective of this paper is to scrutinize the relationship between cohesion and players’ performance. A sample of 296 players from 14sport departments was chosen as respondents. Adopted questionnaire was used to collect the survey data. The findings highlighted the significant (p=.001) relationship between cohesion and players’ performance. It is concluded that the cohesiveness among players is to be developed and expanded regarding players’ performance to fulfil sport requirements. Recommendations have been made to raise the excellence, relevance, and legitimacy in team regarding cohesion with players’ performance

THE SPORT PARTICIPATIONS AND SOCIAL CLASS RELATIONSHIP AMONG FEMALE ATHLETE OF PAKISTAN

The drive of the existing research was to determine the relationship between social class (gender inequality and dress code) and sports participation among successful female athletes of secondary schools of rural areas of Pakistan. The nature of the study was purely quantitative. The adopted and modified survey questionnaire was employed for the purpose of collecting the data. Simple random sampling was used as a sampling technique. In the sense of statistical techniques, descriptive statistics and correlation (Pearson) analysis was utilized to analyze the survey data. The results revealed that gender inequality and dress code had strong and significant relationships with sports participation (health, personal drive and interest), therefore, the direction of all relationships was found negative. It was concluded that both gender inequality and dress code found big hurdles in the way to female sports participation

Cahaya Enterprise : Lamp Installment Services / Ahmad Akmal Azman ...[et al.]

Our product are use to control light by using light dependent resistant (LOR) and timer. The LDR will operate when the light intensity is low. While, the timer is set by the user themselves whenever they want the lamp to light up. Our product and service are suitable for houses, factory and office

The impact of stack parameters on the temperature difference of a thermoacoustic cooler

Thermoacoustics offer alternative solution for cooling needs where a method that is safer to environment is used. The thermodynamic process that needs to be completed by using interaction between inert gaseous and porous material must be made efficient so that the system works properly. This paper reports numerical and experimental investigations of the use of several porous material in air at atmospheric pressure to provide cooling effect. Experimental investigation was also conducted by using cheap and abundant materials as the porous media. Results were collected at two different frequencies and with two different stack lengths. The study showed that thin-walled honeycomb porous structure made of polycarbonate offers the best temperature for thermoacoustic cooler with air at atmospheric pressure. The best COP of 4.73 was recorded. Disparity between numerical and experimental results is expected to be the result of losses that need to be carefully addressed in the future especially when long stack is used in the system

Investigation on standing wave thermoacoustic generator using DeltaEC

There is currently an urgent demand to reuse waste heat from industrial processes with approaches that require minimal investment and low cost of operation. Thermoacoustic generator (TAG) is a device that converts heat energy into useful work through the use of acoustic wave, porous media (honeycomb ceramic celcor) and heat exchangers that are all enclosed in a custom-defined resonator. This paper reports the basic design of thermoacoustic generator that is tested using a design software known as a Design Environmental for Low-amplitude Thermoacoustic Energy Conversion (DeltaEC). Many studies have highlighted the relationships between the geometry of the stack and the performance of the device. In this study, attention is given on the impact of the length of stack which was found to be the best at a length of 0.6 m when the frequency of the flow is at 127.4 Hz. Performance indicators like the acoustic power and the temperature difference across the stack have been used to analyse the results. The result shows that the highest acoustic power can be achieved when the generator that work with air at an atmospheric pressure is designed with a resonator of 2.14 m long and a stack with a length of 0.6 m. The maximum value for acoustic power is predicted to be as much as 24.01 kW

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Mapping disparities in education across low- and middle-income countries

Analyses of the proportions of individuals who have completed key levels of schooling across all low- and middle-income countries from 2000 to 2017 reveal inequalities across countries as well as within populations. Educational attainment is an important social determinant of maternal, newborn, and child health(1-3). As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting(4-6). The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness(7,8); however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health(9-11). Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but-to our knowledge-no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries(12-14). By geolocating subnational data for more than 184 million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations.Peer reviewe