Design analysis of a hybrid jet-pump CO2 compression system

Transport refrigeration contributes to anthropogenic global warming directly because of leakage of refrigerant, usually using high global warming potential (GWP) refrigerants, and indirectly because of the greenhouse gases emitted in driving the vehicle and the refrigeration system. A hybrid jet-pump CO2 compression system is being designed for transport refrigeration so that the GWP of the system is reduced and its performance improved. The jet-pump utilises waste heat from the exhaust gases of the engine to subcool the refrigerant and so enhance performance, reduce energy required from the engine and minimise GWP of the system. The hybrid jet-pump CO2 compression system has been simulated and its performance determined for different operating conditions and optimised using entropy generation minimisation. At an evaporator temperature of -18°C, an ambient temperature of 35°C and a generator temperature of 120°C, the COP increases from about 1.0 to 2.27 as the degree of subcooling increases from 0K to 20K. Similarly, compressor work is reduced by 24% at 20K subcooling. The optimum degree of subcooling was approximately 10K for the operating conditions described above. An improved COP is achieved whilst the size of heat exchangers required to operate the jet-pump are minimised with respect to the overall weight of the system and thus its impact on indirect emissions

Party Systems, Democratization and Governance in Africa: Aligning theory and praxis using Sierra Leone as a case study

There has been an upsurge in the movement towards democracy in developing countries since the end of the Cold War, which has led former autocratic regimes to embrace values of good governance as they transition to democracy (Huntington, 1991: 21-26). Democratic triumphalism has even led some scholars to declare the end of history due to the absence of alternative political systems that rival Western democracy (Fukuyama, 2006). The so-called third wave of democratization has been aided by multilateral institutions, international aid agencies and Western democratic governments, which since the 1990s have used democratization and good governance as collateral for foreign aid, as well as a yardstick to measure the legitimacy of regimes (Carothers, 1999: 40-41). Among the major foundations of democracy advanced by theorists are competition and contestation (Huntington, 1991: 6), which means the acquisition of power must be preceded by a contest among political parties. In sub-Saharan African countries, the main argument for the adoption of democratic forms of government put forward by international institutions and domestic actors alike is that stable multi-party systems provides multiple avenues for citizens to participate broadly in the political process, and by so doing, lay the foundation for the institutionalization of democracy and good governance.;In Sierra Leone, a new constitution was adopted in 1991 that made provision for a multi-party system and a Single Member District (SMD) electoral system as key ingredients of a democracy that produces good governance. Due to the need to hold representative elections even during the war, the SMD system was substituted by the PR system in 1996. When the war ended in 2002, the SMD system was reinstated but subsequent elections show gradual decline in the number of smaller parties that win parliamentary seats. In this dissertation, I aim to find out the extent to which the attainment of multi-party democracy may be constrained by the choice of the SMD systems in Sub Saharan Africa. Specifically, I hypothesize that larger District Magnitudes (DM - i.e., the number of electoral seats per constituency) lead to the formation of ethnically based two party systems, whereas lower district magnitude lead to the formation of multi-party systems. Through longitudinal analysis of election results in Sierra Leone from 1996--2002, I aim to show: first, the extent to which changes in district magnitude influence ethnicity or facilitates the formation or deepening of ethno-political cleavages in the diverse societies of Africa. Second, whether such cleavages in turn influence party system outcomes in Sub-Saharan African countries, and third, the extent to which changes in party systems influence democratization and governance in Sierra Leone. Finally, I extend Lipjhart\u27s typologies (party systems and electoral systems only) in Patterns of Democracy, as alternative paths that sub Saharan African countries could follow in their quest to attain democracy and good governance.;I expect findings that show that PR systems have multiplicative effects on smaller parties whereas SMD systems have a reductive effect on smaller parties. Since current theories show that political parties in Sub-Saharan Africa tend to reflect existing ethno-political cleavage structures, this study will clarify the relationship between party systems, electoral system, and ethnicity and the implications of such relationships for the institutionalization of democracy and good governance in Sub-Saharan Africa. Furthermore, I expect findings that show no significant difference in governance based on a country\u27s party system, which is intriguing given that a recent study finds and points to the significance of such a difference (Janda and Kwak, 2012)

POTRET DINAMIKA KEHIDUPAN MASYARAKAT DESA BOJONG CATANG, SERANG-BANTEN

ABSTRACT The portrait of the dynamics of the Bojong Catang Village community is a description of the life of a village community that is still thick with religious norms and customary law, whose economic needs depend on natural livelihoods. The purpose of this research is to find out the life and development that occurs from time to time in the village of Bojong Catang. The method used in this research is descriptive qualitative. Data collection used interview and observation techniques with the village head, RT and villagers, then documentation. The results showed that Bojong Catang village has a diversity of life dynamics, such as local culture that is still maintained, the main source of livelihood by utilizing natural resources. There are significant changes in life in the community, there are also Bojong Catang Village programs, community migration/urbanization, and local languages are also still preserved in everyday life

Organization Commitment and Career Success as Surrogating Variables between Reward System and Job Performance: A Study from Public Sector Universities of Punjab, Pakistan

Purpose-The main aspiration of this study is to examine the mediating effect of organizational commitment and career success between reward system and job performance. Design/Methodology/Approach- 98 respondents working in public sector universities of Punjab, Pakistan contributed in this study by filling the survey forms (Questionnaire). Findings-The study found the significantly positive mediating relationship of organizational commitment between reward system and job performance. Research Limitations/Implications-As cross sectional study the data were collected once only has the limitations such as the researchers’ convenience, due to this the results might not be generalized in other provinces of Pakistan and other terrorises of the world. Practical Implications-The university must have to improve the higher level of its ranking nationally and internationally; its performance depends on the intrinsic and extrinsic reward system for the faculty members. The construct in Pakistani context is unique in its nature. Originality/Ecological Validity-Main stream studies on this construct in Pakistani context, has focused the public sector universities of Punjab Pakistan. The study is amongst the preliminary studies in this context. The research will be beneficent for the faculty members working in Pakistani DAIs and policy makers as well. Paper Type-Research Paper Keywords:Public Sector Universities, Organizational Commitment, Career Success, Job Performance and Reward System

Vacuum insulated panels for sustainable buildings: a review of research and applications

New research has identified vacuum insulation panels (VIPs) as highly efficient insulators for use in building construction. They are reported to be several times more effective than conventional materials of a similar thickness in terms of thermal conductivity. Because of their smaller space requirement, VIPs maximize the internal usage area of buildings and so reduce the cost of construction. There are however some obstacles that have hindered the application of VIPs, notably their high cost, susceptibility to perforation and the long-term water and gas effects that worsen their performance. This paper reviews the contemporary research on VIP as a state-of-the-art material for building insulation. The main components and physical principles of VIP performance are discussed. Finally, the review of VIPs available on the market and their performance is provided

A smart building material for low/zero carbon applications: heat insulation solar glass—characteristic results from laboratory andin situtests

Heat insulation solar glass (HISG) is a recently developed smart building material to minimize energy consumption of building sector. HISG might be presumed to be a conventional photovoltaic glazing product; however, it is completely unique by having some characteristic features such as superior thermal insulation, which is competitive with triple-glazed windows using argon as inert gas, acoustic and thermal comfort, self-cleaning ability owing to TiO2 nano-coating on module surface and extraordinary energy saving potential in both summer and winter. In our previous works, comprehensive experimental and numerical works have been carried out for power generation and thermal insulation performance of HISG under various climatic conditions. Within the scope of this research, optical- and lighting-related performance parameters of this smart building material are evaluated through extensive laboratory and in situ tests. Shading coefficient, visible light intensity, and UV and IR penetration are investigated via the tests conducted in real operating conditions. It is achieved from the results that the shading coefficient of HISG is only 0.136, which yields almost 80% reduction in solar heat gain compared with ordinary glazing. It is also observed from the in situ tests that HISG has a %100 UV and 99% IR blocking rate, which is of vital importance in terms of human health and thermal comfort conditions. Glaring effects are totally resolved via HISG, which is still a challenge for the buildings with conventional glazing products, especially in summer

THE USE OF SLANG LANGUAGE IN DAILY CONVERSATION AMONG TEENAGERS: DOES GENDER MATTER?

Nowadays, slang words have now become part of teenagers' everyday language, since they use them in everyday speech. However, due to various of factors, there are disparities in the choice of slang phrases used by teenagers. Since the topic of gender's influence on language usage is not remarkably new, one of the factors that may have a large influence on the choice of slang words used is gender. Relying on this situation, the aims of this study are to investigate the types of slang words used by male and female teenagers, the influences of gender on the choice of slang words and the factors causing the differences. This study referred to the theory of types of slang words by Partridge (2004), gender theory by Diekman and Eagly's (2000), and ethnography of speaking theory by Hymes (1974). This study employed descriptive qualitative method. Observation and interview were employed during the study for the purpose of data collections. The participants of the study were 10 teenagers, 6 females and 4 males which are all college students in Surabaya. The analysis of the collected data revealed that English slang words that are commonly used by teenagers were identified as Society Slang. In addition to that, the investigation on the collected data also shows gender had no influence the choice of slang words. Lastly, the result of the study emphasized that the factors of how each person has their own choice of slang words are speech events which refers to Hymes’ SPEAKING term

PEMBUATAN BUKU AJAR SULAM FANTASI UNTUK PESERTA DIDIK KELAS XI JURUSAN KRIYA TEKSTIL SMKN 12 SURABAYA

Penelitian ini dilatarbelakangi keinginan untuk membantu proses pembelajaran di jurusan kriya tekstil kelas XI SMKN 12 Surabaya khususnya pada materi sulam tangan. Tujuan penelitian ini yakni mendeskripsikan proses pembuatan, hasil, dan efektifitas buku ajar sulam fantasi untuk pembelajaran materi tersebut. Metode penelitian menggunakan Research and Development. Pengumpulan data melalui observasi, wawancara, angket, dan dokumentasi, sedangkan analisis validitas data menggunakan metode triangulasi data. Proses pembuatan buku ajar menggunakan aplikasi autodesk dan canva, selanjutnya proses validasi, revisi, dan penerapan pada peserta didik. Pada validasi pertama, validator materi menilai 100% materi sudah layak digunakan, namun validator media menilai bahwa kelayakan media baru 65% sehingga diperlukan revisi. Setelah revisi, kelayakan media mencapai 87,5% dan layak diujicobakan pada peserta didik. Pada uji coba terbatas, kelayakan media mencapai 81% sedangkan respon guru 90% sehingga layak untuk diuji coba lebih luas. Hasilnya, ketercapaian aspek pemahaman sebanyak 79,5% dan aspek berkarya sebanyak 86,5%. Secara keseluruhan prosentase tersebut melampauai 75% (kategori baik) sehingga buku ajar sulam telah layak dan efektif digunakan pada proses pembelajaran. Kata Kunci: buku ajar, tekstil, sulam fantas

An innovative psychometric solar-powered water desalination system

Important advances have been made in solar water desalination technology but their wide application is restricted by relatively high capital and running costs. Until recently, solar concentrator collectors had usually been employed to distill water in compact desalination systems. Currently, it is possible to replace these collectors by the more efficient evacuated tube collectors, which are now widely available on the market at lower prices. This paper describes the results of experimental and theoretical investigations of the operation of a novel small-scale solar water desalination technology using the psychometric humidification and dehumidification process coupled with a heat pipe evacuated tube solar collector with an aperture area of ~1.73 m2. Solar radiation during spring in the Middle East was simulated by an array of halogen floodlights. A synthetic brackish water solution was used for the tests and its total dissolved solids (TDSs) and electrical conductivity were measured. A mathematical model was developed to describe the system's operation. A computer program was written to solve the system of governing equations to perform the theoretical calculations of the humidification and dehumidification processes. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. The test results demonstrate that, at temperatures of 55-60°C, the system produces ~5-6 kg/h of clean water with a high desalination efficiency. Following the experimental calibration of the mathematical model, it was demonstrated that the performance of the system could be improved to produce a considerably higher amount of fresh water