791 research outputs found
Maximising utility savings through appropriate implementation of combined heat and power scheme
Combined Heat And Power (CHP) Scheme, Also Known As Cogeneration Is Widely Accepted As A Highly Efficient Energy Saving Measure, Particularly In Medium To Large Scale Chemical Process Plants. The Advantages Of A CHP Scheme For A Chemical Plant Are Two-Fold: (I) To Drastically Reduce Electricity Bill From On-Site Power Generation (Ii) To Save On Fuel Bills Through Recovery Of The Quality Waste Heat From Power Generation For Process Heating. In Order To Be Effective, A CHP Scheme Must Be Placed At The Right Temperature Level, In The Context Of An Overall Process System. Failure To Do So Might Render A CHP Venture Worthless. This Paper Describes The Procedure For An Effective Implementation Of A CHP Scheme Using An Ethyl Benzene Process As A Case Study. A Key Visualisation Tool In Pinch Analysis Technique Known As The Grand Composite Curve Is Used To Guide CHP Integration, And Allows It To Be Optimally Placed Within The Overall Process Scenario. The Study Shows That Appropriate CHP Integration With The Ethyl Benzene Process Above The Pinch Can Potentially Result In Significant Savings On Electricity Cost Of Up To 87%
Serangan Nematoda Sista Kuning (Globodera Rostochiensis) Pada Tanaman Kentang Di Kabupaten Banjarnegara Attacks of Golden Cyst Nematode (Globodera Rostochiensis) on Potato at Banjarnegera Regency
Golden cyst nematode (Globodera rostochiensis) is the main nematode on potato. In recent years, the nematode has been reported at several potato production centers in Indonesia. This research aimed at knowing distribution of the nematode attacks on potato at Banjarnegara Regency and factors supporting its attack. Survey was conducted by using purposive random sampling as a sampling method. Results of the research showed that G. rostochiensis was found at three districts, i.e., Batur, Pejawaran, and Wanayasa, but its populations were still -1 concentrated at Karangtengah Village, Batur District, namely 37.28 cysts 200 ml -1 soil and 10.76 cysts plant . The nematode presumably entered Banjarnegara
Regency through imported potato seedlings, available potato host, and appropriate environment temperature supporting the nematode growth and development
Microscopic study of emulsion flow in porous media
Emulsion applicability as an oil recovery agent has long been recognized in petroleum industry. However, investigations of emulsion flow in porous media for petroleum recovery applications are scarce; particularly the flow effects have not been explained in detail in term of events occurring at the pore level. Thus, this research was carried out to investigate the physics of emulsion flow in porous media. The objectives of the experiments are to study the behavior and mechanism of emulsion flow in porous media, to evaluate the effectiveness of emulsion as an oil recovery agent, and to determine the emulsion blocking processes. In this research, well characterized emulsions of water-in-oil emulsion (model oil of 86.5% dibutylphthalate + 13.5% n-heptane, and distilled water system) and oil-in-water emulsion (paraffin oil, distilled water, and Triton-X100 surfactant system) were injected into two-dimensional etched glass micromodels. Visualization experiments by using microscope on the micromodels were conducted to observe and record the emulsion droplet motion, captured mechanisms, and blockage processes. The results demonstrate the three possible flow regimes that may occur when emulsion flow in porous media are mainly due to the difference of emulsion droplet size to pore throat ratios. Flow phenomena of emulsion droplet formation, deformation and destruction, blob and rivulet were observed to be associated with less stable emulsion system. Other emulsion flow phenomena were the microstructures of droplets adhesion and entrainment from the solid surface, and droplets undergone snap-off and division from pore-to-pore. The results show that the emulsion droplets were found to be captured at the throat and the pore body according to straining and interception capture mechanisms. Also, the results indicate that wettability has a direct influence on the droplet capture mechanism. Emulsion water droplet colliding with the waterwet surface could easily adhere to the surface and formed thick water films. On the other hand, emulsion water droplet contacting oil-wet surface could be displaced from the surface by the continuous oil phase. Moreover, the results reveal that continuous emulsion injections could provide additional oil recovery, but by injecting smaller size emulsion slugs prior to water injection would result in insignificant additional oil recovery. Microscopic mobility control was found to contribute to the oil recovery processes in homogeneous porous media, while macroscopic mobility control due to the emulsion blocking effect would contribute to the oil recovery processes in heterogeneous porous media. The emulsion blockage process was observed to be accelerated with large ratio of emulsion droplet-to-pore throat, coalescence of captured droplet, low emulsion flow rate, more viscous emulsion droplets, and emulsion droplet wetting the solid surface. In conclusion, this research characterizes the physics of emulsion flow in porous media and demonstrates its application as an effective oil recovery agent through emulsion blocking mechanisms. The novelty is the revelation of the process for emulsion droplet blockage effects in porous media
Subcritical and supercritical fluid extraction a critical review of its analytical usefulness
Subcritical R134a is suggested as a low-pressure alternative to supercritical CO2 in the supercritical fluid extraction technology in particular of palm oil application. Therefore, a measurement of solubility of palm oil in subcritical Rl34a will be carried out at temperatures of 40, 60, 70 and 80°C and pressures up to 300 bar. The solubility of carotene are also will be measured using UV Spectrophotometer. Results obtained from this study will be compared with the previous work and for the first time, simulation for the SFE process of palm oil will be performed using Artificial Neural Network (ANN) and it will be implemented in comparisons as well when the operating conditions of the previous findings are different from this study. It is expected that the solubility of the palm oil in subcritical Rl34a is much higher than SC-C02, and it is expected that R134a could be a viable alternative solvent to supercritical carbon dioxide as R134a could be perform well at a lower pressure used whereas can achieved a higher solubility compared to SC-C0
The influence of employee satisfaction on turnover intention at private colleges in Kuantan: the moderating effects of social support / Normadiana A. Manan
The main objective of this study is to investigate the influence of employee satisfaction on turnover intention and to examine whether social support moderates the relationship between employee satisfaction and turnover intention. This study was conducted among academic staff at three private colleges in Kuantan, namely IKIP International College, Shahputra University College, and Cosmopoint University of Technology. The questionnaire was developed based on 5-point Likert scale and it was personally distributed and collected to the 200 academic staff at these three private colleges in Kuantan. However, only 147 questionnaires were collected and this equivalent to 73.5% of the respondents. The data collected for this study were analysed using Statistical Package for Social Sciences (SPSS), version 20. Pearson Correlation Coefficient and Multiple Regression were applied in analysing and interpreting the data. The result of employee satisfaction on turnover intention generally supports the hypothesis in this study. Pay is the strongest factor that supports the relationship between employee satisfaction and turnover intention. Another factors that contributed to the findings in this study were promotion, workload, and supervision need to be considered and attention by the management to retain the valuable employee in the organization. The results further indicate that social support has a significant but weak impact on employee satisfaction and turnover intention. Some of suggestions and recommendations were provided for future research and private colleges in order to produce more accurate and comprehensive results for upcoming research
Ulama and Fatwa (Pros and cons of the Circular Letter of the Aceh Governor and MPU Decree)
This study critically discusses the pros and cons of the circular letter (surat edaran) of the Aceh governor and Ulama Consultative Council (MPU) Decree No. 2 of 2020 related to responses and public evaluation of the prohibition of the religious learning forums (pengajian) other than Ahlussunnah Waljama’ah. This research is a qualitative research with three data collection techniques: meticulous observation, in-depth interviews, and documentation. The result of the study showed that there were pros and cons related to the circular letter and decision on the prohibition of conducting pengajian that contradicts the I’tiqat of Ahlussunnah Waljama’ah which is based on Syafi’i School of Law. Among them, according to the Aceh government and the MPU, the circular letter is intended to prevent greater abuses in the form of disunity in the Acehnese community due to differences in understanding in matters of worship. Meanwhile, others failed to understand the circular letter and MPU decrees because they consider them weak and were greatly influenced by certain conservative Islamic figures in Aceh, appearing to some people as political activity and power
A Short Review on the Development of Salt Tolerant Cultivars in Rice
Rice is staple food for half of the world. With a population of almost 9.6 billion by the year 2050, there is a dire need of developing techniques to improve the crop plants, not only in terms of better yield but also to withstand harsh environmental conditions and stresses like drought, temperature, flood and salinity. Salinity is second to drought stress and hence it is very important to develop crops tolerant to salinity stress. This review discusses the mechanisms of salt tolerance and the recent developments in understanding the complex tolerance phenomena. One way to address the salinity issue is to develop tolerant rice varieties using conventional and modern breeding techniques for which screening the rice germplasm for the varieties with desired traits is critical. Conventional methods to develop tolerant rice varieties are discussed along with modern biotechnology techniques are also discussed. Quantitative Trait Loci (QTL) and Marker Assisted Selection (MAS) are promising techniques. In addition to these modern techniques, some recent developments in the fields of transgenic plants, haploid breeding and Somaclonal variations have also been discussed. The limited knowledge about molecular and genetic mechanisms to tolerate abiotic stresses, however is a barrier to efficiently develop tolerant cultivars. A combination of conventional and modern biotechnology techniques could possibly open up the new ways
- …