Development of a Microwave Instrumentation System for the Determination of Moisture Content in Oil Palm Fruits

This thesis describes the development of a microwave instrument for moisture content determination of oil palm fruits. The developed PC-based Six Port Reflectometer provides a simple, fast and accurate solution to the more expensive and bulky Vector Network Analyzer for monitoring the ripeness of oil palm fruit at various stages based on the moisture content measurement. The Microwave Office software (MWO) was used to design and analyzed the Six Port Reflectometer. Various coaxial sensors were simulated using FEMLAB to study the reflection coefficient of the sensor corresponding to the moisture content and ripeness stage of oil palm fruit. The developed Six Port Reflectometer operating at 2 GHz consists of a stripline ring junction, three diode detectors and an Analog to Digital converter. Two types of coaxial sensors were selected for this work: the open ended coaxial and monopole sensors. A computer software was developed using Agilent Visual Environment Engineering (VEE) graphical programming for hardware control and implement all computation work. The performance of the developed Six Port Reflectometer in reflection coefficient measurement was tested. The empirical equations which relate the measured reflection coefficient and moisture content were found. The comparison of a batch of 200 fruit samples was done and it is found that the empirical equations is in the best agreement with the samples follow by finite element method (FEM) simulation and capacitance model. The monopole sensor phase shift measurement was found to be the best for moisture content measurement of oil palm fruits with 3.5% mean error. In bunch measurement, the apical region has the highest accuracy of moisture content measurement with 2.7% mean error followed by equatorial region, 3.0%, and basal region, 5.8%. For whole bunch moisture content measurement, the mean error was found to be 3.8%. The uncertainty of the developed Six Port Reflectometer system is calculated to be 5.5% for reflection coefficient measurement. This study shows that the Six Port Reflectometer is suitable for moisture content measurement of oil palm fruit and bunch. It is simple, fast, accurate, and a portable instrumentation system. It is suitable for early quality check of fruit and bunch ripeness

Supertubes in Field Theories

To a domain wall or string object, Noether charge and topological spatial objects can be attracted, forming a composite BPS (Bogomolny-Prasad-Sommerfield) object. We consider two field theories and derive a new BPS bound on composite linear solitons involving multiple charges. Among the BPS objects `supertubes' appear when the wall or string tension is canceled by the bound energy, and could take an arbitrary closed curve. In our theories, supertubes manifest as Chern-Simons solitons, dyonic instantons, charged semi-local vortices, and dyonic instantons on vortex flux sheet.Comment: latex, 10 page

Visible success and invisible failure in post-crisis reform in the Republic of Korea : interplay of the global standards, agents, and local specificity

The reform package in post-crisis Korea was one of the most comprehensively designed and decisively implemented. Though impressed by the quick recovery, many are now raising doubts about real changes in the economy, as the result of a cost-benefits analysis: While the business climate is more stable and supportive, the economy is suffering from weak investment and rising unemployment. This study views the Korean story as one of"visible success and invisible failure,"based on the following findings: First, while some new laws were enacted and several quantifiable targets met, little real progress was made in changing institutional conventions, habits, and beliefs, such as enhancing transparency in management or trust in labor relations. Second, the reform process involved tension between global standards and local specificity, which accounts for the mixed results. Third, special interest politics at the implementation stage, plus the complexities caused by increasing democratization and globalization, have undermined the authorities'implementation capacity, which accounts for uneven outcomes of the reform. While globalization necessitates increasing flexibility, Korean managers are now facing much stronger labor unions. The outcome is not a fully flexible but segmented labor market, divided between the core, unionized workers and unorganized peripheral workers, and between the one overprotected and the other underprotected. Fourth, it is important to have an effective system of legislative bargaining to help resolve disputes. Only with this institutional vehicle will special interest groups reach some consensus. Korea tried to overhaul its financial system and achieve substantial financial liberalization in the early 1990s but those attempts were partly aborted and partly distorted, which paved the way for the financial crisis in 1997. This was due to the lack of clear consensus, without which reforms are more likely to be aborted or be unsuccessful. Fifth, implementation problems stem from institutional complementarities and inappropriate sequencing. One logical sequence might be banking reform, corporate governance, labor relations, and then finally business restructuring. Now, an emerging question is whether the reform blueprint was right. Post-crisis Korea just tried to be more market- or Anglo-Saxon model-oriented without paying attention to growth potential. While firms have now lowered their debt ratios, they are not borrowing to fund investments. The issue of right or wrong blueprint underscores the need to define the reform goal correctly. The goals of reform should not just be a move toward a market-oriented economy but toward a growth-oriented one or a pro-growth market-oriented one.Environmental Economics&Policies,Banks&Banking Reform,Children and Youth,Economic Theory&Research,National Governance

Generic features of the cosmological evolution of density parameters

The evolution of various energy components with dark energy was examined. Recently many non-standard gravity models were suggested to explain the current observational data showing an accelerating phase since the recent past. All suggested models should mimic ΛCDM somehow, especially from the near past to the current epoch. However, most of them do not try to explain or predict what happens if their model were extended to the far past and/or the past. In this paper we want to address this point by analyzing the critical points of the evolution equations and their stability. Standard ΛCDM gives three critical points, radiation dominated, matter dominated, and cosmological constant dominated. Furthermore, the radiation-dominated point corresponds to the past stable point, the matterdominated point to the saddle point, and the cosmological-constant–dominated point to the future stable point. This means that this model predicts that the universe starts from radiation domination then passes through a matter-dominated era and finally evolves into a cosmological-constant–dominated era, that is, the future de Sitter phase. We applied these creteria to few f(R) gravity models to determine viable parameter ranges

Holographic Nuclear Matter in AdS/QCD

We study the physics with finite nuclear density in the framework of AdS/QCD with holographic baryon field included. Based on a mean field type approach, we introduce the nucleon density as a bi-fermion condensate of the lowest mode of the baryon field and calculate the density dependence of the chiral condensate and the nucleon mass. We observe that the chiral condensate as well as the mass of nucleon decrease with increasing nuclear density. We also consider the mass splitting of charged vector mesons in iso-spin asymmetric nuclear matter.Comment: 16 pages, 3 figures, two references are added, typo corrected, section 3.3 remove