A Study of Hydrotropic Pulping

Aspen wood chips and hardwood thermomechanical pulp were cooked with Sodium Xylen Sulfonate solution in various cooking temperature, time length, chemical content and liquor to wood radio. The process had a very high yield but the products produced a poor strength. Brightness was increased slightly by the treatment. Kappa Number was decreased at the beginning of the cook but increased again as the cook proceeded. Based on this experimental data, hydrotropic pulp produced from wood chips and thermomechanical pulp was inferior to ordinary chemical pulp (Kraft or Sulfate) both in terms of physical and optical characteristics

Numerical studies of fluid flow across a cosmo ball by using CFD

Cosmo ball is a media used in wastewater treatment to increase the surface area of contact and provide longer contact time for biological activities. It is usually placed as a media or as packing in the aeration tank, BioFil tank or even in the activated sludge tank. It induces the growth of bacteria on its surface, which will serve as a contact area for the wastewater and the microbial. The objective of this simulation is to analyze the flow pattern around the Cosmo ball which is been packed in the wastewater treatment tank. By conducting this analysis, the overall insights on the interaction of the fluid flow with the Cosmo ball surface can be visualize. The velocity of the fluid flow across the ball is at a speed of 2 cm sec-1. The velocity was obtained from the conventional wastewater treatment plant. During the simulation process, the model will undergo each section of program in ANSYS™ Computational Fluid Dynamics (CFD) such as Design Modeler, Meshing, Pre-Processing, Solver and Post-Processing. The flow distribution across the Cosmo ball was analyzed by varying the angle of attack of the flow. The rationale for this simulation arrangement is that the ball could take any orientation in the bulk media and the fluid flow across it would be at random angle. The result shows that the flow around the Cosmo ball was dispersing sideways thus inducing mixing in the wastewater system. Retention of flow has been observed to occur in the Cosmo ball. The retention of flow provides better microbial interaction with the wastewater

Radiative transfer theory for active and passive remote sensing of sea ice

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (p. 147-153).by Hong Tat Ewe.M.S

An examination of the influences of telecommuting on employee satisfaction and organizational citizenship behaviour in the information technology industry in Singapore

Telecommuting or telework has seen slow adoption over the years with some large corporations rescinding their support for this practice. While studies have linked telecommuting to favorable organizational outcomes such as employee satisfaction, organizational performance, reduced turnover intentions, higher employee commitment, some other studies have shown debatable outcomes. This thesis aims to study the influence of telecommuting support on employee satisfaction and organizational citizenship behaviour in the IT industry in Singapore. Using sequential-mixed methods approach, this study collected data from 100 IT employees familiar with telecommuting using purposive sampling comprising online questionnaires as the first step, followed by in-depth interviews with five managers. The findings conclude that telecommuting support positively impacts employee satisfaction and organizational citizenship behaviour. Disadvantages of telecommuting often cited in literature are not found to be significant variables. The presence of elderly dependents is a predictor for increased organizational citizenship behaviour while employees working in large multinational companies larger than 250 employees are found to have decreased organizational citizenship behaviour. There are 10 factors identified to influence manager’s adoption of telecommuting practice for their work teams. The results from this thesis enable the proposal of a telecommuting adoption conceptual model where managers can lend guidance in the adoption of telecommuting for their organizations

Remote sensing backscattering model for sea ice: Theoretical modelling and analysis

Remote sensing has been used in Antarctic studies as an earth observation technique to study the polar region. A remote sensing forward model is an important tool in polar research to study and understand scattering mechanisms and sensitivity of physical parameters of snow and sea ice. In this paper, a reliable theoretical model to study sea ice is developed. The theoretical model in a prior work was improved by including multiple-surface scattering, based on an existing integral equation model and additional second-order surface-volume scattering. This model is applied to a desalinated ice layer above thick saline ice and analyzed using different frequencies, bottom surface roughness and sea-ice layer thickness. Improvement in calculation of the backscattering coefficient of the sea-ice layer is investigated for both co-polarized and cross-polarized returns. The effect on each scattering mechanism is also investigated, to understand in more detail the effect of surface multiple scattering and second-order surface-volume scattering. Comparisons are also made with field measurement results, to validate the theoretical model. Results show improvement in the total backscattering coefficient for cross-polarized return in the studied range, suggesting that multiple-surface scattering and surface-volume scattering up to second order are important scattering mechanisms in the sea-ice layer and should not be ignored in polar research

Performance Evaluation Of Unidirectional Lightweight Encapsulation Using ns-2 And DVB-S Testbed.

Unidirectional Lightweight Encapsulation (ULE) is a recently published standard to overcome the efficiency problems of Multi-Protocol Encapsulation for satellite data transmission. This paper presents a comparative study of Unidirectional Lightweight Encapsulation performance using ns-2 [ll simulation and a DVB-S testbed. Performance metrics such link utilization packet loss and latency were taken. It was found that the results of both approaches were comparabl

Ceph as WAN Filesystem – Performance and Feasibility Study through Simulation

Recent development in object based distributed file systems (DFS) such as Ceph, GlusterFS as well as the more established ones like Lustre, GPFS, etc. have presented new opportunities to setup next generation of storage infrastructure for cloud computing, big data, and Internet of Things (IoT). However, existing DFSs are typically deployed to Local Area Network (LAN) and generally used for high-performance computing. Extending these DFSs into geographically distributed sites such as Campus Area Network (CAN) and Wide Area Network (WAN) for enterprise applications presents completely different set of challenges and issues. Unlike most implementations that choose a traditional multi sites deployment, i.e., each site implements a virtual storage (via LAN) and links through RESTful APIs (via WAN), we attempt to create a single virtual storage over WAN using Ceph. In this paper, we demonstrate that a properly designed and configured virtualized environment is a valuable tool for researchers to simulate a distributed files system over WAN without an actual physical environment.  By following a few guidelines, the read and write performance results in a simulated environment can indicate the trending of the read and write performance in the actual physical environment.  This implies that the storage design can be verified prior to actual deployment and establish a performance baseline. An obvious benefit is the initial investment of a storage solution is lower. Furthermore, this paper discuss about the challenges of setting up such environment, the feasibility of using Ceph as a single virtual store, and some possible future works