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Water and Environmental Engineering: Embracing Multi-Disciplinary Approach through Advanced and Integrated Technologies for Sustainability

Author(s):Suhaimi Abdul-Talib -- Chia-Chay Tay -- Nor-Azazi Zakaria -- Aminuddin Ab-Ghani -- Lariyah Mohd-Sidek -- Ngai-Weng Chan
Journal: Journal of Asian Scientific Research
Publisher:
Abstract
| Pages: 194-206
This paper addresses how the current changes in climate and economic landscape affect the focus of engineers and scientists in managing the abundant but finite water resources. The important concept of sustainability where the delicate balance between human needs and protection of the environment is further stressed in light of emerging advanced technological platforms. The critical need to embrace these emerging platforms through multi-disciplinary approaches is highlighted through selected research projects covering management of water resources and water demand; innovative treatment of municipal and industrial wastewater; bioremediation of contaminated soil; potential exploitation of bioenergy. The paper concludes on the need for scientists and engineers to adopt both advanced technological platforms and multi-disciplinary approach towards providing innovative and sustainable solution to current and future problems.

About The Study of Stresses for Desmopan Membrane by Finite Elements Method (FEM)

Author(s):Adrian Botean -- Mihaela Suciu -- Lucian Fechete -- Gavril Balc -- Marius Gheres -- Sorin Grozav
Journal: Journal of Asian Scientific Research
Publisher:
Abstract
| Pages: 207-213
This paper presents an original work about the study of stresses for a desmopan membrane by Finite Elements Method (FEM). The desmopan is a thermoplastic polyurethane, so an anisotropic material for which is made in a very wide range of models and types. This requires as input the mechanical characteristics, determined by Digital Image Correlation Method (DICM) and the geometrical characteristics. The stresses, output of FEM, are necessary to calculate the fatigue resistance to limited durability to fracture and after, the reliability studies of membranes. This work forms the basis of reliability studies of the desmopan membranes, that diaphragm pumps are equipped. Determination of fatigue resistance to limited durability for desmopam membrane is very important to estimate the membrane life, respectively, determining the number of failure cycles. 

Robust Flight Control Design to Minimize Aircraft Loss-of-Control Incidents

Author(s):Ronald A. Hess
Journal: Aerospace
Publisher:
Abstract
| Pages: 1-17
A pseudo-sliding mode control synthesis procedure discussed previously in the literature is applied to the design of a control system for a nonlinear model of the NASA Langley Generic Transport Model. The complete vehicle model is included as an appendix. The goal of the design effort is the synthesis of a robust control system to minimize aircraft loss-of-control by preserving fundamental pilot input—system response characteristics across the flight envelope, here including the possibility of actuator damage. The design is carried out completely in the frequency domain and is described by a ten-step synthesis procedure, also previously introduced it the literature. Five different flight tasks are considered in computer simulations of the completed design demonstrating the stability and performance robustness of the control system.

Student Expectations from Participating in a Small Spacecraft Development Program

Author(s):Jeremy Straub -- David Whalen
Journal: Aerospace
Publisher:
Abstract
| Pages: 18-30
The number of small spacecraft development programs in the United States and worldwide have increased significantly over the course of the last 10 years. This paper analyzes reasons for the growth in these programs by assessing what student participants hope to gain from their participation. Participants in the OpenOrbiter Small Spacecraft Development Initiative at the University of North Dakota were surveyed at the beginning of an academic year to determine why they were planning to participate in the program again or join and participate for the first time. This paper presents the results of this survey.

The Space Mission Design Example Using LEO Bolos

Author(s):Oleg Nizhnik
Journal: Aerospace
Publisher:
Abstract
| Pages: 31-51
Four sample space launch missions were designed using rotating momentum transfer tethers (bolos) within low Earth orbit and a previously unknown phenomenon of “aerospinning” was identified and simulated. The momentum transfer tethers were found to be only marginally more efficient than the use of chemical rocket boosters. Insufficient power density of modern spacecrafts was identified as the principal inhibitory factor for tether usage as a means of launch-assistance, with power densities at least 10 W/kg required for effective bolos operation.

Regional Air Quality Model Application of the Aqueous-Phase Photo Reduction of Atmospheric Oxidized Mercury by Dicarboxylic Acids

Author(s):Jesse O. Bash -- Annmarie G. Carlton -- William T. Hutzell -- O. Russell Bullock Jr.
Journal: Atmosphere
Publisher:
Abstract
| Pages: 1-15
In most ecosystems, atmospheric deposition is the primary input of mercury. The total wet deposition of mercury in atmospheric chemistry models is sensitive to parameterization of the aqueous-phase reduction of divalent oxidized mercury (Hg2+). However, most atmospheric chemistry models use a parameterization of the aqueous-phase reduction of Hg2+ that has been shown to be unlikely under normal ambient conditions or use a non mechanistic value derived to optimize wet deposition results. Recent laboratory experiments have shown that Hg2+ can be photochemically reduced to elemental mercury (Hg) in the aqueous-phase by dissolved organic matter and a mechanism and the rate for Hg2+ photochemical reduction by dicarboxylic acids (DCA) has been proposed. For the first time in a regional scale model, the DCA mechanism has been applied. The HO2-Hg2+ reduction mechanism, the proposed DCA reduction mechanism, and no aqueous-phase reduction (NAR) of Hg2+ are evaluated against weekly wet deposition totals, concentrations and precipitation observations from the Mercury Deposition Network (MDN) using the Community Multiscale Air Quality (CMAQ) model version 4.7.1. Regional scale simulations of mercury wet deposition using a DCA reduction mechanism evaluated well against observations, and reduced the bias in model evaluation by at least 13% over the other schemes evaluated, although summertime deposition estimates were still biased by −31.4% against observations. The use of the DCA reduction mechanism physically links Hg2+ reduction to plausible atmospheric processes relevant under typical ambient conditions.

Diurnal Variation of Rainfall Associated with Tropical Depression in South China and its Relationship to Land-Sea Contrast and Topography

Author(s):Yuchun Zhao
Journal: Atmosphere
Publisher:
Abstract
| Pages: 16-44
Convective precipitation associated with tropical depression (TD) is one primary type of post-flooding season rainfall in South China (SC). Observations of the Tropical Rainfall Measuring Mission (TRMM) satellite have shown specific diurnal features of convective rainfall in South China, which is somewhat different from that in other seasons or regions of China. Convective precipitation is usually organized into a rainfall band along the southeastern coast of South China in the early morning hours. The rainfall band develops and intensifies quickly in the morning, then moves inland in the afternoon and, finally, diminishes at night. The daily convective rainfall along the coast is much more than that in the inland region, and heavy rainfall is often found along the coast. A long-duration heavy rainfall event associated with tropical depression “Fitow” during the period from 28 August to 6 September 2001, is selected in this study to explore the diurnal feature of convective rainfall and its formation mechanism. Modeling results of the 10-day heavy rainfall event are compared with both rain-gauge observation and satellite-retrieved rainfall. Total precipitation and its spatial distribution, as well as diurnal variations are reasonably simulated and agree well with observations. Further analysis reveals that the development and movement of convective precipitation is mainly related to the land and sea breezes. The anomalous height-latitudinal circulation in the morning-to-noon hours is completely reversed in the afternoon-to-late-evening hours, with the convective rainfall swinging back and forth, following its updraft branch. Sensitivity experiments show that the afternoon convective rainfall in the inland region of SC is caused by the diurnal variation of solar radiation forcing. The mountain range along the coast and the complex topography in the inland region of SC plays a critical role in the enhancement of diurnal convective rainfall everywhere. The formation of a heavy rainfall band along the southeastern coast of SC and the diurnal variation of the rainfall pattern are mainly the results of the land-sea thermal contrast.

Benefits of European Climate Policies for Mercury Air Pollution

Author(s):Peter Rafaj -- Janusz Cofala -- Jeroen Kuenen -- Artur Wyrwa -- Janusz Zyśk
Journal: Atmosphere
Publisher:
Abstract
| Pages: 45-59
 This paper presents the methodology and results of impact assessment of renewable energy policies on atmospheric emissions of mercury in Europe. The modeling exercise described here involves an interaction of several models. First, a set of energy scenarios has been developed with the REMix (Renewable Energy Mix) model that simulates different levels of penetration of renewable energies in the European power sector. The energy scenarios were input to the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) model, which prepared projections of mercury releases to the atmosphere through 2050, based on the current air pollution control policies in each country. Data on mercury emissions from individual sectors were subsequently disaggregated to a fine spatial resolution using various proxy parameters. Finally, the dispersion of mercury in the atmosphere was computed by the chemistry transport model, implemented to the air quality system, Polyphemus. The simulations provided information on changes in concentrations and depositions of various forms of mercury over Europe. Scenarios that simulate a substantial expansion of renewable energies within the power sector indicate extensive co-benefits for mercury abatement, due to the restructuring of the energy system and changes in the fuel mix. The potential for mercury reductions in Europe depends on the rate of fuel switches and renewable technology deployment, but is also influenced by the stringency and timing of the air quality measures. The overall scope for co-benefits is therefore higher in regions relying on coal combustion as a major energy source.

Data Mining Methods to Generate Severe Wind Gust Models

Author(s):Subana Shanmuganathan -- Philip Sallis
Journal: Atmosphere
Publisher:
Abstract
| Pages: 60-80
Gaining knowledge on weather patterns, trends and the influence of their extremes on various crop production yields and quality continues to be a quest by scientists, agriculturists, and managers. Precise and timely information aids decision-making, which is widely accepted as intrinsically necessary for increased production and improved quality. Studies in this research domain, especially those related to data mining and interpretation are being carried out by the authors and their colleagues. Some of this work that relates to data definition, description, analysis, and modelling is described in this paper. This includes studies that have evaluated extreme dry/wet weather events against reported yield at different scales in general. They indicate the effects of weather extremes such as prolonged high temperatures, heavy rainfall, and severe wind gusts. Occurrences of these events are among the main weather extremes that impact on many crops worldwide. Wind gusts are difficult to anticipate due to their rapid manifestation and yet can have catastrophic effects on crops and buildings. This paper examines the use of data mining methods to reveal patterns in the weather conditions, such as time of the day, month of the year, wind direction, speed, and severity using a data set from a single location. Case study data is used to provide examples of how the methods used can elicit meaningful information and depict it in a fashion usable for management decision making. Historical weather data acquired between 2008 and 2012 has been used for this study from telemetry devices installed in a vineyard in the north of New Zealand. The results show that using data mining techniques and the local weather conditions, such as relative pressure, temperature, wind direction and speed recorded at irregular intervals, can produce new knowledge relating to wind gust patterns for vineyard management decision making.
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