Ozone trends from two decades of ground level observation in Malaysia

We examine the change in surface ozone and its precursor behavior over 20 years at four locations in western Peninsular Malaysia which have undergone urban-commercial development. Trend and correlation analyses were carried out on ozone and oxides of nitrogen observation data over the periods of 1997–2016 as well as the decadal intervals of 1997–2006 and 2007–2016. Diurnal variation composites for decadal intervals were also plotted. Significant increasing ozone concentrations were observed at all locations for the 20-year period, with a range between 0.09 and 0.21 ppb yr−1. The most urbanized location (S3) showed the highest ozone trend. Decadal intervals show that not all stations record significant increasing trends of ozone, with S1 recording decreasing ozone at a rate of −0.44 ppb yr−1 during the latter decade. Correlation analysis showed that only oxides of nitrogen ratios (NO/NO2) had significant inverse relationships with ozone at all stations corresponding to control of ozone by photostationary state reactions. The diurnal composites show that decadal difference in NO/NO2 is mostly influenced by change in nitric oxide concentrations.</jats:p

An overview on convergence acceleration of cyclic adsorption processes

Cyclic adsorption processes are inherently dynamic where the process variables are always varying with time. The cyclic processes have no steady state. Thousands of repeated cycles may be needed before cyclic steady state (CSS) is reached. In this paper, the basic concept and characteristics of cyclic adsorption processes are first introduced, using air separation by rapid pressure swing adsorption as an example. Next, different approaches to calculate and accelerate the convergence of CSS are briefly reviewed. The computational time can be reduced by having an efficient discretisation technique and accelerators to achieve the final CSS. Hybrid methods are potentially attractive

Sediment transport modeling and flood risk mapping in Geographic Information System (GIS)

Most computer models used in the flood risk analysis of rivers have inadequate functions in its spatial analytical capabilities and without sediment transport simulation capacity or suitable equations to represents correctly in-situ hydraulic processes (Sinnakaudan et al., 2001, Sinnakaudan, 2003). Further more, the consistent deficiencies of these models are their inability to connect the information describing the water profiles with their physical locations on the land surface. This is where a Geographic Information System (GIS) becomes a valuable tool in spatial modeling for engineers, planners and geoscientist (Burrough, 1998; Sinnakaudan et.al, 2003)

Hybrid algorithm for acceleration of convergence to cyclic steady state

Cyclic process is inherently dynamic, thus it has no steady state. However, the process, after a sufficient number of cycles, will reach a state called Cyclic Steady State (CSS) where the process state variables at some instant within a cycle have the same value at the corresponding instant within each subsequent cycle. Depending on the nature of the cyclic process, the number of cycles needed before the process reaches CSS may vary from tens to thousands. In this study, a hybrid algorithm that aims to predict and accelerate the convergence of the CSS is developed and tested on a cyclic operation of controlled-cycled stirred tank reactor

Intertwining the arts and sciences to stimulate a creative mind

From the basic motion of a simple pendulum, which acts as a tool that turns a blank canvas into pure abstract art, this particular concept has been applied to science-related art to showcase its tremendous impact on scientific, psychological and educational fields. The Art and Science Program is a collaborative artistic program between the committees from the Chemical and Energy School of Engineering, UTM, and Sekolah Tun Fatimah (STF), with the aim of examining the impacts of the rotational motion of the pendulum which can generate mesmerizing art on blank mahjong papers. The outcome of the art has been influenced by various factors, such as the viscosity of the paint used, the flowrate of the paint drip, the velocity of the paint-pendulum-modelled dripper, the position of the release point, and the motion of the dripper arising from the resultant force of multiple interacting forces. By showing the interconnections between pendulum motion, gravitational force, potential and kinetic energies, and the fundamentals of fluid dynamics, artistic abstract paintings can be created from the science of mechanics. Intertwining the arts and sciences that has been the main focus of this program can garner greater appreciation, even embraced, as it results in a significant effect on the development of both creative and critical thinking among the participants and committees

Corrosion Inhibition on Mild Steel by Phosphonium Salts in 1M HNO3 Aqueous Medium

The corrosion inhibition on mild steel by phosphonium salts in 1 M HNO3 medium has been investigated by weight loss and polarization techniques. The result revealed that these derivatives are excellent inhibitors. Potentiostatic polarization, impedance and electrochemical noise studies showed mixed type inhibitors. Ellipsometer, quantum chemical and FTIR results indicated Phosphonium bromide derivatives exhibit excellent corrosion protective thin layer performance

Impact of financial inclusion in low- and middle-income countries: a systematic review of reviews

Financial inclusion programmes seek to increase access to financial services such as credit, savings, insurance and money transfers and so allow poor and low-income households in low- and middle-income countries to enhance their welfare, grasp opportunities, mitigate shocks, and ultimately escape poverty. This systematic review of reviews assesses the evidence on economic, social, behavioural and gender-related outcomes from financial inclusion. It collects and appraises all of the existing meta-studies - that is systematic reviews and meta-analyses - of the impact of financial inclusion. The authors first analyse the strength of the methods used in those meta-studies, then synthesise the findings from those that are of a sufficient quality, and finally, report the implications for policy, programming, practice and further research arising from the evidence. Eleven studies are included in the analysis

Can We Monitor All Multithreaded Programs?

International audienceRuntime Verification (RV) is a lightweight formal method which consists in verifying that an execution of a program is correct wrt a specification. The specification formalizes with properties the expected correct behavior of the system. Programs are instrumented to extract necessary information from the execution and feed it to monitors tasked with checking the properties. From the perspective of a monitor, the system is a black box; the trace is the only system information provided. Parallel programs generally introduce an added level of complexity on the program execution due to concurrency. A concurrent execution of a parallel program is best represented as a partial order. A large number of RV approaches generate monitors using formalisms that rely on total order, while more recent approaches utilize formalisms that consider multiple traces. In this tutorial, we review some of the main RV approaches and tools that handle multithreaded Java programs. We discuss their assumptions, limitations, ex-pressiveness, and suitability when tackling parallel programs such as producer-consumer and readers-writers. By analyzing the interplay between specification formalisms and concurrent executions of programs, we identify four questions RV practitioners may ask themselves to classify and determine the situations in which it is sound to use the existing tools and approaches