Sensing technology has been widely investigated and utilized for gas detection. Due to the different applicability and inherent limitations of different gas sensing technologies, researchers have been working on different scenarios with enhanced gas sensor calibration. This paper reviews the descriptions, evaluation, comparison and recent developments in existing gas sensing technologies. A classification of sensing technologies is given, based on the variation of electrical and other properties. Detailed introduction to sensing methods based on electrical variation is discussed through further classification according to sensing materials, including metal oxide semiconductors, polymers, carbon nanotubes, and moisture absorbing materials. Methods based on other kinds of variations such as optical, calorimetric, acoustic and gas-chromatographic, are presented in a general way. Several suggestions related to future development are also discussed. Furthermore, this paper focuses on sensitivity and selectivity for performance indicators to compare different sensing technologies, analyzes the factors that influence these two indicators, and lists several corresponding improved approaches.

A Survey on Gas Sensing Technology

Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors), polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types.

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Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

Wearable electronics is expected to be one of the most active research areas in the next decade; therefore, nanomaterials possessing high carrier mobility, optical transparency, mechanical robustness and flexibility, lightweight, and environmental stability will be in immense demand. Graphene is one of the nanomaterials that fulfill all these requirements, along with other inherently unique properties and convenience to fabricate into different morphological nanostructures, from atomically thin single layers to nanoribbons. Graphene-based materials have also been investigated in sensor technologies, from chemical sensing to detection of cancer biomarkers. The progress of graphene-based flexible gas and chemical sensors in terms of material preparation, sensor fabrication, and their performance are reviewed here. The article provides a brief introduction to graphene-based materials and their potential applications in flexible and stretchable wearable electronic devices. The role of graphene in fabricating ...

Flexible Graphene-Based Wearable Gas and Chemical Sensors

Electrically–transduced sensors, with their simplicity and compatibility with standard electronic technologies, produce signals that can be efficiently acquired, processed, stored, and analyzed. Two dimensional (2D) nanomaterials, including graphene, phosphorene (BP), transition metal dichalcogenides (TMDCs), and others, have proven to be attractive for the fabrication of high–performance electrically-transduced chemical sensors due to their remarkable electronic and physical properties originating from their 2D structure. This review highlights the advances in electrically-transduced chemical sensing that rely on 2D materials. The structural components of such sensors are described, and the underlying operating principles for different types of architectures are discussed. The structural features, electronic properties, and surface chemistry of 2D nanostructures that dictate their sensing performance are reviewed. Key advances in the application of 2D materials, from both a historical and analytical pers...

Electrically-Transduced Chemical Sensors Based on Two-Dimensional Nanomaterials

Removal of malachite green from dye wastewater using neem sawdust by adsorption.

An amperometric biosensor for the rapid assessment of histamine level in tiger prawn (Penaeus monodon) spoilage

Dyes are usually present in trace quantities in the treated effluents of many industries. The effectiveness of
adsorption for dye removal from wastewaters has made it an ideal alternative to other expensive treatment
methods. This study investigates the potential use of sugarcane bagasse, pretreated with formaldehyde and
sulphuric acid, for the removal of methyl red, an azo dye from simulated wastewater. The effects of condition
such as adsorbent dosage, initial dye concentration, pH and contact time were studied. The results showed that
as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly. Higher
adsorption percentages were observed at lower concentrations of methyl red. Sulphuric acid treated sugarcane
baggase showed a better performance compared to formaldehyde treated sugarcane baggase, thus making it an
interesting option for dye removal from dilute industrial effluents.

Azo dye removal by adsorption using waste biomass: sugarcane bagasse

Malaysian engineering education is now embracing an Outcome Based Education (OBE) approach. This approach emphasizes on the outcomes, as opposed to the process in an educational strategy. The approach now becomes one of the important for an engineering degree to obtain accreditation from the Malaysian Engineering Accreditation Council (EAC). The approach is relatively new in the country, and it requires extensive assessment and evidence to demonstrate that an outcome has been achieved. The Faculty of Engineering at Universiti Putra Malaysia has developed an office automation system to assist the respective departments to monitor the development of their respective program outcomes. This paper describes the office automation system and its strength and weakness after one year of its first implementation. Introduction Wikipedia defines Outcome-based education (OBE) as “...a recurring education reform model. It is a student-centered learning philosophy that focuses on empirically measuring student performance, which are called outcomes. OBE contrasts with traditional education, which primarily focuses on the resources that are available to the student, which are called inputs. Unlike many pedagogical models, such as project-based learning or whole language reading, OBE does not specify or require any particular style of teaching or learning. Instead, it requires that students demonstrate that they have learned the required skills and content” [1]. There have been many debates on the advantages and disadvantages of OBE. Some of the arguments for the proponents of OBE inlcude [2]; • OBE is able to measure—‘what the students are capable of doing’—something which the traditional education system often fails to do. • OBE goes beyond ‘structured tasks’ (e.g. memorisation) by demanding that students demonstrate his/her skills through more challenging tasks like writing project proposals and completing the projects, analysing case studies and giving case presentations • OBE also identifies higher levels of thinking (e.g. creativity, ability to analyse and synthesise information, ability to plan and organise tasks). Some of disadvantages of OBE as proposed by its opponents are [3]; • OBE is not about academics such as reading, writing and arithmetic, but OBE are about attitudes and outcomes • OBE uses students as guinea pigs in a vast social experiment • OBE offers no method of accountability to students, parents, teachers, or taxpayers – it is expensive • OBE is a dumbed-down egalitarian scheme that stifles individual potential for excellence and achievement by holding the entire class to the level of learning attainable by every child. • In an OBE system, academic and factual subject matter is replaced by vague and subjective learning outcomes Despite the ongoing reservation on its implementation, it is now being implemented in the Faculty of Engineering, UPM. The faculty believes that the approach is appropriate for the types of students it gets, and above all, it is required by the local accreditation body. The OBE implementation is now a compulsory requirement for obtaining the accreditation from the Engineering Accreditation Council (EAC), Malaysia [4]. Its implementation in the Bachelor of Engineering programs is mainly to prepare graduates to have knowledge and skills required by the industry. This paper describes strategies of its implementation, especially with respect to assessment strategy. OBE Implementation Strategy The Faculty of Engineering of Universiti Putra Malaysia (UPM) had taken initiatives to revise its 2000-2005 curriculums. The revised curriculum (based on 2006-2010 programs) was first implemented in the 2006 academic year. The OBE approach requires better planning, implementation and monitoring of an engineering program. It calls for a total support from the management, academic and supporting staff. In general, OBE requires an engineering program to address four important questions that are [5]: i) What do you want the students to have or able to do? ii) How can you best help the students achieve it? iii) How will you know that they have achieved it? iv) How do you close the loop? The questions are to be answered by the head of program and individual lecturers. The first question calls for the development of program objectives, program outcomes and course outcomes. The second question calls for the appropriate teaching/ learning facilities and techniques to be employed in various programs or courses. The third question calls for appropriate assessment to demonstrate that the students have obtained the required outcomes. The fourth question calls for the evaluation on the effectiveness of all the plans and implementation of the learning outcomes and ascertain rooms for improvement either in learning or teaching. The overall OBE implementation strategy at UPM is shown in Figure 1. The figure shows the development of the Bachelor of Engineering (BE) programs and its implementation strategies. Basically it contains three main elements that are (a) development, (b) implementation, and (c) monitoring/review. Appropriate assessment strategies are important in the review process, which will be used to improve the program design and delivery. Assessment Strategy From Figure 1, it is clear that there are two cycles of “develop-implement-review” in order to achieve improvement of the program. There is an internal cycle for continual improvement that involves the courses outcomes i.e. course implementation-course assessment relationship. The other cycle is the external cycle that involves the program outcomes-program implementation-program assessment/evaluation relationship. The faculty had adopted 15 generic program outcomes for all its BE programs that encompass the three main domains and addresses the minimum requirement by EAC and the Department of Higher Education, Ministry of Higher Education. All BE graduates of UPM are expected to have the following attributes by the time they graduate i.e. they are able to; 1. Apply knowledge of mathematics and engineering sciences. 2. Design and conduct experiment 3. Analyse and interpret data. 4. Design a system, component or process to meet the design requirement 5. Use principles of sustainable design and development 6. Function effectively as an individual in a group 7. Demonstrate leadership or managerial characteristics 8. Identify, formulate and provide creative/innovative/effective solution to the problem. 9. Explain of professional and ethical responsibility. 10. Communicate effectively with engineers, other professionals and community at large 11. Explain the impact of engineering solutions in societal, cultural, global and environmental context. 12. Recognize the need for and able to engage in lifelong learning. 13. Discuss relevant contemporary issues 14. Use necessary skills, techniques and modern engineering tools for engineering practice. 15. Solve problems in advanced design and development Output: (Internal Stakeholder) Staff, Students, University Program Development and Review Final Year Project, Program Assessment (Formative) Program Assessment Summative (external) Employer/ Industry Survey External Assessor/ EAC Summative (Internal) Exit survey/Alumni Survey Program Objectives, Program Structures Regulatory Body Self assessment lecturers summary of teaching and learning Develop/ Review Courses Course Outcomes & Content Course Implementation Teaching Plan, Methods/ Activities Course Assessment Learning students assessment by Teaching staff assessment by (includes lecturer, demonstrator, Program Assessment External Assessor External Assessor Employer/ Industry Survey External Stakeholder Course 1 Course 2 Course 3 . . . Course n Course 1 Course 2 Course 3 . . . Course n Figure 1: Overall Flow for the Program Development, Implementation and Monitoring All these outcomes are categorized into three main domains that are: i) Cognitive domains ii) Psychomotor domains iii) Affective domains Each course within a program needs to address each of the domains with appropriate taxonomy level. Taxonomy levels are referred to different level attainment for each domain. Each of the domains and the taxonomy levels need to be addressed and assessed within the appropriate course. The course outcomes to program outcomes matrix is developed in such a way that the domains are appropriately developed. Using appropriate assessment tools, a course lecturer will report to the program head on the achievement of the students with respect to the outcomes he/she was supposed to address. Figure 2 shows a program matrix to indicate the overall plan for assessment at the Faculty of Engineering UPM. The implementation plan starts with the assessment for the entry students. The students’ preparation with respect to knowledge and affective skills are assessed through their grades and self assessment when they first enter into the program. The assessment of students’ attainment for each program outcomes are carried out at the end of every session so their program outcomes may be monitored and any intervention may be adopted. This continuous assessment throughout their four year study is considered as formative assessment. Each faculty member is expected to provide data for this continuous assessment, depending on the outcomes he/she is expected to address within his/her course. To ascertain the effectiveness of the course/ program delivery, summative assessments are conducted using internal and external resources. The internal summative assessment is done by lecturers through final year project, capstone design or industrial training. The external summative assessment is done through the external examiner, exit survey, alumni and employer/ industry survey. The outcomes of all these assessment need to be evaluated and the conclusions from the evaluation are used further improve the program. Exit survey x x x x x x x x x x x x x x x Employer survey x x x x x x x x x x x x x x x Alu

Rahman Wagiran

Papers

Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

An amperometric biosensor for the rapid assessment of histamine level in tiger prawn (Penaeus monodon) spoilage

Azo dye removal by adsorption using waste biomass: sugarcane bagasse

Assessment Strategy for an Outcome Based Education

Screen-printed histamine biosensors fabricated from the entrapment of diamine oxidase in a photocured poly(HEMA) film