Series Of Laboratory Exercises Research Articles

Engineering Critical Thinking in Chemical Engineering-Implementation and Student’s Perception

Chemistry for Engineers is a fundamental subject in the Chemical Engineering curriculum, and it serves as a bridge between science and engineering by integrating theoretical concepts with real-world situations. To be successful in their careers, future engineers must master the skill of critical thinking. The goal of this research is to use the DoIt@Home Laboratory to improve students' critical thinking and problem-solving skills. The Carona pandemic necessitated the development of this component, which consists of a series of laboratory exercises that require pupils to demonstrate critical thinking skills. In order to better understand students' perceptions of and performance in learning CT skills using the new approach, surveys were utilized to evaluate the DoIt@Home Laboratory. We were able to demonstrate that the DoIt@Home Laboratory is an effective method for enhancing critical thinking skills. 75 % of students have adequate reasoning, evaluation, and problem-solving skills. Indicators from both chemistry and statistics lend credence to their arguments. 52 % of students think they have a good grasp on the fundamentals of chemistry, meaning that they can explain phenomena and study results, defend their positions with evidence, and synthesize arguments.

CALEE: A computer-assisted learning system for embedded OS laboratory exercises

With the popularity of embedded systems and the consequently rising demand in the job market for professionals well-versed in them, embedded operating systems (EOSs) have become one of the core courses in computer science studies across the world. The objective of EOS courses is to develop students' ability to port, modify, and customize an embedded operating system through a series of laboratory exercises. However, our teaching experience has revealed that beginners require a considerable amount of time to familiarize themselves with the development environment and the relevant processes, such as operating in a command line interface, setting environment variables, and kernel configurations. Furthermore, students need to constantly handle compiler error messages, malfunctions of the target EOS, and incompatibility issues related to development tools. These problems may frustrate and discourage students. A common strategy to address this problem is to dedicate more hours to teaching or to hire more teaching assistants to help students progress. However, none of these methods is suitable for institutions with limited resources. Therefore, in this paper, we develop a computer-assisted learning system called the Computer-assisted Learning Environment (CALEE) to assist students with their assignments and thus motivate them. CALEE consists of two parts: a self-learning assistant (SLAT) and a collaborative learning website (CLW). SLAT is a software application that provides a set of useful functions to help students perform EOS laboratory exercises, whereas the collaborative learning website seeks to encourage greater interaction among students. Our experiments show that CALEE expedites learning, improves students' motivation, and reduces the teaching load.

Environmental Microbiology: Tannins & Microbial Decomposition of Leaves on the Forest Floor

Tannins are plant chemicals that humans find useful in products as diverse as tea and leather. Why do plants produce these compounds? One possible answer is defense against pathogens and herbivores. In this series of laboratory exercises, student inquiry begins with a simple question: What happens to the multitude of leaves that drop each autumn? This inquiry brings students from the outdoors to the laboratory, where they observe differences in leaf decomposition rates and the natural abundance of bacteria and tannin concentrations in leaf tissues of red oak, white oak, and tulip poplar. In the process, students increase their understanding of plant chemistry, bacterial culture, graphing, and natural history, while experiencing the iterative nature of scientific inquiry.

Teaching the Cache Memory System Using a Reconfigurable Approach

This paper presents a tool that simulates a reconfigurable cache whose parameters can be changed at runtime through a special instruction at the instruction set architecture (ISA) level. The proposed tool simulates a cache system that can be reconfigured within a variety of 298 combinations of cache capacity, number of ways or associativity, and line/block size in words (C, W, and L) without changing its architecture. The simulator was developed through a series of laboratory exercises in computer architecture. The students are introduced to the reconfigurable cache architecture while refreshing their knowledge on computer architecture issues like logic design, and register transfer level and computer system level architectures, as well as reinforcing concepts about memory system organization and architecture. This paper presents an overview of the reconfigurable cache and a description of the simulator interface. Finally, feedback from the students provides assessment on using the simulator in the laboratory.

Promoting Student Involvement with Environmental Laboratory Experiments in a General Microbiology Course

This is a descriptive study of a series of laboratory exercises on environmental microbiology carried out by students in a general microbiology course during eight of the twelve weeks of the semester. The revised laboratory component is predicated upon seawater and sediment samples collected by student pairs using marine sampling equipment on a field trip aboard a research vessel. Two longitudinal studies were performed: assay for antibiotic production from isolated actinomycetes and construction and observation of Winogradsky columns. Two additional experiments: culturing microalgae and water testing for coliforms also used the samples collected by the students. The advantages of long-term, challenging laboratory experiences actively involving the students in group process, self-direction, and scientific practices are discussed. Also considered are development of laboratory skills, scientific competencies, and students' self-confidence in carrying out such environmental investigations. Plans for future assessment of student learning are presented.

Integration of laboratory exercises in developmental biology and neurobiology courses using the Xenopus oocyte expression system

This collaborative laboratory exercise integrates two upper division laboratory courses (Developmental Biology and Neurobiology) offered to biology majors at Wake Forest University. The laboratory exercise involves the use of the Xenopus oocyte expression system to study the function of specific membrane receptors and ligand-activated channels. cDNA or mRNA for receptor proteins is injected into Xenopus oocytes. The oocytes are assayed for expression of receptor proteins and two-electrode voltage clamping is done to determine whether the expressed proteins are functional in the oocyte system. This series of laboratory exercises is innovative in its interdisciplinary and collaborative approach to undergraduate teaching, and in its use of sophisticated molecular biological and physiological techniques in the undergraduate teaching laboratory. Students learn first-hand how these techniques have been used to achieve a new level of understanding of both development and neurobiology. Journal of Industrial Microbiology & Biotechnology (2000) 24, 353–358.

A series of laboratory exercises utilizing luxR gene of Vibrio fischeri and gfp gene of Aequoria victoria to teach the broad applications of polymerase chain reaction

Three experiments are described; directional cloning of the luxR gene from the bioluminescent marine bacterium, Vibrio fischeri, directional cloning of the gfpgene from the marine jelly fish, Aequoria victoria, and the construction of a LuxR-GFP fusion protein. Experiments are presented using lux and gfp in an undergraduate biology curriculum. Journal of Industrial Microbiology & Biotechnology (2000) 24, 345–352.

Using music to teach physics

The analysis and synthesis of tones produced by acoustic musical instruments is used as a tool for teaching physics to students majoring in disciplines other than the sciences. A series of laboratory exercises, based on sound analysis and synthesis software running on microcomputer-based workstations, is described and placed in context with more traditional physics laboratory experiences and written assignments in a one-semester course in the physics of musical sound taught without advanced mathematics. Student reaction to the exercises is discussed.

An Intelligent Control Laboratory Course

This paper describes a unique control laboratory course at The Ohio State University which focuses on implementation of intelligent control algorithms for a variety of processes. Students execute a series of laboratory exercises implementing fuzzy control, adaptive fuzzy control, and other intelligent control techniques. Fully instrumented, independent tesbeds in the laboratory emphasize several sensing and actuation technologies.

Nonlinear acoustic waves in media with absorption and dispersion

A series of laboratory exercises in nonlinear wave physics assigned to students of the Physics Department of the Moscow State University in the laboratory of the Acoustics Section is described. The series consists of three assignments: 1) experimental investigation of nonlinear waves in dissipative media; 2) Investigation of nonlinear phenomena in acoustic beams by mathematical simulation using personal computers, and 3) Experimental investigation of wave propagation in a medium with dispersion (capillary waves on the surface of a liquid). As a result of carrying out these assignments, the students become familiar with the characteristic features of the behavior of nonlinear waves and the modern methods of describing and studying them.

An undergraduate VLSI CMOS circuit design laboratory

The author describes a structured, 13-week series of laboratory exercises which demonstrates very large scale integrated (VLSI) CMOS digital circuit design and simulation for undergraduates in electrical engineering. He also suggests cost effective measures that could make the laboratory exercises economically feasible for vocational schools, colleges, and universities. >

Use of an Expert System for Integrating Weed Control Strategies in a Weed Science Laboratory

Integrated weed management decisions require knowledge of weed taxonomy, weed interference effects, and effectiveness of control. Because they are multifaceted, principles of integrated weed management are difficult to teach in the classroom. A series of laboratory exercises have been developed in which weed taxonomic skills were coupled with the use of a modified version of HERB, a computerized economic threshold-based weed management decision-aid. The laboratory series began with 4 wk of weed taxonomy, followed by a pest management exercise in which two simulated weedy soybean [Glycine max (L.) Merr.] fields (in the greenhouse) were studied. Weed species, density, and size were determined for each field. This information, along with cultivation method, herbicide used, application cost and method, and yield information, serve as inputs to HERB. After inputing information, the decision-aid program then computes the cost of not controlling the weed population (damage estimate). This cost is compared with the costs of available control measures, and appropriate control measures are ranked in order of net-profitability. The student takes the decision-aid output and interprets the results of the damage estimate computations, and its relationship to the costs of control as they relate to the economic threshold principle. In a survey conducted following the lab sequence, 93% of the students agreed the laboratory series increased student appreciation for the importance of weed identification competency. In addition, 87% of the students agreed use of HERB made weed interference and economic threshold principles presented in lecture more meaningful.

Glyphosate: Herbicidal Effects, Mode of Action and Degradation in Soil

Herbicides are part of modern agricultural production systems and therefore contribute significantly to the economy of agricultural products. In the United States, losses caused by weed competition with major crops is approximately $8.9 billion, while the total expenditures for herbicides used is about $2.1 billion and the cost of applying these herbicides, $938 million annually (Chandler 1985). Without current technology to control the weeds, the losses would be doubled or tripled. At the same time, herbicides are potent and specific inhibitors of plant metabolism and may therefore be potentially useful as valuable tools in basic plant physiological research. Unfortunately, few herbicides are known to inhibit plant growth by direct inhibition of enzymes involved in metabolic pathways. Thus, most literature dealing with herbicidal effects on plants describes secondary and tertiary effects (Duke 1985a) such as chlorosis. The environment has been assaulted with a variety of chemical agents, among which herbicides contribute significantly. Some of these have appeared to be relatively innocuous, while others are quite hazardous. Thus, the biodegradability of a herbicide may be a factor in the decision to use it. In this paper we describe the usefulness of a relatively novel herbicideglyphosate-for a laboratory demonstration of herbicidal activity, mode of action and stability in soil. A series of laboratory exercises conducted by students is used to demonstrate several properties of this herbicide. Glyphosate, N-(phosphonomethyl) glycine (see Figure 1), is an extremely effective, non-selective, post-emergence herbicide with an increasing number of international applications. It is the active ingredient of Roundup?, Monsanto's herbicide formulation consisting of glyphosate isopropylamine salt and surfactant solution in water. Roundup? has developed into an extremely important herbicide since its introduction in 1971 (Baird et al. 1971; Franz 1985) and now is marketed in more than 100 countries. Glyphosate has a relatively low molecular weight and high water solubility, factors which aid in its rapid absorption and translocation by plant tissues. Once inside the plant, glyphosate does not break down, nor is it metabolized to a significant degree. In soils, however, the compound is strongly absorbed (preventing leaching) and is rapidly degraded by microorganisms to to non-toxic organic products (see Figure 1) which are then broken down to ammonia, water and carbon dioxide (Hoagland & Duke 1981). Moreover, glyphosate is non-toxic to insects and vertebrates and does not accumulate in animal tissues (Newton et al. 1984; Sullivan 1985). In early studies on the mode of action of glyphosate (Jaworski 1972; Roisch & Lingens 1974), it was found that the growth inhibitory effects on both Rhizobium japonicum and duckweed (Lemna gibba) could be completely reversed by addition of the aromatic amino acids: phenylalanine, tyrosine and tryptophane. In later studies, in which profiles of free pools of aromatic amino acids from higher plants were examined, levels of aromatic amino acids were found to be greatly reduced in comparison to other amino acids (Duke 1985b). Studies by Amrhein (Steinriicken & Amrhein 1984; Duke 1985b) established that reduced levels of aromatic amino acids resulted from inhibition of a single enzyme of shikimate pathway (one of the two metabolic pathways producing aromatic compounds in plants and bacteria; this pathway does not operate in animals) namely 5-enolpyruvylshikimate-3phosphate synthetase. The molecular basis of this inhibition is now well understood (Steinrucken & Amrhein 1984).

X.—Laboratory Note on a Study of Polarisation by means of the Dolezalek Electrometer

The following experiments originated in a series of laboratory exercises which I performed on the use of the Dolezalek electrometer. The instrument which I used was made by Bartels, and had its needle suspended by a phosphor-bronze strip. This needle was raised to a potential of about 160 volts by being connected to one terminal of a battery of eighty small secondary cells, the other terminal of which was connected to earth. When at this potential the instrument gave, for a potential difference of 1 volt between its two pairs of quadrants, a deflection of 200 divisions on a scale 200 centimetres distant from it. The maximum deflection in the experiments described was 166 divisions, i.e. 33·2 cms., giving tan−1 ·166 as maximum angle of deflection; and therefore, by taking the deflection as proportional to the potential difference, a maximum error of 0·7 per cent, is introduced.