Excellence in Research and Innovation for Humanity

International Science Index

Commenced in January 1999 Frequency: Monthly Edition: International Abstract Count: 40435

Industrial and Manufacturing Engineering

Multi-Response Optimization of EDM for Ti-6Al-4V Using Taguchi-Grey Relational Analysis
Ti-6Al-4V is a titanium alloy having high strength, low weight and corrosion resistant which is a required characteristic for a material to be used in aerospace industry. Titanium, being a hard alloy is difficult to the machine via conventional methods, so it is a call to use non-conventional processes. In present work, the effects on Ti-6Al-4V by drilling a hole of Ø 6 mm using copper (99%) electrode in Electric Discharge Machining (EDM) process is analyzed. Effect of various input parameters like peak current, pulse-on time and pulse-off time on output parameters viz material removal rate (MRR) and electrode wear rate (EWR) is studied. Multi-objective optimization technique Grey relational analysis is used for process optimization. Experiments are designed using an L9 orthogonal array. ANOVA is used for finding most contributing parameter followed by confirmation tests for validating the results. Improvement of 7.45% in gray relational grade is observed.
Non-Dominated Sorting Genetic Algorithm (NSGA-II) for the Redistricting Problem in Mexico
The electoral zone design problem consists in redrawing the boundaries of legislative districts for electoral purposes in such a way that federal or state requirements are fulfilled. In Mexico, this process has been historically carried out by the National Electoral Institute (INE), by optimizing an integer nonlinear programming model, in which population equality and compactness of the designed districts are considered as two conflicting objective functions, while contiguity is included as a hard constraint. The solution technique used by the INE is a Simulated Annealing (SA) based algorithm, which handles the multi-objective nature of the problem through an aggregation function. The present work represents the first intent to apply a classical Multi-Objective Evolutionary Algorithm (MOEA), the second version of the Non-dominated Sorting Genetic Algorithm (NSGA-II), to this hard combinatorial problem. First results show that, when compared with the SA algorithm, the NSGA-II obtains promising results. The MOEA manages to produce well-distributed solutions over a wide-spread front, even though some convergence troubles for some instances constitute an issue, which should be corrected in future adaptations of MOEAs to the redistricting problem.
Embodied Empowerment: A Design Framework for Augmenting Human Agency in Assistive Technologies
Persons with cognitive disabilities, such as Autism Spectrum Disorder (ASD) are often dependent on some form of professional support. Recent transformations in Dutch healthcare have spurred institutions to apply new, empowering methods and tools to enable their clients to cope (more) independently in daily life. Assistive Technologies (ATs) seem promising as empowering tools. While ATs can, functionally speaking, help people to perform certain activities without human assistance, we hold that, from a design-theoretical perspective, such technologies often fail to empower in a deeper sense. Most technologies serve either to prescribe or to monitor users’ actions, which in some sense objectifies them, rather than strengthening their agency. This paper proposes that theories of embodied interaction could help formulating a design vision in which interactive assistive devices augment, rather than replace, human agency and thereby add to a persons’ empowerment in daily life settings. It aims to close the gap between empowerment theory and the opportunities provided by assistive technologies, by showing how embodiment and empowerment theory can be applied in practice in the design of new, interactive assistive devices. Taking a Research-through-Design approach, we conducted a case study of designing to support independently living people with ASD with structuring daily activities. In three iterations we interlaced design action, active involvement and prototype evaluations with future end-users and healthcare professionals, and theoretical reflection. Our co-design sessions revealed the issue of handling daily activities being multidimensional. Not having the ability to self-manage one’s daily life has immense consequences on one’s self-image, and also has major effects on the relationship with professional caregivers. Over the course of the project relevant theoretical principles of both embodiment and empowerment theory together with user-insights, informed our design decisions. This resulted in a system of wireless light units that users can program as a reminder for tasks, but also to record and reflect on their actions. The iterative process helped to gradually refine and reframe our growing understanding of what it concretely means for a technology to empower a person in daily life. Drawing on the case study insights we propose a set of concrete design principles that together form what we call the embodied empowerment design framework. The framework includes four main principles: Enabling ‘reflection-in-action’; making information ‘publicly available’ in order to enable co-reflection and social coupling; enabling the implementation of shared reflections into an ‘endurable-external feedback loop’ embedded in the persons familiar ’lifeworld’; and nudging situated actions with self-created action-affordances. In essence, the framework aims for the self-development of a suitable routine, or ‘situated practice’, by building on a growing shared insight of what works for the person. The framework, we propose, may serve as a starting point for AT designers to create truly empowering interactive products. In a set of follow-up projects involving the participation of persons with ASD, Intellectual Disabilities, Dementia and Acquired Brain Injury, the framework will be applied, evaluated and further refined.
Innovation Policy and Development of Creative Industries: Case Study of Lithuanian Animation Industry
The objective of this study is to identify and explore the adequacy of modern innovation support mechanism to developed creative industries. The authors argue that current development and support strategy for creative industries, although acknowledge a high correlation between innovation and creativity, do not seek to improve conditions to promote systematic innovation development in creative sector. Using Lithuanian animation industry as a case study, this paper will examine industrial innovation contribution to creativity and inseparably to competitiveness of animation enterprises. This paper proposes insights that contribute to theoretical and practical discussions on how creative profile companies achieve national and international competitiveness through innovations. The conclusions suggest that development of creative industries could significantly benefit if policy makers would implement the tools that would encourage creative profile enterprises to invest in innovation development at a constant rate.
Digital Transformation of Lean Production: Systematic Approach for the Determination of Digitally Pervasive Value Chains
The increasing digitalization of value chains can help companies to handle rising complexity in their processes and thereby reduce the steadily rising planning and control effort in order to raise performance limits. Due to technological advances, companies face the challenge of smart value chains in the purpose of improvements in productivity, handling the increasing time and cost pressure and the need of individualized production. Therefore, companies need to ensure quick and flexible decisions to create self-optimizing processes and, consequently, to make their production more efficient. Lean production, as most commonly used paradigm for complexity reduction, reaches its limits when it comes to variant flexible production and constantly changing the market and environmental conditions. To lift performance limits, which are inbuilt in current value chains, new methods and tools have to be applied. Digitalization provides the potential to derive this new methods and tools. However, companies lack the experience to harmonize different digital technologies. There is no practicable framework, which instructs the transformation of current value chains into digital pervasive value chains. Current research shows that a connection between lean production and digitalization exists. This link is based on factors such as people, technology, and organization. In this paper, the introduced method for the determination of digitally pervasive value chains takes the factors people, technology, and organization into account and extends existing approaches by a new dimension. It is the first systematic approach for digital transformation of lean production and consists of four steps: The first step ‘target definition’ describes the target situation and defines the depth of the analysis with regards to the inspection area and the level of detail. The second step ‘analysis of the value chain’ verifies the lean-ability of processes and lies a special focus on the integration capacity of digital technologies in order to raise the above mentioned limits of lean production. Furthermore, the ‘digital evaluation process’ ensures the usefulness of digital adaptions regarding their practicability and their integrability into the existing production system. Finally, the method defines actions to be performed based on the evaluation process and in accordance with the target situation. As a result, the validation and optimization of the proposed method in a German company from the electronics industry shows that the digital transformation of current value chains based on lean production achieves a raise of their inbuilt performance limits.
Design and Fabrication of an Optimized Low Cost Cargo Bearing Tricycle
The aim of the work was to design and fabricate an optimized low cost cargo-bearing tricycle which will fulfill the market demand in terms of cost and functionality, and also suitable for Nigerian roads. The integral construction produced a stronger and lighter vehicle which is very cheap when compared to the existing models in the market. The structure can withstand various static dynamic loads, which implied that the body shell is capable of bearing the various frame stresses. The arrangement of the various body panels to form a unitary structure of sufficient strength helped to resist the forces that act in the vehicle body. The floor and roof panels resist the sagging effect caused by the weight of the occupants and cargo. The stresses range from 3.2 MPa to 37.8MPa. The torque of 1372.71N was required to accelerate the tricycle and was derived from multiplying the tractive effort by the radius of the tire used. The material used for the chassis frame (cold rolled steel) has yield strength of 220.6 MPa, while point of maximum stress is 37.8 MPa giving a factor of safety of about 5.0 which is within a safe range. The objective of the research was fully met as the optimization of the existing tricycles was achieved in terms of ergonomics and strength, as well as in the cost effectiveness of the product.
Study of Electrode Profile during Electrical Discharge Machining of Hardened Die Steel
In Electrical Discharge Machining (EDM) operations, the tool cost contributes the maximum effect in total operation cost. In an EDM process, the wear of electrode is a major cause of concern. Therefore, in this present work, the shape of the electrode and the distortions have been studied during the EDM of hardened EN31 die steel using Copper electrodes. The study of roundness was performed on the electrode to observe the profile of electrode before and after machining. Scanning Electron Microscope (SEM) was used to study the distortions of the electrode tip. The effect of process parameters such as discharge current and pulse on time has been studied to understand the behavior of distortion.
Analyzing the Factors Effecting Ceramic Porosity Using Integrated Taguchi-Fuzzy Method
Companies require increase in quality perception level of their products due to competitive conditions. As a result, the tendency to quality and researches to develop the quality are increasing day by day. Cost and time constraints are the biggest problems that companies face in their quality improvement efforts. In this study, factors that affect the porosity of ceramic products are determined and analyzed in a factory producing ceramic tiles. Then, Taguchi method is used in the design phase in order to decrease the number of tests to be performed by means of orthogonal sequences. The most important factors affecting the porosity of ceramic tiles are determined using Taguchi and ANOVA analysis. Based on the analyses, the most affecting factors are determined to be used in the fuzzy implementation stage. Then, the fuzzy rules were established with the factors affecting porosity by the experts’ opinion. Thus, porosity result could be obtained not only for the specified factor levels but also for intermediate values. In this way, it has been provided convenience to the factory in terms of cost and quality improvement.
Solving Process Planning, Weighted Apparent Tardiness Cost Dispatching, and Weighted Processing plus Weight Due-Date Assignment Simultaneously Using a Hybrid Search
Process planning, scheduling, and due date assignment are three important manufacturing functions which are studied independently in literature. There are hundreds of works on IPPS and SWDDA problems but a few works on IPPSDDA problem. Integrating these three functions is very crucial due to the high relationship between them. Since the scheduling problem is in the NP-Hard problem class without any integration, an integrated problem is even harder to solve. This study focuses on the integration of these functions. Sum of weighted tardiness, earliness, and due date related costs are used as a penalty function. Random search and hybrid metaheuristics are used to solve the integrated problem. Marginal improvement in random search is very high in the early iterations and reduces enormously in later iterations. At that point directed search contribute to marginal improvement more than random search. In this study, random and genetic search methods are combined to find better solutions. Results show that overall performance becomes better as the integration level increases.
Solving Process Planning and Scheduling with Number of Operation plus Processing Time Due-Date Assignment Concurrently Using a Genetic Search
Traditionally process planning, scheduling, and due date assignment are performed sequentially and separately. High interrelation between these functions makes integration very useful. Although there are numerous works on integrated process planning and scheduling and many works on scheduling with due date assignment, there are only a few works on the integration of these three functions. Here we tested different integration levels of these three functions, and we found fully integrated version as the best. We applied genetic search, and random search and genetic search found better compared to the random search. We penalized all earliness, tardiness and due date related costs. Since all these three terms are all undesired, it is better to penalize all of them.
Identification of Lipo-Alkaloids and Fatty Acids in Aconitum carmichaelii Using Liquid Chromatography–Mass Spectrometry and Gas Chromatography–Mass Spectrometry
Lipo-alkaloid is a kind of C19-norditerpenoid alkaloids existed in Aconitum species, which usually contains an aconitane skeleton and one or two fatty acid residues. The structures are very similar to that of diester-type alkaloids, which are considered as the main bioactive components in Aconitum carmichaelii. They have anti-inflammatory, anti-nociceptive, and anti-proliferative activities. So far, more than 200 lipo-alkaloids were reported from plants, semisynthesis, and biotransformations. In our research, by the combination of ultra-high performance liquid chromatography-quadruple-time of flight mass spectrometry (UHPLC-Q-TOF-MS) and an in-house database, 148 lipo-alkaloids were identified from A. carmichaelii, including 93 potential new compounds and 38 compounds with oxygenated fatty acid moieties. To our knowledge, this is the first time of the reporting of the oxygenated fatty acids as the side chains in naturally-occurring lipo-alkaloids. Considering the fatty acid residues in lipo-alkaloids should come from the free acids in the plant, the fatty acids and their relationship with lipo-alkaloids were further investigated by GC-MS and LC-MS. Among 17 fatty acids identified by GC-MS, 12 were detected as the side chains of lipo-alkaloids, which accounted for about 1/3 of total lipo-alkaloids, while these fatty acid residues were less than 1/4 of total fatty acid residues. And, a total of 37 fatty acids were determined by UHPCL-Q-TOF-MS, including 18 oxidized fatty acids firstly identified from A. carmichaelii. These fatty acids were observed as the side chains of lipo-alkaloids. In addition, although over 140 lipo-alkaloids were identified, six lipo-alkaloids, 8-O-linoleoyl-14-benzoylmesaconine (1), 8-O-linoleoyl-14-benzoylaconine (2), 8-O-palmitoyl-14-benzoylmesaconine (3), 8-O-oleoyl-14-benzoylmesaconine (4), 8-O-pal-benzoylaconine (5), and 8-O-ole-Benzoylaconine (6), were found to be the main components, which accounted for over 90% content of total lipo-alkaloids. Therefore, using these six components as standards, a UHPLC-Triple Quadrupole-MS (UHPLC-QQQ-MS) approach was established to investigate the influence of processing on the contents of lipo-alkaloids. Although it was commonly supposed that the contents of lipo-alkaloids increased after processing, our research showed that no significant change was observed before and after processing. Using the same methods, the lipo-alkaloids in the lateral roots of A. carmichaelii and the roots of A. kusnezoffii were determined and quantified. The contents of lipo-alkaloids in A. kusnezoffii were close to that of the parent roots of A. carmichaelii, while the lateral roots had less lipo-alkaloids than the parent roots. This work was supported by Macao Science and Technology Development Fund (086/2013/A3 and FDCT-16-008-SKL).
Atmospheric Plasma Treatment to Improve Water and Oil Repellent Finishing for PET and PET/Spandex Fabrics
In this study, the effects of an atmospheric plasma treatment on the durability of water and oil repellent finishes of PET and PET/Spandex fabrics were tested. Fabrics were treated with a low-frequency atmospheric pressure glow discharge. After plasma treatments, the water and oil repellent finishes were applied using pad-dry-cure method. It was observed that plasma treatments improved the durability finish for all fabrics.
Transport Mode Selection under Lead Time Variability and Emissions Constraint
This study is focused on transport mode selection under lead time variability and emissions constraint. In order to reduce the carbon emissions generation due to transportation, organization has often faced a dilemmatic choice of transport mode selection since logistic cost and emissions reduction are complementary with each other. Another important aspect of transportation decision is lead-time variability which is least considered in transport mode selection problem. Thus, in this study, we provide a comprehensive mathematical based analytical model to decide transport mode selection under emissions constraint. We also extend our work through analysing the effect of lead time variability in the transport mode selection by a sensitivity analysis. In order to account lead time variability into the model, two identically normally distributed random variables are incorporated in this study including unit lead time variability and lead time demand variability. Therefore, in this study, we are addressing following questions: How the decisions of transport mode selection will be affected by lead time variability? How lead time variability will impact on total supply chain cost under carbon emissions? To accomplish these objectives, a total transportation cost function is developed including unit purchasing cost, unit transportation cost, emissions cost, holding cost during lead time, and penalty cost for stock out due to lead time variability. A set of modes is available to transport each node, in this paper, we consider only four transport modes such as air, road, rail, and water. Transportation cost, distance, emissions level for each transport mode is considered as deterministic and static in this paper. Each mode is having different emissions level depending on the distance and product characteristics. Emissions cost is indirectly affected by the lead time variability if there is any switching of transport mode from lower emissions prone transport mode to higher emissions prone transport mode in order to reduce penalty cost. We provide a numerical analysis in order to study the effectiveness of the mathematical model. We found that chances of stock out during lead time will be higher due to the higher variability of lead time and lad time demand. Numerical results show that penalty cost of air transport mode is negative that means chances of stock out zero, but, having higher holding and emissions cost. Therefore, air transport mode is only selected when there is any emergency order to reduce penalty cost, otherwise, rail and road transport is the most preferred mode of transportation. Thus, this paper is contributing to the literature by a novel approach to decide transport mode under emissions cost and lead time variability. This model can be extended by studying the effect of lead time variability under some other strategic transportation issues such as modal split option, full truck load strategy, and demand consolidation strategy etc.
Risk of Occupational Exposure to Cytotoxic Drugs: The Role of Handling Procedures in Hospital Workers
Hospitals are particularly relevant occupational environments for risk management, not only because there is a need to comply with legal obligations, but also because health professionals are exposed to a plethora of occupational risks, ranging from biological to chemical risks, which ultimately may impact on their health, in particular due to the frequency and duration of such exposure. Both the health professionals who prepare the cytostatic drugs, and those who administer them, in Day hospitals, are exposed to a significant chemical risk factors. Cytostatic drugs have the ability of inhibiting the development of neoplastic cells, reducing malignant cells and acting on cell division. This study aims at studying the risk prevention procedures used by these health professionals, namely the procedures involving the preparation and administration of two specific types of cytostatic drugs, the 5-fluorouracil and platinum (marker for cis/carbo/oxaliplatin), which are among the most used drugs in the treatment of neoplastic diseases. The study was developed in 3 hospitals and included the preparation procedures of hospital pharmacies and the adopted procedures during the administration of the drugs at the Day hospitals. The objective of this study was also to compare safety procedures and practices between different hospital units, establishing a relationship between the results of the contamination of the laboratory samples and the associated procedures. From a methodological point of view, and in order to establish the procedures and practices used in each hospital, a survey technique was used. To determine the contamination levels, the sample collection applied technique was the so-called 'wipe sampling', which has been used with success in studies developed for 5-fluorouracil (5FU) and platinum (Pt). The survey results show that the hospital professionals handling cytostatic used personal protective equipment in hospital pharmacies, but often they do not use it within Day hospitals. Regarding the procedures, the studied professionals seek to comply with established standards; however, each hospital has their own practices, which tend to be different among the hospitals. One of the backgrounds of this study was to confirm that this is a topic that is scarcely addressed, in particular in Portugal. This is most likely due to the inexistence of laboratory equipment for the quantification and lack of specific legal framework on cytostatics exposure. The obtained results show also that the main cause of the spills, in all the 3 hospitals, was due to the poorly closed wrapper of the cytostatic packages. From the chemical contamination analysis, 45 out of the 112 collected samples were contaminated. The highest contamination levels were found at the Day hospitals. However, important contamination was also found in the laminar flow hood and support treatments, respectively at hospital pharmacies and Day hospital units. The authors of this study strongly believe that by developing a uniform and coherent procedure to handle cytostatic drugs, it would be possible to significantly reduce the risk of occupational contamination. This confidence is strongly supported by the differences found between the analyzed hospital units and, in some cases, between different professionals performing the same tasks.
Visualization-Based Feature Extraction for Classification in Real-Time Interaction
This paper introduces a method of using unsupervised machine learning to visualize the feature space of a dataset in 2D, in order to find most characteristic segments in the set. After dimension reduction, users can select clusters by manual drawing. Selected clusters are recorded into a data model that is used for later predictions, based on realtime data. Predictions are made with supervised learning, using Gesture Recognition Toolkit. The paper introduces two example applications: a semantic audio organizer for analyzing incoming sounds, and a gesture database organizer where gestural data (recorded by a Leap motion) is visualized for further manipulation.
A 0-1 Goal Programming Approach to Optimize the Layout of Hospital Units: A Case Study in an Emergency Department in Seoul
This paper proposes a method to optimize the layout of an emergency department (ED) based on real executions of care processes by considering several planning objectives simultaneously. Recently, demand for healthcare services has been dramatically increased. As the demand for healthcare services increases, so do the need for new healthcare buildings as well as the need for redesign and renovating existing ones. The importance of implementation of a standard set of engineering facilities planning and design techniques has been already proved in both manufacturing and service industry with many significant functional efficiencies. However, high complexity of care processes remains a major challenge to apply these methods in healthcare environments. Process mining techniques applied in this study to tackle the problem of complexity and to enhance care process analysis. Process related information such as clinical pathways extracted from the information system of an ED. A 0-1 goal programming approach is then proposed to find a single layout that simultaneously satisfies several goals. The proposed model solved by optimization software CPLEX 12. The solution reached using the proposed method has 42.2% improvement in terms of walking distance of normal patients and 47.6% improvement in walking distance of critical patients at minimum cost of relocation. It has been observed that lots of patients must unnecessarily walk long distances during their visit to the emergency department because of an inefficient design. A carefully designed layout can significantly decrease patient walking distance and related complications.
Analysis and Improvement of Efficiency for Food Processing Assembly Lines
This study deals with the analysis and improvement of efficiency for assembly lines in Food Processing Industry (FPI). In particular, different factors that affect productivity and efficiency of Manual Mixed-Model Assembly Lines (MMMAL) are investigated. The case company considered had two MMMALs, which are semi-automated for the sandwich line and purely manual for the salad line. Several problems causing delays and inefficiencies on the lines are identified and appropriate solution approaches were implemented to increase efficiency and to minimize balance delays. Line Balancing tools are utilized to redesign the line and to redistribute the workload evenly between the work stations in order to remove the bottleneck from the current assembly line. For semi-automated lines, reliability of each machine, which is subject to failure, is an important issue since it affects line productivity. Failure and repair data was collected over a period of time for the packaging machine and its reliability was calculated for daily production cycles. The results were incorporated into the production cycles for each line and each product to determine the expected production output in a daily shift.
Optimizing Machine Vision System Setup Accuracy by Six–Sigma DMAIC Approach
Machine vision system provides automatic inspection to reduce manufacturing costs considerably. However, only a few principles have been found to optimize machine vision system and help it function more accurately in industrial practice. Mostly, there were complicated and impractical design techniques to improve the accuracy of machine vision system. This paper discusses implementing the Six Sigma DMAIC (Define, Measure, Analyze, Improve, and Control) approach to optimize the setup parameters of machine vision system when it is used as a direct measurement technique. This research follows a case study showing how Six Sigma DMAIC methodology has been put into use.
Development of an Advanced Power Ultrasonic-Assisted Drilling System
The application of ultrasonic vibrations to machining processes has a long history, ranging from slurry-based systems able to drill brittle materials, to more recent developments involving low power ultrasonics for high precision machining, with many of these at the research and laboratory stages. The focus of this development is the application of high levels of ultrasonic power (1,000’s of watts) to standard, heavy duty machine tools – drilling being the immediate focus, with developments in milling in progress – with the objective of dramatically increasing system productivity through faster feed rates, this benefit arising from the thrust force reductions obtained by power ultrasonic vibrations. The presentation will describe development of an advanced drilling system based on a special, acoustically designed, rugged drill module capable of functioning under heavy duty production conditions, and making use of standard tool holder means, and able to obtain thrust force reductions while maintaining or improving surface finish and drilling accuracy. The characterization of the system performance will be described, and results obtained in drilling several materials (Aluminum, Stainless steel, Titanium) presented.
Particle Size Distribution Estimation of a Mixture of Regular and Irregular Sized Particles Using Acoustic Emissions
This works investigates the possibility of using Acoustic Emissions (AE) to estimate the Particle Size Distribution (PSD) of a mixture of particles that comprise of particles of different densities and geometry. The experiments carried out involved the mixture of a set of glass and polyethylene particles that ranged from 150-212 microns and 150-250 microns respectively and an experimental rig that allowed the free fall of a continuous stream of particles on a target plate which the AE sensor was placed. By using a time domain based multiple threshold method, it was observed that the PSD of the particles in the mixture could be estimated.
Using Knowledge Management and Visualisation Concepts to Improve Patients and Hospitals Staff Workflow
This paper focuses on using knowledge management and visualisation concepts to improve patients and hospitals staff workflow. Hospitals workflow are complex and complicated process and poor patient flow can put both patients and a hospital’s reputation at risk, and can threaten the facility’s financial sustainability. Healthcare leaders are under increased pressure to reduce costs while maintaining or increasing patient care standards. In this paper, a framework is proposed to help improving patient experience, staff satisfaction, and operational efficiency across hospitals by using knowledge management based visualisation concepts. This framework is using real-time visibility to track and monitor location and status of patients, staff, rooms, and medical equipment.
Antihypertensive Activity of Alcoholic Extract of Citrus Paradise Juice in One Clip One Kidney Hypertension Model in Rats
Hypertension is one of the most prevalent cardiovascular disorder. It is responsible for several other cardiovascular disorders. Although many drugs are available for the treatment of hypertension, still a large population has uncontrolled blood pressure. Thus there is an unmet need for new therapeutic approaches for the same. Fruit juice of Citrus paradise contains several flavonoids with vasodilatory activity. We hypothesized that alcoholic extract of Citrus paradise, which contains flavonoids, might attenuate hypertension. The objective of the present study was to evaluate the antihypertensive activity of alcoholic extract of Citrus paradise fruit juice in rats. Hypertension was induced using one clip one kidney model in rats. The renal artery was occluded for 4 h after removal of one kidney. Once stabilized, the ganglionic blockade was performed followed by removal of the arterial clip from the kidney. Removal of clip resulted in an increase in blood pressure which is due to release of renin from the kidney. Alcoholic extract of Citrus paradise fruit juice was then administered at 50 mg/kg and 100 mg/kg dose by intravenous injection. Blood pressure was monitored continuously. Alcoholic extract of Citrus paradise fruit juice reduced hypertension in dose-dependent manner. Antihypertensive activity was found to be associated with vasodilation. The results of the present study showed antihypertensive potential of alcoholic extract of Citrus paradise fruit juice.
Drivers of the Performance of Members of a Social Incubator Considering the Values of Work: A Qualitative Study with Social Entrepreneurs
Social entrepreneurship has emerged and driven a new development perspective, and as the literature mentions, it is based on innovation, and mainly, on the creation of social value, rather than personal wealth and shareholders. In this field of study, one of the focuses of discussion refers to the distinct characteristics of the individuals responsible for socially directed initiatives, named as social entrepreneurs. To contribute to this perspective, the present study aims to identify the values related to work that guide the performance of social entrepreneurs, members of enterprises that have developed themselves within a social incubator at a federal institution of higher education in Brazil. Each person's value system is present in different facets of his life, manifesting himself in his choices and in the way he conducts the relationship with other people in society. Especially the values of work, the focus of this research, play a significant role in organizational studies, since they are considered one of the important guiding principles of the behavior of individuals in the work environment. Regarding the method of the study, a descriptive and qualitative research was carried out. In the data collection, 24 entrepreneurs, members of five different enterprises belonging to the social incubator, were interviewed. The research instrument consisted of three open questions, which could be answered with the support of a "disc of values", an artifact organized to clearly demonstrate the values of the work to the respondents. The analysis of the interviews took into account the categories defined a priori, based on the model proposed by previous authors who validated these constructs within their research contexts, contemplating the following dimensions: Self-determination and stimulation; Safety; Conformity; Universalism and benevolence; Achievement; and Power. It should be noted that, in order to provide a better understanding of the interviewees, in the "disc of values" used in the research, these dimensions were represented by the objectives that define them, being respectively: Challenge; Financial independence; Commitment; Welfare of others; Personal success; And Power. Some preliminary results show that, as guiding principles of the investigation, priority is given to work values related to Self-determination and stimulation, Conformity and Universalism and benevolence. Such findings point to the importance given by these individuals to independent thinking and acting, as well as to novelty and constant challenge. Still, they demonstrate the appreciation of commitment to their enterprise, the people who make it and the quality of their work. They also point to the relevance of the possibility of contributing to the greater social good, that is, of the search for the well-being of close people and of society, as it is implied in models of social entrepreneurship coming from literature. With a lower degree of priority, the values denominated Safety and Realization, as the financial question at work and the search for satisfaction and personal success, through the use of socially recognized skills were mentioned aspects with little emphasis by social entrepreneurs. The Power value was not considered as guiding principle of the work for the respondents.
Effect of Repellent Coatings, Aerosol Protective Liners, and Lamination on the Properties of Chemical/Biological Protective Textiles
The primary research question to be answered for Chemical/Biological (CB) protective clothing, is how to protect wearers from a range of chemical and biological threats in liquid, vapor, and aerosol form, while reducing the thermal burden. Currently, CB protective garments are hot, heavy, and wearers are limited by short work times in order to prevent heat injury. This study demonstrates how to incorporate different levels of protection on a material level and modify fabric composites such that the thermal burden is reduced to such an extent it approaches that of a standard duty uniform with no CB protection. CB protective materials are usually comprised of several fabric layers: a cover fabric with a liquid repellent coating, a protective layer which is comprised of a carbon-based sorptive material or semi-permeable membrane, and a comfort next-to-skin liner. In order to reduce thermal burden, all of these layers were laminated together to form one fabric composite which had no insulative air gap in between layers. However, the elimination of the air gap also reduced the CB protection of the fabric composite. In order to increase protection in the laminated composite, different nonwoven aerosol protective liners were added, and a super repellent coating was applied to the cover fabric, prior to lamination. Different adhesive patterns were investigated to determine the durability of the laminate with the super repellent coating, and the effect on air permeation. After evaluating the thermal properties, textile properties and protective properties of the iterations of these fabric composites, it was found that the thermal burden of these materials was greatly reduced by decreasing the thermal resistance with the elimination of the air gap between layers. While the level of protection was reduced in laminate composites, the addition of a super repellent coating increased protection towards low volatility agents without impacting thermal burden. Similarly, the addition of aerosol protective liner increased protection without reducing water vapor transport, depending on the nonwoven used, however, the air permeability was significantly decreased. The balance of all these properties and exploration of the trade space between thermal burden and protection will be discussed.
An Innovative Green Cooling Approach Using Peltier Chip in Milling Operation for Surface Roughness Improvement
Surface roughness is one of the key quality parameters of the finished product. During any machining operation, high temperatures are generated at the tool-chip interface impairing surface quality and dimensional accuracy of products. Cutting fluids are generally applied during machining to reduce temperature at the tool-chip interface. However, usages of cutting fluids give rise to problems such as waste disposal, pollution, high cost and human health hazard. Researchers, nowadays, are opting towards dry machining and other cooling techniques to minimize use of coolants during machining while keeping surface roughness of products within desirable limits. In this paper, a new concept of using peltier cooling effects during aluminium milling operation has been proposed and adopted with an aim to improve surface roughness of the machined surface. Experimental evidence shows that peltier cooling effect provides better surface roughness of the machined surface compared to dry machining.
Solving Process Planning, Weighted Earliest Due Date Scheduling and Weighted Due Date Assignment Using Simulated Annealing and Evolutionary Strategies
Traditionally three important manufacturing functions which are process planning, scheduling and due-date assignment are performed sequentially and separately. Although there are numerous works on integration of process planning and scheduling and plenty of works on scheduling with due date assignment, there are only a few works on integrated process planning, scheduling and due-date assignment. Although due-dates are determined without taking into account of weights of the customers in the literature, here weighted due-date assignment is employed to get better performance. Jobs are scheduled according to weighted earliest due date dispatching rule and due dates are determined according to some popular due date assignment methods by taking into account of the weights of the each job. As a solution techniques Simulated Annealing, Evolutionary Strategies, Random Search, Random search and simulated annealing hybrid and Random and Evolutionary Strategies hybrid are applied. Three important manufacturing functions are integrated step by step and higher integration levels are found better. Search meta-heuristics are found very useful while improving performance measure.
Multi Robot Path Planning Integrated with Assignment Problem in Dynamic Environment
Along with the development of technology, mobile robots are going to substitute humans for doing repetitive and dangerous tasks. Path planning is one of the most interesting problems in the field of mobile robotics. Recently this problem has taken into consideration the form of multi-robot. In this paper, a mathematical model with the flexible and dynamic environment is proposed for multi-robot path planning. In addition, the model considers task assignments to robots. Despite the environment that is assumed to be two-dimensional, the proposed model can be generalized to three-dimensional space easily. An ant colony optimization algorithm is developed to solve this model, and its performance is investigated in comparison with exact solutions obtained from the model on some examples with different sizes. Results reveal that the proposed algorithm gives less smooth but shortest paths very faster than what was obtained from general standard solvers.
A Genetic Algorithm Based Permutation and Non-Permutation Scheduling Heuristics for Multi-Stage Capacitated Material Requirement Planning Problem
This paper proposes a genetic algorithm (GA) based permutation and non-permutation scheduling heuristics (GAPNP) to solve a multi-stage capacitated material requirement planning problem (MSCMRP). It is intently developed for the automotive assembly flow shop with unrelated parallel machines. In the proposed algorithm, the sequences of orders are iteratively improved by the GA characteristics, whereas the required operations are scheduled based on the proposed permutation and non-permutation heuristics. Finally, a linear programming is applied to minimize the total cost. The proposed GAPNP algorithm is evaluated by using real data sets from automotive companies, and the required parameters for GA are intently tuned to obtain a common parameter setting for all case studies rather than obtain the best setting for an individual case. The results show that GAPNP significantly outperforms the benchmark algorithm about 30% on average.
Development of a Work-Related Stress Management Program Guaranteeing Fitness-For-Duty for Human Error Prevention
Human error is one of the most dreaded factors that may result in unexpected accidents, especially in nuclear power plants. For accident prevention, it is quite indispensable to analyze and to manage the influence of any factor which may raise the possibility of human errors. Out of lots factors, stress has been reported to have a significant influence on human performance. Therefore, this research aimed to develop a work-related stress management program which can guarantee Fitness-for-Duty (FFD) of the workers in nuclear power plants, especially those working in main control rooms. Major stress factors were elicited through literal surveys and classified into major categories such as demands, supports, and relationships. To manage those factors, a test and intervention program based on 4-level approaches was developed over the whole employment cycle including selection and screening of workers, job allocation, and job rotation. In addition, a managerial care program was introduced with the concept of Employee-Assistance-Program (EAP) program. Reviews on the program conducted by ex-operators in nuclear power plants showed responses in the affirmative, and suggested additional treatment to guarantee high performance of human workers, not in normal operations but also in emergency situations.
Cars Redistribution Optimization Problem in the Free-Float Car-Sharing
Free-Float car-sharing is an one-way car-sharing service where cars are available anytime and anywhere in the streets such that no dedicated stations are needed. This means that after driving a car you can park it anywhere. This car-sharing system creates an imbalance car distribution in the cites which can be regulated by staff agents through the redistribution of cars. In this paper, we aim to solve the car-reservation and agents traveling problem so that the number of successful cars’ reservations could be maximized. Beside, we also tend to minimize the distance traveled by agents for cars redistribution. To this end, we present a mixed integer linear programming formulation for the car-sharing problem.