An holistic implementation of lean six sigma methodology on maintenance subsystem

Purpose: One of the main problems relevant with enterprises is to be able to cope with maintenance problems in order to maintain decrease of stoppages, time and economical losses in the production area. In order to acquire an effective and profitable maintenance policy in a production company, there is high demand of methodological strategy to improve the maintenance subsystem. Purpose of this research is to be able to implement the lean six sigma methodology on maintenance subsystem as successfully and supply more effective sustainable maintenance system. Design/methodology/approach: Lean six sigma methodology purpose on eliminating defects and improve the effectiveness of a process. Research methodology is designed according to the purpose and goals of the research which is based on DMAIC tool within the phases those include quality tools relevant with lean six sigma methodology. Findings: According to the research results; it is estimated that by implementing improvements and eliminating root causes, wastes; 50% performance increase is possible in maintenance related effectiveness. Lean philosophy and six sigma methodology has high improvement potential on maintenance processes; also successful with gaining on the eliminating of defects and consequently increasing the economical outputs. Research limitations/implications: This research is limited with the experience and information from real case companies, information from relevant scientific books and theory from scientific databases. Practical implications: Lean six sigma methodology can be applied appropriately for improving the quality of the maintenance system and maintenance activities those will induce maintenance effectiveness as consequently. More effective maintenance system means decrease in the maintenance related cost, decrease in the maintenance related time due to increase in the speed and increase in the maintenance related quality. Originality/value: The originality of this research work base on implementation of advanced quality tools in DMAIC phases on maintenance subsystem and studying the quality of maintenance in multi perspective scale. © International OCSCO World Press. All rights reserved. 2015

Can Minimum Prices Assure the Quality of Professional Services?

This papers studies the effects on service quality and consumer surplus of a minimum price which is fixed by a bureaucratic non-monopolistic professional association. It shows that the price floor set by a Niskanen-type professional assocation will maximize consumer surplus only if consumers demand the highest possible average quality. If consumers demand services of lesser quality, the association's price floor will be too high if measured by consumer surplus. Moreover we show that a de-regulated market will always reproduce the favorable result of a uniformly high price in the case of top quality demand while delivering superior results in the case of a mixed demand for high and low quality services. The general picture that emerges from this discussion is that the current EU Commission's initiative to abolish fixed price schemes for professional services will not lead to a decrease in quality that would be undesirable from a standpoint of consumer protection. This holds even if we acknowledge the opponent's claim that there is a chance of deprivation of professional ethics due to price competition.Liberal professions; Price regulation; Quality; Professional association; Self-regulation; EU competition policy; Intrinsic motivation

A Modified Yardstick Competition Mechanism

This paper analyzes a modified yardstick competition mechanism (MYC), where the yardstick employed consists of a tariff basket and total costs. This mechanism has a significant information advantage: the regulator "only" needs to observe total costs and output of all firms. The modified yardstick competition mechanism can ensure a socially optimal outcome when allowing for spatial and second degree price discrimination, without increasing the informational requirements. We also introduce regulatory lags in the model. A systematic comparison between the results of traditional yardstick regulation and modified yardstick regulation is carried out. Finally, we discuss the applicability of the mechanism.Regulation, Yardstick competition, Mechanism design, Information asymmetry

Corporate Self-Regulation vs. Ex-Ante Regulation of Network Access: A Model of the German Gas Sector

This paper compares the outcomes of corporate self-regulation and traditional ex-ante regulation of network access to monopolistic bottlenecks. In the model of self-regulation, the domestic gas supplier and network owner and the monopsonistic gas customer fix quantities and the network access price, whereas the competitive fringe of foreign gas producers (third party) and the household customers are excluded from the agreement. The results are then compared with the outcome of traditional ex-ante regulation. We find that while industrial self-regulation leads to an exploitation of households, the effect on the foreign producers is unclear.Ex-ante regulation; Competition policy; Non-discriminatory network access; Bargaining

Increasing Block Tariffs in the Water Sector: A Semi-Welfarist Approach

We analyze the properties of progressive water tariffs that are often applied in the sector in the form of discretely increasing block tariffs (IBT). We are particularly interested in water tarification in a poverty context where a subsistence level of water has to be allocated to each household. Our approach is "semi-welfarist" to the extent that we analyze second-best pricing schemes that may be applied in practice due to "fairness" or other, non-welfarist considerations. In our theoretical model we compare a modified Coase-tariff and a progressively increasing block tariff with respect to water consumption, water expenses and utility levels. When we impose cost coverage on the water utility, there are clearly adverse effects on the "almost poor" by introducing a progressive tariff. This result is supported with a numerical application using real data from Bangladesh: progressive tariffs may fail to achieve "fair" cross-subsidization of low-income groups.water, tarification, prices, fairness, distribution, institutions

Bioengineering Functional Human Jejunal Grafts for Intestinal Failure

Intestinal failure (IF), following extensive anatomical or functional loss of small intestine, has debilitating long-term effects on infants born with this condition. Priority of care is to increase the child’s length of functional intestine, jejunum in particular, to improve nutritional independence. Children with irreversible IF suffering complications of parenteral nutrition may be referred for intestinal transplantation. However, mortality rates are as high as 60% at 5 years. The aim of my project was to develop an innovative treatment strategy to rebuild the patients’ own jejunum for autologous transplantation. Here I report the reconstruction of transplantable intestinal mucosal grafts using primary human materials. Human jejunal intestinal organoids derived from paediatric patients with IF can be cultured and expanded efficiently in vitro with region-specific markers preserved. Decellularised human intestinal matrix with intact ultrastructure is used as biological scaffold. I show that the biochemical composition of decellularised human small intestine and colon matrix are virtually analogous, suggesting that they both can be used as scaffolds for jejunal graft reconstruction. Functional jejunal grafts with digestive enzyme-producing enterocytes can be efficiently engineered by repopulating human intestinal scaffolds with human jejunal organoids and fibroblasts in vitro, which can further survive and mature after in vivo transplantation. These primary human material based jejunal grafts provide proof-of-concept data for autologous transplantation of tissue engineered intestine in patients with IF

The Use of Silver Nanoparticles as an Antifungal Coating on Silicone Facial Prosthesis

Abstract Introduction Maxillofacial prostheses are used to substitute lost facial parts, but give variable clinical results due to complications such as contamination and infection. Candida albicans infection remains a significant problem for facial prostheses made of silicone, as the organism causes degradation of the material and infection of the surrounding tissue. This study investigated the antifungal properties of silver nanoparticles (Ag NPs) as a coating on silicone facial prostheses to eliminate infection. Methods The experimental approach used fibroblast cell cultures to test the biocompatibility of Ag NPs and to demonstrate the safety of Ag NPs compared to AgNO3 at concentrations of 5 and 50 mg l-1. Cells cultures with and without the prosthetic material coated with Ag NPs were tested for cell viability and adherence to the prosthetic. An addition of yeast (C. albicans) was used as a pathogenic challenge to test the “antifungal” properties of the new facial prosthetics. End points included the determination of the cytotoxic response of the cells to nanoparticles including; protein and lactate dehydrogenase enzyme (LDH) leak, as well as electrolytes relating to the osmotic health of the cells (measuring pH, Na+, K+). Total Ag concentrations were also measured. In addition, an ethanol assay was used to follow metabolic activity associated with C. albicans, as fibroblasts do not produce ethanol. Results This study revealed that facial prostheses coated with Ag NPs preserved fibroblast cells from fungal infection compared to uncoated silicone prosthesis at a concentration of 50 mg l-1. Cell viability measures showed Ag NPs were not toxic to fibroblast cells compared to AgNO3 after 24h exposure. LDH leak was 9.7 % at a concentration of 50 mg l-l Ag NPs, while LDH leak for cells exposed to AgNO3 was 97%. Additionally, fibroblast cells exposed to AgNO3 showed significant change in cell Na+ content, as a coating, and when silver was added directly to the culture media (Kruskal Wallis, p< 0.05). However, when cells were exposed for 24 h to Ag NPs prepared in the media, this caused a significant change in cell K+ content (One way ANOVA, p< 0.05) and inhibition of Na+ K+-ATPase activity. In contrast, when the cells were exposed to the same concentrations of Ag NPs as a coating on silicone prostheses for 72 h, there was no effect on the Na+ pump or on cell K+. This study also showed that silver released from Ag NPs as a coating was less compared to that from AgNO3. Moreover, the production of ethanol by C. albicans was 30-fold lower when the silicone coated with Ag NPs compered to uncoated silicone, and 8-fold lower when coated with AgNO3. Conclusion The coating of silicone materials with Ag NPs could be of great use clinically to prevent fungal infection for patients with maxillofacial prostheses. A practical coating on the surface of the silicone prosthesis of 50 mg l-1 Ag NPs should be antifungal without any toxic effects to human dermal fibroblast cells. In clinical situations Candida infection occur at lower inoculations than used here and a lower concentration of Ag NPs could therefore also be effective in real patients.Kurdistan Regional Governmen

A tribological study in the perspective of vibro-electric analysis

Purpose: In this case study, oil starvation failure that is a common problem for mechanical constructions has been studied within perspective of vibro-electric analysis. The purpose of this research is testing material properties of a ball bearing under the oil starving failure and condition of resonance for inspecting predictive maintenance approaches. Design/methodology/approach: A test setup construction designed, built and placed in a laboratory location. An electrical motor has been selected for collecting electrical and vibrational data over a bearing by making tests. Test has been implemented under the electricity frequency of 63.8 Hz that was induced the rotation of electrical motor in order to set rotational speed. Findings: Respect to results of the analysis, inspecting of oil starving failure and resonance problem has been detected more clearly and informative by vibration analysis. Research limitations/implications: This research study is limited with some experience and data from case companies, data from relevant scientific literature and theories through scientific databases. Practical implications: Implementation of condition monitoring technologies on mechanical systems brings similarities with the health systems of the human beings. Such as developments in technologies of human health management, consultation of the mechanical systems should be practised in order to prevent breakdowns which cause unplanned stoppages. Vibrational and electrical monitoring techniques can be applied at enterprises in order to ease and reach higher accuracy for detection of symptoms cause from mechanical fault initiations. Originality/value: The originality of this research receive resources from comparison of traditional condition monitoring tool vibration analysis and more recently developed electrical consumption analysis used for predictive maintenance. © International OCSCO World Press. All rights reserved. 2016

A Theory of Optimal Green Defaults

This paper develops an analytical framework for studying the Baumol–Oates efficiency of traditional single instrument abatement policies vis-à-vis green defaults in the face of price inertia and passive choice by subpopulations. In this special case of behavioural heterogeneity, command and control approaches can outperform price-based instruments while pure tax/subsidy schemes need to be adjusted in order to achieve politically desired levels of abatement. We also prove that choice-preserving nudges are superior to any single-instrument policy in this case. An average marginal abatement cost rule is developed to optimize the green defaults and traditional policies of standards and prices under different degrees of market rigidity.EC/H2020/653255/EU/PLAtform for Climate Adaptation and Risk reDuction/PLACAR

A theory of optimal green defaults

This paper develops an analytical framework for studying the Baumol-Oates efficiency of traditional single instrument abatementpolicies vis-à-vis green defaults in the face of price inertia and deliberate defaultingby subpopulations. In this special case ofbehavioural heterogeneity, command and control approaches can outperform price-based instruments while pure tax/subsidy schemes need tobe adjusted in order to achievepolitically desired levels of abatement. We also prove that choice-preserving nudges are superior to any single-instrument policy in this case. An average marginal abatement cost rule is developed to optimise the green defaults and traditional policies of standards and prices under different degrees of market rigidity