An Ordinal Multi-Dimensional Classification (OMDC) for Predictive Maintenance

Predictive Maintenance is a type of condition-based maintenance that assesses the equipment's states and estimates its failure probability and when maintenance should be performed. Although machine learning techniques have been frequently implemented in this area, the existing studies disregard to the natural order between the target attribute values of the historical sensor data. Thus, these methods cause losing the inherent order of the data that positively affects the prediction performances. To deal with this problem, a novel approach, named Ordinal Multi-dimensional Classification (OMDC), is proposed for estimating the conditions of a hydraulic system's four components by taking into the natural order of class values. To demonstrate the prediction ability of the proposed approach, eleven different multi-dimensional classification algorithms (traditional Binary Relevance (BR), Classifier Chain (CC), Bayesian Classifier Chain (BCC), Monte Carlo Classifier Chain (MCC), Probabilistic Classifier Chain (PCC), Classifier Dependency Network (CDN), Classifier Trellis (CT), Classifier Dependency Trellis (CDT), Label Powerset (LP), Pruned Sets (PS), and Random k-Labelsets (RAKEL)) were implemented using the Ordinal Class Classifier (OCC) algorithm. Besides, seven different classification algorithms (Multilayer Perceptron (MLP), Support Vector Machine (SVM), k-Nearest Neighbour (kNN), Decision Tree (C4.5), Bagging, Random Forest (RF), and Adaptive Boosting (AdaBoost)) were chosen as base learners for the OCC algorithm. The experimental results present that the proposed OMDC approach using binary relevance multi-dimensional classification methods predicts the conditions of a hydraulic system's multiple components with high accuracy. Also, it is clearly seen from the results that the OMDC models that utilize ensemble-based classification algorithms give more reliable prediction performances with an average Hamming score of 0.853 than the others that use traditional algorithms as base learners.     

Dry reforming of methane has no future for hydrogen production: Comparison with steam reforming at high pressure in standard and membrane reactors

The methane dry-reforming and steam reforming reactions were studied as a function of pressure (1–20 atm) at 973 K in conventional packed-bed reactors and a membrane reactors. For the dry-reforming reaction in a conventional reactor the production yield of hydrogen rose and then decreased with increasing pressure as a result of the reverse water-gas shift reaction in which the hydrogen reacted with the reactant CO₂ to produce water. For the steam reforming reaction the production yield of hydrogen kept increasing with pressure because the forward water-gas shift reaction produced additional hydrogen by the reaction of CO with water. In the membrane reactors the methane conversion and the hydrogen production yields were higher for both the dry-reforming and steam reforming reactions, but for the dry reforming at high pressure half of the hydrogen was transformed into water. Thus, the dry-reforming reaction is not practical for producing hydrogen.     

Properties of blended cements with thermally activated kaolin

Kaolin, one of the materials of major importance for the ceramic and paper industry, is also used in the construction industry as a raw material for the production of white cement clinker and, in the form of metakaolin, as an artificial pozzolanic additive for concrete. Metakaolin is a vital component of high-performance and architectural concrete; however, its application in regular concrete is very limited due to relatively high production costs. This report evaluates the performance of a low-cost metakaolin-based additive called thermally activated kaolin (TAK), in cement. Due to its pozzolanic properties and the densification of cement matrix, the application of TAK provides a 15% improvement of the compressive strength. It was shown that TAK of optimal quality can be manufactured by the thermal treatment of raw kaolin with 74% of kaolinite at 750 °C without the intermediate beneficiation stage. The application of a developed approach can significantly reduce production expenditures and make the application of such an additive feasible even in regular-grade cement and concrete.     

Housing development and policy change: what has changed in Turkey in the last decade in the owner-occupied and rented sectors?

Since 2002, The Justice and Development Party has been governing in Turkey. From their first period to the current, major changes have been observed in the Turkish housing system, regarding both owner occupied and rented sectors. First one is the introduction of Mortgage Law in 2007. As already a home-owner society with a 64.16 % share in urban areas (2003), home ownership ratios can be argued to increase in coming periods. Second modification in owner occupied sector was significant policy change in Housing Development Administration (HDA) of Turkey. With a “housing mobilization” project, almost 500,000 new dwellings were built by HDA all over the country in 10 years. This has been a record in HDA’s history. Remarkable changes occurred in the rented sector as well. Originally, Turkey has been characterized with absence of public renting and considerable proportion of private rented stock especially in the big cities. Governments did not develop social rented housing and pro-owner laws have been followed. Renters could face eviction under certain situations determined by the Law on Property Rents, however these were subject to misuse by homeowners. As a third major change, a new Code of Obligations was introduced superseding Law on Property Rents. In this paper, recent changes in both rented and owner occupied sectors of the Turkish housing system are analyzed with reference to mortgage law, HDA’s new policies and changes in private renting legislation. In doing so, several key figures like buildings produced, inflation rate and physical attributes of private renting are provided.     

Degradation of β-carotene with the effects of light and sulfur dioxide may be responsible for the formation of white spot in dried apricots

Light and sulfur-induced degradation of -carotene flushing out of cells with the effect of salivary pectolytic enzymes of bugs belonging to the family of Heteroptera have been shown to be responsible for the formation of white spot in dried apricots affecting the product quality adversely. The effects of light and sulfur dioxide on the degradation of -carotene were studied in the model systems. Light-induced degradation rate of -carotene was higher at shorter wavelengths. Sulfur-induced degradation reaction of -carotene followed a second-order rate law with a rate constant of 1687 M^–1 min^–1.At shorter wavelengths, light energy was mainly responsible for the degradation of -carotene while sulfur dioxide was more effective on -carotene degradation at higher wavelengths.     

Radical Innovation with Limited Resources in High‐Turbulent Markets: The Role of Lean Innovation Capability

How do firms radically innovate with limited resources in high‐turbulent environments? We examine this question via in‐depth comparative case studies of ten start‐up firms in diverse high‐turbulent markets. Evidence shows that the perceived value of resources depends on two contextual factors: market type and business model type. More interestingly, firms that see resource limitation as an enabler rather than an inhibitor seem to have a distinct capability that we call lean innovation capability. It is defined as a distinct capability that reflects a firm's ability to experiment with ideas that meet core customer needs by constantly iterating the initial offering with the purpose of validating the learning through continuous market feedback to achieve sustainable performance. The three main qualities of these companies are (1) adopting abductive reasoning, (2) embracing a validity‐driven approach, and (3) operating in the overlapping spaces of fundamental customer needs, business viability and technological feasibility. Lean firms adopt design‐thinking methodology and act like bricoleurs, such as make‐do by applying combinations of the available resources through rapid prototyping to new problems and opportunities in an experimental way. Briefly, lean innovation capability enables firms to manage limited resources by reconfiguring and reallocating existing resources, and, thereby, helps empower resource‐limited radical innovation.     

The evaluation of low‐cost biosorbents for removal of an azo dye from aqueous solution

There is a need to develop innovative and alternative technologies that can remove dyes from wastewater. In this study, low‐cost and locally available two renewable biosorbents (cotton stalk and apricot seed) were investigated to remove of Astrazone Black from aqueous solution. The effects of various experimental parameters such as dye concentration, adsorbent amount, adsorbent particle size and initial pH were tested, and optimal experimental conditions were examined. The results showed that as the amount of adsorbent was increased, the percentage of dye removal increased accordingly. The ratios of dye sorbed increased as the adsorbent particle size decreased. In addition, antibacterial effect of untreated and treated (decolourized) dye on a soil bacterium, Pseudomonas aeruginosa, was determined. The removal of this dye with agricultural wastes reduced the toxic effect on P. aeruginosa. This reduction in toxic effect is important both in respect of environmental biotechnology and waste detoxification.     

Effects of Tungsten and Boron Contents on Crystallization Temperature and Microhardness of Tungsten Based Metallic Glasses

Effects of tungsten and boron contents on the thermal properties and microhardness of W-Fe-B metallic glass system were studied. Thin foils, with thicknesses of 20 and 100 μm, of the alloys were produced by piston and anvil method in an arc furnace. The structures of the foils were investigated by X-ray diffraction. Thermal stabilities of the alloys were examined by using differential scanning calorimetry. 20-μm- thick foils of all the alloys were determined to be fully amorphous, but crystalline phases were detected in the 100-μm-thick foils. It was found that crystallization temperatures of the alloys are between 1060 and 1177 K. Tungsten and boron content increases improve the crystallization temperature and microhardness of the alloys significantly, but deteriorate the glass forming ability of the alloys. It was also observed that for constant Fe content, increasing tungsten content to the level higher than that of boron content does not result in any further improvement in crystallization temperature, but improves glass forming ability significantly. The alloy containing highest total amount of tungsten and boron, W₃₅Fe₃₅B₃₀, has the highest crystallization temperature, 1177 K, and microhardness, 1634 HV.     

Iron‐encapsulated cold‐set whey protein isolate gel powder ‐ Part 2: Effect of iron fortification on sensory and storage qualities of Yoghurt

Iron was incorporated at 20–60 mg/kg of yoghurt using iron‐encapsulated cold‐set whey protein isolate gel powder (WPI‐Fe) and by direct addition of ferrous sulphate solution. The changes in physicochemical and sensory qualities of the yoghurt samples were determined over 14 days of storage. Quality attributes of the yoghurt fortified using WPI‐Fe particles at up to 60 mg iron/kg were similar to those of unfortified control samples, especially in terms of colour and flavour, while the samples fortified by direct addition of ferrous sulphate exhibited noticeable adverse effects even at 20 mg iron/kg.