Characterization of Tool Wear Measurement with Relation to the Surface Roughness in Turning

In turning, an accurate gauging of tool wear condition is an essential part of process control due to adverse effects on dimensional tolerance and surface finish quality. When the surface roughness is the primary concern, the conventional measure of tool wear is found to be imprecise because it provides very little information on the wear patterns in tool nose and flank. A tool wear model, developed in this study, represents the wear condition more comprehensively and accurately with relation to the surface roughness. Experimental results validate the model, showing 92% accuracy between the predicted surface roughness and the actual measurements.     

Approximating the crowd

The problem of “approximating the crowd” is that of estimating the crowd’s majority opinion by querying only a subset of it. Algorithms that approximate the crowd can intelligently stretch a limited budget for a crowdsourcing task. We present an algorithm, “CrowdSense,” that works in an online fashion where items come one at a time. CrowdSense dynamically samples subsets of the crowd based on an exploration/exploitation criterion. The algorithm produces a weighted combination of the subset’s votes that approximates the crowd’s opinion. We then introduce two variations of CrowdSense that make various distributional approximations to handle distinct crowd characteristics. In particular, the first algorithm makes a statistical independence approximation of the labelers for large crowds, whereas the second algorithm finds a lower bound on how often the current subcrowd agrees with the crowd’s majority vote. Our experiments on CrowdSense and several baselines demonstrate that we can reliably approximate the entire crowd’s vote by collecting opinions from a representative subset of the crowd.     

Experimental investigation of three different solar air heaters: Energy and exergy analyses

The present study aims to compare three different types of designed flat-plate solar air heaters, two having fins (Type II and Type III) and the other without fins (Type I), one of the heater with a fin had single glass cover (Type III) and the others had double glass covers (Type I and Type II). The energy and exergy output rates of the solar air heaters were evaluated for various air flow rates (25, 50 and 100 m³/m² h), tilt angle (0°, 15° and 30°) and temperature conditions versus time. Based on the energy and exergy output rates, heater with double glass covers and fins (Type II) is more effective and the difference between the input and output air temperature is higher than of the others. Besides, it is found that the circulation time of air inside the heater played a role more important than of the number of transparent sheet. Lower air flow rates should be preferred in the applications of which temperature differences is more important.     

Spray Drying of Yogurt: Optimization of Process Conditions for Improving Viability and Other Quality Attributes

Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150–180°C) and outlet air temperatures (60–90°C) and the feed temperature (4–30°C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171°C, air outlet temperature of 60.5°C, and feed temperature of 15°C as the optimum processing condition. The mathematical optimum condition was experimentally verified.     

Tillage effects on energy use for corn silage in Mediterranean Coastal of Turkey

One of the main concepts of tillage should be to create the most appropriate soil conditions by taking into consideration energy use efficiency because it allows financial savings, fossil resources preservation and environment pollution decrease. Therefore, the study was perform to evaluate the effects of different tillage systems on energy use, the energy output/input ratios and profitability for silage corn (Zea mays L) production. The tillage systems were consisted of conventional tillage without stubble (CT), minimum tillage (MT), band tillage (BT), ridge tillage (RT) and no-tillage (NT).The effects of tillage were found to be statistically on energy parameters. The highest energy use efficiency (8.78), energy productivity (2.12 kg MJ⁻¹), and energy profitability (7.78) were in MT while the lowest in NT. But, the highest energy intensiveness was in NT (24.83 MJ EUR⁻¹). Indirect energy, non-renewable energy and commercial energy shares were higher for all the systems. More renewable energy was used in NT than the other treatments. The highest benefit/cost ratio and productivity were in the MT (2.13), and followed by NT (2.07). For this reason, conservation tillage treatments (i.e. MT and NT) should be supported for the energy and profitability sustainability of corn silage agriculture.     

Effect of fat replacers on kefir quality

The purpose of the study was to determine the effects of fat replacers on the quality of non‐fat kefir. Skim milk fortified with Dairy Lo^® (DL) and inulin (INU) was fermented with kefir grains to manufacture kefir. The results of compositional, microbiological, rheological and sensorial analyses were compared with whole kefir (WK) and non‐fat kefir (NFK) controls. Results for dry matter, pH and lactic acid ranged between 82.4 and 109.1 g kg^?1, 4.26 and 4.40, and 7.0 and 9.2 g L^?1, respectively. Acetaldehyde and ethanol contents of samples were between 2.89 and 7.28 mg L^?1, and 151.46 and 323.89 mg L^?1, respectively. In all samples, Lactobacillus spp., Streptococcus spp. and yeast counts were between 9.1 and 9.9, 9.3 and 9.9, and 5.2 and 5.6 log cfu mL^?1, respectively. Kefir samples had non‐Newtonian behaviour and pseudoplastic fluid with thixotropy. At the first day, DL had the highest apparent viscosity (3.119 Pa s) while NFK had the lowest value (1.830 Pa s). In the sensory evaluation, odour and taste scores of samples were not different. Dairy Lo^® and inulin could be used without any adverse effect for the production of non‐fat kefir. Copyright © 2009 Society of Chemical Industry     

Structural and luminescent properties of Er3+ and Tb3+-doped sol–gel-based bioactive glass powders and electrospun nanofibers

In this study, sol–gel-based erbium (Er³⁺), terbium (Tb³⁺) and Er³⁺: Tb³ co-doped 1393 bioactive glass powders and electrospun nanofibers were prepared. Structural and morphological properties of the bioactive glasses as well as the photoluminescence characteristics were investigated in detail. The median particle size and average diameter of the prepared glass powders and fibers were in the range of ~ 1.5–3.5 μm and 280–660 nm, respectively. The steady-state photoluminescence and decay kinetics of the samples were investigated under excitation (374 nm) where only Er³⁺ and Tb³⁺ ions close to Si nanoclusters can be excited. All the samples prepared in the study exhibited bright green emission upon excitation at 374 nm. Results showed that the dopant concentration and the sample morphology have significant influence on the photoluminescence and decay properties of the glasses. Sol–gel-derived bioactive glass particles exhibited stronger emission intensity, whereas electrospun nanofibers showed extended decay times. In vitro bioactivity experiments revealed that Er³⁺ and Tb³⁺ doping did not inhibit the conversion of the glass samples to hydroxyapatite treated in simulated body fluid for 30 days. It was concluded that Er³⁺ and Tb³⁺-containing 1393 bioactive glasses have a potential to be used in tissue engineering applications as well as bioimaging studies.

     

Fuel effects on Li2CuP2O7 synthesized by solution combustion method for lithium-ion batteries

Lithium copper pyrophosphate has been synthesized by the solution combustion method for the first time. Urea and hexamethylenetetramine were used as fuel. The samples were successfully prepared in low reaction temperature and short reaction time. The products were structurally characterized by FT-IR and p-XRD. Thermal behavior of samples was also investigated through TG/DT analyses. Magnetic measurements showed that the urea- and hexamethylenetetramine-assisted Li₂CuP₂O₇ were paramagnetic at room temperature. Surface analyses indicated that the fuel types changed the surface properties of samples because of exothermic redox reaction during combustion, and electrochemical performances showed clear differences. The charge capacity of urea- and hexamethylenetetramine-assisted synthesized Li₂CuP₂O₇ was calculated as 180?mAhg^?1 and 146?mAhg^?1. Synthesis method enlarged the charge capacity and prepared lithium copper pyrophosphate to have a potential for use in lithium-ion batteries.