Comparison of experimental results obtained by designed dynamometer to fuzzy model for predicting cutting forces in turning

This paper presents a comparison of experimental results and consistent fuzzy rule-based model for estimating the cutting forces in turning. A dynamometer that can measure static and dynamic cutting forces by using strain gauge and piezo-electric accelerometer, respectively, was used for measuring the forces. AISI 1040 steel was used as the workpiece material. Feed force, thrust force and main cutting force were measured for three combinations of cutting speeds, feedrates and depth of cuts. The rake angle and approach angle of the cutting tool were kept constant throughout the experiments. The fuzzy model consists of 27 rules. In this research, a Mamdani max–min inference for inference mechanism and the centre of gravity (Centroid) defuzzifier formula method for defuzzification were used as these operators assure a linear interpolation of the output between the rules. It has a wide range of applications over many types of steels and turning conditions. It is also simple to implement, from a rule-chart mode to an intelligent on-line adaptive control mode. Experimental results were compared with the predicted fuzzy model. The difference between experimental and predicted results was obtained as around 99.6%.     

Development of empirical models for performance evaluation of UASB reactors treating poultry manure wastewater under different operational conditions

A nonlinear modeling study was carried out to evaluate the performance of UASB reactors treating poultry manure wastewater under different organic and hydraulic loading conditions. Two identical pilot scale up-flow anaerobic sludge blanket (UASB) reactors (15.7 L) were run at mesophilic conditions (30-35 degrees C) in a temperature-controlled environment with three hydraulic retention times (theta) of 15.7, 12 and 8.0 days. Imposed volumetric organic loading rates (L(V)) ranged from 0.65 to 4.257 kg COD/(m(3) day). The pH of the feed varied between 6.68 and 7.82. The hydraulic loading rates (L(H)) were controlled between 0.105 and 0.21 m(3)/(m(2)day). The daily biogas production rates ranged between 4.2 and 29.4 L/day. High volumetric COD removal rates (R(V)) ranging from 0.546 to 3.779 kg COD(removed)/(m(3)day) were achieved. On the basis of experimental results, two empirical models having a satisfactory correlation coefficient of about 0.9954 and 0.9416 were developed to predict daily biogas production (Q(g)) and effluent COD concentration (S(e)), respectively. Findings of this modeling study showed that optimal COD removals ranging from 86.3% to 90.6% were predicted with HRTs of 7.9, 9.5, 11.2, 12.6, 13.7 and 14.3 days, and L(V) of 1.27, 1.58, 1.78, 1.99, 2.20 and 2.45 kg COD/(m(3)day) for the corresponding influent substrate concentrations (S(i)) of 10,000, 15,000, 20,000, 25,000, 30,000 and 35,000 mg/L, respectively.     

Chemical bonding structure of TiO2 thin films grown on n-type Si

Titanium dioxide thin films were obtained by RF magnetron sputtering system with different Ar and O atmospheres. Chemical bonding structures of the thin films were investigated using the Fourier transform infrared spectroscopy (FTIR) in the range of 400-7500 cm^− 1 for as-deposited and conventionally thermal annealed films at different temperature in air. These structural characterizations of the films were carried out by describing the low-frequency fluctuations of the FTIR spectra using the noninvasive (i.e. error controllable) procedure of the optimal linear smoothing. This approach is based on the criterion of the minimal relative error in selection of the proper smoothing window. It allows the receiving an optimal separation of a possible trend from the high-frequency fluctuations, defined as a random sequence of the relative fluctuations possessing zero trends. Thus, the noise can be read and extra information about the structures was then obtained by comparing with the experimental results. In the film annealed at 900 °C, the rutile phase was the dominant crystalline phase as revealed by infrared spectroscopy. At the annealing temperatures lower than 900 °C, both the anatase and the rutile phases were coexisting. In addition, symmetric and asymmetric Si-O-Si vibrations modes were observed at around 1000 cm^− 1 and 800 cm^− 1, respectively. These peaks suggest that a thin SiO₂ film was formed at the TiO₂/Si interface during the growth and the annealing of the TiO₂ films. It was also observed that the reactivity between TiO₂ film and Si substrate is increased with the increasing annealing temperature.     

Porous Silicon： Volume-Specific Surface Area Determination from AFM Measurement Data

Porous silicon layers manufactured by using （100）, 1-5 ohm-cm p-type （boron doped） wafer by electrochemical etching in HF etanol solution. Photoluminescence （PL） spectra of anodically etched silicon obtained for different conditions studied and surface characteristics are investigated by AFM. This study gives a simple way to determine specific surface are of porous silicon which plays a major role with porosity for explaining the blue shift in photoluminescence peak. Properties such as specific surface area, pore size, and pore size distribution, the main surface properties of layer are investigated from AFM data which are important material characteristics in many processing applications. The ＂specific surface area＂ （Sspecific） generally defined as the area of solid surface per unit mass of material, solid volume or cross section area. From 3-D reconstructions of AFM data, the surface area and the volume of the porous layer can be estimated directly and volume-surface specific area is calculated. For porous silicon this feature can be defined as the total surface area per volume and given by the unit m2/cm3. The method is simple not need to construct a special set up for measurement and non destructive.     

Physical disability, psychological status, and health-related quality of life in older hemodialysis patients and age-matched controls

We aimed at comparing the elderly adults and normal subjects with regard to their disability, psychological status, and quality of life (QOL). One hundred and twenty-five dialysis patients and 61 controls were recruited in the study. Depression and anxiety symptoms of the patients were evaluated with the Psychological Symptom Screening List (SCL 90-R). For evaluating the disability, the Rivermead mobility index (RMI) was utilized. For evaluating the QOL, we used the short form-36 (SF-36) scale. The Rivermead mobility index of the patients (9.6 +/- 3.4) was found. When compared with controls, dialysis patients had higher levels of disability (p = 0.0001). Depression and anxiety symptom scores of these patients were also significantly higher than that of the controls (p < 0.05). There was a correlation between the disability and depression symptom scores (r: 0.171, p = 0.037). Both physical and mental capacity scores of the dialysis patients were lower than those of the controls (p < 0.05 and p < 0.05) QOL scores for elderly hemodialysis patients were found to be lower. Their disability was higher, making them dependable on others during their daily lives. Specific exercise programs should be developed for these patients. Even the smallest effort in this regard will result in improvements in physical functioning while bringing them significant benefits.     

Strain analysis of the GaN epitaxial layers grown on nitridated Si(111) substrate by metal organic chemical vapor deposition

The strain analysis of GaN film on nitridated Si(111) substrate with different growth times between 0 and 660 s via metal organic chemical vapor deposition (MOCVD) was conducted based on the precise measurement of the lattice parameters by using high-resolution X-ray diffraction (HR-XRD). The nitridation time (NT) was changed at a fixed growth condition. The a- and c-lattice parameters were measured, followed by the in-plane and out-of-plane strains. Then, the biaxial and hydrostatic components were extracted from the total strain values obtained, and were then discussed in the present study as functions of the NT. The biaxial strain and stress are also strongly affected by the non-uniformity of the SiN_x buffer layer thickness.     

Moringa oleifera seeds as a flocculant in waste sludge treatment

In this study the results of a laboratory based investigation to determine the effectiveness of Moringa oleifera seeds as a flocculant for activated sludge treatment are presented. Waste sludge samples are activated sludge from Taman Dr. Tun. Ismail Activated Sludge Wastewater Treatment plant, Kuala Lumpur, Malaysia. Moringa oleifera seed was applied as dry powder (shelled blended), solution (shelled blended), and solution (shelled blended oil extracted). Results of vacuum filtration studies showed that residual sludge volume of up to 11%, 20% and 45% for shelled blended oil extracted, shelled blended, and control (no Moringa applied), respectively, was achievable. Sludge volume reduction of up to 67% was achievable using gravity settling for shelled blended solution and 48% for shelled blended oil extracted respectively compared to the control. The shelled blended category applied in powder form performed the same as the solution of shelled blended but performed better than the shelled blended oil extracted category in gravity settling. The specific cake resistance of sludge treated with shelled blended Moringa oleifera averaged 2.5 x 10¹²m/kg at 4000mg/l dosage. Vegetable oil from the shelled Moringa oleifera of up to 30% was obtained as a by product.     

Coenzyme Q10 supplementation and diastolic heart functions in hemodialysis patients: A randomized double‐blind placebo‐controlled trial

Coenzyme Q10 (CoQ10) supplementation has been shown to improve diastolic heart function in various patient cohorts. Systolic and diastolic dysfunctions are common in patients with end‐stage renal disease. Favorable effects of CoQ10 on cardiac functions are yet to be seen in hemodialysis patients. We aimed to evaluate effect of CoQ10 supplementation on diastolic function in a cohort of maintenance hemodialysis patients. This was a prospective, double‐blind, placebo‐controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d during the 8 weeks in each phase, with a 4‐week washout period. Participants underwent conventional and tissue Doppler echocardiography before and after each study phase. Parameters characterizing left ventricle diastolic function and other standard echocardiographic measurements were recorded. Twenty‐eight patients were randomized, but 22 patients completed study protocol. Intraventricular septum (IVS) thickness and left ventricle mass were significantly decreased in CoQ10 group (P = 0.03 and P = 0.01, respectively). Myocardial peak systolic and early diastolic velocities derived from IVS were significantly increased (P = 0.048 and P = 0.04, respectively). Isovolumetric relaxation time and E/Em ratio calculated for IVS also significantly reduced in CoQ10 group (p = 0.02 and p = 0.04, respectively). There was no significant difference in any of the studied echocardiographic parameters in placebo group. The results of this study showed that CoQ10 supplementation did not significantly improved diastolic heart functions compared with placebo in maintenance hemodialysis patients.     

A transparent electrode with water-oxidizing activity

Hydrogen production by water splitting is a promising method to store energy. Water-oxidation reaction is a bottleneck in water-splitting systems. Herein, a mononuclear nickel(II) phosphine complex with 1,2-bis(dicyclohexylphosphino)ethane ligand, was synthesized and characterized by X-ray crystallography method. The water-oxidizing catalyst under the electrochemical condition was studied. The role of Ni compound for the water-oxidation reaction on the surface of fluorine-doped tin oxide as one of the true catalysts was investigated by the electrochemical methods and Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM/EDX) Spectroscopy. The big ligand around the Ni ion causes a very small size of Ni-based particles on the surface of the electrode, which are the active catalysts for the water-oxidation reaction. Such small nanosized Ni-based compounds are transparent and have no effect on the transparency of the obtained fluorine-doped tin oxide. Thus, it is a promising method to synthesize a transparent fluorine-doped tin oxide with water-oxidizing activity.