Design and implementation of Type-2 fuzzy neural system controller for PWM rectifiers

It is necessary to convert AC to DC for the systems that do not work with AC sources. For this reason, diode and thyristor rectifiers were developed and designed. However, these rectifiers are not well suited for industrial applications requiring high performance. With the advances in power electronics and semiconductor technology, Pulse width modulation (PWM) rectifiers have been successfully employed in various industrial applications including variable-speed drives and uninterruptible power supplies. PWM rectifiers have the advantages of being low input current harmonic, adjustable input power factor, and controllable DC voltage and bidirectional energy flow. Because of all these features of the PWM rectifiers, the control and design of these rectifiers are very important topic. The aim of this paper is to control DC-link voltage of PWM rectifier with type-2 fuzzy neural system (T2FNS) instead of PI controller. For this aim, three-phase PWM rectifier with proposed controller is designed and simulated for four scenarios in this paper. A simulation model of the PWM rectifier is designed in MATLAB/Simulink and the performance of PWM rectifier with proposed controller is analyzed.     

Arsenic removal from drinking water by electrocoagulation using iron electrodes

Arsenic removal from drinking water was investigated using electrocoagulation (EC) followed by filtration. A sand filter was used to remove flocs generated in the EC process. Experiments were performed in a batch electrochemical reactor using iron electrodes with monopolar parallel electrode connection mode to assess their efficiency. The effects of several operating parameters on arsenic removal such as current density (1.5–9.0 mA cm^?2), initial arsenic concentration (50–500 μg L^?1), operating time (0–15 min), electrode surface area (266–665 cm²), and sodium chloride concentrations (0.01 and 0.02M) were examined. The EC process was able to decrease the residual arsenic concentration to less than 10 μg L^?1. Optimum operating conditions were determined as an operating time of 5 min and current density of 4.5 mA cm^?2 at pH of 7. The optimum electrode surface area for arsenic removal was found to be 266 cm² taking into consideration cost effectiveness. The residual iron concentration increased with increasing residence time, and maximum residual iron value was measured as 287 μg L^?1 for electrode surface area of 266 cm². The addition of sodium chloride had no significant effect on residual arsenic concentration, but an increase in current density was observed.     

Briquetting soda weed (Salsola tragus) to be used as a rural fuel source

Amount of traditional fuel sources in the world has been decreasing and there is a definite need to produce and utilize alternative fuels such as biomass materials. In this study, briquetting conditions of Russian tumbleweed, Salsola tragus, (commonly named soda weed in Turkey) which grows in salty soils were investigated.Soda weeds were first chopped coarsely in a local tresher, then chopped finely in a hammer mill. Weed materials at three moisture levels (7%, 10%, and 13%) were prepared in the lab. Chopped weed materials were filled in cylindrical and square dies and compressed using a hydraulic press at three pressure levels of 15.7, 19.6 and 31.4 MPa. Optimum temperature, moisture rate, and pressure values were determined to produce stable briquettes. Further experiments were conducted to produce briquettes using sawdust and walnut shells as additives in conical dies of two different sizes.Results of a statistical analysis of parameters to produce briquettes in different dies indicated that moisture rates of 7–10%, pressure of 31.4 MPa, and temperatures of 85–105 °C were suitable for briquetting soda weed. Furthermore, sawdust and walnut shells additives increased briquette density without any negative effects on production process and product stability.     

Bacterial Cellulose: Production,Characterization, and Application as Antimicrobial Agent

Bacterial cellulose (BC) is recognized as a multifaceted, versatile biomaterial with abundant applications. Groups of microorganisms such as bacteria are accountable for BC synthesis through static or agitated fermentation processes in the presence of competent media. In comparison to static cultivation, agitated cultivation provides the maximum yield of the BC. A pure cellulose BC can positively interact with hydrophilic or hydrophobic biopolymers while being used in the biomedical domain. From the last two decades, the reinforcement of biopolymer-based biocomposites and its applicability with BC have increased in the research field. The harmony of hydrophobic biopolymers can be reduced due to the high moisture content of BC in comparison to hydrophilic biopolymers. Mechanical properties are the important parameters not only in producing green composite but also in dealing with tissue engineering, medical implants, and biofilm. The wide requisition of BC in medical as well as industrial fields has warranted the scaling up of the production of BC with added economy. This review provides a detailed overview of the production and properties of BC and several parameters affecting the production of BC and its biocomposites, elucidating their antimicrobial and antibiofilm efficacy with an insight to highlight their therapeutic potential.     

Preparation,characterization and drug release behavior of poly(acrylic acid–co-2-hydroxyethyl methacrylate-co-2-acrylamido-2-methyl-1-propanesulfonic acid) microgels

In this paper, Poly(acrylic acid-co-2-hydroxyethyl methacrylate-co-2-acrylamido-2–methyl-1–propanesulfonic acid (AAc-HEMA-AMPS) microgels were synthesized by using an inverse suspension polymerization technique. The increase in the AMPS content of the microgels composition caused a large increase in water uptake. The morphology of the microgels was examined by environmental scanning electron microscopy (ESEM). The AMPS containing microgels had a mean particle diameter of 10 μm. The glass transition temperature of the microgels were examined by DSC and found that they show single Tg. Lidocaine (LD) and Methylene blue (MB) were used as model drugs for the investigation of drug release behavior of the microgels. Different drug release patterns were observed, for LD and MB loaded microgels. The release studies showed that some of the basic parameters affecting the drug release behavior of microgels were the specific and non-specific interactions between microgel and drug structure and pH of the dissolution medium. These hydrogels may be potential candidates for pH-sensitive applications.     

Special Features of the Kinetics of Boriding of Binary Fe – Ni Alloys

Metal Science and Heat Treatment - The kinetics of boriding of Fe – Ni alloys containing 60, 70, 80, and 90 wt.% Ni at 1073 – 1373 K for 2 – 8 h in powdered mixtures with the use...     

The Influences of Natural Zeolite (cliptinolite) on Ammonia and Biogenic Amine Formation by Foodborne Pathogen

The influence of natural zeolite on biogenic amines (BAs) and ammonia (AMN) production by eight common gram negative and positive foodborne pathogens (FBP) were investigated in histidine decarboxylase broth (HDB). Presence of 1% zeolite in the HDB resulted in significantly higher AMN production. Histamine (HIS) production by gram positive bacteria was as low as 0.5 mg/L, whereas Escherichia coli produced 18.96 mg/L of HIS. The use of zeolite also significantly suppressed HIS accumulation by E. coli, Pseudomonas aeruginosa, S. paratyphi A (P < 0.05), although zeolite addition stimulated HIS production by K. pneumonia and Aeromonas hydrophila. The range of tyramine (TYR) production by gram positive bacteria was 1.19 and 4.06 mg/L for Enteroccus faecalis and Listeria monocytogenes respectively. The results of study showed that the effect of zeolite on BAs and AMN production was dependent on bacterial strains, as well as zeolite concentrations used. Practical Application: Natural zeolites are the main absorptive, low-cost material used in agriculture and industry. Although the effect of zeolite on ammonia formation in some industrial systems is well known, there is limited information regarding the impact of zeolite on biogenic amine (BA) production by foodborne pathogens. The data presented in this article will help us to understand the impact of natural zeolite on BA and ammonia production by eight common foodborne pathogens.     

Influence of fat replacers on the chemical,textural and sensory properties of low‐fat Beyaz pickled cheese produced from ewe's milk

In this study, low‐fat Beyaz pickled cheeses were produced from ewe's milk using a protein‐based fat replacer (1.0% w/w Simplesse^®), a carbohydrate‐based fat replacer (0.5% w/w Maltrin^®) and a blend of both (0.5% w/w Simplesse^® + 0.25% w/w Maltrin^®). The chemical, textural and sensory properties of cheeses were examined during storage for 60 days. The use of fat replacers affected chemical (except pH and acidity), textural and sensory properties of the cheeses. The cheeses produced with Simplesse^® (Sample B) were similar to full‐fat cheese and had the highest sensory scores.     

A survey on in-network querying and tracking services for wireless sensor networks

In wireless sensor networks, querying services purpose to detect static events while tracking services continuously monitor mobile events. This paper surveys and discusses in-network querying and tracking services for static and mobile networks. Querying and tracking services are categorized by tree-based, hierarchical cluster-based, geometrical and hash-based. Mobility effects of network units and several design metrics including energy-efficiency, distance-sensitivity, scalability and fault-tolerance are also discussed. The paper includes open research issues for querying and tracking services in various domains.     

Olive Cake as a Biomass Fuel for Energy Production

Olive cake (OC) is a by-product of olive oil production and is a solid material consisting of seed particles and the fleshy parts of olive. The Mediterranean region represents 98% of the world's olive tree population, and Turkey is among the top five main olive oil producer countries around the world. The main objective of the present study is to investigate the potential and utilization of olive cake (OC) in the country. It is estimated that over 360,000 tons of OC, corresponding to an average of 150,000 tons of oil equivalent (toe), were produced in the season of 2000–2001 in Turkey. From the combustion experiments performed in the conventional OC-fired boilers in the country, the values for CO-emissions were found to vary from 1,800 to 10,000 mg/m ³ . Suitable combustion systems, such as fluidized bed systems, stoker fed from the bottom with secondary air supply, etc., should be used for efficient energy production from the OC. Determination of values of the flue gas can be used in calculating for heating surfaces.