Experimental investigation on water injected twin screw compressor for fuel cell humidification

A water injection in Twin Screw compressors was examined in order to develop effective humidification and cooling schemes for fuel cell stacks as well as cooling for compressors. The temperature and the relative humidity of the air at suction and exhaust of the compressor were monitored under constant pressure and water injection rate and at variable compressor’s operating speeds. The experimental results showed that the relative humidity of the outlet air was increased by the water injection. The injection tends to have more effect on humidity at low operating speeds/ mass flow rates. Further humidification can be achieved at higher speeds as higher evaporation rate becomes available. It was also found that the rate of power produced by the fuel cell stack was higher than the rate used to run the compressor for the same amount of air supplied. The efficiency of the Balance-Of-Plant (BOP) was therefore higher when more air is delivered to the stack. However, this increase in the air supply needs additional subsystems for further humidification/ cooling of the BOP system

Development of a high pressure compressed natural gas mixer for a 1.5 litre CNG-diesel dual engine

[Abstract]: The Computational Fluid Dynamics (CFD) analysis software was used to study the flow behaviour of compressed natural gas (CNG) and air in a CNG-air mixer to be introduced through the air inlet of a CNG-Diesel dual fuel stationary engine. The results of the simulation show that the Venturi mixer with more holes gives superior engine performance compared to the 4-hole Venturi mixer. Further analysis is done on the different holes mixer to investigate the effect of engine speed on the mass flow rate of CNG and the equivalence ratio Lambda. The second part of the paper represents a comparison results between the performances of a single cylinder research Compression Ignition CI engine fuelled with CNG-diesel system and conventional CI engine fuelled by conventional diesel. The engine was equipped with the simulated Venturi mixer, the result showed significant reduction in the exhaust gas emission compared to the conventional diesel engine. The average power output generated by dual fuel engine was slightly higher than that diesel one at different engine speeds

Two rarities together: A free peritoneal body in a hernia en pantaloon sac and case series of our experience of finding loose peritoneal bodies

Peritoneal loose bodies (PLBs) are rare findings that were reported extensively in the early nineteenth and twentieth century in theform of case series by Littre, Riedel and Macintosh. In the recent past, focus has shifted more towards symptomatic free peritonealbodies. Although a proper intrabdominal examination and histopathology can help to clear the diagnosis, there is still no consensusin the surgical circle as to how to deal with them. Here, we report a case series of 4 cases of finding loose peritoneal bodies duringintra-abdominal procedures, three of them were found during laparoscopic procedures (laparoscopic appendectomy, Robotic meshrectopexy and laparoscopic bowel resection) while one was an open surgery (open inguinal hernia repair). This paper is unique asfor the first time in the history it brings two surgical rarities together i.e. ‘hernia en pantaloon’ and free peritoneal body along withrecommendations based on the literature, review to diagnose and treat loose peritoneal bodies

Conversational Use of Photographic Images on Facebook: Modeling Visual Thinking on Social Media

Modeling the "thick description" of photographs began at the intersection of personal and institutional descriptions. Comparing institutional descriptions of particular photos that were also used in personal online conversations was the initial phase. Analyzing conversations that started with a photographic image from the collection of the Library of Congress (LC) or the collection of the Manchester Historic Association (MHA) provided insights into how cultural heritage institutions could enrich the description of photographs by using informal descriptions such as those applied by Facebook users. Taking photos of family members, friends, places, and interesting objects is something people do often in their daily lives. Some photographic images are stored, and some are shared with others in gatherings, occasions, and holidays. Face-to-face conversations about remembering some of the details of photographs and the event they record are themselves rarely recorded. Digital cameras make it easy to share personal photos in Web conversations and to duplicate old photos and share them on the Internet. The World Wide Web even makes it simple to insert images from cultural heritage institutions in order to enhance conversations. Images have been used as tokens within conversations along with the sharing of information and background knowledge about them. The recorded knowledge from conversations using photographic images on Social Media (SM) has resulted in a repository of rich descriptions of photographs that often include information of a type that does not result from standard archival practices. Closed group conversations on Facebook among members of a community of interest/practice often involve the use of photographs to start conversations, convey details, and initiate story-telling about objets, events, and people. Modeling of the conversational use of photographic images on SM developed from the exploratory analyses of the historical photographic images of the Manchester, NH group on Facebook. The model was influenced by the typical model of Representation by Agency from O'Connor in O'Connor, Kearns, and Anderson Doing Things with Information: Beyond Indexing and Abstracting, by considerations of how people make and use photographs, and by the notion of functionality from Patrick Wilson's Public Knowledge, Private Ignorance: Toward a Library and Information Policy. The model offers paths for thickening the descriptions of photographs in archives and for enriching the use of photographs on social media

A radiotracer study of the adsorption behavior of aqueous Ba2+ ions on nanoparticles of zero-valent iron

Recently, iron nanoparticles are increasingly being tested as adsorbents for various types of organic and inorganic pollutants. In this study, nanoparticles of zero-valent iron (NZVI) synthesized under atmospheric conditions were employed for the removal of Ba2+ ions in a concentration range 10-3 to 10-6 M. Throughout the study, 133Ba was used as a tracer to study the effects of time, concentration, and temperature. The obtained data was analyzed using various kinetic models and adsorption isotherms. Pseudo-second-order kinetics and Dubinin-Radushkevich isotherm model provided the best correlation with the obtained data. Observed thermodynamic parameters showed that the process is exothermic and hence enthalpy-driven.2006 İYTE 1

ToF-SIMS depth profiling analysis of the uptake of Ba2+ and Co2+ ions by natural kaolinite clay

The sorption behavior of Ba2+ and Co2+ ions on a natural clay sample rich in kaolinite was studied using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling at 10-Å steps was performed up to a 70-Å matrix depth of the clay prior to and following sorption. The results showed that Co2+ is sorbed in slightly larger quantities than Ba2+, with significant numbers of ions fixed on the outermost surface of the clay. Depletion of the ions K+, Mg 2+, and Ca2+ from the clay lattice was observed to accompany enrichment with Co2+ and Ba2+ ions. The data obtained using X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) indicated insignificant structural and morphological changes in the lattice of the clay upon sorption of both Ba2+ and Co2+ ions. Analysis using energy dispersive X-ray spectroscopy (EDS) showed that the average atomic percentage (±S.D.) of Ba and Co on kaolinite surface were 0.49±0.11 and 0.61±0.19, respectively, indicating a limited uptake capacity of natural kaolinite for both ions

Reductive Decomposition of A Diazonium Intermediate by Dithiothreitol Affects The Determination of NOS Turnover Rates

Accurate determination of nitrite either as such or as the breakdown product of nitric oxide (NO) is critical in a host of enzymatic reactions in various settings addressing structure–function relationships, as well as mechanisms and kinetics of molecular operation of enzymes. The most common way to quantify nitrite, for instance in nitric oxide synthase (NOS) mechanistic investigations, is the spectrophotometric assay based on the Griess reaction through external standard calibration. This assay is based on a two-step diazotization reaction, in which a cationic diazonium derivative of sulfanilamide is formed as intermediate before the final absorbing azo-product. We show that this intermediate is very sensitive to reducing agents that may be transferred from the reaction media under investigation. The interaction of this vital intermediate with the reducing agent, dithiothreitol (DTT), which is widely used in NOS reactions, is characterized by both electrochemical and spectroscopic means. The effect of DTT on the performance of external calibration, both in sample recovery studies and in actual NOS reactions, is presented. Finally an alternative method of standard additions, which partially compensates for the accuracy and sensitivity problems of external calibration, is proposed and discussed

Combined DWT-DISB based image watermarking optimized for decision making problems

Currently, the protection of digital information, especially in the form of multimedia information such as images, video, text, and audio. The digital nature of the multimedia data has made it prone to misuse and attack, such as is of duplication, transformation, modification, and diffusion. In this sense, it is significant to create a system for protecting the intellectual property rights of the multimedia content. The system should guarantee copyright protection, authentication, and protection against duplication of the material. The drastic development in network multimedia system has made the development of these protection systems challenging. Numerous researches have proposed the use of watermarking to address these issues. The watermarking technique obscures vital information in the original multimedia data in which the hidden data is utilized for copyright protection and authentication. The primary need for any watermarking system should be to guarantee robustness against imminent attack while retaining the quality of the watermark images. This research presents a robust image watermarking technique used to hide details of the RGB Color elements. The proposed approach is an integration of the discrete wavelet transform (DWT) and the relatively new dual intermediate significant bit (DISB). The performance evaluation of the proposed approach produced quality watermarked images that are robust. The proposed method has a PSNR of 101.97 and an NCC of 0.9780 which compare considerable well with the individual techniques

Effect of castration and sex hormone treatment on survival, anti-nucleic acid antibodies, and glomerulonephritis in NZB/NZW F1 mice.

NZB/NZW F1 mice of both sexes were castrated at 2 wk of age and implanted subcutaneously with silastic tubes containing either 5-alpha-dihydrotestosterone or estradiol-17-beta. Mice receiving androgen showed improved survival, reduced anti-nucleic acid antibodies, or less evidence of glomerulonephritis as determined by light, immunofluorescent, and electron microscopy. By contrast, opposite effects were observed in castrated mice receiving estrogen. Intact male NZB/NZW F1 mice received androgen implants at 8 mo, an age when they develop an accelerated autoimmune disease associated with a decline in serum testosterone concentration. Such treated mice had improved survival and reduced concentrations of antibodies to DNA and to polyadenylic acid (Poly A). Prepubertal castration of male NZB/NZW F1 mice results in an earlier appearance of IgG antibodies to Poly A. This effect of castration was prevented if neonatal thymectomy was also performed