Experimental and analytical performance investigation of air to air two phase closed thermosyphon based heat exchangers

In recent years, the use of wickless heat pipes (thermosyphons) in heat exchangers has been on the rise, particularly in gas to gas heat recovery applications due to their reliability and the level of contingency they offer compared to conventional heat exchangers. Recent technological advances in the manufacturing processes and production of gravity assisted heat pipes (thermosyphons) have resulted in significant improvements in both quality and cost of industrial heat pipe heat exchangers. This in turn has broadened the potential for their usage in industrial waste heat recovery applications. In this paper, a tool to predict the performance of an air to air thermosyphon based heat exchanger using the ε-NTU method is explored. This tool allows the predetermination of variables such as the overall heat transfer coefficient, effectiveness, pressure drop and heat exchanger duty according to the flow characteristics and the thermosyphons configuration within the heat exchanger. The new tool's predictions were validated experimentally and a good correlation between the theoretical predictions and the experimental data, was observed. © 2014 Elsevier Ltd. All rights reserved

On-board demux/demod

To make satellite channels cost competitive with optical cables, the use of small, inexpensive earth stations with reduced antenna size and high powered amplifier (HPA) power will be needed. This will necessitate the use of high e.i.r.p. and gain-to-noise temperature ratio (G/T) multibeam satellites. For a multibeam satellite, onboard switching is required in order to maintain the needed connectivity between beams. This switching function can be realized by either an receive frequency (RF) or a baseband unit. The baseband switching approach has the additional advantage of decoupling the up-link and down-link, thus enabling rate and format conversion as well as improving the link performance. A baseband switching satellite requires the demultiplexing and demodulation of the up-link carriers before they can be switched to their assigned down-link beams. Principles of operation, design and implementation issues of such an onboard demultiplexer/demodulator (bulk demodulator) that was recently built at COMSAT Labs. are discussed

A case of severe osteomalacia secondary to phosphate diabetes in a renal transplant recipient

Transient hypophosphatemia is frequently observed during the first months after renal transplantation and is usually asymptomatic. Phosphate diabetes is defined as inadequate tubular phosphorus reabsorption leading to persistent renal phosphorus wasting, which is an important but overlooked cause of osteodystrophy in the post-renal transplantation population. We report the case of a 58-year-old male who presented with severe multiple osteoarticular pains within 3 months after successful first kidney transplantation. Bone disease was attributed initially to mild hyperparathyroidism secondary to vitamin D deficiency. Despite the correction of the hyperparathyroidism, the withdrawal of corticosteroids, and the reduction of immunosuppressive treatment to tacrolimus-based monotherapy, the osteoarticular pains persisted. Skeletal investigations at month 9 post-transplantation demonstrated a significant bone mineral density loss associated with osteomalacia and osteoporosis on the bone biopsy. Laboratory data showed persistent hypophosphatemia, and phosphate diabetes was then diagnosed explaining the post-transplant bone disease. A tacrolimus-induced renal tubular disorder was suspected to contribute to the excessive renal phosphorus wasting. The replacement of tacrolimus by sirolimus, in addition to oral phosphorus and vitamin D supplementations, led to the disappearance of pains, the normalization of urinary and plasma phosphate level, and a significant improvement of bone mineralization

Treatment of Hydrothermal-Liquefaction Wastewater with Crossflow UF for Oil and Particle Removal

This study aims to evaluate the application of ceramic ultrafiltration membranes in the crossflow mode for the separation of particles and oil in water emulsions (free oil droplets and micelles) from hydrothermal-liquefaction wastewater (HTL-WW) from the hydrothermal liquefaction of municipal sewage sludge. The experiments were carried out using one-channel TiO$_{2}$ membranes with pore sizes of 30, 10 and 5 nm. The results showed that the highest stable permeability could be achieved with a membrane-pore size of 10 nm, which experienced less fouling, especially through pore blockage, in comparison to the two other pore sizes. Instead of observing an increase in the permeability, the application of a higher feed temperature as well as backwash cycles led to a clear increase in irreversible fouling due to the presence of surfactants in the HTL-WW. Among several physical and chemical cleaning methods, alkaline cleaning at pH 12 proved to be the most efficient in removing fouling and maintaining stable performance on a long-term basis. Ceramic-membrane ultrafiltration can be considered as an adequate first-stage treatment of real HTL wastewater

Immunocompetent murine models for the study of glioblastoma immunotherapy.

Glioblastoma remains a lethal diagnosis with a 5-year survival rate of less than 10%. (NEJM 352:987-96, 2005) Although immunotherapy-based approaches are capable of inducing detectable immune responses against tumor-specific antigens, improvements in clinical outcomes are modest, in no small part due to tumor-induced immunosuppressive mechanisms that promote immune escape and immuno-resistance. Immunotherapeutic strategies aimed at bolstering the immune response while neutralizing immunosuppression will play a critical role in improving treatment outcomes for glioblastoma patients. In vivo murine models of glioma provide an invaluable resource to achieving that end, and their use is an essential part of the preclinical workup for novel therapeutics that need to be tested in animal models prior to testing experimental therapies in patients. In this article, we review five contemporary immunocompetent mouse models, GL261 (C57BL/6), GL26 (C57BL/6) CT-2A (C57BL/6), SMA-560 (VM/Dk), and 4C8 (B6D2F1), each of which offer a suitable platform for testing novel immunotherapeutic approaches

Heat-induced changes in soil water-extractable organic matter characterized using fluorescence and FTIR spectroscopies coupled with dimensionality reduction methods

[Abstract:] Water extractable organic matter (WEOM) is a very mobile and reactive soil OM fraction, critical in the translocation of carbon (C) from soils to other environmental compartments. Transformations of WEOM due to soil heating can have implications not only at a local scale, but in places far away from the location of the event. However, their accurate characterization is costly when analyzing a large number of samples. The objectives of this work were to identify common patterns for the changes in WEOM caused by the heating of various soil types using a combination of spectroscopic and dimensionality reduction techniques. Six soils from Spain, Kenya and Israel were collected at depths 0–10 cm and analysed before and after heating in air to temperatures of 300 and 600 °C. Fluorescence EEMs were measured in soil–water extracts containing WEOM, and decomposed using parallel factor (PARAFAC) analysis. The FTIR spectra were measured in freeze-dried extracts and further analysed using non-negative matrix factorization (NMF). Total organic C and SUVA254 values of the extracts experienced changes with the heating treatments that were soil dependant. Four PARAFAC and three NMF components were sufficient to characterize WEOM changes in all soils, which showed common thermal transformation patterns irrespective of their origin and properties. Thermal transformation of fluorescent WEOM led to the increase in the proportion of a component with an emission maximum at Ex 300/Em 392 nm, and to a lower extent one with the emission maximum at Ex 300/Em 426 nm. Concomitantly, the proportion of components with emission maxima at longer excitation wavelengths was reduced. These changes occurred at the lowest heating temperature and were maintained at 600 °C, and they seem to indicate a depletion of fluorescent components more conjugated, bigger in size, and an enrichment in smaller ones. The NMF components obtained from FTIR spectra showed an increase of the proportion of compounds with Csingle bondO bonds, more oxidized. No correlations were found between the components obtained with each method, thus indicating that the information obtained from the fluorescence EEMs-PARAFAC analysis and the NMF decomposition of FTIR spectra is complementary. It can be concluded that there is a common pattern of WEOM changes induced by thermal soil transformations irrespective of the origin and properties of the soils studied, and that the combination of different spectroscopic techniques coupled with dimensionality reduction methods can be used as a simple and low-cost method to fingerprint changes in WEOM composition, in general, and those caused by soil heating, in particular

Severe episodes of extra cellular dehydration : an atypical adult presentation of cystic fibrosis

Cystic fibrosis (CF) is usually diagnosed during childhood by respiratory or gastro-intestinal symptoms. Hyponatremic hypochloremic dehydration with metabolic alkalosis is a rare but typical presentation of CF in infants. In contrast, only 3 cases have been described in adults. We report a case of CF in a 33-year-old Caucasian female presenting with a severe sodium and chloride depletion caused by inappropriate sweating. She experienced three episodes of severe dehydration before the diagnosis was suspected. Sweat chloride test was pathological and mild pulmonary involvement was found on CT scan. AF508 mutation and a rare mutation (3849+40 A/G) on the intron 19 of CFTR gene were found. Interestingly, our patient has a heterozygote twin sister, carrier of the same mutations of CFTR gene who also developed CF but with a different phenotype. We suspect modifier genes to be implicated in the differences observed between the two phenotypes. We discuss the physiopathology of electrolyte disturbance and review the other similar adults cases

Inter-individual variation in postprandial glycaemic responses in women co-ingesting green leafy vegetables with a carbohydrate meal : interactions with the sirtuin system

The authors acknowledge the support of the Scottish Government Rural and Environment Science and Analytical Services (RESAS) Strategic Research Programme. Clinical biochemistry lab at the Foresterhill hospital for analysing sex hormone samples, Human Nutrition Unit staff and analytical staff and the Rowett Institute, University of Aberdeen and Alex Stewart for providing the compositional information for the meal interventions used. Finally, we would like to thank the volunteers participating in VegGI study. Open access via Wiley agreementPeer reviewedPublisher PD

Concomitant ipsilateral intracapsular and extracapsular femoral neck fracture: a case report

<p>Abstract</p> <p>Introduction</p> <p>Intracapsular and extracapsular hip fractures are common amongst elderly patients but simultaneous intracapsular and extracapsular hip fractures are rare.</p> <p>Case presentation</p> <p>We present the case of an elderly woman who sustained simultaneous intracapsular and extracapsular hip fractures and describe the complications which ensued following fixation.</p> <p>Conclusion</p> <p>Concomitant ipsilateral intracapsular and extracapsular femoral neck fracture is an uncommon injury pattern. It occurs most commonly in osteoporotic patients with low energy falls. Close examination of radiographs must be made to ensure that more subtle fractures are not overlooked and the injury managed appropriately. If doubt exists on initial radiographs further imaging should be considered.</p