Comparison of two kiln-drying schedules for turkish hazel ( Corylus colurna ) lumber of 5-cm thickness

OpenAIRE

Korkut, Süleyman; As, Nusret; Büyüksari, Ümit

2018-01-01

Abstract: Turkish hazel (Corylus colurna) lumber with a nominal thickness of 5 cm from the Kastamonu region, Turkey, was dried through conventional kiln drying using two different programs, a non-protective drying schedule and a protective drying schedule. The goal of the study was to obtain a kiln schedule that would maintain wood quality and also save drying time until a final moisture content of 8 ± 2% was reached. The intensity of warping (twisting, bowing, cupping, crooking), superficial...

Electroplating moulds using dry film thick negative photoresist

Science.gov (United States)

Kukharenka, E.; Farooqui, M. M.; Grigore, L.; Kraft, M.; Hollinshead, N.

2003-07-01

This paper reports on progress on the feasibility of fabricating moulds for electroplating using Ordyl P-50100 (negative) acrylate polymer based dry film photoresist, commercially available from Elga Europe (http://www.elgaeurope.it). We used this photoresist as an alternative to SU8 negative epoxy based photoresist, which is very difficult to process and remove after electroplating (Lorenz et al 1998 Microelectron. Eng. 41/42 371-4, Eyre et al 1998 Proc. MEMS'98 (Heidelberg) (Piscataway, NJ: IEEE) pp 218-22). Ordyl P-50100 is easy to work with and can be easily removed after processing. A single layer of Ordyl P-50100 was deposited by lamination up to 20 µm thickness. Thicker layers (200 µm and more) can be achieved with multilayer lamination using a manual laminator. For our applications we found that Ordyl P-50100 dry film photoresist is a very good alternative to SU8 for the realization of 100 µm high moulds. The results presented will open up new possibilities for low-cost LIGA-type processes for MEMS applications.

Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

Directory of Open Access Journals (Sweden)

M.I. Choudhary

1998-06-01

Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

Electric Resistance Tests on Compacted Clay Material under Dynamic Load Coupled with Dry-Wet Cycling

Directory of Open Access Journals (Sweden)

Zheng Lu

2018-01-01

Full Text Available The study of compacted clay material under dynamic load coupled with dry-wet cycling is one of the most important areas in the field of transportation. In this paper, experiments in terms of compacted clay under dynamic load coupled with dry-wet cycling are performed, and synchronous resistivity tests are also conducted. According to the test results, the influences of cumulative plastic strain, dry-wet cycles, and amplitudes on the soil resistivity are analyzed. Then a new damage factor based on resistivity is proposed to evaluate the long-term performance of compacted clay material. The result of research shows that the evolution of the soil resistivity can be divided into two stages, which has a contrary tendency with that of cumulative plastic strain. The dry-wet cycles and amplitudes have a significant effect on the damage of the compacted soil, which indicates that the dry-wet cycling of compacted soil materials should not be ignored in road engineering, especially in rainy and humid areas.

Thickness of Weathering Profiles:Relaying Tectonic Signal to Biogeochemical Cycles

Science.gov (United States)

Yoo, K.; Weinman, B. A.; Hurst, M. D.; Mudd, S. M.; Gabet, E. J.; Attal, M.; Maher, K.

2011-12-01

Generation and transport of sediment across hillslopes and rivers are closely tied to mechanisms that produce and remove weathered material; in uplands this production and transport controls the thicknesses of weathering profiles. These processes, by controlling the residence time of minerals in the weathering profiles, further regulate the interactions between these minerals and largely biologically cycled elements like carbon and calcium. Here, we present and discuss the thicknesses of colluvial soils and underlying saprolites along three hillslopes that are subject to different rates of basal channel incision. Our field site is within a tributary basin to the Middle Folk Feather River in the Northern Sierra Nevada of California where the river has been down cutting through an uplifting granitic batholith over the past five to ten million years. Conventional modeling predicts that colluvial soil thickness declines with increasing denudation rates. Contrary to this expectation, intensive measurements of colluvial soil thickness show largely consistent values across the three hillslopes examined. This finding, in combination with the abrupt transitions to partial or full bare-rock landscapes with further increase in slope curvature or greater proximity to the Middle Folk Feather River, suggests that the mechanisms of soil production are capable of keeping pace with physical erosion rate until a certain threshold erosion rate is reached. We observe, however, that thicknesses of the underlying saprolite and the morphology (eg., color and texture) and geochemistry (eg., elemental concentration and extraction chemistry of iron) of both colluvial soil and saprolite materials vary systematically with the total denudation rates. This finding further allows us to build a simple relationship to describe and predict how the changes in erosion rates translate to the soils' capacity to store biologically cycled elements within rooting depths. Therefore, geomorphic and

Role of wetting and drying cycles in formation and growth of soil aggregates

Science.gov (United States)

Ghezzehei, T. A.; Lopez, J. P.

2009-12-01

Soil structure directly determines important soil physical properties including porosity, hydraulic conductivity, water retention, and mechanical strength and indirectly influences most biological and chemical processes that occur in and around soil. In response to the various processes that occur within it, soil structure evolves continuously at multiple spatial and temporal scales. We hypothesize that the rhythm of the evolution is controlled by wetting and drying cycles. Here, we will present a mathematical description of the role of wetting and drying cycles in the formation and stabilization of soil aggregates with emphasis on two important roles of wetting and drying cycles: (1) transport and deposition of organic and inorganic cementing agents at the most effective locations, (2) chemical and physical alteration of cementing agents during desiccation and the resultant semi-permanent bonding (or bond hardening). Our results demonstrate that size and strength of aggregates are determined by particle size, degree of dryness, number of wetting-drying cycles, as well as concentration and solubility of dissolved and/or colloidal cementing agents. These results are in general agreement with experimental observations obtained from the literature.

Nutritional responses to soil drying and rewetting cycles under partial root-zone drying irrigation

DEFF Research Database (Denmark)

Wang, Yaosheng; Jensen, Christian Richardt; Liu, Fulai

2017-01-01

signaling that regulates stomatal aperture. PRI induced soil DRW cycles and more soil water dynamics in the root zone enhance soil nutrient mineralization process and thus increase the bioavailability of soil nutrients, resulting in improved nitrogen (N) and phosphorus (P) uptake, in which soil microbial...... processes play a key role. Studies investigating how soil DRW cycles and water dynamics under PRI on nutrient transport in soil solution, soil microbe mediated P transformation, interactions between phytohormones and nutrient uptake, root morphological and architectural traits for nutrient acquisition......Abstract Repeated soil drying and rewetting (DRW) cycles occur in rainfed and irrigated agriculture. The intensity and frequency of DRW cycles regulate both microbial physiology and soil physical processes, hereby affecting the mineralization and immobilization of soil nutrients...

Shrinkage of spray-freeze-dried microparticles of pure protein for ballistic injection by manipulation of freeze-drying cycle.

Science.gov (United States)

Straller, Georg; Lee, Geoffrey

2017-10-30

Spray-freeze-drying was used to produce shrivelled, partially-collapsed microparticles of pure proteins that may be suitable for use in a ballistic injector. Various modifications of the freeze drying cycle were examined for their effects on collapse of the pure protein microparticles. The use of annealing at a shelf temperature of up to +10°C resulted in no visible particle shrinkage. This was because of the high T g ' of the pure protein. Inclusion of trehalose or sucrose led to particle shrinkage because of the plasticizing effects of the disaccharides on the protein. Only by extending the duration of primary drying from 240 to 2745min at shelf temperatures in the range -12 to -8°C were shrivelled, wrinkled particles of bSA and bCA of reduced porosity obtained. Manipulation of the freeze-drying cycle used for SFD can therefore be used to modify particle morphology and increase particle density. Copyright © 2017 Elsevier B.V. All rights reserved.

Integration of energy-efficient empty fruit bunch drying with gasification/combined cycle systems

International Nuclear Information System (INIS)

Aziz, Muhammad; Prawisudha, Pandji; Prabowo, Bayu; Budiman, Bentang Arief

2015-01-01

Highlights: • Novel integrated drying, gasification and combined cycle for empty fruit bunch. • Application of enhanced process integration to achieve high total energy efficiency. • The technology covers exergy recovery and process integration. • High overall energy efficiency can be achieved (about 44% including drying). - Abstract: A high-energy-efficient process for empty fruit bunch drying with integration to gasification and combined cycle processes is proposed. The enhancement is due to greater exergy recovery and more efficient process integration. Basically, the energy/heat involved in a single process is recovered as much as possible, leading to minimization of exergy destruction. In addition, the unrecoverable energy/heat is utilized for other processes through process integration. During drying, a fluidized bed dryer with superheated steam is used as the main evaporator. Exergy recovery is performed through exergy elevation via compression and effective heat coupling in a dryer and heat exchangers. The dried empty fruit bunches are gasified in a fluidized bed gasifier using air as the fluidizing gas. Furthermore, the produced syngas is utilized as fuel in the combined cycle module. From process analysis, the proposed integrated processes can achieve a relatively high energy efficiency. Compared to a standalone drying process employing exergy recovery, the proposed integrated drying can reduce consumed energy by about 1/3. In addition, the overall integrated processes can reach a total power generation efficiency of about 44%

Effect of wet and dry cycles on dissolution of relatively insoluble particles containing Pu

International Nuclear Information System (INIS)

Mewhinney, J.A.; Eidson, A.F.; Wong, V.A.

1987-01-01

Dissolution of gross alpha emitter radioactivity from particles composed of mixed uranium and plutonium oxides or of plutonium dioxide continually immersed in solvent typically display at least a two-phase dissolution pattern. Rapid dissolution of a small fraction of the total particulate mass is followed by much slower dissolution for the majority of the particulate mass. In this study, respirable particles of (U, Pu)O 2 and PuO 2 were subjected to dissolution using an alternate wetting and drying cycle. Particles were continuously immersed in solvent for 4 d and then dried in air for 3 d. This cycle was repeated weekly for 7 wk. Four solvents were used to represent a range of potential environmental conditions and a fifth solvent was used for comparison to other continuous immersion studies. In contrast to dissolution studies involving continuous immersion over periods of two or more weeks that exhibit a three-phase dissolution process, the alternate wet-dry cycling resulted in repetition of the first two phases of the dissolution pattern for each cycle. This led to significantly enhanced dissolution of both particulate materials. The enhancement in total dissolution ranged from two to ten times larger during each wet-dry cycle compared to studies involving continuous immersion. The results indicate a potential need to re-evaluate environmental models of actinide element bioavailability for particulate materials released to environments where wet-dry cycling may be routine, i.e. intermittent rainfall in an otherwise arid climate or in stream beds with intermittent flow

Shrinkage stress in concrete under dry-wet cycles: an example with concrete column

Science.gov (United States)

Gao, Yuan; Zhang, Jun; Luosun, Yiming

2014-02-01

This paper focuses on the simulation of shrinkage stress in concrete structures under dry-wet environments. In the modeling, an integrative model for autogenous and drying shrinkage predictions of concrete under dry-wet cycles is introduced first. Second, a model taking both cement hydration and moisture diffusion into account synchronously is used to calculate the distribution of interior humidity in concrete. Using the above two models, the distributions of shrinkage strain and stress in concrete columns made by normal and high strength concrete respectively under dry-wet cycles are calculated. The model results show that shrinkage gradient along the radial direction of the column from the center to outer surface increases with age as the outer circumference suffers to dry. The maximum and minimum shrinkage occur at the outer surface and the center of the column, respectively, under drying condition. As wetting starts, the shrinkage strain decreases with increase of interior humidity. The closer to the wetting face, the higher the humidity and the lower the shrinkage strain, as well as the lower the shrinkage stress. As results of the dry-wet cycles acting on the outer circumference of the column, cyclic stress status is developed within the area close to the outer surface of the column. The depth of the influencing zone of dry-wet cyclic action is influenced by concrete strength and dry-wet regime. For low strength concrete, relatively deeper influencing zone is expected compared with that of high strength concrete. The models are verified by concrete-steel composite ring tests and a good agreement between model and test results is found.

The microstructure of self-healed PVA ECC under wet and dry cycles

Directory of Open Access Journals (Sweden)

Jia Huan Yu

2010-06-01

Full Text Available Self-healing of ECC (Engineered Cementitious Composites subjected to cyclic wetting and drying regimes is investigated in this paper. ECC structures subjected to outdoor environmental conditions such as wind and rain runoff can be simulated by accelerated test method of wetting and drying cycles. Uniaxial tensile tests of ECC M45 and ECC 2.8FA specimen are conducted respectively. It is found that crack width of ECC 2.8FA is around 10 μm with increased amount of fly ash, while the crack width of ECC M45 is around 100 μm. New insights about the microstructure and chemical composition analysis of ECC specimens initially cracked to 2% strain and then self-healed under wet-dry cycles are presented.

Effects of arbuscular mycorrhizal fungi and soil nutrient addition on the growth of Phragmites australis under different drying-rewetting cycles.

Science.gov (United States)

Liang, Jin-Feng; An, Jing; Gao, Jun-Qin; Zhang, Xiao-Ya; Yu, Fei-Hai

2018-01-01

The frequency of soil drying-rewetting cycles is predicted to increase under future global climate change, and arbuscular mycorrhizal fungi (AMF) are symbiotic with most plants. However, it remains unknown how AMF affect plant growth under different frequencies of soil drying-rewetting cycles. We subjected a clonal wetland plant Phragmites australis to three frequencies of drying-rewetting cycles (1, 2, or 4 cycles), two nutrient treatments (with or without), and two AMF treatments (with or without) for 64 days. AMF promoted the growth of P. australis, especially in the 2 cycles of the drying-rewetting treatment. AMF had a significant positive effect on leaf mass and number of ramets in the 2 cycles of the drying-rewetting treatment with nutrient addition. In the 2 cycles of drying-rewetting treatment without nutrient addition, AMF increased leaf area and decreased belowground to aboveground biomass ratio. These results indicate that AMF may assist P. australis in coping with medium frequency of drying-rewetting cycles, and provide theoretical guidance for predicting how wetland plants respond to future global climate change.

Effect of drying-wetting cycles on leaching behavior of cement solidified lead-contaminated soil.

Science.gov (United States)

Li, Jiang-Shan; Xue, Qiang; Wang, Ping; Li, Zhen-Ze; Liu, Lei

2014-12-01

Lead contaminated soil was treated by different concentration of ordinary Portland cement (OPC). Solidified cylindrical samples were dried at 40°C in oven for 48 h subsequent to 24h of immersing in different solution for one drying-wetting. 10 cycles were conducted on specimens. The changes in mass loss of specimens, as well as leaching concentration and pH of filtered leachates were studied after each cycle. Results indicated that drying-wetting cycles could accelerate the leaching and deterioration of solidified specimens. The cumulative leached lead with acetic acid (pH=2.88) in this study was 109, 83 and 71 mg respectively for solidified specimens of cement-to-dry soil (C/Sd) ratios 0.2, 0.3 and 0.4, compared to 37, 30, and 25mg for a semi-dynamic leaching test. With the increase of cycle times, the cumulative mass loss of specimens increased linearly, but pH of filtered leachates decreased. The leachability and deterioration of solidified specimens increased with acidity of solution. Increases of C/Sd clearly reduced the leachability and deterioration behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

Endometrial thickness as a predictor of the reproductive outcomes in fresh and frozen embryo transfer cycles: A retrospective cohort study of 1512 IVF cycles with morphologically good-quality blastocyst.

Science.gov (United States)

Zhang, Tao; Li, Zhou; Ren, Xinling; Huang, Bo; Zhu, Guijin; Yang, Wei; Jin, Lei

2018-01-01

To evaluate the relationship between endometrial thickness during fresh in vitro fertilization (IVF) cycles and the clinical outcomes of subsequent frozen embryo transfer (FET) cycles.FET cycles using at least one morphological good-quality blastocyst conducted between 2012 and 2013 at a university-based reproductive center were reviewed retrospectively. Endometrial ultrasonographic characteristics were recorded both on the oocyte retrieval day and on the day of progesterone supplementation in FET cycles. Clinical pregnancy rate, spontaneous abortion rate, and live birth rate were analyzed.One thousand five hundred twelve FET cycles was included. The results showed that significant difference in endometrial thickness on day of oocyte retrieval (P = .03) was observed between the live birth group (n = 844) and no live birth group (n = 668), while no significant difference in FET endometrial thickness was found (P = .261) between the live birth group and no live birth group. For endometrial thickness on oocyte retrieval day, clinical pregnancy rate ranged from 50.0% among patients with an endometrial thickness of ≤6 mm to 84.2% among patients with an endometrial thickness of >16 mm, with live birth rate from 33.3% to 63.2%. Multiple logistic regression analysis of factors related to live birth indicated endometrial thickness on oocyte retrieval day was associated with improved live birth rate (OR was 1.069, 95% CI: 1.011-1.130, P = .019), while FET endometrial thickness did not contribute significantly to pregnancy outcomes following FET cycles. The ROC curves revealed the cut-off points of endometrial thickness on oocyte retrieval day was 8.75 mm for live birth.Endometrial thickness during fresh IVF cycles was a better predictor of endometrial receptivity in subsequent FET cycles than FET cycle endometrial thickness. For those females with thin endometrium in fresh cycles, additional estradiol stimulation might be helpful for adequate

Soil aggregate formation: the role of wetting-drying cycles in the genesis of interparticle bonding

Science.gov (United States)

Albalasmeh, Ammar; Ghezzehei, Teamrat

2013-04-01

Soil structure influences many soil properties including aeration, water retention, drainage, bulk density, and resistance to erosion and indirectly influences most biological and chemical processes that occur in and around soil. In nature, soil is continually exposed to wetting (e.g., rainfall and diffusive flow) and drying (e.g., evaporation, diffusive flow and plant uptake). These natural wetting and drying cycles of soils are physical events that profoundly affect the development of soil structure, aggregate stability, carbon (C) flux and mineralization. We hypothesize that drying of capillary water transports suspended and/or dissolved cementing agents toward inter-particle contacts and eventually deposits part of the colloidal mass forming inter-particle bonds. Here, we will show the role of wetting and drying cycles on soil aggregation and stabilization and how these cycles transport and deposit organic cementing agents at the inter-particle contact. We found that aggregates of sand and silt particles can be formed by subjecting loose particles to wetting-drying cycles in the presence of dilute solutions of organic matter that mimic root or microbial exudates. Moreover, majority of the organic matter was deposited in the contact region between the sand particles, where the water accumulates during drying. The model predictions and aggregate stability measurements are supported by scanning electron micrographs that clearly show the process of aggregate formation.

Conceptual Modeling of the Influence of Wetting and Drying Cycles on Soil Aggregation and Stabilization

Science.gov (United States)

Albalasmeh, A. A.; Ghezzehei, T.

2011-12-01

Soil structure directly determines important soil physical properties including porosity, hydraulic conductivity, water retention, and mechanical strength and indirectly influences most biological and chemical processes that occur in and around soil. The interaction of environmental and biotic agents influences the physical condition of the soil, particularly through soil structural evolution. Wetting and drying cycles are important environmental processes known to enhance aggregation, while clay minerals, sesquioxides and soil organic matter (SOM) are the soil solids most involved in soil structural development. We hypothesize that drying of capillary water transports suspended and/or dissolved cementing agents toward inter-particle contacts and eventually deposits part of the colloidal mass forming inter-particle bonds. Here, we will show the role of wetting and drying cycles on soil aggregation and stabilization and how these cycles transport and deposit organic cementing agents at the inter-particle contact. We will present results of the effect of particle size, number of wetting and drying cycles, viscosity, molecule length and concentration of suspended and/or dissolved cementing agents on soil aggregation and stabilization.

Determination of optimum insulation thickness in pipe for exergetic life cycle assessment

International Nuclear Information System (INIS)

Keçebaş, Ali

2015-01-01

Highlights: • It is aimed to determine optimum insulation thickness in pipe. • A new methodology is used as exergetic life cycle assessment for this purpose. • It is evaluated for various fuels, different pipe diameters and some combustion parameters. • This methodology is not suitable for determining optimum insulation thickness of a pipe. • There are benefits to our understanding of the need for insulation use in pipes. - Abstract: The energy saving and the environmental impacts’ reduction in the world building sector have gained great importance. Therefore, great efforts have been invested to create energy-saving green buildings. To do so, one of the many things to be done is the insulation of cylindrical pipes, canals and tanks. In the current study, the main focus is on the determination of the optimum insulation thickness of the pipes with varying diameters when different fuels are used. Therefore, through a new method combining exergy analysis and life cycle assessment, optimum insulation thickness of the pipes, total exergetic environmental impact, net saving and payback period were calculated. The effects of the insulation thickness on environmental and combustion parameters were analyzed in a detailed manner. The results revealed that optimum insulation thickness was affected by the temperature of the fuel when it enters into the combustion chamber, the temperature of the stack gas and the temperature of the combustion chamber. Under these optimum effects, the optimum insulation thickness of a 100 mm pipe was determined to be 55.7 cm, 57.2 cm and 59.3 cm for coal, natural gas and fuel–oil, respectively with the ratios of 76.32%, 81.84% and 84.04% net savings in the exergetic environmental impact. As the environmental impacts of the fuels and their products are bigger than those of the insulation material, the values of the optimum insulation thickness of the method used this study was found greater. Moreover, in the pipes with greater

Core characteristics of fast reactor cycle with simple dry pyrochemical processing

International Nuclear Information System (INIS)

Ikegami, Tetsuo

2008-01-01

Fast reactor core concept and core nuclear characteristics are studied for the application of the simple dry pyrochemical processing for fast reactor mixed oxide spent fuels, that is, the Compound Process Fuel Cycle, large FR core with of loaded fuels are recycled by the simple dry pyrochemical processing. Results of the core nuclear analyses show that it is possible to recycle FR spent fuel once and to have 1.01 of breeding ratio without radial blanket region. The comparison is made among three kinds of recycle fuels, LWR UO 2 spent fuel, LWR MOX spent fuel, and FR spent fuel. The recycle fuels reach an equilibrium state after recycles regardless of their starting heavy metal compositions, and the recycled FR fuel has the lowest radio-activity and the same level of heat generation among the recycle fuels. Therefore, the compound process fuel cycle has flexibility to recycle both LWR spent fuel and FR spent fuel. The concept has a possibility of enhancement of nuclear non-proliferation and process simplification of fuel cycle. (author)

Determination of the dried product resistance variability and its influence on the product temperature in pharmaceutical freeze-drying.

Science.gov (United States)

Scutellà, Bernadette; Trelea, Ioan Cristian; Bourlès, Erwan; Fonseca, Fernanda; Passot, Stephanie

2018-07-01

During the primary drying step of the freeze-drying process, mass transfer resistance strongly affects the product temperature, and consequently the final product quality. The main objective of this study was to evaluate the variability of the mass transfer resistance resulting from the dried product layer (R p ) in a manufacturing batch of vials, and its potential effect on the product temperature, from data obtained in a pilot scale freeze-dryer. Sublimation experiments were run at -25 °C and 10 Pa using two different freezing protocols: with spontaneous or controlled ice nucleation. Five repetitions of each condition were performed. Global (pressure rise test) and local (gravimetric) methods were applied as complementary approaches to estimate R p . The global method allowed to assess variability of the evolution of R p with the dried layer thickness between different experiments whereas the local method informed about R p variability at a fixed time within the vial batch. A product temperature variability of approximately ±4.4 °C was defined for a product dried layer thickness of 5 mm. The present approach can be used to estimate the risk of failure of the process due to mass transfer variability when designing freeze-drying cycle. Copyright © 2018 Elsevier B.V. All rights reserved.

Soil structure restoration by wet/dry cycles assessed by computed tomography

Energy Technology Data Exchange (ETDEWEB)

Pires, L.F. [Univ. of Sao Paulo, Center for Nuclear Energy in Agriculture, Piracicaba, Sao Paulo (Brazil)

2005-07-01

Some studies have shown that soil structures can be restored through the sequence of wetting and drying cycles. These cycles causes changes in the soil pore system, which is very important to agriculture, because directly affect plant growth by root penetration, retention and movement of water and gases. The aim of this study was to follow by gamma-ray computed tomography (CT) the effect of soil wetting/drying process on the soil structure repairing of samples collected in cylinders. A first-generation tomograph with an {sup 241}Am source and a 7.62 x 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube was employed. Image analysis and tomographic unit profiles show that CT can provide an insight to sample structure restoration, which helps to have a better comprehension of soil physical hydraulic phenomena. (author)

Soil structure restoration by wet/dry cycles assessed by computed tomography

International Nuclear Information System (INIS)

Pires, L.F.

2005-01-01

Some studies have shown that soil structures can be restored through the sequence of wetting and drying cycles. These cycles causes changes in the soil pore system, which is very important to agriculture, because directly affect plant growth by root penetration, retention and movement of water and gases. The aim of this study was to follow by gamma-ray computed tomography (CT) the effect of soil wetting/drying process on the soil structure repairing of samples collected in cylinders. A first-generation tomograph with an 241 Am source and a 7.62 x 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube was employed. Image analysis and tomographic unit profiles show that CT can provide an insight to sample structure restoration, which helps to have a better comprehension of soil physical hydraulic phenomena. (author)

Implementation of a dry process fuel cycle model into the DYMOND code

International Nuclear Information System (INIS)

Park, Joo Hwan; Jeong, Chang Joon; Choi, Hang Bok

2004-01-01

For the analysis of a dry process fuel cycle, new modules were implemented into the fuel cycle analysis code DYMOND, which was developed by the Argonne National Laboratory. The modifications were made to the energy demand prediction model, a Canada Deuterium Uranium (CANDU) reactor, direct use of spent Pressurized Water Reactor (PWR) fuel in CANDU reactors (DUPIC) fuel cycle model, the fuel cycle calculation module, and the input/output modules. The performance of the modified DYMOND code was assessed for the postulated once-through fuel cycle models including both the PWR and CANDU reactor. This paper presents modifications of the DYMOND code and the results of sample calculations for the PWR once-through and DUPIC fuel cycles

Endometrial thickness significantly affects clinical pregnancy and live birth rates in frozen-thawed embryo transfer cycles.

Science.gov (United States)

Bu, Zhiqin; Wang, Keyan; Dai, Wei; Sun, Yingpu

2016-07-01

In order to explore the relationship between endometrial thickness on the day of embryo transfer and pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles, we retrospectively analyzed data from 2997 patients undergoing their first FET cycles from January 2010 to December 2012. All patients were divided into three groups (Group A, ≤8 mm; Group B, 9-13 mm; Group C, ≥14 mm) according to the endometrial thickness on embryo transfer day. Compared with patients in the other two groups, patients with thin endometrial thickness in Group A had significantly lower clinical pregnancy rate (33.4%, 41.3% and 45.4%, p birth rate (23.8%, 32.2% and 34.0%, p confidence interval (CI): 1.10-1.77, p birth rate (aOR: 1.50; 95% CI: 1.16-1.95, p < 0.01) were significant. We conclude that for patients undergoing FET, endometrial thickness on the embryo transfer day significantly affects IVF outcomes in cleavage embryo transfer cycles independent of other factors.

Mid-menstrual cycle ultrasound evaluation of endometrial thickness of fertile women and women with secondary infertility in Nsukka, Nigeria

International Nuclear Information System (INIS)

Ochie, K.; Eze, C.U.; Okoye, G.C.; Ohagwu, C.C.; Luntsi, G.

2016-01-01

Background: The prognostic value of endometrial thickness in achieving conception is still debatable. Objective: To compare the mid menstrual cycle thickness of the endometrium of fertile women and women with unexplained secondary infertility. Materials and methods: A cross-sectional study targeting women of reproductive ages was conducted. The mid menstrual cycle endometrial thickness was measured at sonography in a group of fertile women and in another group of women with secondary infertility. The endometrial thicknesses in the two groups of women were statistically compared. Results: There was a preponderance of thickened endometrium among the fertile women. The majority of women with secondary infertility, 21 (30.0%) with a thickness range of 2.0–3.9 mm and 17 (24.29%) with 4.0–5.9 mm had thin endometrium and only a few of them, 8 (11.43%) had endometrium of 12 mm thickness of greater. The median value of mid menstrual cycle endometrial thickness for the fertile group was 10.8 mm (range 7.8–12.4 mm) and the interquartile range was 1.45 mm. For the group with secondary infertility, the median was 5.0 mm (range 2.0–17.0 mm) and the interquartile range 6.0 mm. The endometrium was significantly thinner in subjects with secondary infertility compared to fertile subjects (p < 0.05). Conclusion: The mid menstrual cycle endometrial thickness differs significantly between fertile women and women with secondary infertility. It is thicker in fertile women compared to women with secondary infertility. Therefore, mid menstrual cycle endometrial thickness has potential as a prognostic factor for secondary infertility in the studied population. - Highlights: • Endometrial thickness has potential as a prognostic factor for secondary infertility. • Endometrial thickness differs between fertile and secondarily infertile women. • Thin endometrium is common among women with secondary infertility. • Few women with secondary infertility may have

Drying characteristics of zucchini and empirical modeling of its drying process

Directory of Open Access Journals (Sweden)

Naciye Kutlu

2017-10-01

Full Text Available The aim of the study was to dry zucchini (Cucurbita pepo by two different methods (convective hot-air (CHD and microwave-assisted drying (MWD. The effect of air temperature (60, 70 and 80°C, microwave (MW power (180, 360, 540 W and sample thickness (5 and 10 mm on some drying characteristics of zucchini were investigated. Thirteen mathematical models available in the literature were fitted to the experimental moisture ratio data. The coefficients of the models were determined by non-linear regression analysis. It was determined that the model that fits the moisture ratio data the best varies at different drying conditions. Increasing drying temperature and MW power and reducing sample thickness improved the drying rate and drying time. Drying in microwave has reduced the drying time by 52-64% for zucchini. It was found that the effective moisture diffusivities increased with increasing temperature and MW power. MWD samples had better rehydration ratios compared to ones dried only in tray drier for 5 mm thickness.  

Do drying and rewetting cycles modulate effects of sulfadiazine spiked manure in soil?

Science.gov (United States)

Jechalke, Sven; Radl, Viviane; Schloter, Michael; Heuer, Holger; Smalla, Kornelia

2016-05-01

Naturally occurring drying-rewetting events in soil have been shown to affect the dissipation of veterinary antibiotics entering soil by manure fertilization. However, knowledge of effects on the soil microbial community structure and resistome is scarce. Here, consequences of drying-rewetting cycles on effects of sulfadiazine (SDZ) in soil planted with Dactylis glomerata L. were investigated in microcosms. Manure containing SDZ or not was applied to the pregrown grass and incubated for 56 days in a climate chamber. Water was either added daily or reduced during two drying events of 7 days, each followed by a recovery phase. Total community DNA was analyzed to reveal the effects on the bacterial community structure and on the abundance of sul1, sul2, intI1 ,intI2, qacE+qacEΔ1, traN and korB genes relative to 16S rRNA genes. 16S rRNA gene-based DGGE fingerprints indicated that drying-rewetting cycles modulated the effects of SDZ on the bacterial community structure in the soil. Furthermore, the SDZ treatment increased the relative abundance of sulfonamide resistance and integrase genes compared to the control. However, this increase was not different between moisture regimes, indicating that drying-rewetting had only a negligible effect on the selection of the resistome by SDZ in the manured soil. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Real-time measurement system for tracking birefringence, weight, thickness, and surface temperature during drying of solution cast coatings and films

Science.gov (United States)

Unsal, E.; Drum, J.; Yucel, O.; Nugay, I. I.; Yalcin, B.; Cakmak, M.

2012-02-01

This paper describes the design and performance of a new instrument to track temporal changes in physical parameters during the drying behavior of solutions, as well as curing of monomers. This real-time instrument follows in-plane and out-of-plane birefringence, weight, thickness, and surface temperature during the course of solidification of coatings and films through solvent evaporation and thermal or photocuring in a controlled atmosphere. It is specifically designed to simulate behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations where resins are subjected to ultraviolet (UV) curing from monomer precursors. Controlled processing parameters include air speed, temperature, initial cast thickness, and solute concentration, while measured parameters are thickness, weight, film temperature, in-plane and out-of-plane birefringence. In this paper, we illustrate the utility of this instrument with solution cast and dried poly (amide-imide)/DMAc (Dimethylacetamide) solution, water based black paint, and organo-modified clay/NMP (N-Methylpyrrolidone) solution. In addition, the physical changes that take place during UV photo polymerization of a monomer are tracked. This instrument is designed to be generic and it can be used for tracking any drying/swelling/solidification systems including paper, foodstuffs such as; grains, milk as well as pharmaceutical thin paste and slurries.

Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems

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Rabidin Zairul Amin

2017-01-01

Full Text Available Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be achieved in artificial drying kilns such as conventional kiln, dehumidification kiln, solar kiln, radio frequency-vacuum, etc. The objective of this study was to evaluate the characteristics of 30 mm and 50 mm thick kekatong (Cynometra spp. timber dried using kiln drying (KD and radio frequency-vacuum drying (RFV system. The investigation involved drying time, moisture content (MC variations between and within boards, drying defects, shrinkage, and drying stress. Drying defects include checks (surface, end, and internal checks and warping (bowing, cuping, spring, and twisting. The results showed that RFV drying time was reduced to 50% compared to the KD. RFV dried boards demonstrated a more uniform MC between and within boards. Shrinkage in width and thickness, as well as tangential/radial and volumetric shrinkages were substantially less in RFV boards. The amount of cupping, bowing and spring were very low and negligible in all drying runs. There was no twisting observed in all drying methods. The number of stress-free RFV board was higher than KD. With proper procedure, the RFV technology could be used for drying heavy hardwoods which are difficult to dry in conventional kilns due to excessive drying times and degradation.

Nitrogen supply modulates the effect of changes in drying-rewetting frequency on soil C and N cycling and greenhouse gas exchange.

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Morillas, Lourdes; Durán, Jorge; Rodríguez, Alexandra; Roales, Javier; Gallardo, Antonio; Lovett, Gary M; Groffman, Peter M

2015-10-01

Climate change and atmospheric nitrogen (N) deposition are two of the most important global change drivers. However, the interactions of these drivers have not been well studied. We aimed to assess how the combined effect of soil N additions and more frequent soil drying-rewetting events affects carbon (C) and N cycling, soil:atmosphere greenhouse gas (GHG) exchange, and functional microbial diversity. We manipulated the frequency of soil drying-rewetting events in soils from ambient and N-treated plots in a temperate forest and calculated the Orwin & Wardle Resistance index to compare the response of the different treatments. Increases in drying-rewetting cycles led to reductions in soil NO3- levels, potential net nitrification rate, and soil : atmosphere GHG exchange, and increases in NH4+ and total soil inorganic N levels. N-treated soils were more resistant to changes in the frequency of drying-rewetting cycles, and this resistance was stronger for C- than for N-related variables. Both the long-term N addition and the drying-rewetting treatment altered the functionality of the soil microbial population and its functional diversity. Our results suggest that increasing the frequency of drying-rewetting cycles can affect the ability of soil to cycle C and N and soil : atmosphere GHG exchange and that the response to this increase is modulated by soil N enrichment. © 2015 John Wiley & Sons Ltd.

Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

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Wuman Zhang

2017-01-01

Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

Drying Spirulina with Foam Mat Drying at Medium Temperature

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Aji Prasetyaningrum

2012-10-01

Full Text Available Spirulina is a single cell blue green microalgae (Cyanobacteria containing many Phytonutrients (Beta-carotene, Chlorophyl, Xanthophyl, Phyocianin using as anti-carcinogen in food. Producing dry spirulina by quick drying process at medium temperature is very important to retain the Phytonutrient quality. Currently, the work is still challenging due to the gel formation that block the water diffusion from inside to the surface.  This research studies the performance of foam-mat drying on production of dry spirulina. In this method the spirulina was mixed with foaming agent (glair/egg albumen, popular as white egg at 2.5% by weight at air velocity 2.2 m/sec. Here, the effect of spirulina thickness and operational temperature on drying time and quality (Beta-carotene and color were observed. The drying time was estimated based on the measurement of water content in spirulina versus time. Result showed that the thicker spirulina, the longer drying time. Conversely, the higher operational temperature, faster drying time. At thickness ranging 1-3 mm and operational temperature below 70oC, the quality of spirulina can fit the market requirement

Noninvasive characterization of the fission yeast cell cycle by monitoring dry mass with digital holographic microscopy.

Science.gov (United States)

Rappaz, Benjamin; Cano, Elena; Colomb, Tristan; Kühn, Jonas; Depeursinge, Christian; Simanis, Viesturs; Magistretti, Pierre J; Marquet, Pierre

2009-01-01

Digital holography microscopy (DHM) is an optical technique which provides phase images yielding quantitative information about cell structure and cellular dynamics. Furthermore, the quantitative phase images allow the derivation of other parameters, including dry mass production, density, and spatial distribution. We have applied DHM to study the dry mass production rate and the dry mass surface density in wild-type and mutant fission yeast cells. Our study demonstrates the applicability of DHM as a tool for label-free quantitative analysis of the cell cycle and opens the possibility for its use in high-throughput screening.

Mitigation of Prion Infectivity and Conversion Capacity by a Simulated Natural Process—Repeated Cycles of Drying and Wetting

Science.gov (United States)

Yuan, Qi; Eckland, Thomas; Telling, Glenn; Bartz, Jason; Bartelt-Hunt, Shannon

2015-01-01

Prions enter the environment from infected hosts, bind to a wide range of soil and soil minerals, and remain highly infectious. Environmental sources of prions almost certainly contribute to the transmission of chronic wasting disease in cervids and scrapie in sheep and goats. While much is known about the introduction of prions into the environment and their interaction with soil, relatively little is known about prion degradation and inactivation by natural environmental processes. In this study, we examined the effect of repeated cycles of drying and wetting on prion fitness and determined that 10 cycles of repeated drying and wetting could reduce PrPSc abundance, PMCA amplification efficiency and extend the incubation period of disease. Importantly, prions bound to soil were more susceptible to inactivation by repeated cycles of drying and wetting compared to unbound prions, a result which may be due to conformational changes in soil-bound PrPSc or consolidation of the bonding between PrPSc and soil. This novel finding demonstrates that naturally-occurring environmental process can degrade prions. PMID:25665187

Two-dimensional mathematical model for simulation of the drying process of thick layers of natural materials in a conveyor-belt dryer

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Salemović Duško R.

2017-01-01

Full Text Available This paper presents the mathematical model and numerical analysis of the convective drying process of thick slices of colloidal capillary-porous materials slowly moving through conveyor-belt dryer. A flow of hot moist air was used as drying agent. The drying process has been analyzed in the form of a 2-D mathematical model, in two directions: along the conveyor and perpendicular on it. The mathematical model consists of two non-linear differential equations and one equation with a transcendent character and it is based on the mathematical model developed for drying process in a form of a 1-D thin layer. The appropriate boundary conditions were introduced. The presented model is suitable for the automated control of conveyor-belt dryers. The obtained results with analysis could be useful in predicting the drying kinetics of potato slices and similar natural products.

Rapid freeze-drying cycle optimization using computer programs developed based on heat and mass transfer models and facilitated by tunable diode laser absorption spectroscopy (TDLAS).

Science.gov (United States)

Kuu, Wei Y; Nail, Steven L

2009-09-01

Computer programs in FORTRAN were developed to rapidly determine the optimal shelf temperature, T(f), and chamber pressure, P(c), to achieve the shortest primary drying time. The constraint for the optimization is to ensure that the product temperature profile, T(b), is below the target temperature, T(target). Five percent mannitol was chosen as the model formulation. After obtaining the optimal sets of T(f) and P(c), each cycle was assigned with a cycle rank number in terms of the length of drying time. Further optimization was achieved by dividing the drying time into a series of ramping steps for T(f), in a cascading manner (termed the cascading T(f) cycle), to further shorten the cycle time. For the purpose of demonstrating the validity of the optimized T(f) and P(c), four cycles with different predicted lengths of drying time, along with the cascading T(f) cycle, were chosen for experimental cycle runs. Tunable diode laser absorption spectroscopy (TDLAS) was used to continuously measure the sublimation rate. As predicted, maximum product temperatures were controlled slightly below the target temperature of -25 degrees C, and the cascading T(f)-ramping cycle is the most efficient cycle design. In addition, the experimental cycle rank order closely matches with that determined by modeling.

Increased sensitivity in thick-target particle induced X-ray emission analyses using dry ashing for preconcentration

International Nuclear Information System (INIS)

Lill, J.-O.; Harju, L.; Saarela, K.-E.; Lindroos, A.; Heselius, S.-J.

1999-01-01

The sensitivity in thick-target particle induced X-ray emission (PIXE) analyses of biological materials can be enhanced by dry ashing. The gain depends mainly on the mass reduction factor and the composition of the residual ash. The enhancement factor was 7 for the certified reference material Pine Needles and the limits of detection (LODs) were below 0.2 μg/g for Zn, Cu, Rb and Sr. When ashing biological materials with low ash contents such as wood of pine or spruce (0.3% of dry weight) and honey (0.1% of wet weight) the gain was far greater. The LODs for these materials were 30 ng/g for wood and below 10 ng/g for honey. In addition, the ashed samples were more homogenous and more resistant to changes during the irradiation than the original biological samples. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Model for heat and mass transfer in freeze-drying of pellets.

Science.gov (United States)

Trelea, Ioan Cristian; Passot, Stéphanie; Marin, Michèle; Fonseca, Fernanda

2009-07-01

Lyophilizing frozen pellets, and especially spray freeze-drying, have been receiving growing interest. To design efficient and safe freeze-drying cycles, local temperature and moisture content in the product bed have to be known, but both are difficult to measure in the industry. Mathematical modeling of heat and mass transfer helps to determine local freeze-drying conditions and predict effects of operation policy, and equipment and recipe changes on drying time and product quality. Representative pellets situated at different positions in the product slab were considered. One-dimensional transfer in the slab and radial transfer in the pellets were assumed. Coupled heat and vapor transfer equations between the temperature-controlled shelf, the product bulk, the sublimation front inside the pellets, and the chamber were established and solved numerically. The model was validated based on bulk temperature measurement performed at two different locations in the product slab and on partial vapor pressure measurement in the freeze-drying chamber. Fair agreement between measured and calculated values was found. In contrast, a previously developed model for compact product layer was found inadequate in describing freeze-drying of pellets. The developed model represents a good starting basis for studying freeze-drying of pellets. It has to be further improved and validated for a variety of product types and freeze-drying conditions (shelf temperature, total chamber pressure, pellet size, slab thickness, etc.). It could be used to develop freeze-drying cycles based on product quality criteria such as local moisture content and glass transition temperature.

Carrageenan drying with dehumidified air: drying characteristics and product quality

NARCIS (Netherlands)

Djaeni, M.; Sasongko, S.B.; Prasetyaningrum, Aji A A.A.; Jin, X.; Boxtel, van A.J.B.

2012-01-01

Applying dehumidified air is considered as an option to retain quality in carrageenan drying. This work concerns the effects of operational temperature, air velocity, and carrageenan thickness on the progress of drying and product quality when using dehumidified air. Final product quality and

Dry eyes and corneal sensation after laser in situ keratomileusis with femtosecond laser flap creation Effect of hinge position, hinge angle, and flap thickness.

Science.gov (United States)

Mian, Shahzad I; Li, Amy Y; Dutta, Satavisha; Musch, David C; Shtein, Roni M

2009-12-01

To determine whether corneal sensation and dry-eye signs and symptoms after myopic laser in situ keratomileusis (LASIK) surgery with a femtosecond laser are affected by varying hinge position, hinge angle, or flap thickness. University-based academic practice, Ann Arbor, Michigan, USA. This prospective randomized contralateral-eye study evaluated eyes after bilateral myopic LASIK with a femtosecond laser (IntraLase). Superior and temporal hinge positions, 45-degree and 90-degree hinge angles, and 100 microm and 130 microm corneal flap thicknesses were compared. Postoperative follow-up at 1 week and 1, 3, 6, and 12 months included central Cochet-Bonnet esthesiometry, the Ocular Surface Disease Index questionnaire, a Schirmer test with anesthesia, tear breakup time (TBUT), corneal fluorescein staining, and conjunctival lissamine green staining. The study evaluated 190 consecutive eyes (95 patients). Corneal sensation was reduced at all postoperative visits, with improvement over 12 months (P<.001). There was no difference in corneal sensation between the different hinge positions, angles, or flap thicknesses at any time point. The overall ocular surface disease index score was increased at 1 week, 1 month, and 3 months (P<.0001, P<.0001, and P = .046, respectively). The percentage of patients with a TBUT longer than 10 seconds was significantly lower at 1 week and 1 month (P<.0001). Dry-eye syndrome after myopic LASIK with a femtosecond laser was mild and improved after 3 months. Corneal flap hinge position, hinge angle, and thickness had no effect on corneal sensation or dry-eye syndrome.

Mid-Ocean Ridge Melt Supply and Glacial Cycles: A 3D EPR Study of Crustal Thickness, Layer 2A, and Bathymetry

Science.gov (United States)

Boulahanis, B.; Aghaei, O.; Carbotte, S. M.; Huybers, P. J.; Langmuir, C. H.; Nedimovic, M. R.; Carton, H. D.; Canales, J. P.

2017-12-01

Recent studies suggest that eustatic sea level fluctuations induced by glacial cycles in the Pleistocene may influence mantle-melting and volcanic eruptions at mid-ocean ridges (MOR), with models predicting variation in oceanic crustal thickness linked to sea level change. Previous analyses of seafloor bathymetry as a proxy for crustal thickness show significant spectral energy at frequencies linked to Milankovitch cycles of 1/23, 1/41, and 1/100 ky-1, however the effects of faulting in seafloor relief and its spectral characteristics are difficult to separate from climatic signals. Here we investigate the hypothesis of climate driven periodicity in MOR magmatism through spectral analysis, time series comparisons, and statistical characterization of bathymetry data, seismic layer 2A thickness (as a proxy for extrusive volcanism), and seafloor-to-Moho thickness (as a proxy for total magma production). We utilize information from a three-dimensional multichannel seismic study of the East Pacific Rise and its flanks from 9°36`N to 9°57`N. We compare these datasets to the paleoclimate "LR04" benthic δ18O stack. The seismic dataset covers 770 km2 and provides resolution of Moho for 92% of the imaged region. This is the only existing high-resolution 3-D image across oceanic crust, making it ideal for assessing the possibility that glacial cycles modulate magma supply at fast spreading MORs. The layer 2A grid extends 9 km (170 ky) from the ridge axis, while Moho imaging extends to a maximum of 16 km (310 ky). Initial results from the East Pacific Rise show a relationship between sea level and both crustal thickness and sea floor depth, consistent with the hypothesis that magma supply to MORs may be modulated by glacial cycles. Analysis of crustal thickness and bathymetry data reveals spectral peaks at Milankovitch frequencies of 1/100 ky-1 and 1/41 ky-1 where datasets extend sufficiently far from the ridge. The layer 2A grid does not extend sufficiently far from the

Thickness and roughness measurements for air-dried longleaf pine bark

Science.gov (United States)

Thomas L. Eberhardt

2015-01-01

Bark thicknesses for longleaf pine (Pinus palustris Mill.) were investigated using disks collected from trees harvested on a 70-year-old plantation. Maximum inner bark thickness was relatively constant along the tree bole whereas maximum outer bark thickness showed a definite decrease from the base of the tree to the top. The minimum whole bark thickness followed the...

Some mechanical properties of small specimens cut from 1.79-inch-thick southern pine dried for 6 hours at 300°F or for 5 days at 180°F- A Comparison

Science.gov (United States)

P. Koch; W.L. Wellford

1978-01-01

Small specimens cut from 1.79-inch-thick southern pine dried from green condition for 6 hours at a dry-bulb temperature of 300 F suffered no diminution in the mechanical properties determined, when compared to matched wood dried for 5 days at 180 F.

Behaviour of slag HPC submitted to immersion-drying cycles

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Rabah Chaid

2016-04-01

Full Text Available This article is part of a summary of the work developed in conjunction with the Laboratory of Civil Engineering and Mechanical Engineering from INSA Rennes and Research Unit: Materials, Processes and Environment, University of Boumerdes. One of the objectives was indeed to promote, through studies of variants, the use of local cementitious additions in the formulation of high performance concretes (HPC. The binding contribution of mineral additions to the physical, mechanical and durability of concrete was evaluated by an experimental methodology to subjugate their original granular and pozzolanic effect. The results show that the contribution of couple cement -slag intensification of the matrix is higher than that obtained when the cement is not substituted by addition. Therefore, a significant improvement in performance of concretes was observed, despite the adverse action immersion cycles - drying maintained for 365 days.

Drying kinetics of atemoya pulp

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Plúvia O. Galdino

Full Text Available ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm. The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson & Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2 above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.

Understanding spatial heterogeneity in soil carbon and nitrogen cycling in regenerating tropical dry forests

Science.gov (United States)

Waring, B. G.; Powers, J. S.; Branco, S.; Adams, R.; Schilling, E.

2015-12-01

Tropical dry forests (TDFs) currently store significant amounts of carbon in their biomass and soils, but these highly seasonal ecosystems may be uniquely sensitive to altered climates. The ability to quantitatively predict C cycling in TDFs under global change is constrained by tremendous spatial heterogeneity in soil parent material, land-use history, and plant community composition. To explore this variation, we examined soil carbon and nitrogen dynamics in 18 permanent plots spanning orthogonal gradients of stand age and soil fertility. Soil C and N pools, microbial biomass, and microbial extracellular enzyme activities were most variable at small (m2) spatial scales. However, the ratio of organic vs. inorganic N cycling was consistently higher in forest stands dominated by slow-growing, evergreen trees that associate with ectomycorrhizal fungi. Similarly, although bulk litter stocks and turnover rates varied greatly among plots, litter decomposition tended to be slower in ectomycorrhizae-dominated stands. Soil N cycling tended to be more conservative in older plots, although the relationship between stand age and element cycling was weak. Our results emphasize that microscale processes, particularly interactions between mycorrhizal fungi and free-living decomposers, are important controls on ecosystem-scale element cycling.

Fast freeze-drying cycle design and optimization using a PAT based on the measurement of product temperature.

Science.gov (United States)

Bosca, Serena; Barresi, Antonello A; Fissore, Davide

2013-10-01

This paper is focused on the use of an innovative Process Analytical Technology for the fast design and optimization of freeze-drying cycles for pharmaceuticals. The tool is based on a soft-sensor, a device that uses the experimental measure of product temperature during freeze-drying, a mathematical model of the process, and the Extended Kalman Filter algorithm to estimate the sublimation flux, the residual amount of ice in the vial, and some model parameters (heat and mass transfer coefficients). The accuracy of the estimations provided by the soft-sensor has been shown using as test case aqueous solutions containing different excipients (sucrose, polyvinylpyrrolidone), processed at various operating conditions, pointing out that the soft-sensor allows a fast estimation of model parameters and product dynamics without involving expensive hardware or time consuming analysis. The possibility of using the soft-sensor to calculate in-line (or off-line) the design space of the primary drying phase is here presented and discussed. Results evidences that by this way, it is possible to identify the values of the heating fluid temperature that maintain product temperature below the limit value, as well as the operating conditions that maximize the sublimation flux. Various experiments have been carried out to test the effectiveness of the proposed approach for a fast design of the cycle, evidencing that drying time can be significantly reduced, without impairing product quality. Copyright © 2013 Elsevier B.V. All rights reserved.

The Effect of Pseudoexfoliation and Pseudoexfoliation Induced Dry Eye on Central Corneal Thickness.

Science.gov (United States)

Akdemir, M Orcun; Kirgiz, Ahmet; Ayar, Orhan; Kaldirim, Havva; Mert, Metin; Cabuk, Kubra Serefoglu; Taskapili, Muhittin

2016-01-01

The aim of this study is to investigate the effect of pseudoexfoliation (PEX) and PEX-induced dry eye on central corneal thickness (CCT). This cross-sectional study consists of total 270 eyes of 135 patients (67 females, 68 males) in total. After excluding the PEX (-) 32 eyes with PEX in the other eye, totally 130 eyes in PEX (-) group and 108 eyes in the PEX (+) group were included in the study. The PEX (+) group was regrouped as PEX syndrome (80 eyes of 50 patients) and PEX glaucoma (28 eyes of 20 patients). In the PEX (-) group, the mean Schirmer test result was 12 ± 4 mm (4-25 mm), in the PEX syndrome group 10 ± 4 mm (4-22 mm), in the PEX glaucoma group 9 ± 3 mm (4-15 mm). The difference among the PEX (-) group, the PEX syndrome and the PEX glaucoma groups was statistically significant (p eyes with PEX (r = 0.307, p = 0.001). However, there was no statistically significant correlation between CCT, Schirmer and tear break up time tests in the eyes with PEX. PEX material can cause decrease in tear film secretion and disturb tear film stability. There is no effect of PEX-induced dry eye on CCT. Lower CCT values in the eyes with PEX material may be a result of decrease in corneal stromal cell density. Moreover, higher CCT values may be because of decreased endothelial cells in PEX glaucoma patients.

Influence of the menstrual cycle on compression-induced pain during mammography: correlation with the thickness and volume of the mammary gland.

Science.gov (United States)

Kitaoka, Hitomi; Kawashima, Hiroko

2018-03-01

In mammography, breast compression is necessary and an important factor influencing image quality. The purpose of this study was to determine the influence of the menstrual cycle on compression-induced pain during mammography and to evaluate the association between the thickness and volume of the mammary gland and pain. We examined basal body temperature and categorized the menstrual cycle into five phases. We executed breast compression in the craniocaudal view using a customized compression plate, to which we introduced an opening. We measured the thickness of the mammary gland under compression using echography. Immediately after releasing the compression, we evaluated pain using the visual analogue scale. We performed magnetic resonance imaging (MRI) on the same day and measured the volume of the mammary gland. The thickness of the mammary gland, pain, and the volume of the mammary gland were minimal in the late follicular phase and maximal in the late luteal and early follicular phases. It was shown that the changes in the thickness and volume of the mammary gland during the menstrual cycle accounted for the changes in compression-induced pain. On MRI examination of each breast quadrant, the same changes were observed in areas A and C. In area A, it was shown that both the anatomical characteristics and the increase in volume of the mammary gland were associated with pain. We concluded that the late follicular phase constitutes the optimal timing for mammography.

Generalized drying curves in conductive/convective paper drying

Directory of Open Access Journals (Sweden)

O.C. Motta Lima

2000-12-01

Full Text Available This work presents a study related to conductive/convective drying of paper (cellulose sheets over heated surfaces, under natural and forced air conditions. The experimental apparatus consists in a metallic box heated by a thermostatic bath containing an upper surface on which the paper samples (about 1 mm thick are placed. The system is submitted to ambient air under two different conditions: natural convection and forced convection provide by an adjustable blower. The influence of initial paper moisture content, drying (heated surface temperature and air velocity on drying curves behavior is observed under different drying conditions. Hence, these influence is studied through the proposal of generalized drying curves. Those curves are analyzed individually for each air condition exposed above and for both together. A set of equations to fit them is proposed and discussed.

Modelling of chloride penetration in concrete under wet/dry cycle

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Hong Sung-In

2017-01-01

Full Text Available This present study concerns modelling of chloride penetration in partially saturated concrete. To mimic the intermittent exposure of sea water to concrete, varying environmental conditions for relative humidity and chloride concentration were considered. As for the moisture distribution in concrete, statistical permeability model based on pore size distribution was used to represent influence of material properties on moisture transport. Then, a combined chloride diffusion and convection was modelled in variation of moisture level in concrete. As a result, smaller relative wet duration induces higher rate of chloride penetration due to enhanced moisture permeability from the surface, and also higher concentration gradient near the surface of concrete due to repeated wet/dry cycle. This implies that only diffusion analysis on chloride induced corrosion in concrete structure may underestimate the serviceability in given material performance.

Dry Orgasm (Orgasm without Discharge of Semen)

Science.gov (United States)

Symptoms Dry orgasm By Mayo Clinic Staff Dry orgasm occurs when a man reaches sexual climax but doesn't release (ejaculate) ... the thick, white fluid that carries sperm. Dry orgasm usually isn't harmful, but it can interfere ...

On the influence of cloud fraction diurnal cycle and sub-grid cloud optical thickness variability on all-sky direct aerosol radiative forcing

International Nuclear Information System (INIS)

Min, Min; Zhang, Zhibo

2014-01-01

The objective of this study is to understand how cloud fraction diurnal cycle and sub-grid cloud optical thickness variability influence the all-sky direct aerosol radiative forcing (DARF). We focus on the southeast Atlantic region where transported smoke is often observed above low-level water clouds during burning seasons. We use the CALIOP observations to derive the optical properties of aerosols. We developed two diurnal cloud fraction variation models. One is based on sinusoidal fitting of MODIS observations from Terra and Aqua satellites. The other is based on high-temporal frequency diurnal cloud fraction observations from SEVIRI on board of geostationary satellite. Both models indicate a strong cloud fraction diurnal cycle over the southeast Atlantic region. Sensitivity studies indicate that using a constant cloud fraction corresponding to Aqua local equatorial crossing time (1:30 PM) generally leads to an underestimated (less positive) diurnal mean DARF even if solar diurnal variation is considered. Using cloud fraction corresponding to Terra local equatorial crossing time (10:30 AM) generally leads overestimation. The biases are a typically around 10–20%, but up to more than 50%. The influence of sub-grid cloud optical thickness variability on DARF is studied utilizing the cloud optical thickness histogram available in MODIS Level-3 daily data. Similar to previous studies, we found the above-cloud smoke in the southeast Atlantic region has a strong warming effect at the top of the atmosphere. However, because of the plane-parallel albedo bias the warming effect of above-cloud smoke could be significantly overestimated if the grid-mean, instead of the full histogram, of cloud optical thickness is used in the computation. This bias generally increases with increasing above-cloud aerosol optical thickness and sub-grid cloud optical thickness inhomogeneity. Our results suggest that the cloud diurnal cycle and sub-grid cloud variability are important factors

Future needs for dry or peak shaved dry/wet cooling and significance to nuclear power plants. Final report

International Nuclear Information System (INIS)

Clukey, H.V.; McNelly, M.J.; Mitchell, R.C.

1976-02-01

U.S. requirements for uncommitted nuclear installations in water scarce areas that might require dry cooling tower systems are minimal through the year 2000 (6 to 23 GWe). In these areas it appears that peak-shaved dry/wet cooling systems are more attractive than all-dry tower cooling unless water costs were to approach the high level of several cents per gallon. The differential cooling system evaluated cost of peak-shaved dry/wet cooling systems above wet towers is typically $20 to $30/kWe for steam turbines; whereas, dry towers can represent an incremental burden of as much as $80/kWe. Gas turbine (Brayton Cycle) systems show similar benefits from an evaporative heat sink to those for steam turbine cycles--lower cooling system evaluated costs for peak-shaved dry/wet cooling systems than for conventional wet towers. These cooling system cost differentials do not reflect total costs for Brayton Cycle gas turbine plants. Together these added costs and uncertainties may substantially exceed the dollar incentives available for development of the Brayton Cycle for power generation needs for water deficient sites

Pipe Wall Thickness Monitoring Using Dry-Coupled Ultrasonic Waveguide Technique

International Nuclear Information System (INIS)

Cheong, Yong Moo; Kim, Ha Nam; Kim, Hong Pyo

2012-01-01

In order to monitor a corrosion or FAC (Flow Accelerated Corrosion) in a pipe, there is a need to measure pipe wall thickness at high temperature. Ultrasonic thickness gauging is the most commonly used non-destructive testing technique for wall thickness measurement. However, current commonly available ultrasonic transducers cannot withstand high temperatures, such as above 200 .deg. C. It is therefore necessary to carry out manual measurements during plant shutdowns. The current method thus reveals several disadvantages: inspection have to be performed during shutdowns with the possible consequences of prolonging down time and increasing production losses, insulation has to be removed and replaced for each manual measurement, and scaffolding has to be installed to inaccessible areas, resulting in considerable cost for interventions. It has been suggested that a structural health monitoring approach with permanently installed ultrasonic thickness gauges could have substantial benefits over current practices. The main reasons why conventional piezoelectric ultrasonic transducers cannot be used at high temperatures are that the piezo-ceramic becomes depolarized at temperature above the Curie temperature and because differential thermal expansion of the substrate, couplant, and piezoelectric materials cause failure. In this paper, a shear horizontal waveguide technique for wall thickness monitoring at high temperature is investigated. Two different designs for contact to strip waveguide are shown and the quality of output signal is compared and reviewed. After a success of acquiring high quality ultrasonic signal, experiment on the wall thickness monitoring at high temperature is planned

Drying/rewetting cycles mobilize old C from deep soils from a California annual grassland

OpenAIRE

Schimel, JP; Wetterstedt, JAM; Holden, PA; Trumbore, SE

2011-01-01

We measured the 14 C and 13 C signatures of CO 2 respired from surface and deep soils released through multiple dry/rewetting cycles in laboratory incubations. The C respired from surface soils included components fixed before and after the 1960s. However, that respired from deep soils was derived from organic matter with a mean turnover time estimated in the range of 650-850 years. This reinforces previous research suggesting that a substantial amount of deep soil C is chemically labile b...

Study of Energy Consumption of Potato Slices During Drying Process

Directory of Open Access Journals (Sweden)

Hafezi Negar

2015-06-01

Full Text Available One of the new methods of food drying using infrared heating under vacuum is to increase the drying rate and maintain the quality of dried product. In this study, potato slices were dried using vacuum-infrared drying. Experiments were performed with the infrared lamp power levels 100, 150 and 200 W, absolute pressure levels 20, 80, 140 and 760 mmHg, and with three thicknesses of slices 1, 2 and 3 mm, in three repetitions. The results showed that the infrared lamp power, absolute pressure and slice thickness have important effects on the drying of potato. With increasing the radiation power, reducing the absolute pressure (acts of vacuum in the dryer chamber and also reducing the thickness of potato slices, drying time and the amount of energy consumed is reduced. In relation to thermal utilization efficiency, results indicated that with increasing the infrared radiation power and decreasing the absolute pressure, thermal efficiency increased.

Nuclear closed-cycle gas turbine (HTGR-GT): dry cooled commercial power plant studies

International Nuclear Information System (INIS)

McDonald, C.F.; Boland, C.R.

1979-11-01

Combining the modern and proven power conversion system of the closed-cycle gas turbine (CCGT) with an advanced high-temperature gas-cooled reactor (HTGR) results in a power plant well suited to projected utility needs into the 21st century. The gas turbine HTGR (HTGR-GT) power plant benefits are consistent with national energy goals, and the high power conversion efficiency potential satisfies increasingly important resource conservation demands. Established technology bases for the HTGR-GT are outlined, together with the extensive design and development program necessary to commercialize the nuclear CCGT plant for utility service in the 1990s. This paper outlines the most recent design studies by General Atomic for a dry-cooled commercial plant of 800 to 1200 MW(e) power, based on both non-intercooled and intercooled cycles, and discusses various primary system aspects. Details are given of the reactor turbine system (RTS) and on integrating the major power conversion components in the prestressed concrete reactor vessel

Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes

Energy Technology Data Exchange (ETDEWEB)

Deng, Kai [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Yang, Shouye, E-mail: syyang@tongji.edu.cn [State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061 (China); Lian, Ergang [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Li, Chao [State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Yang, Chengfan; Wei, Hailun [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China)

2016-08-15

As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter “deuterium excess” (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons. - Highlights: • Stable H-O isotopes indicate the Changjiang river water cycle in dry seasons. • The isotopic parameter “d-excess” reveals the origins of

Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes

International Nuclear Information System (INIS)

Deng, Kai; Yang, Shouye; Lian, Ergang; Li, Chao; Yang, Chengfan; Wei, Hailun

2016-01-01

As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter “deuterium excess” (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons. - Highlights: • Stable H-O isotopes indicate the Changjiang river water cycle in dry seasons. • The isotopic parameter “d-excess” reveals the origins of

A Study on the Effect of Electrolyte Thickness on Atmospheric Corrosion of Carbon Steel

International Nuclear Information System (INIS)

Chung, Kyeong Woo; Kim, Kwang Bum

1998-01-01

Effect of electrolyte layer thickness and increase in concentration of electrolyte during electrolyte thining on the atmospheric corrosion of carbon steel were investigated using EIS and cathodic polarization technique. The electrolyte layer thickness was controlled via two methods : one is mechanical method with microsyringe applying a different amount of electrolyte onto the metal surface to give different electrolyte thickness with the same electrolyte concentration. The other is drying method in which water layer thickness decreases through drying, causing increase in concentration of electrolyte during electrolyte thinning. In the region whose corrosion rate is controlled by cathodic reaction, corrosion rate for mechanical method is larger than that for drying method. However, for the electrolyte layers thinner than 20 ∼ 30 m, increase in concentration of electrolyte cause a higher corrosion rate for the case of the mechanical method compared with that of drying method. For a carbon steel covered with 0.1M Na 2 SO 4 , maximum corrosion rate is found at an electrolyte thickness of 45 ∼ 55 μm for mechanical method. However, maximum corrosion rate is found at an electrolyte thickness of 20 ∼ 35 μm for drying method. The limiting current is inversely proportional to electrolyte thickness for electrolyte thicker than 20 ∼ 30 μm. However, further decrease of the electrolyte thickness leads to an electrolyte thickness-independent limiting current reagion, where the oxygen rate is controlled by the solvation of oxygen at the electrolyte/gas interface. Diffusion limiting current for drying method is smaller compared with that for mechanica control. This can be attributed to decreasing in O 2 solubility caused by increase in concentration of electrolyte during electrolyte thining

X-ray microanalysis of freeze-dried and frozen-hydrated cryosections

International Nuclear Information System (INIS)

Zierold, K.

1988-01-01

The elemental composition and the ultrastructure of biological cells were studied by scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray microanalysis. The preparation technique involves cryofixation, cryoultramicrotomy, cryotransfer, and freeze-drying of samples. Freeze-dried cryosections 100-nm thick appeared to be appropriate for measuring the distribution of diffusible elements and water in different compartments of the cells. The lateral analytical resolution was less than 50 nm, depending on ice crystal damage and section thickness. The detection limit was in the range of 10 mmol/kg dry weight for all elements with an atomic number higher than 12; for sodium and magnesium the detection limits were about 30 and 20 mmol/kg dry weight, respectively. The darkfield intensity in STEM is linearly related to the mass thickness. Thus, it becomes possible to measure the water content in intracellular compartments by using the darkfield signal of the dry mass remaining after freeze-drying. By combining the X-ray microanalytical data expressed as dry weight concentrations with the measurements of the water content, physiologically more meaningful wet weight concentrations of elements were determined. In comparison to freeze-dried cryosections frozen-hydrated sections showed poor contrast and were very sensitive against radiation damage, resulting in mass loss. The high electron exposure required for recording X-ray spectra made reproducible microanalysis of ultrathin (about 100-nm thick) frozen-hydrated sections impossible. The mass loss could be reduced by carbon coating; however, the improvement achieved thus far is still insufficient for applications in X-ray microanalysis. Therefore, at present only bulk specimens or at least 1-micron thick sections can be used for X-ray microanalysis of frozen-hydrated biological samples

Analysis of mechano-sorptive effect in oscillatory drying of beech timber

Directory of Open Access Journals (Sweden)

Milić Goran

2016-01-01

Full Text Available The paper shows results of analysis of influences of oscillating parameters of drying on measuring wood moisture content in the kiln, rate and quality of drying. For this analysis, we used a conventional drying cycle, a cycle with oscillating equilibrium moisture content (EMC, and a cycle with oscillating temperatures. A special software tool was created for managing the oscillations. It was shown that oscillations of EMC and temperatures result in cyclic changes in wood MC, but also in the additional inaccuracies of MC measurements in the kiln. The drying process of the cycle with oscillating EMC lasted somewhat shorter than the other two cycles. Drying quality was the same or better in the cycles with oscillations as compared to the conventionally dried cycle, and the smaller tensions in the wood confirmed the activation of the additional mechano-sorptive effect during cyclic changes of MC in surface layers. [Projekat Ministarstva nauke Republike Srbije, br. TR 31041 i br. TR 37008

OPTIMIZATION OF MICROWAVE AND AIR DRYING CONDITIONS OF QUINCE (CYDONIA OBLONGA, MILLER USING RESPONSE SURFACE METHODOLOGY

Directory of Open Access Journals (Sweden)

Cem Baltacioglu

2015-03-01

Full Text Available Effects of slice thickness of quince (Cydonia oblonga Miller , microwave incident power and air drying temperature on antioxidant activity and total phenolic content of quince were investigated during drying in microwave and air drying. Optimum conditions were found to be: i for microwave drying, 285 W and 4.14 mm thick (maximum antioxidant activity and 285 W and 6.85 mm thick (maximum total phenolic content, and ii for air drying, 75 ºC and 1.2 mm thick (both maximum antioxidant activity and total phenolic content. Drying conditions were optimized by using the response surface methodology. 13 experiments were carried out considering incident microwave powers from 285 to 795 W, air temperature from 46 to 74 ºC and slice thickness from 1.2 to 6.8 mm.

Infrared Drying Parameter Optimization

Science.gov (United States)

Jackson, Matthew R.

In recent years, much research has been done to explore direct printing methods, such as screen and inkjet printing, as alternatives to the traditional lithographic process. The primary motivation is reduction of the material costs associated with producing common electronic devices. Much of this research has focused on developing inkjet or screen paste formulations that can be printed on a variety of substrates, and which have similar conductivity performance to the materials currently used in the manufacturing of circuit boards and other electronic devices. Very little research has been done to develop a process that would use direct printing methods to manufacture electronic devices in high volumes. This study focuses on developing and optimizing a drying process for conductive copper ink in a high volume manufacturing setting. Using an infrared (IR) dryer, it was determined that conductive copper prints could be dried in seconds or minutes as opposed to tens of minutes or hours that it would take with other drying devices, such as a vacuum oven. In addition, this study also identifies significant parameters that can affect the conductivity of IR dried prints. Using designed experiments and statistical analysis; the dryer parameters were optimized to produce the best conductivity performance for a specific ink formulation and substrate combination. It was determined that for an ethylene glycol, butanol, 1-methoxy 2- propanol ink formulation printed on Kapton, the optimal drying parameters consisted of a dryer height of 4 inches, a temperature setting between 190 - 200°C, and a dry time of 50-65 seconds depending on the printed film thickness as determined by the number of print passes. It is important to note that these parameters are optimized specifically for the ink formulation and substrate used in this study. There is still much research that needs to be done into optimizing the IR dryer for different ink substrate combinations, as well as developing a

Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

KAUST Repository

Zong, Baoyu; Goh, J. Y.; Guo, Zaibing; Luo, Ping; Wang, Chenchen; Qiu, Jinjun; Ho, Pin; Chen, Yunjie; Zhang, Mingsheng; Han, Guchang

2013-01-01

A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half

The effect of endometrial thickness and pattern measured by ultrasonography on pregnancy outcomes during IVF-ET cycles

Directory of Open Access Journals (Sweden)

Zhao Jing

2012-11-01

Full Text Available Abstract Background To study the effect of endometrial thickness and pattern measured using ultrasound upon pregnancy outcomes in patients undergoing IVF-ET. Method One thousand nine hundred thirty-three women undergoing IVF treatment participated in the study. We assessed and recorded endometrial patterns and thickness on the day of human chorionic gonadotropin (hCG administration. Receiver operator curves (ROC were used to determine the predictive accuracy of endometrial thickness. Cycles were divided into 3 groups depending on the thickness (group 1: ≤ 7 mm; group 2: > 7 mm to ≤ 14 mm; group 3: > 14 mm. Each group was subdivided into three groups according to the endometrial pattern as follows: pattern A (a triple-line pattern consisting of a central hyperechoic line surround by two hypoechoic layers; pattern B (an intermediate isoechogenic pattern with the same reflectivity as the surrounding myometrium and a poorly defined central echogenic line; and pattern C (homogenous, hyperechogenic endometrium. Clinical outcomes such as implantation and clinical pregnancy rates were analyzed. Results The endometrial thickness predicts pregnancy outcome with high sensitivity and specificity. The cutoff value was 9 mm. The implantation rate and clinical pregnancy rate in group 3 were 39.1% and 63.5%, respectively, which were significantly higher than those in group 2 (33.8% and 52.1%, respectively and group 1 (13% and 25.5%, respectively. Among those with Pattern A, the implantation rate and clinical pregnancy rate were 35.3% and 55.2%, respectively, which were significantly higher than among women with Pattern B (32.1% and 50.9%, respectively and Pattern C (23.4% and 37.4%, respectively. In groups 1 and 3, clinical pregnancy and implantation rates did not show any significant differences between different endometrial patterns (P > 0.05, whereas in group 2, the clinical pregnancy rate and implantation rate in women with pattern A were

Thermodynamic properties and drying kinetics of Bauhinia forficata Link leaves

Directory of Open Access Journals (Sweden)

Fernanda P. da Silva

Full Text Available ABSTRACT The aim of this study was to determine the effective diffusion coefficient and the thermodynamic properties of Bauhinia forficata Link leaves, considering two forms of thickness measurements and to describe the process by fitting mathematical models. The leaves were collected, taken to the laboratory and prepared to start the drying process in which four temperatures (40, 50, 60 and 70 °C were applied. After the drying process, the effective diffusion coefficient was determined through the theory of diffusion in liquid, allowing to obtain the values of the activation energy, enthalpy, entropy and Gibbs free energy. The description of the drying process was performed by setting the thirteen mathematical models used to represent constant drying of agricultural products. The Valcam model was selected to represent the drying kinetics B. forficata Link. Increased temperature promotes: decreasing enthalpy and entropy; increasing Gibbs free energy and effective diffusion coefficient. The effective diffusion coefficient is higher when the rib thickness is considered; thus, it is recommended to standardize and/or specify the points of measurement of leaf thickness.

Effects of drying methods of lamellas used in multilayer parquet ...

African Journals Online (AJOL)

Flat sawn green lamellas with 5 and 2 mm thicknesses, which were cut away from Iroko lumber by means of thin cutting frame saw, were dried with 3 different drying methods such as drying in lumber drying kiln, jet ventilated automatic veneer roller dryer and veneer press dryer. Effect of drying temperature on surface ...

The effect of slicing type on drying kinetics and quality of dried carrot

Directory of Open Access Journals (Sweden)

M Naghipour zadeh mahani

2016-04-01

Full Text Available Introduction: Carrot is one of the most common vegetables used for human nutrition because of its high vitamin and fiber contents. Drying improves the product shelf life without addition of any chemical preservative and reduces both the size of package and the transport cost. Drying also aidsto reduce postharvest losses of fruits and vegetables especially, which can be as high as 70%. Dried carrots are used in dehydrated soups and in the form of powder in pastries and sauces. The main aim of drying agricultural products is decrease the moisture content to a level which allows safe storage over an extended period. Many fruits and vegetables can be sliced before drying.because of different tissue of a fruit or vegetable, cutting them in different direction and shape created different tissue slices. Due to drying is the exiting process of the moisture from internal tissue so different tissue slices caused different drying kinetics. Therefore, the study on effect of cutting parameters on drying is necessary. Materials and Methods: Carrots (Daucus carota L. were purchased from the local market (Kerman, Iran and stored in a refrigerator at 5°C. The initial moisture contents of the Carrot samples were determined by the oven drying method. The sample was dried in an oven at 105±2°C about 24 hours. The carrots cut by 3 models blade at 3 directions. The samples were dried in an oven at 70°C. Moisture content of the carrot slices were determined by weighting of samples during drying. Volume changes because of sample shrinkage were measured by a water displacement method. Rehydration experiment was performed by immersing a weighted amount of dried samples into hot water 50 °C for 30 min. In this study the effect of some cutting parameters was considered on carrot drying and the quality of final drying product. The tests were performed as a completely random design. The effects of carrot thickness at two levels (3 and 6 mm, blade in 3 models (flat blade

Development of heat pump and infrared-convective dryer and performance analysis for stale bread drying

International Nuclear Information System (INIS)

Aktaş, Mustafa; Şevik, Seyfi; Aktekeli, Burak

2016-01-01

Highlights: • Investigation of stale bread drying behaviors by developing the HPD and IRD. • New techniques for the HP and IR dryers are proposed and found to be efficient. • Evaluations on potential uses low temperature applications of the dryers were reported. • 35.6% of energy saving was provided by heat recovery device. • The overall system efficiency of HPD was calculated as 13–60%. - Abstract: This experimental study aims to develop a heat pump dryer (HPD) and an infrared dryer (IRD) also the comparative empirical analyses of these two methods and to analyze the drying kinetic of stale bread sliced 15 mm thickness and effectiveness on the drying kinetics of the stale bread of dryers. Dryers have been developed by using different techniques such as heat recovery unit, proportional control (PC) of drying air temperature, simultaneous control of the relative humidity–temperature–air flow rate, water cycle dehumidifier and closed-loop cycle to increase the drying efficiency of industrial drying applications. The highest coefficient of performance of the whole heat pump system (COP_w_s_,_H_P) was calculated as 3.7 and drying efficiencies of the IRD and HPD systems were calculated as 39% and 25%, respectively. When the HPD and IRD systems were compared in terms of drying time and energy consumption, it was observed that the IRD system did not only shortened the drying time up to 69%, but also decreased the energy consumption of the system by 43.2%. Based on the obtained results the effective moisture diffusivity (D_e) was calculated in the range from 8.3 × 10"−"8 to 3.2 × 10"−"7 m"2/s and mass transfer coefficient (h_m) was varied from 1.17 × 10"−"5 to 4.52 × 10"−"5 m/s. It was concluded that both dryers have significant effect in reduction of water content; the relative humidity controlled HPD can be applied efficiently for dryers and the dried stale bread can be reused as bread crumb by food industry.

700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

Science.gov (United States)

Ruan, Dianbo; Kim, Myeong-Seong; Yang, Bin; Qin, Jun; Kim, Kwang-Bum; Lee, Sang-Hyun; Liu, Qiuxiang; Tan, Lei; Qiao, Zhijun

2017-10-01

To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g-1), good rate capabilities (148 mAhh g-1 at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg-1, a maximum power density of 2466 W kg-1, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.

Radiation disinfestation studies on sun dried fish

International Nuclear Information System (INIS)

Ahmed, M.; Bhuiya, A.D.; Alam, M.S.; Huda, S.M.S.

1989-01-01

A large quantity of dried fish is lost in Bangladesh due to infestation by earwigs, hide beetles and copra beetles in storage godowns. The most destructive pest is the hide beetle, Dermestes maculatus Deg. Earwigs of different developmental stages were exposed to 0.10, 0.20 or 0.30 kGy of gamma rays for disinfestation. There was apparent damage to the control but all treated samples were in good condition and no live insect was observed 3 weeks after starting the experiment. Disinfestation studies of dried mackerel showed that eggs, larval and pupal stages of hide beetles could be inactivated at a dose of 0.20 kGy. A dose of 0.30 kGy killed all adults 2 weeks after irradiation. In the packaging studies, dried mackerel was packed in polythene pouches of different thicknesses. Two controls were maintained, i.e. dried fish with no treatment, control, and dried fish disinfested with heat at 60 deg. C, disinfested control. In experiments with 50 μm thick polythene pouches, the dried fish of irradiation treatments with 0.10 to 1.0 kGy doses and the controls had around 20% moisture content with the exception of disinfested controls which had 13% moisture content. All irradiated samples were free from insect damage. There was heavy damage in the controls due to insects. However, all these treated fish had heavy fungal growth with the exception of the disinfested control. Similar results were obtained with pouches made of 75 μm thick polythene irradiated at doses of 0.50, 1.0, 2.0 and 4.0 kGy. In the final experiments pouches were made of 50, 75 and 100 μm thick polythene and exposed to similar radiation as in the previous experiment. In all the treatments, moisture content was reduced to 13%. heavy insect damage was observed in the control, while all the treated samples were in excellent condition after 5 months of storage. (author). 20 refs, 2 figs, 5 tabs

Design of dry barriers for containment of contaminants in unsaturated soils

International Nuclear Information System (INIS)

Morris, C.E.; Thomson, B.M.; Stormont, J.C.

1997-01-01

A dry barrier is a region of very dry conditions in unsaturated soil that prevents vertical migration of water created by circulating dry air through the formation. Dry soil creates a barrier to vertical water movement by decreasing the soil's hydraulic conductivity, a concept also used in capillary barriers. A dry barrier may be a viable method for providing containment of a contaminant plume in a setting with a thick unsaturated zone and dry climate. The principal factors which determine the feasibility of a dry barrier include: (1) an and environment, (2) thick vadose zone, and (3) the ability to circulate air through the vadose zone. This study investigated the technical and economic considerations associated with creating a dry barrier to provide containment of a hypothetical 1 ha aqueous contaminant plume. The concept appears to be competitive with other interim containment methods such as ground freezing

Cracking in Drying Colloidal Films

Science.gov (United States)

Singh, Karnail B.; Tirumkudulu, Mahesh S.

2007-05-01

It has long been known that thick films of colloidal dispersions such as wet clays, paints, and coatings crack under drying. Although capillary stresses generated during drying have been recently identified as the cause for cracking, the existence of a maximum crack-free film thickness that depends on particle size, rigidity, and packing has not been understood. Here, we identify two distinct regimes for crack-free films based on the magnitude of compressive strain at the maximum attainable capillary pressure and show remarkable agreement of measurements with our theory. We anticipate our results to not only form the basis for design of coating formulations for the paints, coatings, and ceramics industry but also assist in the production of crack-free photonic band gap crystals.

Self-protection in dry recycle technologies

International Nuclear Information System (INIS)

Hannum, W.H.; Wade, D.; Stanford, G.

1995-01-01

In response to the INFCE conclusions, the U.S. undertook development of a new dry fuel cycle. Dry recycle processes have been demonstrated to be feasible. Safeguarding such fuel cycles will be dramatically simpler than the PUREX fuel cycle. At every step of the processes, the materials meet the open-quotes spent-fuel standard.close quotes The scale is compatible with collocation of power reactors and their recycle facility, eliminating off-site transportation and storage of plutonium-bearing materials. Material diverted either covertly or overtly would be difficult (relative to material available by other means) to process into weapons feedstock

Drying of Concrete

DEFF Research Database (Denmark)

Hansen, Kurt Kielsgaard; Geiker, Mette Rica; Nygaard, Peter Vagn

2002-01-01

Estimated and measured relative humidity (RH) change during drying are compared for two concretes, 1: w/c=0.46 and 2: w/(c+0.5fa+2sf)=0.50. The estimations were undertaken by means of the Swedish program TorkaS 1.0. Measurements were performed by RH-sensors type Humi-Guard. Drying of 150 mm thick...... samples from sides at 60% RH and 22 °C took place from 4 to 56 days after casting. At the end of the drying period the measured RH was about 4% lower than the estimated RH at 1/5th depth from the exposed surface for both concretes. In the middle of the samples, the measured RH of concretes 1 and 2 were 2...

Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

KAUST Repository

Jeong, Hoon Eui

2010-02-16

We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

KAUST Repository

Jeong, Hoon Eui; Kwak, Moon Kyu; Suh, Kahp Y.

2010-01-01

We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

Using laser to measure stem thickness and cut weed stems

DEFF Research Database (Denmark)

Heisel, T.; Schou, Jørgen; Andreasen, C.

2002-01-01

Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not...

[Effects of drying and wetting cycles induced by tides on net ecosystem exchange of CO2 over a salt marsh in the Yellow River Delta, China.

Science.gov (United States)

He, Wen Jun; Han, Guang Xuan; Xu, Yan Ning; Zhang, Xi Tao; Wang, An Dong; Che, Chun Guang; Sun, Bao Yu; Zhang, Xiao Shuai

2018-01-01

As a unique hydrological characteristic, the tidal action can strongly affect carbon balance in a salt marsh despite their short duration. Using the eddy covariance technique, we measured the net ecosystem CO 2 exchange (NEE) and its environmental factors and tidal change over a salt marsh in the Yellow River Delta. It aimed to investigate the effect of tidal process and drying and wetting cycles induced by tides on NEE. The results showed that the tidal process promoted the daytime CO 2 uptake, but it didn't clearly affect the nighttime CO 2 release. Tidal inundation was a major factor influencing daytime NEE. The diurnal change of NEE showed a distinct U-shaped curve on both drought and wet stages, but not with substantial variation in its amplitude during the drought stage. The drying and wetting cycles enhanced the absorption of daytime CO 2 . Under drought stage, the mean of the maximum photosynthetic rate (A max ), apparent quantum yield (α) and ecosystem respiration (R eco ) were higher than those in wet stage. In addition, the drying and wetting cycles suppressed the nighttime CO 2 release from the salt marsh but increased its temperature sensitivity.

Effect of Rare Earth on Corrosion Products and Impedance Behavior of AZ91 Magnesium Alloy Under Dry-wet Cycles

Directory of Open Access Journals (Sweden)

ZHAO Xi

2017-04-01

Full Text Available The effect of mischmetal of lanthanum and cerium on the composition and structure of the corrosion products on the surface of AZ91 Mg alloy in deicing salt solution under dry-wet cycles was investigated by scanning electron microscopy (SEM, X-ray diffraction (XRD and energy dispersive spectrometer (EDS. The results show that the corrosion products of AZ91 Mg alloy without mischmetal addition (La,Ce are mainly composed of Mg(OH2, MgO, CaCO3 and Mg6Al2CO3(OH16·4H2O; and (La,CeAlO3 can be found in the products of AZ91 with mischmetal addition, meanwhile dense layer occurs in the corrosion products. Electrochemical impedance spectroscopy (EIS measurements show that the charge transfer resistance of AZ91 alloy with mischmetal addition tested in the same dry-wet cycles is much higher than that of AZ91 alloy, the addition of mischmetal helps to reduce the dispersing effect of impedance spectroscopy, indicating that the corrosion resistance of AZ91 Mg alloy and the stability of corrosion product films can be improved by mischmetal of La and Ce.

PWR-to-PWR fuel cycle model using dry process

International Nuclear Information System (INIS)

Iqbal, M.; Jeong, Chang Joon; Rho, Gyu Hong

2002-03-01

PWR-to-PWR fuel cycle model has been developed to recycle the spent fuel using the dry fabrication process. Two types of fuels were considered; first fuel was based on low initial enrichment with low discharge burnup and second one was based on more initial enrichment with high discharge burnup in PWR. For recycling calculations, the HELIOS code was used, in which all of the available fission products were considered. The decay of 10 years was applied for reuse of the spent fuel. Sensitivity analysis for the fresh feed material enrichment has also been carried out. If enrichment of the mixing material is increased the saving of uranium reserves would be decreased. The uranium saving of low burned fuel increased from 4.2% to 7.4% in fifth recycling step for 5 wt% to 19.00wt% mixing material enrichment. While for high burned fuel, there was no uranium saving, which implies that higher uranium enrichment required than 5 wt%. For mixing of 15 wt% enriched fuel, the required mixing is about 21.0% and 37.0% of total fuel volume for low and high burned fuel, respectively. With multiple recycling, reductions in waste for low and high burned fuel became 80% and 60%, for first recycling, respectively. In this way, waste can be reduced more and the cost of the waste disposal reduction can provide the economic balance

Dry process potentials

International Nuclear Information System (INIS)

Faugeras, P.

1997-01-01

Various dry processes have been studied and more or less developed in order particularly to reduce the waste quantities but none of them had replaced the PUREX process, for reasons departing to policy errors, un-appropriate demonstration examples or too late development, although realistic and efficient dry processes such as a fluoride selective volatility based processes have been demonstrated in France (CLOVIS, ATILA) and would be ten times cheaper than the PUREX process. Dry processes could regain interest in case of a nuclear revival (following global warming fears) or thermal wastes over-production. In the near future, dry processes could be introduced in complement to the PUREX process, especially at the end of the process cycle, for a more efficient recycling and safer storage (inactivation)

Drying kinetics and quality aspects during heat pump drying of onion (Allium cepa L.

Directory of Open Access Journals (Sweden)

Nihar Ranjan Sahoo

2012-10-01

Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H., 40ºC (26 % R.H., 45ºC (19 % R.H. and 50ºC (15 % R.H.. Samples were also dried in a hot air dryer at 50ºC (52 % R.H. for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.

Development of examination technique for oxide layer thickness measurement of irradiated fuel rods

International Nuclear Information System (INIS)

Koo, D. S.; Park, S. W.; Kim, J. H.; Seo, H. S.; Min, D. K.; Kim, E. K.; Chun, Y. B.; Bang, K. S.

1999-06-01

Technique for oxide layer thickness measurement of irradiated fuel rods was developed to measure oxide layer thickness and study characteristic of fuel rods. Oxide layer thickness of irradiated fuels were measured, analyzed. Outer oxide layer thickness of 3 cycle-irradiated fuel rods were 20 - 30 μm, inner oxide layer thickness 0 - 10 μm and inner oxide layer thickness on cracked cladding about 30 μm. Oxide layer thickness of 4 cycle-irradiated fuel rods were about 2 times as thick as those of 1 cycle-irradiated fuel rods. Oxide layer on lower region of irradiated fuel rods was thin and oxide layer from lower region to upper region indicated gradual increase in thickness. Oxide layer thickness from 2500 to 3000 mm showed maximum and oxide layer thickness from 3000 to top region of irradiated fuel rods showed decreasing trend. Inner oxide layer thicknesses of 4 cycle-irradiated fuel rod were about 8 μm at 750 - 3500 mm from the bottom end of fuel rod. Outer oxide layer thickness were about 8 μm at 750 - 1000 mm from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel rod. These indicated gradual increase up to upper region from the bottom end of fuel. Oxide layer thickness technique will apply safety evaluation and study of reactor fuels. (author). 6 refs., 14 figs

Dry/Wet Cycling and the Thermodynamics and Kinetics of Prebiotic Polymer Synthesis

Directory of Open Access Journals (Sweden)

David S. Ross

2016-07-01

Full Text Available The endoergic nature of protein and nucleic acid assembly in aqueous media presents two questions that are fundamental to the understanding of life’s origins: (i how did the polymers arise in an aqueous prebiotic world; and (ii once formed in some manner, how were they sufficiently persistent to engage in further chemistry. We propose here a quantitative resolution of these issues that evolved from recent accounts in which RNA-like polymers were produced in evaporation/rehydration cycles. The equilibrium Nm + Nn ↔ Nm+n + H2O is endoergic by about 3.3 kcal/mol for polynucleotide formation, and the system thus lies far to the left in the starting solutions. Kinetic simulations of the evaporation showed that simple Le Châtelier’s principle shifts were insufficient, but the introduction of oligomer-stabilizing factors of 5–10 kcal/mol both moved the process to the right and respectively boosted and retarded the elongation and hydrolysis rates. Molecular crowding and excluded volume effects in present-day cells yield stabilizing factors of that order, and we argue here that the crowded conditions in the evaporites generate similar effects. Oligomer formation is thus energetically preferred in those settings, but the process is thwarted in each evaporation step as diffusion becomes rate limiting. Rehydration dissipates disordered oligomer clusters in the evaporites, however, and subsequent dry/wet cycling accordingly “ratchets up” the system to an ultimate population of kinetically trappedthermodynamically preferred biopolymers.

Effect of Glass Thickness on Performance of Flat Plate Solar Collectors for Fruits Drying

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Ramadhani Bakari

2014-01-01

Full Text Available This study aimed at investigating the effect of thickness of glazing material on the performance of flat plate solar collectors. Performance of solar collector is affected by glaze transmittance, absorptance, and reflectance which results into major heat losses in the system. Four solar collector models with different glass thicknesses were designed, constructed, and experimentally tested for their performances. Collectors were both oriented to northsouth direction and tilted to an angle of 10° with the ground toward north direction. The area of each collector model was 0.72 m2 with a depth of 0.15 m. Low iron (extra clear glass of thicknesses 3 mm, 4 mm, 5 mm, and 6 mm was used as glazing materials. As a control, all collector performances were analysed and compared using a glass of 5 mm thickness and then with glass of different thickness. The results showed that change in glass thickness results into variation in collector efficiency. Collector with 4 mm glass thick gave the best efficiency of 35.4% compared to 27.8% for 6 mm glass thick. However, the use of glass of 4 mm thick needs precautions in handling and during placement to the collector to avoid extra costs due to breakage.

Corneal thickness in dry eyes in an Iraqi population

OpenAIRE

Ali,Noora Mauwafak; Hamied,Furkaan M; Farhood,Qasim K

2017-01-01

Noora Mauwafak Ali,1 Furkaan M Hamied,1 Qasim K Farhood2 1Department of Surgery, College of Medicine, Al-Qadisiya University, Diwaniyah, 2Department of Surgery, College of Medicine, University of Babylon, Hillah, Iraq Background: Dry eye disorder is a multifactorial disease of the tears and ocular surface that results in discomfort and visual disturbance. Corneal pachymetry becomes increasingly important in refractive surgery, for the accurate assessment of intraocular pressure, and in the ...

Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

KAUST Repository

Zong, Baoyu

2013-05-20

A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half-pitch without alignment issues. Depending on the different dry-etch mechanisms in transferring high and low density nanopatterns, suitable dry-etch angles and methods are studied for the transfer of high density nanopatterns. Some novel process methods have also been developed to eliminate the sidewall and other conversion obstacles for obtaining high density of uniform metallic nanopatterns. With these methods, ultrahigh density trilayer crossbar devices (∼2 × 1010 bit cm-2-kilobit electronic memory), which are composed of built-in practical magnetoresistive nanocells, have been achieved. This scalable process that we have developed provides the relevant industries with a cheap means to commercially fabricate three-dimensional high density metal-cell-metal nanodevices. © 2013 IOP Publishing Ltd.

Gelcasting compositions having improved drying characteristics and machinability

Science.gov (United States)

Janney, Mark A.; Walls, Claudia A. H.

2001-01-01

A gelcasting composition has improved drying behavior, machinability and shelf life in the dried and unfired state. The composition includes an inorganic powder, solvent, monomer system soluble in the solvent, an initiator system for polymerizing the monomer system, and a plasticizer soluble in the solvent. Dispersants and other processing aides to control slurry properties can be added. The plasticizer imparts an ability to dry thick section parts, to store samples in the dried state without cracking under conditions of varying relative humidity, and to machine dry gelcast parts without cracking or chipping. A method of making gelcast parts is also disclosed.

Fabrication of polyacrylate core–shell nanoparticles via spray drying method

Energy Technology Data Exchange (ETDEWEB)

Chen, Pengpeng, E-mail: chenpp@ahu.edu.cn [Anhui University, College of Chemistry and Chemical Engineering (China); Cheng, Zenghui; Chu, Fuxiang; Xu, Yuzhi; Wang, Chunpeng, E-mail: wangcpg@163.com [Chinese Academy of Forestry, Institute of Chemical Industry of Forest Products (China)

2016-05-15

Fine polyacrylate particles are thought to be environmental plastisols for car industry. However, these particles are mainly dried through demulsification of the latexes, which is not reproducible and hard to be scaled up. In this work, a spray drying method had been applied to the plastisols-used acrylate latex. By adjusting the core/shell ratio, spray drying process of the latex was fully studied. Scanning electronic microscopy observation of the nanoparticles before and after spray drying indicated that the core–shell structures could be well preserved and particles were well separated by spray drying if the shell was thick enough. Otherwise, the particles fused into each other and core–shell structures were destroyed. Polyacrylate plastisols were developed using diisononylphthalate as a plasticizer, and plastigels were obtained after heat treatment of the sols. Results showed that the shell thickness also had a great influence on the storage stability of the plastisols and mechanical properties of the plastigels.Graphical Abstract.

Fabrication of polyacrylate core–shell nanoparticles via spray drying method

International Nuclear Information System (INIS)

Chen, Pengpeng; Cheng, Zenghui; Chu, Fuxiang; Xu, Yuzhi; Wang, Chunpeng

2016-01-01

Fine polyacrylate particles are thought to be environmental plastisols for car industry. However, these particles are mainly dried through demulsification of the latexes, which is not reproducible and hard to be scaled up. In this work, a spray drying method had been applied to the plastisols-used acrylate latex. By adjusting the core/shell ratio, spray drying process of the latex was fully studied. Scanning electronic microscopy observation of the nanoparticles before and after spray drying indicated that the core–shell structures could be well preserved and particles were well separated by spray drying if the shell was thick enough. Otherwise, the particles fused into each other and core–shell structures were destroyed. Polyacrylate plastisols were developed using diisononylphthalate as a plasticizer, and plastigels were obtained after heat treatment of the sols. Results showed that the shell thickness also had a great influence on the storage stability of the plastisols and mechanical properties of the plastigels.Graphical Abstract

COMPARISON BETWEEN WOOD DRYING DEFECT SCORES: SPECIMEN TESTING X ANALYSIS OF KILN-DRIED BOARDS

Directory of Open Access Journals (Sweden)

Djeison Cesar Batista

2015-04-01

Full Text Available It is important to develop drying technologies for Eucalyptus grandis lumber, which is one of the most planted species of this genus in Brazil and plays an important role as raw material for the wood industry. The general aim of this work was to assess the conventional kiln drying of juvenile wood of three clones of Eucalyptus grandis. The specific aims were to compare the behavior between: i drying defects indicated by tests with wood specimens and conventional kiln-dried boards; and ii physical properties and the drying quality. Five 11-year-old trees of each clone were felled, and only flatsawn boards of the first log were used. Basic density and total shrinkage were determined, and the drying test with wood specimens at 100 °C was carried out. Kiln drying of boards was performed, and initial and final moisture content, moisture gradient in thickness, drying stresses and drying defects were assessed. The defect scoring method was used to verify the behavior between the defects detected by specimen testing and the defects detected in kiln-dried boards. As main results, the drying schedule was too severe for the wood, resulting in a high level of boards with defects. The behavior between the defects in the drying test with specimens and the defects of kiln-dried boards was different, there was no correspondence, according to the defect scoring method.

[Assessment of lipid layer thickness of tear film in the diagnosis of dry-eye syndrome in children after the hematopoietic stem cell transplantation].

Science.gov (United States)

Kurpińska, Małgorzata; Gorczyńska, Ewa; Owoc-Lempach, Joanna; Bernacka, Aleksandra; Misiuk-Hojło, Marta; Chybicka, Alicja

2011-01-01

Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS) is recognized as the most frequent ocular complication after allogeneic stem cell transplantation (allo-SCT). KCS can appear either due to insufficient tear production or excessive tear evaporation, both resulting in tears hyperosmolarity that leads to ocular damage. The evaporation rate and better film stability is determined primarily by the status of the lipid layer. Observation and classification of tear film lipid layer interference patterns in normal and dry eyes in patients after allogeneic stem cell transplantation with a follow-up time of 6 months-5 years (median 26.54 months). Investigation of the relation between the lipid layer interference patterns in normal and dry eyes and the results of other dry eye examinations and complaints. Relation between DES and conditioning regimes, including total body irradiation and high-dose chemotherapy, immunosuppressive drugs, the time after allogeneic stem cell transplantation and chronic graft-versus-host disease. Precorneal tears lipid layer interference patterns, were examined in 114 eyes in treatment group with the Tearscope-plus. Patient with dry eye were identified on the basis of Schirmer test scores and/or tear breakup time, and positive lissamine and/or fluorescein staining. 42 of 114 eyes (36.8%) developed DES after allo-SCT A significant correlation between thickness of lipid layer and BUT, Schirmer test, lissamine green and fluorescein staining was found in the treatment group. A significant association was found between present chronic GVHD and DES in children. DES was not associated with TBI, corticosteroids, immunosuppressive drugs and the time in the present study. Tears lipid layer interference patterns are highly correlated with the diagnosis of DES. Tears lipid layer interference patterns ( noninvasive method), can be used to diagnose early DES in children after allo-SCT. Chronic GVHD play a major role in development of DES

Radiation preservation of dry fruits and nuts

International Nuclear Information System (INIS)

Jan, M.; Sattar, A.; Ahmad, W.A.; Khan, I.

1990-06-01

Present studies were conducted to investigate insect infestation and oxidative changes of packaging materials. Dry fruits and nuts such as apricots, dates raisins, almonds, pinenuts and walnuts were used for these experiments. Insect infestation and other physico-chemical parameters were used for quality evaluation of the stored dry fruits and nuts. The effect of irradiation and polyethylene (PE) thickness on the over all acceptance of dry fruits on their color, texture, taste and flavor were evaluated. Radiation treatment and low temperature independently inhibited insect infestation during storage. (A.B.)

Quantitative risk assessment via uncertainty analysis in combination with error propagation for the determination of the dynamic Design Space of the primary drying step during freeze-drying

DEFF Research Database (Denmark)

Van Bockstal, Pieter Jan; Mortier, Séverine Thérèse F.C.; Corver, Jos

2017-01-01

of a freeze-drying process, allowing to quantitatively estimate and control the risk of cake collapse (i.e., the Risk of Failure (RoF)). The propagation of the error on the estimation of the thickness of the dried layer Ldried as function of primary drying time was included in the uncertainty analysis...

The effects of drying conditions on moisture transfer and quality of pomegranate fruit leather (pestil

Directory of Open Access Journals (Sweden)

Fatih Mehmet Yılmaz

2017-01-01

Full Text Available Vacuum, cabinet and open air drying of pomegranate fruit leather were carried out at various drying conditions to monitor the drying kinetics together with bionutrient degradation of the product. Drying curves exhibited first order drying kinetics and effective moisture diffusivity values varied between 3.1 × 10−9 and 52.6 × 10−9 m2/s. The temperature dependence of the effective moisture diffusivity was satisfactorily described by an Arrhenius-type relationship. Drying conditions, product thickness and operation temperature had various effects on drying rate and final quality of the product. In terms of drying kinetics and final quality of product, vacuum drying had higher drying rate with higher conservation of phenolic, anthocyanin and ascorbic acid that is connected to faster drying condition and oxygen deficient medium. Anthocyanin content was significantly affected by drying method, drying temperature and product thickness. Scatter plot using principle component analysis enabled better understanding of moisture transfer rate and anthocyanin change under various drying conditions.

Effect of drying methods on the rheological characteristics and ...

African Journals Online (AJOL)

The effect of drying methods (sun and oven-drying) on the rheological properties and colour of amala, a thick paste from yam flour, was investigated using two varieties of yam (Dioscorea rotundata and. Dioscorea alata). The yam flour produced was later reconstituted to produce amala of different pasting characteristics, ...

Thick and low-stress PECVD amorphous silicon for MEMS applications

International Nuclear Information System (INIS)

Iliescu, Ciprian; Chen Bangtao

2008-01-01

This paper presents a solution for the deposition of thick amorphous silicon (α-Si:H) in PECVD reactors for MEMS applications, such as sacrificial layer or mask layer for dry or wet etching of glass. This achievement was possible by tuning the deposition parameters to a 'zero' value of the residual stress in the α-Si:H layer. The influence of the process parameters, such as power, frequency mode, temperature, pressure and SiH 4 /Ar flow rates for tuning the residual stress and for a good deposition rate is analyzed. The deposition of low-stress and thick (more than 12 µm in our case) α-Si:H layers was possible without generation of hillock defects (previously reported in literature for layers thicker then 2 µm). Finally, the paper presents some MEMS applications of such a deposited α-Si:H layer: masking layer for deep wet etching as well as dry etching of glass, and sacrificial layer for dry or wet release

Studies on the radiation drying method for grain, 2: A good drying method of paddy rice from the viewpoint of the drying rate and the crack generation of rice

International Nuclear Information System (INIS)

Horibe, K.; Nakagawa, K.; Tohjo, T.

1990-01-01

A drying rate of paddy rice in a solar heat drying plant was studied. Solar-heated air at the upper part of a plastic house was blasted to the surface of the layer of paddy rice which was piled on the floor of the house. The drying rate increased with higher wind velocity, but it was found that the velocity was limited to 6m/s by the crack generation of the paddy rice. The effects of the layer thickness, the number of layer agitations and the heat supplied on the drying rate at a given wind velocity (6m/s) were expressed with a multiple regression equation. Then, the equation positively proposed appropriate conditions for effective operation of the plant in fine days

Belowground in situ redox dynamics and methanogenesis recovery in a degraded fen during dry-wet cycles and flooding

Directory of Open Access Journals (Sweden)

C. Estop-Aragonés

2013-01-01

generation and consumption of electron acceptors in the solid phase or other mechanisms. In contrast to flooding, dry-wet cycles negatively affect methane production on a seasonal scale, but this impact might strongly depend on drying intensity and on the peat matrix, of which structure and physical properties influence moisture content.

To What Degree Thermal Cycles Affect Chalk Strength

DEFF Research Database (Denmark)

Livada, Tijana; Nermoen, Anders; Korsnes, Reidar Inger

triaxial cell experiments. For dry rock, no significant effects of temperature cycling was found on average tensile strength, however the range of the tensile failure stress is doubled for the samples exposed to 50 temperature cycles, as opposed to those to none. For water saturated cores, the temperature......Chalk reservoirs could potentially undergo destabilization as the result of repeated cold water injection into a hot reservoir during water flooding. Preliminary results of an ongoing study are presented in this paper, which compare the impact of temperature cycling on mechanical behavior on dry...... and water saturated chalk. Sixty disks of dry Kansas chalk exposed to different number of temperature cycles were tested for tensile strength using a Brazilian test. Changes in elastic properties as function of number of temperature cycles of the same chalk, but now saturated in water, were studied using...

Influence of slice thickness of computed tomography and type of rapid protyping on the accuracy of 3-dimensional medical model

Energy Technology Data Exchange (ETDEWEB)

Um, Ki Doo; Lee, Byung Do [Wonkwang University College of Medicine, Iksan (Korea, Republic of)

2004-03-15

This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works 3.0) and RP model fabrication were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. There were relative error percentage in absolute value of 0.97, 1.98, 3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.

Influence of slice thickness of computed tomography and type of rapid protyping on the accuracy of 3-dimensional medical model

International Nuclear Information System (INIS)

Um, Ki Doo; Lee, Byung Do

2004-01-01

This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works 3.0) and RP model fabrication were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. There were relative error percentage in absolute value of 0.97, 1.98, 3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.

Investment opportunity : the FPL low-cost solar dry kiln

Science.gov (United States)

George B. Harpole

1988-01-01

Two equations are presented that may be used to estimate a maximum investment limit and working capital requirements for the FPL low-cost solar dry kiln systems. The equations require data for drying cycle time, green lumber cost, and kiln-dried lumber costs. Results are intended to provide a preliminary estimate.

Generalization of drying curves in conductive/convective drying of cellulose

Directory of Open Access Journals (Sweden)

M. Stenzel

2003-03-01

Full Text Available The objective of this work is to analyze the possibility of applying the drying curves generalization methodology to the conductive/convective hot plate drying of cellulose. The experiments were carried out at different heated plate temperatures and air velocities over the surface of the samples. This kind of approach is very interesting because it permits comparison of the results of different experiments by reducing them to only one set, which can be divided into two groups: the generalized drying curves and the generalized drying rate curves. The experimental apparatus is an attempt to reproduce the operational conditions of conventional paper dryers (ratio of paper/air movement and consists of a metallic box heated by a thermostatic bath containing an upper surface on which the cellulose samples are placed. Sample material is short- and long-fiber cellulose sheets, about 1 mm thick, and ambient air was introduced into the system by a adjustable blower under different conditions. Long-fiber cellulose generalized curves were obtained and analyzed first individually and then together with the short-fiber cellulose results from Motta Lima et al. (2000 a,b. Finally, a set of equations to fit the generalized curves obtained was proposed and discussed.

Crack propagation under thermal cycling loading inducing a thermal gradient in the specimen thickness

International Nuclear Information System (INIS)

Le, H.N.

2009-05-01

This study aims to figure out the crack growth phenomenon by thermal fatigue induced by thermal gradient through thickness of specimen. Firstly, an experimental facility has been developed: a rectangular parallelepiped specimen is subjected to thermal cycling between 350 C and 100 C; the specimen is freed to expand and contract. Two semi-circular notches (0,1 mm depth and 4 mm length) have been machined on the surface of the specimen. A series of interrupted tests has been carried out to characterize and quantify the crack growth in depth and surface of the pre-existing crack. Next, a three-dimensional crack growth simulation has been implemented in ABAQUS. Automation using Python was used to simulate the propagation of a crack under thermal cycling, with re-meshing at crack front after each calculation step. No assumption has been taken on the crack front during the crack propagation. A comparison with test results showed very good agreement on the evolution of crack front shape and on the kinetics of propagation on the edge and the heart of pre-existing crack. An analytical approach was also developed based on the calculation of stress intensity factors (SIC). A two-dimensional approach was first introduced enabling us to better understand the influence of various thermal and geometric parameters. Finally, a three dimensional approach, with an elliptical assumption crack shape during the propagation, leading to a prediction of crack growth on the surface and in depth which is very similar to that obtained numerically, but with computational time much lower. (author)

Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

Directory of Open Access Journals (Sweden)

Omer Kaynakli

2011-06-01

Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

Evaluation of kiln-drying schedules for wild cherry wood (Cerasus avium)

OpenAIRE

Korkut, Süleyman; Ünsal, Öner; Kocaefe, Duygu; Aytin, Ayhan; Gökyar, Asli

2013-01-01

Wild cherry wood (Cerasus avium (L.) Monench) lumber with a nominal thickness of 5 cm from Duzce region in Turkey was dried through conventional kiln drying using two different programs which are unprotective drying schedules, and protective drying schedules. The aim was to obtain the most desirable kiln schedule for keeping the wood quality at an appropriate level up to final moisture content of 12±2% was reached. Intensity of warping (twist, bow, cup, crook) occurrence, superficial, interna...

Evaluation of central and peripheral corneal thicknesses in patients with rheumatoid arthritis

Directory of Open Access Journals (Sweden)

Alime Gunes

2015-08-01

Full Text Available ABSTRACTPurpose:To evaluate central corneal thickness (CCT and peripheral corneal thickness (PCT in patients with rheumatoid arthritis (RA and to assess the relationships among the corneal parameters, dry eye disease, and clinical variables of RA.Methods:A total of 58 RA patients and 58 control subjects participated in this study. A detailed ophthalmological examination was performed on each subject. Dry eye evaluation was performed using Schirmer’s test, tear break-up time (TBUT, corneal fluorescein staining, and Ocular Surface Disease Index (OSDI. Corneal thickness at the apex point, the center of the pupil, the thinnest point, and PCT (3 mm from the apex to the superior, inferior, nasal, and temporal locations were evaluated using Scheimpflug imaging (Pentacam®. Additionally, the relative peripheral index (RPI was calculated by dividing the PCT by the CCT. The disease severity and quality of life were evaluated with DAS28 and HAQ, respectively. The laboratory evaluation comprised ESR and CRP.Results:The mean corneal thicknesses at the apex point, the center of the pupil, the thinnest point, and the superior, inferior, nasal, and temporal points were significantly thinner in RA patients than controls. Schirmer’s test scores and TBUT were significantly lower, and corneal staining and OSDI scores were significantly higher in RA patients. There were no significant correlations between the corneal parameters and the clinical variables of RA or dry eye tests.Conclusion:The CCT and PCT were thinner in RA patients compared to those in control subjects. However, there were no significant correlations between the corneal parameters and the clinical variables of RA or dry eye tests.

Thickness effect on electric resistivity on polystyrene and carbon black- based composites

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Lopez, S; Vigueras-Santiago, E [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA) Facultad de Quimica, Paseo Colon Esquina con Paseo Tollocan, s/n, CP 50000, Toluca (Mexico); Mayorga-Rojas, M; Reyes-Contreras, D, E-mail: eviguerass@uaemex.m [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico. Av. Instituto Literario 100 Ote. C. P. 50000, Toluca (Mexico)

2009-05-01

Changes on electrical resistivity were experimentally studied for polystyrene and carbon black-based composites respect to the temperature. 22% w/w carbon black composite films at 30{mu}m, 2mm y 1cm thick were submitted to thermal heating-cooling cycles from room temperature to 100 deg. C, slightly up to T{sub g} of the composite. For each cycle changes on electrical resistivity constituent a hysteresis loop that depends on the sample thickness. The changes during the heating stage could be explained as a consequence of the thermal expansion and mobility of the polymer chains at T{sub g}, producing a disconnecting of the electrical contacts among carbon black particles and an important increasing (200%) of the electrical resistivity. For each cycle, the hysteresis loop was observed in thicker samples, whereas for 30 mu m thickness sample the hysteresis loop was lost after four cycles.

Community Geothermal Technology Program: Fruit drying with geothermal energy. Final report

Energy Technology Data Exchange (ETDEWEB)

1988-03-14

Largest problem was lack of proper recording and controlling instrumentation. Agricultural products tested were green papaya powder, banana slices, and pineapple slices. Results show that a temperature of 120 F is a good drying temperature. Papaya should be mature green and not overly ripe; banana ripeness is also important; and pineapple slice thickness should be very uniform for even drying. Geothermal drying is feasible. Figs, tabs.

Assessment of Osmotic Pre-Drying Treatment on Drying Rates of Fresh Tomato Fruits

Directory of Open Access Journals (Sweden)

P. A. Idah

2014-06-01

Full Text Available The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying rates of tomato (Lycopersiconesculentum at various drying temperatures. Fresh Roma tomato fruit samples were sliced to a thickness of 5 mm and the seeds were removed. Weight of 300 g was measured for each of the three replicates and immersed in a hypertonic solution of sucrose of different concentrations 40 and 60 oBrix each held for osmotic duration of 1 and 2 hours, drained for 10 min and then dried at 50, 60, and 70 oC in a mechanical dryer. Control samples were also weighed 300 g per replicate and dried at 50, 60, and 70 oC without pre-drying treatment. The initial moisture content of fresh tomato used was 94.5% (wb. Moisture loss of each sample was monitored and recorded hourly until the product has reached the desired final moisture content (≤ 7%.The data collected were subjected to statistical analysis of variance (ANOVA and Duncan New Multiple range tests (DNMRT to ascertain the level of significance differences between the individual treatments and their interaction at p ≤ 0.05.The results show that at all the drying temperatures used, the control tomato samples exhibited the fastest drying rate with an average of 35.2 g/hr, samples pre-treated at 40 oBrix has an average drying rate of 26.6 g/hr, while samples pre-treated at 60 oBrix has the slowest drying rate of 25.2 g/hr. It was also revealed that samples subjected to 1 hour osmotic time have faster drying rates than those treated for 2 hours osmotic time.

Montmorillonite based artificial nacre prepared via a drying process

International Nuclear Information System (INIS)

Bennadji-Gridi, Fayza; Smith, Agnes; Bonnet, Jean-Pierre

2006-01-01

Taking advantage of the specific behaviour of Na/Ca montmorillonite in aqueous dispersion, textured films were prepared by progressive evaporation of dispersions with low concentrations of delaminated platelets. The increase of the concentration of ions during evaporation changes the nature of the clay mineral platelet face interactions from repulsive to attractive. After complete drying, a dense brick-like structure is obtained when a sodium salt is used as deflocculant. The bending strength of the textured film is strongly affected by cracks formation during drying, specially when the sample thickness increases. After optimisation, crack-free textured samples with a 140 μm thickness, 20 cm x 25 cm area and 120 MPa bending strength were obtained

Effect of Temperature, Time, and Material Thickness on the Dehydration Process of Tomato

Directory of Open Access Journals (Sweden)

A. F. K. Correia

2015-01-01

Full Text Available This study aimed to evaluate the effects of temperature, time, and thickness of tomatoes fruits during adiabatic drying process. Dehydration, a simple and inexpensive process compared to other conservation methods, is widely used in the food industry in order to ensure a long shelf life for the product due to the low water activity. This study aimed to obtain the best processing conditions to avoid losses and keep product quality. Factorial design and surface response methodology were applied to fit predictive mathematical models. In the dehydration of tomatoes through the adiabatic process, temperature, time, and sample thickness, which greatly contribute to the physicochemical and sensory characteristics of the final product, were evaluated. The optimum drying conditions were 60°C with the lowest thickness level and shorter time.

Carbon behavior in the cyclic operation of dry desulfurization process for oxy-fuel integrated gasification combined cycle power generation

International Nuclear Information System (INIS)

Kobayashi, Makoto; Akiho, Hiroyuki

2016-01-01

Highlights: • Power plant with semi-closed gas turbine and O_2–CO_2 coal gasifier was studied. • Dry gas sulfur removal sorbent was improved for durability to carbon deposition. • The improved sorbent showed very low amount of deposited carbon during operation. • The sorbent is regenerable to be used repeatedly in the cyclic operation. • The sorbent exhibited high sulfur-removal performance in the cyclic operation. - Abstract: The dry sulfur-removal process is essential to provide suitable syngas treatment for the oxy-fuel integrated gasification combined cycle power generation plant. It is required that the dry sulfur-removal process to be durable to the carbon deposition due to syngas containing high concentration of carbon monoxide in addition to achieve sufficient performance for sulfur removal. Zinc ferrite sorbent is the most promising candidate for the dry sulfur-removal process. The sorbent was improved to enhance durability to the carbon deposition by modifying preparation. The improved sorbent was prepared from sulfates as the raw materials of zinc ferrite, while the former sorbent was using nitrates as the raw materials. The improved sorbent as well as the former sorbent were evaluated on the performance and carbon deposition tendency in oxy-fuel syngas condition in a fixed bed reactor at elevated pressure and temperature. The results expressed that the improved sorbent has higher desulfurization performance and durability to carbon deposition in the condition expected for cyclic operation of the sulfur-removal process in comparison with the former sorbent. The improved sorbent possessed the superior desulfurization performance as well as the capability for inhibit carbon deposition in the oxy-fuel syngas conditions. The results confirmed the enhanced feasibility of the dry sulfur-removal process by utilizing the improved sorbent.

Advanced Drying Process for Lower Manufacturing Cost of Electrodes

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Iftikhar [Lambda Technologies, Inc., Morrisville, NC (United States); Zhang, Pu [Lambda Technologies, Inc., Morrisville, NC (United States)

2016-11-30

For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much faster than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying of

Use of a soft sensor for the fast estimation of dried cake resistance during a freeze-drying cycle.

Science.gov (United States)

Bosca, Serena; Barresi, Antonello A; Fissore, Davide

2013-07-15

This paper deals with the determination of dried cake resistance in a freeze-drying process using the Smart Soft Sensor, a process analytical technology recently proposed by the authors to monitor the primary drying stage of a freeze-drying process. This sensor uses the measurement of product temperature, a mathematical model of the process, and the Kalman filter algorithm to estimate the residual amount of ice in the vial as a function of time, as well as the coefficient of heat transfer between the shelf and the product and the resistance of the dried cake to vapor flow. It does not require expensive (additional) hardware in a freeze-dryer, provided that thermocouples are available. At first, the effect of the insertion of the thermocouple in a vial on the structure of the product is investigated by means of experimental tests, comparing both sublimation rate and cake structure in vials with and without thermocouple. This is required to assess that the temperature measured by the thermocouple is the same of the product in the non-monitored vials, at least in a non-GMP environment, or when controlled nucleation methods are used. Then, results about cake resistance obtained in an extended experimental campaign with aqueous solutions containing different excipients (sucrose, mannitol and polyvinylpyrrolidone), processed in various operating conditions, are presented, with the goal to point out the accuracy of the proposed methodology. Copyright © 2013 Elsevier B.V. All rights reserved.

Thickness effects of yttria-doped ceria interlayers on solid oxide fuel cells

Science.gov (United States)

Fan, Zeng; An, Jihwan; Iancu, Andrei; Prinz, Fritz B.

2012-11-01

Determining the optimal thickness range of the interlayed yttria-doped ceria (YDC) films promises to further enhance the performance of solid oxide fuel cells (SOFCs) at low operating temperatures. The YDC interlayers are fabricated by the atomic layer deposition (ALD) method with one super cycle of the YDC deposition consisting of 6 ceria deposition cycles and one yttria deposition cycle. YDC films of various numbers of ALD super cycles, ranging from 2 to 35, are interlayered into bulk fuel cells with a 200 um thick yttria-stabilized zirconia (YSZ) electrolyte. Measurements and analysis of the linear sweep voltammetry of these fuel cells reveal that the performance of the given cells is maximized at 10 super cycles. Auger elemental mapping and X-ray photoelectron spectroscopy (XPS) techniques are employed to determine the film completeness, and they verify 10 super cycles of YDC to be the critical thickness point. This optimal YDC interlayer condition (6Ce1Y × 10 super cycles) is applied to the case of micro fuel cells as well, and the average performance enhancement factor is 1.4 at operating temperatures of 400 and 450 °C. A power density of 1.04 W cm-2 at 500 °C is also achieved with the optimal YDC recipe.

Drying of lucuma (Pouteria obovata) using the technique of Refracting WindowTM

OpenAIRE

Diego Gamboa; Deiner Ibáñez; Marcela Meléndez; Edgar Paredes; Raúl Siche

2014-01-01

Lucuma is a fruit that is experiencing a growing trend in commercial ground into flour for use in the food industry. This study aimed to obtain lucuma flour using the method of refractive window drying and evaluate the effect of the thickness of lucuma pulp and drying time on flour moisture and color. It was used a Composite Design Central Rotary (DCCR) with time between 10 and 50 min and the thickness between 1 and 3 mm. A fixed temperature of 95 °C and mylar film (metallized polyethylene te...

Flexible, Transparent, Thickness-Controllable SWCNT/PEDOT:PSS Hybrid Films Based on Coffee-Ring Lithography for Functional Noncontact Sensing Device

KAUST Repository

Tai, Yanlong

2015-12-08

Flexible transparent conductive films (FTCFs) as the essential components of the next generation of functional circuits and devices are presently attracting more attention. Here, a new strategy has been demonstrated to fabricate thickness-controllable FTCFs through coffee ring lithography (CRL) of single-wall carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS) hybrid ink. The influence of ink concentration and volume on the thickness and size of hybrid film has been investigated systematically. Results show that the final FTCFs present a high performance, including a homogeneous thickness of 60-65 nm, a sheet resistance of 1.8 kohm/sq, a visible/infrared-range transmittance (79%, PET = 90%), and a dynamic mechanical property (>1000 cycle, much better than ITO film), respectively, when SWCNT concentration is 0.2 mg/mL, ink volume is 0.4 μL, drying at room temperature. Moreover, the benefits of these kinds of FTCFs have been verified through a full transparent, flexible noncontact sensing panel (3 × 4 sensing pixels) and a flexible battery-free wireless sensor based on a humidity sensing mechanism, showing excellent human/machine interaction with high sensitivity, good stability, and fast response/recovery ability. © 2015 American Chemical Society.

Flexible, Transparent, Thickness-Controllable SWCNT/PEDOT:PSS Hybrid Films Based on Coffee-Ring Lithography for Functional Noncontact Sensing Device

KAUST Repository

Tai, Yanlong; Yang, Zhen Guo

2015-01-01

Flexible transparent conductive films (FTCFs) as the essential components of the next generation of functional circuits and devices are presently attracting more attention. Here, a new strategy has been demonstrated to fabricate thickness-controllable FTCFs through coffee ring lithography (CRL) of single-wall carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS) hybrid ink. The influence of ink concentration and volume on the thickness and size of hybrid film has been investigated systematically. Results show that the final FTCFs present a high performance, including a homogeneous thickness of 60-65 nm, a sheet resistance of 1.8 kohm/sq, a visible/infrared-range transmittance (79%, PET = 90%), and a dynamic mechanical property (>1000 cycle, much better than ITO film), respectively, when SWCNT concentration is 0.2 mg/mL, ink volume is 0.4 μL, drying at room temperature. Moreover, the benefits of these kinds of FTCFs have been verified through a full transparent, flexible noncontact sensing panel (3 × 4 sensing pixels) and a flexible battery-free wireless sensor based on a humidity sensing mechanism, showing excellent human/machine interaction with high sensitivity, good stability, and fast response/recovery ability. © 2015 American Chemical Society.

Thin-layer catalytic far-infrared radiation drying and flavour of tomato slices

Directory of Open Access Journals (Sweden)

Ernest Ekow Abano

2014-06-01

Full Text Available A far-infrared radiation (FIR catalytic laboratory dryer was designed by us and used to dry tomato. The kinetics of drying of tomato slices with FIR energy was dependent on both the distance from the heat source and the sample thickness. Numerical evaluation of the simplified Fick’s law for Fourier number showed that the effective moisture diffusivity increased from 0.193×10–9 to 1.893×10–9 m2/s, from 0.059×10–9 to 2.885×10–9 m2/s, and, from 0.170×10–9 to 4.531×10–9 m2/s for the 7, 9, and 11 mm thick slices as moisture content decreased. Application of FIR enhanced the flavour of the dried tomatoes by 36.6% when compared with the raw ones. The results demonstrate that in addition to shorter drying times, the flavour of the products can be enhanced with FIR. Therefore, FIR drying should be considered as an efficient drying method for tomato with respect to minimization of processing time, enhancement in flavour, and improvements in the quality and functional property of dried tomatoes.

Effect of Adding Sugarcane Bagasse and Filter Cake and Wetting and Drying Cycles on Pre-Compaction Stress of Soil

Directory of Open Access Journals (Sweden)

Z Nemati

2018-03-01

Full Text Available Introduction The compaction of soil by agricultural equipment has become a matter of increasing concern because compaction of arable lands may reduce crop growth and yield, and it also has environmental impacts. In nature, soils could be compacted due to its own weights, external loads and internal forces as a result of wetting and drying processes. Soil compaction in sugarcane fields usually occurs due to mechanized harvesting operations by using heavy machinery in wet soils. Adding plant residues to the soil can improve soil structure. To improve soil physical quality of sugarcane fields, it might be suggested to add the bagasse and filter cake, which are the by-products of the sugar industry, to the soils. When a soil has been compacted by field traffic or has settled owing to natural forces, a threshold stress is believed to exist such that loadings inducing lower than the threshold cause little additional compaction, whilst loadings inducing greater stresses than the threshold cause much additional compaction. This threshold is called pre-compaction stress (σpc. The σpc is considered as an index of soil compactibility, the maximum pressure a soil has experienced in the past (i.e. soil management history, and the maximum major principal stress a soil can resist without major plastic deformation and compaction. Therefore, the main objective of this study was to investigate the effects of wetting and drying cycles, soil water content, residues type and percent on stress at compaction threshold (σpc. Materials and Methods In this research, the effect of adding sugarcane residues (i.e., bagasse and filter cake with two different rates (1 and 2% on pre-compaction stress (σpc in a silty clay loam soil which was prepared at two relative water contents of 0.9PL (PL= plastic limit, moist and 1.1PL (wet with or without wetting and drying cycles. This study was conducted using a factorial experiment in a completely randomized design with three

Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles

Directory of Open Access Journals (Sweden)

Sukon Phanichphant

2007-02-01

Full Text Available ZnO nanoparticles were produced by flame spray pyrolysis (FSP using zincnaphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%. The particleproperties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced bymixing the particles into an organic paste composed of terpineol and ethyl cellulose as avehicle binder and were fabricated by doctor-blade technique with various thicknesses (5,10, 15 μm. The morphology of the sensing films was analyzed by SEM and EDS analyses.The gas sensing characteristics to ethanol (25-250 ppm were evaluated as a function of filmthickness at 400°C in dry air. The relationship between thickness and ethanol sensingcharacteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes wereinvestigated. The effects of film thickness, as well as the cracking phenomenon, though,many cracks were observed for thicker sensing films. Crack widths increased withincreasing film thickness. The film thickness, cracking and ethanol concentration havesignificant effect on the sensing characteristics. The sensing characteristics with variousthicknesses were compared, showing the tendency of the sensitivity to ethanol decreasedwith increasing film thickness and response time. The relationship between gas sensingproperties and film thickness was discussed on the basis of diffusively and reactivity of thegases inside the oxide films. The thinnest sensing film (5 μm showed the highest sensitivityand the fastest response time (within seconds.

Kinetics of varnish long-term drying process monitored by a heterogeneous optical sensor system

International Nuclear Information System (INIS)

Saccon, F A M; De Oliveira, F M D R; Ribas, M O; Zambianchi, P Jr; Muller, M; Fabris, J L

2013-01-01

The drying process of an acrylic varnish film was monitored over 24 h by a heterogeneous optical sensor system. The system employs a fibre optic transducer based on Bragg gratings and optical coherence tomography, operating respectively around 1.55 and 1.3 µm. The sensor is able to provide information about the temporal evolution of temperature, mechanical deformation, thickness and average refractive index of the coating during the drying process. Resolutions for these optically measured parameters are 0.05 °C (temperature), 0.5 µε (strain), 1.5 µm (thickness) and 0.004 (refractive index). Besides, the sensor can detect the growth of a surface dry skin and supply information about the film bulk uniformity. A model for the mass loss of solvent as the drying process evolves is also discussed. (paper)

The ocular surface and tear film and their dysfunction in dry eye disease.

Science.gov (United States)

Rolando, M; Zierhut, M

2001-03-01

The ocular surface, tear film, lacrimal glands, and eyelids act as a functional unit to preserve the quality of the refractive surface of the eye and to resist injury and protect the eye against changing bodily and environmental conditions. Events that disturb the homeostasis of this functional unit can result in a vicious cycle of ocular surface disease. The tear film is the most dynamic structure of the functional unit, and its production and turnover is essential to maintaining the health of the ocular surface. Classically, the tear film is reported to be composed of three layers: the mucin, aqueous, and lipid layers. The boundaries and real thickness of such layers is still under discussion. A dysfunction of any of these layers can result in dry eye disease.

On the production of thick pellicles of Kodak NTB-3 nuclear track emulsion

International Nuclear Information System (INIS)

Claesson, G.; Soederstroem, K.; Ingelman, G.

1980-11-01

We describe procedures for making thick pellicles of Kodak NTB-3 nuclear emulsion. The technique has successfully been applied for the production of a 15 liter emulsion target, consisting of 600 μm thick pellicles. Melting and pouring of the gel is discussed as well as the conditions during the drying and processing. (author)

The process research of drying UF4 by microwave

International Nuclear Information System (INIS)

Wen Guo; Wang Yunbo; Liu Long

2010-01-01

This paper make use of microwave to dry UF 4 filter cake, the aim is desorbed adsorption water. The research focus on such process conditions, boat material, thickness of filter cake, drying time, setting temperature, heating power and so on. the research of desorption crystal water of UF 4 that dried by microwave in fixed bed .When UF 4 drying by microwave and claiming by fixed bed, the qualified UF 4 powder is prepared. The research is shown that microwave can desorbs adsorption water which contain in UF 4 filter cake. There is a stable water contents in UF 4 after drying, and the sum of two members is less. After drying by microwave and claiming by fixed bed, the contents of water, UO 2 and UO 2 F 2 are all according to the quality standard. (authors)

A comparison of Zircaloy oxide thicknesses on Millstone-3 and North Anna-1 PWR fuel cladding

International Nuclear Information System (INIS)

Polley, M.V.; Evans, H.E.

1993-08-01

High concentrations of lithium in the coolant may enhance the corrosion rate of Zircaloy fuel cladding. In the present work, oxide thicknesses on fuel cladding from the Millstone 3 PWR were compared with those from the North Anna 1 PWR. The intention was to identify whether the higher lithium levels (up to 3.5 ppM) in the Millstone 3 primary coolant during cycles 2 and 3 led to significantly greater oxidation rates than in North Anna 1 which operated generally with lithium levels lower than 2.2 ppM. The comparisons were made by comparing the measurements with code predictions of Zircaloy oxidation in order to factor out the effect of operational variables on the oxide thicknesses achieved. Overall, Millstone 3 oxide thicknesses were found to be approximately 14% greater than North Anna 1 values. However, approximately 29% lower oxide thicknesses were found on reload Millstone 3 rods exposed to one cycle of elevated lithium chemistry than on Millstone 3 initial fuel exposed to one cycle of normal lithium chemistry during cycle 1. Furthermore, oxide thicknesses on Millstone 3 rods exposed to two cycles of elevated lithium chemistry were approximately 36% lower than on Millstone 3 rods exposed to one cycle of normal lithium chemistry plus one cycle of elevated lithium chemistry. Therefore, it cannot be concluded that elevated lithium operation in Millstone 3 led to enhanced Zircaloy fuel clad corrosion

The state of the art on the dry decontamination technologies applicable to highly radioactive contaminants and their needs for the national nuclear fuel cycle developent

International Nuclear Information System (INIS)

Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. H.; Chol, W. K.; Kim, G. N.; Moon, J. K.

2000-12-01

This report is intended to establish their needs to support the dry decontamination activities applicable to highly radioactive contaminants based on the requirement of technologies development suggested from the national nuclear fuel cycle projects, such as DUPIC, advanced spent fuel management and long-lived radionuclides conversion. The technology needs associated with decontamination addressed the requirements associated with the efficiency of decontamination technology, the reduction of secondary wastes, applicabilities and the remote operation. And also, Characterization and decontamination technologies for various contaminants are reviewed and analysed. Based on the assessment, Unit dry decontamination processes are selected and the schematic flow diagram for decontamination of highly radioactive contaminants

The state of the art on the dry decontamination technologies applicable to highly radioactive contaminants and their needs for the national nuclear fuel cycle developent

Energy Technology Data Exchange (ETDEWEB)

Oh, Won Zin; Lee, K.W.; Won, H.J.; Jung, C.H.; Chol, W.K.; Kim, G.N.; Moon, J.K

2000-12-01

This report is intended to establish their needs to support the dry decontamination activities applicable to highly radioactive contaminants based on the requirement of technologies development suggested from the national nuclear fuel cycle projects, such as DUPIC, advanced spent fuel management and long-lived radionuclides conversion. The technology needs associated with decontamination addressed the requirements associated with the efficiency of decontamination technology, the reduction of secondary wastes, applicabilities and the remote operation. And also, Characterization and decontamination technologies for various contaminants are reviewed and analysed. Based on the assessment, Unit dry decontamination processes are selected and the schematic flow diagram for decontamination of highly radioactive contaminants.

Comparison of choroidal thickness using swept-source and spectral-domain optical coherence tomography in normal Indian eyes.

Science.gov (United States)

Narendran, Siddharth; Manayath, George; Venkatapathy, Narendran

2018-01-01

Choroidal thickness measurements are reported to differ between spectral-domain optical coherence tomography (SD-OCT) and swept-source OCT (SS-OCT). The aim of this study was to assess the comparability of choroidal thickness measurements using SS-OCT and SD-OCT devices among normal participants. This was a prospective study of 31 (62 eyes) normal participants. Choroidal imaging was performed sequentially with the Spectralis OCT (SD-OCT) and the deep range imaging OCT (DRI OCT-1) (SS-OCT) using standardized imaging protocols. The subfoveal choroidal thickness (SFChT) was measured manually by two masked retinal specialists. Paired t -tests and intraclass correlation coefficients (ICCs) were used to compare the measurements. The mean SFChT was 319.5 μm and 325.3 μm for DRI OCT-1 and Spectralis OCT, respectively ( P = 0.001), with a mean difference of 5.9 with ICC of 0.97. The mean difference in choroidal thickness between the OCT devices was larger among eyes with choroidal thickness > 350 μm compared with eyes with thinner choroids (8.0 μm vs. 4.7 μm). SFChT measurements are comparable between DRI OCT-1 and Spectralis OCT. The variability between the devices increases in thicker choroids.

Simulating the Current Water Cycle with the NASA Ames Mars Global Climate Model

Science.gov (United States)

Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Brecht, A. S.; Urata, R. A.; Montmessin, F.

2017-12-01

The water cycle is a critical component of the current Mars climate system, and it is now widely recognized that water ice clouds significantly affect the nature of the simulated water cycle. Two processes are key to implementing clouds in a Mars global climate model (GCM): the microphysical processes of formation and dissipation, and their radiative effects on atmospheric heating/cooling rates. Together, these processes alter the thermal structure, change the atmospheric dynamics, and regulate inter-hemispheric transport. We have made considerable progress using the NASA Ames Mars GCM to simulate the current-day water cycle with radiatively active clouds. Cloud fields from our baseline simulation are in generally good agreement with observations. The predicted seasonal extent and peak IR optical depths are consistent MGS/TES observations. Additionally, the thermal response to the clouds in the aphelion cloud belt (ACB) is generally consistent with observations and other climate model predictions. Notably, there is a distinct gap in the predicted clouds over the North Residual Cap (NRC) during local summer, but the clouds reappear in this simulation over the NRC earlier than the observations indicate. Polar clouds are predicted near the seasonal CO2 ice caps, but the column thicknesses of these clouds are generally too thick compared to observations. Our baseline simulation is dry compared to MGS/TES-observed water vapor abundances, particularly in the tropics and subtropics. These areas of disagreement appear to be a consistent with other current water cycle GCMs. Future avenues of investigation will target improving our understanding of what controls the vertical extent of clouds and the apparent seasonal evolution of cloud particle sizes within the ACB.

Gamma irradiation for disinfestation of salted and dried fish

International Nuclear Information System (INIS)

Loaharanu, S.

1975-01-01

About 60-70% of commercially salted and dried fish were found to be infested by flies of 6 different species, i.e. the Cheese skipper (Piophila casei, L.) the Bronze bottle fly (Paenicia cuprina), the Screw worm fly (Chrysomya megacephala, Fab.), the Red-tailed flesh fly (Sarcophaga haemorrhoidalis, Fallen), Lucilia illustris, Meigen and Chrysomya marginalis, Weidemann. Larvae of the Cheese skipper were found to be the least radiation-sensitive, as 225 krad was required to prevent 99% of the larvae from developing into pupae. This dose was completely lethal to other developmental stages of the Cheese skipper and to all stages of other species. Irradiation at this doselevel also has some beneficial microbiological effects. Doses between 3 and 12,5 krad prevented larvae of all insects mentioned above from reaching the adult stage, though they did not inhibit the transition into the pupal form. No significant difference was observed on the organoleptic properties between salted and dried mackerel and Pla salid (Trichogaster pectoralis, Regan), a fresh water fish, irradiated up to 300 krad and those of untreated samples when tested up to 6 months of storage time at room temperature. Polypropylene bags of 0,13 and 0,20 mm thickness and polyethylene bags of 0,20 mm thickness could prevent re-infestation of the samples. Transportation tests by truck for a distance of 800 km revealed that both polypropylene and polyethylene bags of 0,13 and 0,20 mm thickness were suitable to package the mackerel samples but only polypropylene bags of 0,20 mm thickness were sufficient to protect the Pla salid samples. It appeared that salted and dried mackerel irradiated up to 300 krad and stored for 4 months was not considered rancid. No change in fat, protein and ash contents of irradiated samples was observed. It was concluded that gamma irradation could be considered as an effective method for disinfesting and preserving salted and dried fish. (author)

Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

Science.gov (United States)

Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

2015-10-01

Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

Effect of pre-drying treatments on solution-coated organic thin films for active-matrix organic light-emitting diodes

Science.gov (United States)

Shin, Dongkyun; Hong, Ki-Young; Park, Jongwoon

2017-12-01

Due to capillary rise, organic thin films fabricated by solution coating exhibit the concave thickness profile. It is found that the thickness and emission uniformities within pixels vary depending sensitively on the pre-drying treatment that has been done before hard bake. We investigate its effect on the film quality by varying the temperature, time, pressure, fluid flow-related solute concentration, and evaporation-related solvent. To this end, we carry out spin coatings of a non-aqueous poly(N-vinylcarbazole) (PVK) for a hole transporting blanket layer. With a low-boiling-point (BP) organic solvent, the pre-drying makes no significant impact on the thickness profiles. With a high-BP organic solvent, the PVK films pre-dried in a vacuum for a sufficient time exhibit very uniform light emission in the central region, but non-emission phenomenon near the perimeter of pixels. It is addressed that such a non-emission phenomenon can be suppressed to some extent by decreasing the vacuum pressure. However, the rapid evaporation by heat conduction during the pre-drying degrades the thickness uniformity due to a rapid microflow of solute from the edge to the center. No further enhancement in the thickness uniformity is obtained by varying the solute concentration and using a mixture of low- and high-BP solvents.

Development of an oven drying protocol to improve biodiesel production for an indigenous chlorophycean microalga Scenedesmus sp.

Science.gov (United States)

Bagchi, Sourav Kumar; Rao, Pavuluri Srinivasa; Mallick, Nirupama

2015-03-01

Drying of wet algal biomass is a major bottleneck in viable commercial production of the microalgal biodiesel. In the present investigation, an oven drying protocol was standardized for drying of wet Scenedesmus biomass at 60, 80 and 100°C with initial sample thickness of 5.0, 7.5 and 10.0mm. The optimum drying temperature was found to be 80°C with a maximum lipid yield of 425.0±5.9mgg(-1) at 15h drying time for 5.0mm thick samples with 0.033kWh power consumption. Partial drying at 80°C up to 10% residual moisture content was efficient showing 93% lipid recovery with 8h drying and a power consumption of 0.017kWh. Scenedesmus biomass was also found to be rich in saturated and mono-unsaturated fatty acids. Thus, the drying protocol demonstrates its suitability to improve the downstream processing of biodiesel production by significantly lowering the power consumption and the drying time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of Factors Associated With the Tear Film Lipid Layer Thickness in Normal Eyes and Patients With Dry Eye Syndrome.

Science.gov (United States)

Jung, Ji Won; Park, Si Yoon; Kim, Jin Sun; Kim, Eung Kweon; Seo, Kyoung Yul; Kim, Tae-Im

2016-08-01

To determine the effects of clinical variables, including age, sex, history of refractive or cataract surgery, contact lens use, and ocular surface and meibomian gland parameters on the lipid layer thickness (LLT) in normal subjects and patients with dry eye syndrome (DES). A total of 64 normal subjects and 326 patients with DES were enrolled, and they underwent measurements of LLT with a LipiView interferometer and tear meniscus height using optical coherence tomography, tear film break-up time (TBUT) determination, ocular surface staining, Schirmer's test, examination of the lid margins and meibomian glands, and assessment using the Ocular Surface Disease Index (OSDI). In normal subjects, the median (range) LLT was 67 (33-100) nm, and age was the only factor that was significantly associated with LLT (β = 0.678, P = 0.028). In patients with DES, the median (range) LLT was 84 (20-100) nm, and 79.0% of the participants fulfilled the diagnostic criteria for meibomian gland dysfunction (MGD). In a multivariate analysis, increased age and female sex were significantly related to increased LLT (β = 0.282, P = 0.005 and β = 11.493, P < 0.001), and hypersecretory MGD and lid margin inflammation were independently associated with increased LLT (β = 11.299, P = 0.001 and β = 12.747, P = 0.001). Lipid layer thickness measurements using a new interferometer are significantly affected by demographic factors such as age, sex, ocular surgical history, and MGD type. Therefore, all of these factors must be considered in the diagnosis of ocular surface diseases.

Vacuum drying of apples (cv. Golden Delicious): drying characteristics, thermodynamic properties, and mass transfer parameters

Science.gov (United States)

Nadi, Fatemeh; Tzempelikos, Dimitrios

2018-01-01

In this work, apples of cv. Golden Delicious were cut into slices that were 5 and 7 mm thick and then vacuum dried at 50, 60 and 70 °C and pressure of 0.02 bar. The thin layer model drying kinetics was studied, and mass transfer properties, specifically effective moisture diffusivity and convective mass transfer coefficient, were evaluated using the Fick's equation of diffusion. Also, thermodynamic parameters of the process, i.e. enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG), were determined. Colour properties were evaluated as one of the important indicators of food quality and marketability. Determination of mass transfer parameters and thermodynamic properties of vacuum dried apple slices has not been discussed much in the literature. In conclusion, the Nadi's model fitted best the observed data that represent the drying process. Thermodynamic properties were determined based on the dependence of the drying constant of the Henderson and Pabis model on temperature, and it was concluded that the variation in drying kinetics depends on the energy contribution of the surrounding environment. The enthalpy and entropy diminished, while the Gibbs free energy increased with the increase of the temperature of drying; therefore, it was possible to verify that variation in the diffusion process in the apple during drying depends on energetic contributions of the environment. The obtained results showed that diffusivity increased for 69%, while the mass transfer coefficient increase was even higher, 75%, at the variation of temperature of 20 °C. The increase in the dimensionless Biot number was 20%.

Multimodal imaging of ocular surface of dry eye subjects

Science.gov (United States)

Zhang, Aizhong; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Aquavella, James V.; Zavislan, James M.

2016-03-01

To study the relationship between the corneal lipid layer and the ocular surface temperature (OST), we conducted a clinical trial for 20 subjects. Subjects were clinically screened prior to the trial. Of the 20 subjects, 15 have Meibomian gland dysfunction (MGD), and 5 have aqueous-deficient dry eye (ADDE). A custom, circularly polarized illumination video tearscope measured the lipid layer thickness of the ocular tear film. A long-wave infrared video camera recorded the dynamic thermal properties of the ocular team film. The results of these two methods were analyzed and compared. Using principal component analysis (PCA) of the lipid layer distribution, we find that the 20 subjects could be categorized into five statistically significant groups, independent of their original clinical classification: thin (6 subjects), medium (5 subjects), medium and homogenous (3 subjects), thick (4 subjects), and very thick (2 subjects) lipids, respectively. We also conducted PCA of the OST data, and recategorized the subjects into two thermal groups by k-means clustering: one includes all ADDE subjects and some MGD subjects; the other includes the remaining MGD subjects. By comparing these two methods, we find that dry eye subjects with thin ( 40 nm), there is no strong correlation between the lipid layer thickness and heterogeneity and the OST patterns.

Fuel cycle studies

International Nuclear Information System (INIS)

Anon.

1978-01-01

Programs are being conducted in the following areas: advanced solvent extraction techniques, accident consequences, fuel cycles for nonproliferation, pyrochemical and dry processes, waste encapsulation, radionuclide transport in geologic media, hull treatment, and analytical support for LWBR

Analysis of the use of waste heat obtained from coal-fired units in Organic Rankine Cycles and for brown coal drying

International Nuclear Information System (INIS)

Łukowicz, Henryk; Kochaniewicz, Andrzej

2012-01-01

The ever-increasing restrictions on greenhouse gas emissions have created a need for new energy technologies. One way to meet these new requirements is to optimise the efficiency of power units. This paper presents two energy technologies that, if used, will increase the efficiency of electricity generation. One of the most effective ways to improve the efficiency of brown coal-fired units is by drying the coal that is fed into the boiler. Here, we describe a technology that uses the waste heat obtained from exhaust gases. This paper also presents an analysis of the feasibility of and potential for using waste heat obtained from exhaust gases to feed Organic Rankine Cycles (ORCs). Several low-temperature working fluids were considered, which were selected based on properties that were best suited for these types of cycles. The impact of these working fluids on the efficiency and capacity of the ORC was also examined. The calculations for ORCs fed with waste heat obtained from exhaust gases from hard coal- and brown coal-fired boilers were compared. -- Highlights: ► We describe a technology that uses the waste heat obtained from exhaust gases. ► The impact of using different working fluids with a low boiling point is examined. ► We describe integrating the ORC with the power unit. ► The use of waste heat from boiler exhaust gases to dry brown coal is proposed. ► We demonstrate a possible increase in power unit efficiency.

A method for reducing the sloughing of thick blood films for malaria diagnosis.

Science.gov (United States)

Norgan, Andrew P; Arguello, Heather E; Sloan, Lynne M; Fernholz, Emily C; Pritt, Bobbi S

2013-07-08

The gold standard for malaria diagnosis is the examination of thick and thin blood films. Thick films contain 10 to 20 times more blood than thin films, correspondingly providing increased sensitivity for malaria screening. A potential complication of thick film preparations is sloughing of the blood droplet from the slide during staining or rinsing, resulting in the loss of sample. In this work, two methods for improving thick film slide adherence ('scratch' (SCM) and 'acetone dip' (ADM) methods) were compared to the 'standard method' (SM) of thick film preparation. Standardized blood droplets from 26 previously examined EDTA whole blood specimens (22 positive and four negative) were concurrently spread on glass slides using the SM, ADM, and SCM. For the SM and ADM prepared slides, the droplet was gently spread to an approximate 22 millimeters in diameter spot on the slide using the edge of a second glass slide. For the SCM, the droplet was spread by carefully grinding (or scratching) it into the slide with the point of a second glass slide. Slides were dried for one hour in a laminar flow hood. For the ADM, slides were dipped once in an acetone filled Coplin jar and allowed to air dry. All slides were then Giemsa-stained and examined in a blinded manner. Adherence was assessed by blinded reviewers. No significant or severe defects were observed for slides prepared with the SCM. In contrast, 8 slides prepared by the ADM and 3 prepared using the SM displayed significant or severe defects. Thick films prepared by the three methods were microscopically indistinguishable and concordant results (positive or negative) were obtained for the three methods. Estimated parasitaemia of the blood samples ranged from 25 to 429,169 parasites/μL of blood. The SCM is an inexpensive, rapid, and simple method that improves the adherence of thick blood films to standard glass slides without altering general slide preparation, microscopic appearance or interpretability. Using the SCM

Parameters Optimization of Curtain Grouting Reinforcement Cycle in Yonglian Tunnel and Its Application

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Qingsong Zhang

2015-01-01

Full Text Available For practical purposes, the curtain grouting method is an effective method to treat geological disasters and can be used to improve the strength and permeability resistance of surrounding rock. Selection of the optimal parameters of grouting reinforcement cycle especially reinforcement cycle thickness is one of the most interesting areas of research in curtain grouting designs. Based on the fluid-structure interaction theory and orthogonal analysis method, the influence of reinforcement cycle thickness, elastic modulus, and permeability on water inflow of tunnel after grouting and stability of surrounding rock was analyzed. As to the water inflow of tunnel after grouting used as performance evaluation index of grouting reinforcement cycle, it can be concluded that the permeability was the most important factor followed by reinforcement cycle thickness and elastic modulus. Furthermore, pore water pressure field, stress field, and plastic zone of surrounding rock were calculated by using COMSOL software under different conditions of reinforcement cycle thickness. It also can be concluded that the optimal thickness of reinforcement cycle and permeability can be adopted as 8 m and 1/100 of the surrounding rock permeability in the curtain grouting reinforcement cycle. The engineering case provides a reference for similar engineering.

Exploratory radio-frequency/vacuum drying of three B.C. coastal softwoods

International Nuclear Information System (INIS)

Avramidis, S.; Zwick, R.L.

1992-01-01

Five exploratory drying runs were carried out in a commercial size (23 m3) radio-frequency/vacuum (RF/V) kiln. The species investigated were Pacific Coast hemlock, Douglas-fir, and western redcedar of different sizes and grades. Evaluation of the dried lumber showed that the three species can be dried in very short times with a low amount of degrade with the exception of clear cedar, which exhibited severe internal honeycombing; indicating the need to develop proper kiln schedules for this drying process. The thermodynamic and sensitivity analyses performed showed that above certain efficiency levels, RF/V drying is economical and fast. This finding was particularly true with lumber thicknesses over 8 cm

Scale-dependent variation in nitrogen cycling and soil fungal communities along gradients of forest composition and age in regenerating tropical dry forests.

Science.gov (United States)

Waring, Bonnie G; Adams, Rachel; Branco, Sara; Powers, Jennifer S

2016-01-01

Rates of ecosystem nitrogen (N) cycling may be mediated by the presence of ectomycorrhizal fungi, which compete directly with free-living microbes for N. In the regenerating tropical dry forests of Central America, the distribution of ectomycorrhizal trees is affected by succession and soil parent material, both of which may exert independent influence over soil N fluxes. In order to quantify these interacting controls, we used a scale-explicit sampling strategy to examine soil N cycling at scales ranging from the microsite to ecosystem level. We measured fungal community composition, total and inorganic N pools, gross proteolytic rate, net N mineralization and microbial extracellular enzyme activity at multiple locations within 18 permanent plots that span dramatic gradients of soil N concentration, stand age and forest composition. The ratio of inorganic to organic N cycling was correlated with variation in fungal community structure, consistent with a strong influence of ectomycorrhiza on ecosystem-scale N cycling. However, on average, > 61% of the variation in soil biogeochemistry occurred within plots, and the effects of forest composition were mediated by this local-scale heterogeneity in total soil N concentrations. These cross-scale interactions demonstrate the importance of a spatially explicit approach towards an understanding of controls on element cycling. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Dried fruit breadfruit slices by Refractive Window™ technique

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Diego F. Tirado

2016-01-01

Full Text Available A large amount of products are dried due several reasons as preservation, weight reduction and improvement of stability. However, on the market are not offered low-cost and high quality products simultaneously. Although there are effective methods of dehydrating foods such as freeze drying, which preserves the flavor, color and vitamins, they are poor accessibility technologies. Therefore, alternative processes are required to be efficient and economical. The aim of this research was compare drying kinetics of sliced of breadfruit (Artocarpus communis using the technique of Refractive Window® (VR with the tray drying. To carry out this study, sliced of 1 and 2 mm thick were used. Refractive window drying was performed with the water bath temperature to 92 °C; and tray drying at 62 °C and an air velocity of 0.52 m/s. During the Refractive window drying technique, the moisture content reached the lower than tray drying levels. Similarly it happened with samples of 1 mm, which, having a smaller diameter reached lower moisture levels than samples 2 mm. The higher diffusivities were obtained during drying sliced VR 1 and 2 mm with coefficients of 6.13 and 3.90*10-9 m2/s respectively.

Numerical predictions of dry oxidation of iron and low-carbon steel at moderately elevated temperatures

International Nuclear Information System (INIS)

Henshall, G.A.

1996-11-01

Wrought and cast low-carbon steel are candidate materials for the thick (e.g. 10 cm) outer barrier of nuclear waste packages being considered for use in the potential geological repository at Yucca Mountain. Dry oxidation is possible at the moderately elevated temperatures expected at the container surface (323-533 K or 50-260 C). Numerical predictions of dry oxidation damage were made based on experimental data for iron and low-carbon steel and parabolic oxidation theory. The Forward Euler method was implemented to integrate the parabolic rate law for arbitrary, complex temperature histories. Assuming growth of a defect-free, adherent oxide, the surface penetration of a low-carbon steel barrier following 5000 years of exposure to a severe, but repository-relevant, temperature history is predicted to be only about 0.127 mm, less than 0.13% of the expected container thickness of 10 cm. Allowing the oxide to spall upon reaching a critical thickness increases the predicted metal penetration values, but degradation is still computed to be negligible. Thus, dry oxidation is not expected to significantly degrade the performance of thick, corrosion allowance barriers constructed of low-carbon steel

Dry separation technology of transuranic elements

International Nuclear Information System (INIS)

Inoue, Tadashi

1999-01-01

The separation principle of transuranic elements (TRU) by a dry method, the separation technique of TRU from a high level waste solution and a dry recycle technology of LWR and FBR fuel cycle are explained. The dry method used molten salt and liquid metal. TRU and the rare earth elements in the molten salt (LiCl-KCl, LiCl-KCl/Cd and LiCl-KCl/Bi system) were separated by two methods such as the electrolytic refining and the reduction-extraction method. The former method separated 98% U, Np and Pu, but low Am. The latter method was able to separate more than 99.9% Np and Pu and 99.7% Am. (S.Y.)

Evaluation of a solar-powered organic Rankine cycle using dry organic working fluids

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Emily Spayde

2015-12-01

Full Text Available This paper presents a model to evaluate the performance of a solar-powered organic Rankine cycle (ORC. The system was evaluated in Jackson, MS, using five dry organic working fluids, R218, R227ea, R236ea, R236fa, and RC318. The purpose of this study is to investigate how hourly temperature change affects the electricity production and exergy destruction rates of the solar ORC, and to determine the effect of the working fluid on the proposed system. The system was also evaluated in Tucson, AZ, to investigate the effect of average hourly outdoor temperatures on its performance. The potential of the system to reduce primary energy consumption and carbon dioxide emissions is also investigated. A parametric analysis to determine how temperature and pressure of the organic working fluid, the solar collector area, and the turbine efficiency affect the electricity production is performed. Results show that the ORC produces the most electricity during the middle of the day, when the temperatures are the highest and when the solar collectors have the highest efficiency. Also, R-236ea is the working fluid that shows the best performance of the evaluated fluids. An economic analysis was performed to determine the capital cost available for the proposed system.

Drying of lucuma (Pouteria obovata using the technique of Refracting WindowTM

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Diego Gamboa

2014-06-01

Full Text Available Lucuma is a fruit that is experiencing a growing trend in commercial ground into flour for use in the food industry. This study aimed to obtain lucuma flour using the method of refractive window drying and evaluate the effect of the thickness of lucuma pulp and drying time on flour moisture and color. It was used a Composite Design Central Rotary (DCCR with time between 10 and 50 min and the thickness between 1 and 3 mm. A fixed temperature of 95 °C and mylar film (metallized polyethylene terephthalate as a refractory film of 0.1 mm was used. It was determined that the optimal conditions for lucuma flour (9.8% moisture with this technique is when the thickness was 1.3 mm and with a time of 15 minutes; in these conditions, the effective diffusivity of water is 2.53 E-7 m2 /s.

Monitoring of corrosion rates of Fe-Cu alloys under wet/dry condition in weakly alkaline environments

International Nuclear Information System (INIS)

Kim, Je Kyoung; Nishikata, Atsushi; Tsuru, Tooru

2002-01-01

When the steel, containing scrap elements like copper, is used as reinforcing steel bars for concrete, the steel is exposed to alkaline environments. in this study, AC impedance technique has been applied to the monitoring of corrosion rates of iron and several Fe-Cu (0.4, 10wt%) alloys in a wet-dry cycle condition. The wet-dry cycle was conducted by exposure to alternate conditions of 1 hour-immersion in a simulated pH10 concrete solution (Ca(OH) 2 ) containing 0.01M NaCl and 3 hour-drying at 298K and 50%RH. The corrosion rate of the iron is greatly accelerated by the wet-dry cycles. Because the active FeOOH species, which are produced by the oxidation of Fe(II, III)oxide in air during drying, act as very strong oxidants to the corrosion in the wet condition. As the drying progresses, iron shows a large increase in the corrosion rate and a small shift of the corrosion potential to the positive values. This can be explained by acceleration of oxygen transport through the thin electrolyte layer In contrast to iron, the Fe-Cu alloys show low corrosion rates and the high corrosion potentials in whole cycles

Crystallization of Trehalose in Frozen Solutions and its Phase Behavior during Drying

Energy Technology Data Exchange (ETDEWEB)

Sundaramurthi, Prakash; Patapoff, Thomas W.; Suryanarayanan, Raj (Genentech); (UMM)

2015-02-19

To study the crystallization of trehalose in frozen solutions and to understand the phase transitions during the entire freeze-drying cycle. Aqueous trehalose solution was cooled to -40 C in a custom-designed sample holder. The frozen solution was warmed to -18 C and annealed, and then dried in the sample chamber of the diffractometer. XRD patterns were continuously collected during cooling, annealing and drying. After cooling, hexagonal ice was the only crystalline phase observed. However, upon annealing, crystallization of trehalose dihydrate was evident. Seeding the frozen solution accelerated the solute crystallization. Thus, phase separation of the lyoprotectant was observed in frozen solutions. During drying, dehydration of trehalose dihydrate yielded a substantially amorphous anhydrous trehalose. Crystallization of trehalose, as trehalose dihydrate, was observed in frozen solutions. The dehydration of the crystalline trehalose dihydrate to substantially amorphous anhydrate occurred during drying. Therefore, analyzing the final lyophile will not reveal crystallization of the lyoprotectant during freeze-drying. The lyoprotectant crystallization can only become evident by continuous monitoring of the system during the entire freeze-drying cycle. In light of the phase separation of trehalose in frozen solutions, its ability to serve as a lyoprotectant warrants further investigation.

Application of freeze-drying technology in manufacturing orally disintegrating films.

Science.gov (United States)

Liew, Kai Bin; Odeniyi, Michael Ayodele; Peh, Kok-Khiang

2016-01-01

Freeze drying technology has not been maximized and reported in manufacturing orally disintegrating films. The aim of this study was to explore the freeze drying technology in the formulation of sildenafil orally disintegrating films and compare the physical properties with heat-dried orally disintegrating film. Central composite design was used to investigate the effects of three factors, namely concentration of carbopol, wheat starch and polyethylene glycol 400 on the tensile strength and disintegration time of the film. Heat-dried films had higher tensile strength than films prepared using freeze-dried method. For folding endurance, freeze-dried films showed improved endurance than heat-dried films. Moreover, films prepared using freeze-dried methods were thicker and had faster disintegration time. Formulations with higher amount of carbopol and starch showed higher tensile strength and thickness whereas formulations with higher PEG 400 content showed better flexibility. Scanning electron microscopy showed that the freeze-dried films had more porous structure compared to the heat-dried film as a result of the release of water molecule from the frozen structure when it was subjected to freeze drying process. The sildenafil film was palatable. The dissolution profiles of freeze-dried and heat-dried films were similar to Viagra® with f2 of 51.04 and 65.98, respectively.

Shear dilatancy and acoustic emission in dry and saturated granular materials

Science.gov (United States)

Brodsky, E. E.; Siman-Tov, S.

2017-12-01

Shearing of granular materials plays a strong role in naturally sheared systems as landslides and faults. Many works on granular flows have concentrated on dry materials, but relatively little work has been done on water saturated sands. Here we experimentally investigate dry versus saturated quartz-rich sand to understand the effect of the fluid medium on the rheology and acoustic waves emission of the sheared sand. The sand was sheared in a rotary shear rheometer under applied constant normal stress boundary at low (100 µm/s) to high (1 m/s) velocities. Mechanical, acoustic data and deformation were continuously recorded and imaged. For dry and water saturated experiments the granular volume remains constant for low shear velocities ( 10-3 m/s) and increases during shearing at higher velocities ( 1 m/s). Continuous imaging of the sheared sand show that the steady state shear band thickness is thicker during the high velocity steps. No significant change observed in the shear band thickness between dry and water saturated experiments. In contrast, the amount of dilation during water saturated experiments is about half the value measured for dry material. The measured decrease cannot be explained by shear band thickness change as such is not exist. However, the reduced dilation is supported by our acoustic measurements. In general, the event rate and acoustic event amplitudes increase with shear velocity. While isolated events are clearly detected during low velocities at higher the events overlap, resulting in a noisy signal. Although detection is better for saturated experiments, during the high velocity steps the acoustic energy measured from the signal is lower compared to that recorded for dry experiments. We suggest that the presence of fluid suppresses grain motion and particles impacts leading to mild increase in the internal pressure and therefore for the reduced dilation. In addition, the viscosity of fluids may influence the internal pressure via

Influence of Dry Cleaning on the Electrical Resistance of Screen Printed Conductors on Textiles

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Kazani Ilda

2016-09-01

Full Text Available Electrically conducting inks were screen printed on various textile substrates. The samples were dry cleaned with the usual chemicals in order to investigate the influence of the mechanical treatment on the electrical conductivity. It was found that dry cleaning has a tremendous influence on this electrical conductivity. For several samples, it is observed that the electrical resistance increases with the square of the number of dry cleaning cycles. In order to explain this observation a theoretical model and a numerical simulation have been carried out, by assuming that dry cleaning cycles introduce a crack in the conducting layer. The theoretical analysis and the numerical analysis both confirmed the experimental observations.

Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico.

Science.gov (United States)

de la Rosa-Manzano, Edilia; Andrade, José Luis; García-Mendoza, Ernesto; Zotz, Gerhard; Reyes-García, Casandra

2015-12-01

Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5 m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH(+)) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH(+) and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of

In situ observation of initial rust formation process on carbon steel under Na2SO4 and NaCl solution films with wet/dry cycles using synchrotron radiation X-rays

International Nuclear Information System (INIS)

Yamashita, M.; Konishi, H.; Kozakura, T.; Mizuki, J.; Uchida, H.

2005-01-01

Atmospheric corrosion of steel proceeds under thin electrolyte film formed by rain and dew condensation followed by wet and dry cycles. It is said that rust layer formed on steel as a result of atmospheric corrosion strongly affects the corrosion behavior of steel. The effect of environmental corrosiveness on the formation process and structure of the rust layer is, however, not clear to date. In this study, in situ observation of the rusting process of a carbon steel covered with a thin film of Na 2 SO 4 or NaCl solution was performed under a wet/dry repeating condition by X-ray diffraction spectroscopy with white X-rays obtained from synchrotron radiation. The present in situ experiments successfully detected initial process of the rust formation. In the early cycles, the rust constituents were not well crystallized yet, but the presence of Fe(OH) 2 and Fe(OH) 3 was confirmed. In the subsequent cycles, two different solutions resulted in difference in preferential phase of the rust constituents. α-FeOOH was preferentially formed in the case of the Na 2 SO 4 solution film, whereas β-FeOOH appeared only under the NaCl solution film

Detrital illite crystals identified from crystallite thickness measurements in siliciclastic sediments

Science.gov (United States)

Aldega, L.; Eberl, D.D.

2005-01-01

Illite crystals in siliciclastic sediments are heterogeneous assemblages of detrital material coming from various source rocks and, at paleotemperatures >70 ??C, of superimposed diagenetic modification in the parent sediment. We distinguished the relative proportions of 2M1 detrital illite and possible diagenetic 1Md + 1M illite by a combined analysis of crystal-size distribution and illite polytype quantification. We found that the proportions of 1Md + 1M and 2M1 illite could be determined from crystallite thickness measurements (BWA method, using the MudMaster program) by unmixing measured crystallite thickness distributions using theoretical and calculated log-normal and/or asymptotic distributions. The end-member components that we used to unmix the measured distributions were three asymptotic-shaped distributions (assumed to be the diagenetic component of the mixture, the 1Md + 1M polytypes) calculated using the Galoper program (Phase A was simulated using 500 crystals per cycle of nucleation and growth, Phase B = 333/cycle, and Phase C = 250/ cycle), and one theoretical log-normal distribution (Phase D, assumed to approximate the detrital 2M1 component of the mixture). In addition, quantitative polytype analysis was carried out using the RockJock software for comparison. The two techniques gave comparable results (r2 = 0.93), which indicates that the unmixing method permits one to calculate the proportion of illite polytypes and, therefore, the proportion of 2M1 detrital illite, from crystallite thickness measurements. The overall illite crystallite thicknesses in the samples were found to be a function of the relative proportions of thick 2M1 and thin 1Md + 1M illite. The percentage of illite layers in I-S mixed layers correlates with the mean crystallite thickness of the 1Md + 1M polytypes, indicating that these polytypes, rather than the 2M1 polytype, participate in I-S mixed layering.

High-throughput measurement of polymer film thickness using optical dyes

Science.gov (United States)

Grunlan, Jaime C.; Mehrabi, Ali R.; Ly, Tien

2005-01-01

Optical dyes were added to polymer solutions in an effort to create a technique for high-throughput screening of dry polymer film thickness. Arrays of polystyrene films, cast from a toluene solution, containing methyl red or solvent green were used to demonstrate the feasibility of this technique. Measurements of the peak visible absorbance of each film were converted to thickness using the Beer-Lambert relationship. These absorbance-based thickness calculations agreed within 10% of thickness measured using a micrometer for polystyrene films that were 10-50 µm. At these thicknesses it is believed that the absorbance values are actually more accurate. At least for this solvent-based system, thickness was shown to be accurately measured in a high-throughput manner that could potentially be applied to other equivalent systems. Similar water-based films made with poly(sodium 4-styrenesulfonate) dyed with malachite green oxalate or congo red did not show the same level of agreement with the micrometer measurements. Extensive phase separation between polymer and dye resulted in inflated absorbance values and calculated thickness that was often more than 25% greater than that measured with the micrometer. Only at thicknesses below 15 µm could reasonable accuracy be achieved for the water-based films.

Role of the SiO2 buffer layer thickness in the formation of Si/SiO2/nc-Ge/SiO2 structures by dry oxidation

International Nuclear Information System (INIS)

Kling, A.; Ortiz, M.I.; Prieto, A.C.; Rodriguez, A.; Rodriguez, T.; Jimenez, J.; Ballesteros, C.; Soares, J.C.

2006-01-01

Nanomemories, containing Ge-nanoparticles in a SiO 2 matrix, can be produced by dry thermal oxidation of a SiGe layer deposited onto a Si-wafer with a barrier SiO 2 layer on its top. Rutherford backscattering spectrometry has been used to characterize the kinetics of the oxidation process, the composition profile of the growing oxide, the Ge-segregation and its diffusion into the barrier oxide in samples with thin and thick barrier oxide layers. The Ge segregated during the oxidation of the SiGe layer diffuses into the barrier oxide. In the first case the diffusion through the thin oxide is enhanced by the proximity of the substrate that acts as a sink for the Ge, resulting in the formation of a low Ge concentration SiGe layer in the surface of the Si-wafer. In the second case, the Ge-diffusion progresses as slowly as in bulk SiO 2 . Since barrier oxide layers as thin as possible are favoured for device fabrication, the structures should be oxidized at lower temperatures and the initial SiGe layer thickness reduced to minimize the Ge-diffusion

Freeze-drying behaviour of pasteurized whole egg

International Nuclear Information System (INIS)

Melike Sakin; Merve Samli; Gizem Kor, A.; Figen Kaymak-Ertekin

2009-01-01

Because it provides full nutritional and certain desirable functional attributes, egg products are widely used as ingredients in many food products. Dried egg is especially valuable for being stable, easily mixable and having a long shelf life. It is necessary to know the effects of drying conditions onto the moisture removal behaviour and the functional properties of the powder product, to serve the egg powder as an alternative. An experimental study was conducted to achieve an understanding of the freeze-drying behaviour of pasteurized whole egg having 24% dry solids. In order to determine the moisture removal behaviour; the percent moisture loss (w/w), the average moisture content and the drying rates were obtained, the drying curves were developed and total drying times were determined, also the movement of the dry-wet boundary between the frozen layer and the dry porous layer formed by sublimation of ice crystals were investigated during a complete process. The physical properties of pasteurized whole egg such as; colour, water activity (a w ), the morphological structure (through SEM analysis) and functional properties (foam stability and dissolubility) were determined. The net colour change (ΔE) was about 22, independent of layer thickness. The water activity decreased to 0.22 at the end of drying. The SEM images of freeze-dried and slightly milled egg powder samples at magnification levels of 500 and 1000 showed the porous structure caused by sublimation of ice crystals generated within the egg structure during air blast freezing. The dissolubility and foaming capacity of powder egg were observed to be lower compared to those of pasteurized liquid egg. (author)

Drying results of K-Basin fuel element 3128W (run 2)

International Nuclear Information System (INIS)

Abrefah, J.; Klinger, G.S.; Oliver, B.M.; Marshman, S.C.; MacFarlan, P.J.; Ritter, G.A.; Flament, T.A.

1998-07-01

An N-Reactor outer fuel element that had been stored underwater in the Hanford 100 Area K-East Basin was subjected to a combination of low- and high-temperature vacuum drying treatments. These studies are part of a series of tests being conducted by Pacific Northwest National Laboratory on the drying behavior of N-Reactor spent nuclear fuel elements removed from both the K-West and K-East Basins. The drying test series was designed to test fuel elements that ranged from intact to severely damaged. The fuel element discussed in this report was removed from an open K-East canister (3128W) during the first fuel selection campaign conducted in 1995, and has remained in wet storage in the Postirradiation Testing Laboratory (PTL, 327 Building) since that time. Although it was judged to be breached during in-basin (i.e., K-Basin) examinations, visual inspection of this fuel element in the hot cell indicated that it was likely intact. Some scratches on the coating covering the cladding were identified before the furnace test. The drying test was conducted in the Whole Element Furnace Testing System located in G-Cell within the PTL. This test system is composed of three basic systems: the in-cell furnace equipment, the system gas loop, and the analytical instrument package. Element 3128W was subjected to the drying processes based on those proposed under the Integrated Process Strategy, which included a hot drying step. Results of the Pressure Rise and Gas Evolution Tests suggest that most of the free water in the system was released during the extended CVD cycle (68 hr versus 8 hr for the first run). An additional ∼0.34 g of water was released during the subsequent HVD phase, characterized by multiple water release peaks, with a principle peak at ∼180 C. This additional water is attributed to decomposition of a uranium hydrate (UO 4 ·4H 2 O/UO 4 ·2H 2 O) coating that was observed to be covering the surface of the fuel element to a thickness of ∼1.6 mg/cm 2 . A

Hanford spent nuclear fuel cold vacuum drying proof of performance test procedure

International Nuclear Information System (INIS)

McCracken, K.J.

1998-01-01

This document provides the test procedure for cold testing of the first article skids for the Cold Vacuum Drying (CVD) process at the Facility. The primary objective of this testing is to confirm design choices and provide data for the initial start-up parameters for the process. The current scope of testing in this document includes design verification, drying cycle determination equipment performance testing of the CVD process and MCC components, heat up and cool-down cycle determination, and thermal model validation

Empirical Modeling on Hot Air Drying of Fresh and Pre-treated Pineapples

Directory of Open Access Journals (Sweden)

Tanongkankit Yardfon

2016-01-01

Full Text Available This research was aimed to study drying kinetics and determine empirical model of fresh pineapple and pre-treated pineapple with sucrose solution at different concentrations during drying. 3 mm thick samples were immersed into 30, 40 and 50 Brix of sucrose solution before hot air drying at temperatures of 60, 70 and 80°C. The empirical models to predict the drying kinetics were investigated. The results showed that the moisture content decreased when increasing the drying temperatures and times. Increase in sucrose concentration led to longer drying time. According to the statistical values of the highest coefficients (R2, the lowest least of chi-square (χ2 and root mean square error (RMSE, Logarithmic model was the best models for describing the drying behavior of soaked samples into 30, 40 and 50 Brix of sucrose solution.

Mass transfer characteristics of bisporus mushroom ( Agaricus bisporus) slices during convective hot air drying

Science.gov (United States)

Ghanbarian, Davoud; Baraani Dastjerdi, Mojtaba; Torki-Harchegani, Mehdi

2016-05-01

An accurate understanding of moisture transfer parameters, including moisture diffusivity and moisture transfer coefficient, is essential for efficient mass transfer analysis and to design new dryers or improve existing drying equipments. The main objective of the present study was to carry out an experimental and theoretical investigation of mushroom slices drying and determine the mass transfer characteristics of the samples dried under different conditions. The mushroom slices with two thicknesses of 3 and 5 mm were dried at air temperatures of 40, 50 and 60 °C and air flow rates of 1 and 1.5 m s-1. The Dincer and Dost model was used to determine the moisture transfer parameters and predict the drying curves. It was observed that the entire drying process took place in the falling drying rate period. The obtained lag factor and Biot number indicated that the moisture transfer in the samples was controlled by both internal and external resistance. The effective moisture diffusivity and the moisture transfer coefficient increased with increasing air temperature, air flow rate and samples thickness and varied in the ranges of 6.5175 × 10-10 to 1.6726 × 10-9 m2 s-1 and 2.7715 × 10-7 to 3.5512 × 10-7 m s-1, respectively. The validation of the Dincer and Dost model indicated a good capability of the model to describe the drying curves of the mushroom slices.

Contact angles of water-repellent porous media inferred by tensiometer - TDR probe measurement under controlled wetting and drying cycles

DEFF Research Database (Denmark)

Subedi, Shaphal; Kawamoto, Ken; Komatsu, Toshiko

2013-01-01

with water, eventually allowing water imbibition. However, the effect of the reduction in CA with soil-water contact time on the water retention function of hydrophobic media is not yet fully understood. In this study, water retention characteristics were measured using a hanging water column apparatus...... retention curves. For both water-repellent VAS and hydrophobized sand samples, the calculated CA–SWRC increased with increasing WR. This was determined from both the water drop penetration time and the initial contact angle (CAi) by the sessile drop method. Calculated CA–SWRC values ranged from 20° to 48......-filled pore distributions under controlled wetting and drying cycles was found on calculating the soil water capacity and pore size density as a function of water potential....

Effect of gamma irradiation on quality of dried potato

International Nuclear Information System (INIS)

Wang, J.; Chao, Y.

2003-01-01

The objectives of this study were to obtain the effect of gamma irradiation on the quality of dried potato. Experiments were conducted to study the influence of different doses, air temperatures, slice thickness of potatoes on the dehydration rate, appearance quality (L-values), vitamin C content, and the rehydration ratio of dried potatoes. The greater the dose, the higher the dehydration rate, the lesser the vitamin C content, and the lower the rehydration ratio. The L-values for low-dose irradiation was greater than that for non-irradiated potatoes

Effect of gamma irradiation on quality of dried potato

Energy Technology Data Exchange (ETDEWEB)

Wang, J. E-mail: jwang@zju.edu.cn; Chao, Y

2003-03-01

The objectives of this study were to obtain the effect of gamma irradiation on the quality of dried potato. Experiments were conducted to study the influence of different doses, air temperatures, slice thickness of potatoes on the dehydration rate, appearance quality (L-values), vitamin C content, and the rehydration ratio of dried potatoes. The greater the dose, the higher the dehydration rate, the lesser the vitamin C content, and the lower the rehydration ratio. The L-values for low-dose irradiation was greater than that for non-irradiated potatoes.

Effect of drying on the desorption of diuron and terbuthylazine from natural soils

Energy Technology Data Exchange (ETDEWEB)

Lennartz, Bernd [Institute for Land Use, Rostock University, Justus-von-Liebig-Weg 6, D-18051 Rostock (Germany)]. E-mail: bernd.lennartz@uni-rostock.de; Louchart, Xavier [Laboratory on Interactions between Soils, Agrosystems and Hydrosystems (LISAH), National Institute for Agricultural Research (INRA), 2 place Viala, 34060 Montpellier Cedex 1 (France)

2007-03-15

This work was initiated to study the effects of climate induced soil water status variations which can reach extreme values under natural conditions on the sorption process of hydrophobic organic compounds. Based on the classical slurry batch methodology an approach is developed that allows the fast and careful complete drying of soil suspensions (microwave technique). Classical adsorption experiments were followed by three desorption steps with and without drying cycles. Drying and re-wetting enhanced the sorption-desorption hysteresis and Freundlich adsorption coefficients increased from 5.9 to 16 and 5.2 to 21 over three drying cycles for diuron and terbuthylazine respectively. Assuming the validity of a dual stage adsorption process, model evaluation suggests that drying is as a shrinking-like process leading to conformational changes of the dominant sorbent (soil organic matter) which restrict the intra-micro-particle diffusion. Rewetting only leads to a partial recovery of the diffusional pore space. - Drying of soil samples increased the binding of herbicidal compounds which is interpreted as a reduction of diffusional mass transfer into and out of the soil organic matter.

Effect of drying on the desorption of diuron and terbuthylazine from natural soils

International Nuclear Information System (INIS)

Lennartz, Bernd; Louchart, Xavier

2007-01-01

This work was initiated to study the effects of climate induced soil water status variations which can reach extreme values under natural conditions on the sorption process of hydrophobic organic compounds. Based on the classical slurry batch methodology an approach is developed that allows the fast and careful complete drying of soil suspensions (microwave technique). Classical adsorption experiments were followed by three desorption steps with and without drying cycles. Drying and re-wetting enhanced the sorption-desorption hysteresis and Freundlich adsorption coefficients increased from 5.9 to 16 and 5.2 to 21 over three drying cycles for diuron and terbuthylazine respectively. Assuming the validity of a dual stage adsorption process, model evaluation suggests that drying is as a shrinking-like process leading to conformational changes of the dominant sorbent (soil organic matter) which restrict the intra-micro-particle diffusion. Rewetting only leads to a partial recovery of the diffusional pore space. - Drying of soil samples increased the binding of herbicidal compounds which is interpreted as a reduction of diffusional mass transfer into and out of the soil organic matter

Characteristics of a Dry Fog Ionizer

International Nuclear Information System (INIS)

Murata, Y; Kudo, Y; Yonezawa, M

2008-01-01

The newly developed 'Dry Fog Ionizer' generates charged dry fog. The dry fog consists of very fine water droplets 8μm in mean diameter. This system consists of a dry fog nozzle (H.Ikeuchi and Co., LTD.), a ring electrode for induction charging (50mm outside diameter, and 10mm thick) in front of the nozzle, and a fan for dissipating charged dry fog. The ring electrode is DC or AC-biased and fine droplets ejected from the nozzle are electrified by induction charging. The particle size of the charged water droplets are reduced through evaporation during the transporting process by air flow, and completely evaporate approximately 2m from the nozzle under normal atmospheric conditions (25 deg. C, 60%R.H.) leaving high density ions. Using this system, high density ionic space charge can be realized in a remote spot from the ionizer. By this principle, the Dry Fog Ionizer shows strong charge-eliminating ability in the region away from the ionizer. When a dc bias of 5kV was applied to a ring electrode with the rate of water flow from the nozzle being 21/h, an ionic space-charge density of 1200nC /m 3 was able to be obtained at a distance 2m away from the ionizer, which was 10 2 times the value produced by an ordinary corona-type ionizer with an air blower.

Effect of drying on the desorption of diuron and terbuthylazine from natural soils.

Science.gov (United States)

Lennartz, Bernd; Louchart, Xavier

2007-03-01

This work was initiated to study the effects of climate induced soil water status variations which can reach extreme values under natural conditions on the sorption process of hydrophobic organic compounds. Based on the classical slurry batch methodology an approach is developed that allows the fast and careful complete drying of soil suspensions (microwave technique). Classical adsorption experiments were followed by three desorption steps with and without drying cycles. Drying and re-wetting enhanced the sorption-desorption hysteresis and Freundlich adsorption coefficients increased from 5.9 to 16 and 5.2 to 21 over three drying cycles for diuron and terbuthylazine respectively. Assuming the validity of a dual stage adsorption process, model evaluation suggests that drying is as a shrinking-like process leading to conformational changes of the dominant sorbent (soil organic matter) which restrict the intra-micro-particle diffusion. Rewetting only leads to a partial recovery of the diffusional pore space.

Film thickness determining method of the silicon isotope superlattices by SIMS

International Nuclear Information System (INIS)

Takano, Akio; Shimizu, Yasuo; Itoh, Kohei M.

2008-01-01

It is becoming important to evaluate silicon self-diffusion with progress of a silicon semiconductor industry. In order to evaluate the self-diffusion of silicon, silicon isotope superlattices (SLs) is the only marker. For this reason, it is important to correctly evaluate a film thickness and a depth distribution of isotope SLs by secondary ion mass spectrometry (SIMS). As for film thickness, it is difficult to estimate the thicknesses correctly if the cycles of SLs are short. In this work, first, we report the determination of the film thickness for short-period SLs using mixing roughness-information (MRI) analysis to SIMS profile. Next, the uncertainty of the conventional method to determine the film thicknesses of SLs is determined. It was found that the conventional methods cannot correctly determine film thickness of short-period-isotope SLs where film thickness differs for every layer

Investigation of pre-drying lignite in an existing Greek power plant

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Agraniotis Michalis

2012-01-01

Full Text Available The application of lignite pre-drying technologies in next generation of lignite power plants by utilizing low pressure steam as a drying medium instead of hot recirculated flue gas - combined with thermal utilization of the vaporized coal moisture - is expected to bring efficiency increase of 2-4 percentage points in future lignite power plants compared with today’s state of the art. The pre-drying concept is of particular importance in Greek boilers firing lignite with a high water and ash content. The combustion of Greek predried lignite has been investigated experimentally and via numerical simulations in our previous research. This study focuses on the potential integration of a lignite pre-drying system in an existing Greek power plant with dry lignite co-firing thermal share of up to 30%. The radiative and convective heat fluxes to the boiler and the overall boiler heat balance is calculated for reference and dry lignite co-firing conditions by an in-house calculation code. The overall plant’s thermal cycle is then simulated using commercial thermal cycle calculation software. The net plant efficiency is in this way determined for reference and dry coal co-firing conditions. According to the simulation results the integration of a pre-drying system and the implementation of dry lignite co-firing may bring an efficiency increase of about 1.5 percentage points in existing Greek boilers. It is therefore considered as an important measure towards improving plant efficiency and reducing specific CO2 emissions in existing plants.

Hydration and dehydration cycles in polymer electrolyte fuel cells operated with wet anode and dry cathode feed: A neutron imaging and modeling study

Science.gov (United States)

García-Salaberri, P. A.; Sánchez, D. G.; Boillat, P.; Vera, M.; Friedrich, K. A.

2017-08-01

Proper water management plays an essential role in the performance and durability of Polymer Electrolyte Fuel Cells (PEFCs), but it is challenged by the variety of water transport phenomena that take place in these devices. Previous experimental work has shown the existence of fluctuations between low and high current density levels in PEFCs operated with wet hydrogen and dry air feed. The alternation between both performance states is accompanied by strong changes in the high frequency resistance, suggesting a cyclic hydration and dehydration of the membrane. This peculiar scenario is examined here considering liquid water distributions from neutron imaging and predictions from a 3D two-phase non-isothermal model. The results show that the hydration-dehydration cycles are triggered by the periodic condensation and shedding of liquid water at the anode inlet. The input of liquid water humidifies the anode channel and offsets the membrane dry-out induced by the dry air stream, thus leading to the high-performance state. When liquid water is flushed out of the anode channel, the dehydration process takes over, and the cell comes back to the low-performance state. The predicted amplitude of the current oscillations grows with decreasing hydrogen and increasing air flow rates, in agreement with previous experimental data.

A new dry-surface biofilm model: An essential tool for efficacy testing of hospital surface decontamination procedures.

Science.gov (United States)

Almatroudi, Ahmad; Hu, Honghua; Deva, Anand; Gosbell, Iain B; Jacombs, Anita; Jensen, Slade O; Whiteley, Greg; Glasbey, Trevor; Vickery, Karen

2015-10-01

The environment has been shown to be a source of pathogens causing infections in hospitalised patients. Incorporation of pathogens into biofilms, contaminating dry hospital surfaces, prolongs their survival and renders them tolerant to normal hospital cleaning and disinfection procedures. Currently there is no standard method for testing efficacy of detergents and disinfectants against biofilm formed on dry surfaces. The aim of this study was to develop a reproducible method of producing Staphylococcus aureus biofilm with properties similar to those of biofilm obtained from dry hospital clinical surfaces, for use in efficacy testing of decontamination products. The properties (composition, architecture) of model biofilm and biofilm obtained from clinical dry surfaces within an intensive care unit were compared. The CDC Biofilm Reactor was adapted to create a dry surface biofilm model. S. aureus ATCC 25923 was grown on polycarbonate coupons. Alternating cycles of dehydration and hydration in tryptone soy broth (TSB) were performed over 12 days. Number of biofilm bacteria attached to individual coupons was determined by plate culture and the coefficient of variation (CV%) calculated. The DNA, glycoconjugates and protein content of the biofilm were determined by analysing biofilm stained with SYTO 60, Alexa-488-labelled Aleuria aurantia lectin and SyproOrange respectively using Image J and Imaris software. Biofilm architecture was analysed using live/dead staining and confocal microscopy (CM) and scanning electron microscopy (SEM). Model biofilm was compared to naturally formed biofilm containing S. aureus on dry clinical surfaces. The CDC Biofilm reactor reproducibly formed a multi-layered, biofilm containing about 10(7) CFU/coupon embedded in thick extracellular polymeric substances. Within run CV was 9.5% and the between run CV was 10.1%. Protein was the principal component of both the in vitro model biofilm and the biofilms found on clinical surfaces. Continued

Determination of Sliced Pineapple Drying Characteristics in A Closed Loop Heat Pump Assisted Drying System

Directory of Open Access Journals (Sweden)

Cüneyt Tunçkal

2018-02-01

Full Text Available Pineapple (Ananascomosus slices were dried with the aid of a heat pump assisted dryer (HPD. During this process, air velocity was kept constant at 1m/s, while air temperatures were changed as 37°C, 40°C and 43°C. The drying air was also circulated by using an axial fan in a closed cycle and fresh air was not allowed into the system. The drying rate and drying time were significantly influenced by drying temperature. It was observed that drying temperatures had significant effects on the drying rate and drying time. During the conduct of the study, pineapple slices were dried at 37, 40 and 43°C for 465, 360 and 290 min, respectively. The specific moisture extraction ratio (SMER values were observed to change as drying temperatures were changed. The drying rate curves indicated that the whole drying process occurred in the falling rate period. Seven well-known thin-layer models (Lewis, Henderson &Pabis, Logarithmic, Page, Midilli & Kucuk, Weibull and Aghbashlo et al. were employed to make a prediction about drying kinetics through nonlinear regression analysis. The Midilli & Kucuk and Aghbashlo et al. models were consistent with the experimental data. Fick’s second law of diffusion was used to determine the moisture diffusivity coefficient ranging from 3.78×10–9 to 6.57×10-9  m2/s the each of the above mentioned temperatures. The dependence of effective diffusivity coefficient on temperature was defined by means a fan Arrhenius type equation. The activation energy of moisture diffusion was found to be 75.24kJ/mol.   Article History: Received: July 18th 2017; Received: October 27th 2017; Accepted: January 16th 2018; Available online How to Cite This Article: Tunçkal, C., Coşkun, S., Doymaz, I. and Ergun, E. (2018 Determination of Sliced Pineapple Drying Characteristics in A Closed Loop Heat Pump Assisted Drying System. International Journal of Renewable Energy Development, 7(1, 35-41. https://doi.org/10.14710/ijred.7.1.35-41

Drying of latex films and coatings: Reconsidering the fundamental mechanisms

DEFF Research Database (Denmark)

Kiil, Søren

2006-01-01

The two existing theories describing drying of latex films or coatings are reconsidered. Subsequently, a novel mathematical drying model is presented, the simulations of which can match and explain experimental drying rate data of two previous investigations with latex films. In contrast to previ......The two existing theories describing drying of latex films or coatings are reconsidered. Subsequently, a novel mathematical drying model is presented, the simulations of which can match and explain experimental drying rate data of two previous investigations with latex films. In contrast...... to previous model studies, but in agreement with observations, simulations suggest that during the falling rate period of the drying process of a latex film, a porous skin of partly coalesced latex particles is indeed formed, which limits transport of water vapour from the receding air-liquid interphase...... to the surface of the film. The value of the effective diffusion coefficient of water vapour in the dry and partly coalesced layer (7 x 10(-7) m(2)/s at 19-24 degrees C), the adjustable parameter of the model for the falling rate period, was found to be independent of initial wet film thickness (89-1322 mu m...

Effects of superheated steam on the drying of rubberwood

Directory of Open Access Journals (Sweden)

Kanokwan Buaphud

2006-07-01

Full Text Available Rubberwood drying is the most time and energy consuming step in the processing of wood product. This research studied the effect of superheated steam drying on the drying time required and the physical and mechanical properties of rubberwood after drying. In this study, a cylindrical drying chamber with a length of 1.2 m and a diameter of 0.5 m was constructed and injected with superheated steam. The dimensions of the wood lumber were 1 m × 7.62 cm × 2.54 cm. The wood samples were impinged with alternating cycles of superheated steam and hot air at ratios of 6:1, 4:1 and 1:6 hours until the moisture content was less than 15% dry basis. The conditions inside the chamber were 110ºC and ambient pressure. Continuous superheated steam and continuous hot air were also used for comparisons. The drying rate and the temperature profile for each process were determined.Initial acceptability of the dried wood was conducted using the prong test and visual inspection. Results showed that if the drying rate was too fast, the dried wood did not pass the prong test due to stress buildup. Therefore, an optimum drying condition was developed based on minimizing defects and reducing the drying time. For the optimum condition, the following schedule was carried out: (1 saturated steam at 100ºC was used during the first 4 hours of drying to prevent the wood surface from drying too quickly which would minimize the moisture gradient between the center and wood surface, (2 superheated steam at 105ºC and 110ºC was used in alternating cycle with hot air (80ºC during the main drying stages to rapidly remove the free water and majority of the bound water inside the wood, and (3 hot air was used continuously during the final stages of drying to reduce the relative humidity inside the chamber making it possible for the removal of the residual bound water. This process successfully reduced the drying time to less than 2 days without causing any defects which compared

Surface microhardness of three thicknesses of mineral trioxide aggregate in different setting conditions

Directory of Open Access Journals (Sweden)

Noushin Shokouhinejad

2014-11-01

Full Text Available Objectives This study aimed to compare the surface microhardness of mineral trioxide aggregate (MTA samples having different thicknesses and exposed to human blood from one side and with or without a moist cotton pellet on the other side. Materials and Methods Ninety cylindrical molds with three heights of 2, 4, and 6 mm were fabricated. In group 1 (dry condition, molds with heights of 2, 4, and 6 mm (10 molds of each were filled with ProRoot MTA (Dentsply Tulsa Dental, and the upper surface of the material was not exposed to any additional moisture. In groups 2 and 3, a distilled water- or phosphate-buffered saline (PBS-moistened cotton pellet was placed on the upper side of MTA, respectively. The lower side of the molds in all the groups was in contact with human blood-wetted foams. After 4 day, the Vickers microhardness of the upper surface of MTA was measured. Results In the dry condition, the 4 and 6 mm-thick MTA samples showed significantly lower microhardness than the 2 mm-thick samples (p = 0.003 and p = 0.001, respectively. However, when a distilled water- or PBS-moistened cotton pellet was placed over the MTA, no significant difference was found between the surface microhardness of samples having the abovementioned three thicknesses of the material (p = 0.210 and p = 0.112, respectively. Conclusions It could be concluded that a moist cotton pellet must be placed over the 4 to 6 mm-thick MTA for better hydration of the material. However, this might not be necessary when 2 mm-thick MTA is used.

Influence of processing parameters on PZT thick films

International Nuclear Information System (INIS)

Huang, Oliver; Bandyopadhyay, Amit; Bose, Susmita

2005-01-01

We have studied influence of processing parameters on the microstructure and ferroelectric properties of lead zirconate titanate (PZT)-based thick films in the range of 5-25 μm. PZT and 2% La-doped PZT thick films were processed using a modified sol-gel process. In this process, PZT- and La-doped PZT powders were first prepared via sol-gel. These powders were calcined and then used with respective sols to form a slurry. Slurry composition was optimized to spin-coat thick films on platinized Si substrate (Si/SiO 2 /Ti/Pt). Spinning rate, acceleration and slurry deposition techniques were optimized to form thick films with uniform thickness and without any cracking. Increasing solids loading was found to enhance the surface smoothness of the film and decrease porosity. Films were tested for their electrical properties and ferroelectric fatigue response. The maximum polarization obtained was 40 μC/cm 2 at 250 kV/cm for PZT thick film and 30 μC/cm 2 at 450 kV/cm for La-doped PZT thick film. After 10 9 cycles of fatiguing at 35 kHz, La-doped PZT showed better resistance for ferroelectric fatigue compared with un-doped PZT films

Percolation effect in thick film superconductors

Energy Technology Data Exchange (ETDEWEB)

Sali, R.; Harsanyi, G. [Technical Univ. of Budapest (Hungary)

1994-12-31

A thick film superconductor paste has been developed to study the properties of granulated superconductor materials, to observe the percolation effect and to confirm the theory of the conducting mechanism in the superconducting thick films. This paste was also applied to make a superconducting planar transformer. Due to high T{sub c} and advantageous current density properties the base of the paste was chosen to be of Bi(Pb)SrCaCuO system. For contacts a conventional Ag/Pt paste was used. The critical temperature of the samples were between 110 K and 115 K depending on the printed layer thickness. The critical current density at the boiling temperature of the liquid He- was between 200-300 A/cm{sup 2}. The R(T) and V(I) functions were measured with different parameters. The results of the measurements have confirmed the theory of conducting mechanism in the material. The percolation structure model has been built and described. As an application, a superconducting planar thick film transformer was planned and produced. Ten windings of the transformer were printed on one side of the alumina substrate and one winding was printed on the other side. The coupling between the two sides was possible through the substrate. The samples did not need special drying and firing parameters. After the preparation, the properties of the transformer were measured. The efficiency and the losses were determined. Finally, some fundamental advantages and problems of the process were discussed.

Percolation effect in thick film superconductors

International Nuclear Information System (INIS)

Sali, R.; Harsanyi, G.

1994-01-01

A thick film superconductor paste has been developed to study the properties of granulated superconductor materials, to observe the percolation effect and to confirm the theory of the conducting mechanism in the superconducting thick films. This paste was also applied to make a superconducting planar transformer. Due to high T c and advantageous current density properties the base of the paste was chosen to be of Bi(Pb)SrCaCuO system. For contacts a conventional Ag/Pt paste was used. The critical temperature of the samples were between 110 K and 115 K depending on the printed layer thickness. The critical current density at the boiling temperature of the liquid He- was between 200-300 A/cm 2 . The R(T) and V(I) functions were measured with different parameters. The results of the measurements have confirmed the theory of conducting mechanism in the material. The percolation structure model has been built and described. As an application, a superconducting planar thick film transformer was planned and produced. Ten windings of the transformer were printed on one side of the alumina substrate and one winding was printed on the other side. The coupling between the two sides was possible through the substrate. The samples did not need special drying and firing parameters. After the preparation, the properties of the transformer were measured. The efficiency and the losses were determined. Finally, some fundamental advantages and problems of the process were discussed

Low-temperature plasma-enhanced atomic layer deposition of 2-D MoS2 : Large area, thickness control and tuneable morphology

NARCIS (Netherlands)

Sharma, A.; Verheijen, M.A.; Wu, L.; Karwal, S.; Vandalon, V.; Knoops, H.C.M.; Sundaram, R.S.; Hofmann, J.P.; Kessels, W.M.M.; Bol, A.A.

2018-01-01

Low-temperature controllable synthesis of monolayer-to-multilayer thick MoS2 with tuneable morphology is demonstrated by using plasma enhanced atomic layer deposition (PEALD). The characteristic self-limiting ALD growth with a growth-per-cycle of 0.1 nm per cycle and digital thickness control down

Intelligent processing for thick composites

Science.gov (United States)

Shin, Daniel Dong-Ok

2000-10-01

Manufacturing thick composite parts are associated with adverse curing conditions such as large in-plane temperature gradient and exotherms. The condition is further aggravated because the manufacturer's cycle and the existing cure control systems do not adequately counter such affects. In response, the forecast-based thermal control system is developed to have better cure control for thick composites. Accurate cure kinetic model is crucial for correctly identifying the amount of heat generated for composite process simulation. A new technique for identifying cure parameters for Hercules AS4/3502 prepreg is presented by normalizing the DSC data. The cure kinetics is based on an autocatalytic model for the proposed method, which uses dynamic and isothermal DSC data to determine its parameters. Existing models are also used to determine kinetic parameters but rendered inadequate because of the material's temperature dependent final degree of cure. The model predictions determined from the new technique showed good agreement to both isothermal and dynamic DSC data. The final degree of cure was also in good agreement with experimental data. A realistic cure simulation model including bleeder ply analysis and compaction is validated with Hercules AS4/3501-6 based laminates. The nonsymmetrical temperature distribution resulting from the presence of bleeder plies agreed well to the model prediction. Some of the discrepancies in the predicted compaction behavior were attributed to inaccurate viscosity and permeability models. The temperature prediction was quite good for the 3cm laminate. The validated process simulation model along with cure kinetics model for AS4/3502 prepreg were integrated into the thermal control system. The 3cm Hercules AS4/3501-6 and AS4/3502 laminate were fabricated. The resulting cure cycles satisfied all imposed requirements by minimizing exotherms and temperature gradient. Although the duration of the cure cycles increased, such phenomena was

Spreading of Trisiloxanes on Thin Water Film: Dry Spot Profile

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Derrick Ovunda NJOBUENWU

2007-08-01

Full Text Available This paper reports the results of an experimental investigation of the spreading of trisiloxanes EO6, EO7, EO8, EO9 and sodium dodecyl sulphate SDS on thin films which are 320 microns in thickness; the concentrations covered are above the CMC. The spreading of SDS is accompanied by the formation of a “dry spot” which advances in time roughly as t1/4. The trisiloxanes spreading gave rise to dry spot formation that was accompanied by “irregularities”, which corresponded to an abrupt jump in the plot of dry spot radius versus time. The behaviour is attributed to a variety of factors: disjoining pressure effects or the fact that the Petri dish was too small so that backward propagating waves were set up due to reflections from the walls which interacted with the outspreading dry spot.

Preparation and evaluation of freeze-dried Mag3 kits for 99m Tc-labelling

International Nuclear Information System (INIS)

El-Mohty, A.A.; El-Ghany, E.A.; El-Kolaly, M.T.; Raieh, M.; EL-Bary, A.A.

1996-01-01

The freeze-dried Mag 3 kits were designed for both ligand trans chelation and direct labelling techniques. The solution of Sn-Mag 3 was sterilized by 0.22 μU mill pore filtration and dispensed in a laminar flow hood (1 m I / vial) then, the vials were introduced to the lyophilized. The process of lyophilization was continued for 24 hours. At end of the cycle, the vials were closed under nitrogen. The moisture content of the freeze-dried Mag 3 kits was determined and it was found equal to 0.1% also, the losses of tin (II) during the freeze-drying cycle did not exceed 5%. It was found that the Mag 3 freeze-dried kits were sterile, pyrogen free and does not have any unexpected toxicity. The prepared Mag 3 freeze-dried kits have high radiochemical purity > 97% and high stability for more than 8 h after labelling. The biodistribution shows rapid renal excretion at 15 min post injection. 3 figs., 4 tabs

Tuning the thickness of electrochemically grafted layers in large area molecular junctions

Energy Technology Data Exchange (ETDEWEB)

Fluteau, T.; Bessis, C.; Barraud, C., E-mail: clement.barraud@univ-paris-diderot.fr; Della Rocca, M. L.; Lafarge, P. [Université Paris Diderot, Sorbonne Paris Cité, MPQ, UMR 7162, CNRS, 75205 Paris Cedex 13 (France); Martin, P.; Lacroix, J.-C. [Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, 15 rue J.-A. de Baïf, 75205 Paris Cedex 13 (France)

2014-09-21

We have investigated the thickness, the surface roughness, and the transport properties of oligo(1-(2-bisthienyl)benzene) (BTB) thin films grafted on evaporated Au electrodes, thanks to a diazonium-based electro-reduction process. The thickness of the organic film is tuned by varying the number of electrochemical cycles during the growth process. Atomic force microscopy measurements reveal the evolution of the thickness in the range of 2–27 nm. Its variation displays a linear dependence with the number of cycles followed by a saturation attributed to the insulating behavior of the organic films. Both ultrathin (2 nm) and thin (12 and 27 nm) large area BTB-based junctions have then been fabricated using standard CMOS processes and finally electrically characterized. The electronic responses are fully consistent with a tunneling barrier in case of ultrathin BTB film whereas a pronounced rectifying behavior is reported for thicker molecular films.

Sea ice - Multiyear cycles and white ice

Science.gov (United States)

Ledley, T. S.

1985-01-01

The multiyear thickness cycles represent one of the interesting features of the sea ice studies performed by Semtner (1976) and Washington et al. (1976) with simple thermodynamic models of sea ice. In the present article, a description is given of results which show that the insulating effect of snow on the surface of the sea ice is important in producing these multiyear cycles given the physics included in the model. However, when the formation of white ice is included, the cycles almost disappear. White ice is the ice which forms at the snow-ice interface when the snow layer becomes thick enough to depress the ice below the water level. Water infiltrates the snow by coming through the ice at leads and generally freezes there, forming white ice.

Radiation preservation of dried fish indigenous to Asia

International Nuclear Information System (INIS)

Hussain, A.M.; Haz, I.; Chaudry, M.A.

1989-01-01

Commercially dried marine fish such as mackerel, shark, tuna and saram (Scomboromorus commersoni) contain 36-50% moisture and 10-12% salt. During preliminary studies, there was visible mould growth on sun or over dried freshwater rahu (Labeo sp.) fish containing moisture levels above 15.5%. Fusarium was present in samples containing a moisture level of 46% and above, while below this level Aspergillus sp. and Penicillium sp. were present. Dipping of fish fillets in 2% potassium sorbate checked the visible mould growth on irradiated (0.25-1 kGy) and non-irradiated rahu fish containing moisture levels of 20-40%. Radiation doses of 0.5-0.75 kGy were found suitable for keeping sun or oven dried samples in good and acceptable conditions for six months at room temperature. Polyethylene film about 0.1 mm thick was suitable for packing dried fish as far as insect penetration, bacterial permeability, water permeability, water vapour transfer rate and weight loss of dried fish during storage were concerned. An oxygen absorber was effective for six months in maintaining colour, odour and texture of irradiated dried fish packaged in an oxygen impermeable film. Dried fish was acceptable to consumers except to some extent for its texture. Bulk storage of dried fish fillets at an ambient temperature for 3 months produced no adverse changes in the fillets. About 5% of the fillets were badly shredded during transportation of irradiated dried fish over a distance of about 2,400 km. (author). 27 refs, 6 figs, 13 tabs

Optimum thickness evaluation of ZrO2 coating on type 304L stainless steel for corrosion protection

International Nuclear Information System (INIS)

Garg, Nidhi; Bera, Santanu; Velmurugan, S.; Tripathi, V.S.; Karki, Vijay

2015-01-01

Nano-crystalline ZrO 2 coatings of different thickness have been grown on pre-oxidized stainless steel (SS) surface by hydrothermal method in an autoclave. Thickness of the coating has been enhanced by repeating the deposition process several times using same precursor concentration. Several cycles of the deposition process lead to the increase of the coating thickness from 200 nm to ∼1 μm after the fourth round of deposition. The samples after different rounds of the coating have been extensively characterized by SEM-EDS technique to find the surface topography, coating thickness and composition. Corrosion resistance properties of the plain SS, pre-oxidized SS and all the ZrO 2 coated samples were studied by potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). Corrosion current densities (I corr /cm 2 ) of the coated samples are found to reduce significantly with the increase in thickness. After a certain critical thickness, the corrosion resistance properties found to deteriorate due to the formation of coating defects caused by lattice strain. The coating was found to be continuous but porous after the first cycle but porosity of zirconia coating have been reduced drastically after the second cycle itself. EIS analysis confirms that the zirconia coated samples show insulating, barrier like characteristics in terms of high charge transfer resistance after the second cycle of zirconia deposition. The role of pre-oxidized surface composition and the interface between the pre-oxidized surface and the coating has been discussed in details by showing the depth distribution of Zr in the coating. (author)

Tear dynamics in healthy and dry eyes.

Science.gov (United States)

Cerretani, Colin F; Radke, C J

2014-06-01

Dry-eye disease, an increasingly prevalent ocular-surface disorder, significantly alters tear physiology. Understanding the basic physics of tear dynamics in healthy and dry eyes benefits both diagnosis and treatment of dry eye. We present a physiological-based model to describe tear dynamics during blinking. Tears are compartmentalized over the ocular surface; the blink cycle is divided into three repeating phases. Conservation laws quantify the tear volume and tear osmolarity of each compartment during each blink phase. Lacrimal-supply and tear-evaporation rates are varied to reveal the dependence of tear dynamics on dry-eye conditions, specifically tear osmolarity, tear volume, tear-turnover rate (TTR), and osmotic water flow. Predicted periodic-steady tear-meniscus osmolarity is 309 and 321 mOsM in normal and dry eyes, respectively. Tear osmolarity, volume, and TTR all match available clinical measurements. Osmotic water flow through the cornea and conjunctiva contribute 10 and 50% to the total tear supply in healthy and dry-eye conditions, respectively. TTR in aqueous-deficient dry eye (ADDE) is only half that in evaporative dry eye (EDE). The compartmental periodic-steady tear-dynamics model accurately predicts tear behavior in normal and dry eyes. Inclusion of osmotic water flow is crucial to match measured tear osmolarity. Tear-dynamics predictions corroborate the use of TTR as a clinical discriminator between ADDE and EDE. The proposed model is readily extended to predict the dynamics of aqueous solutes such as drugs or fluorescent tags.

Influence of γ-irradiation on drying of slice potato

International Nuclear Information System (INIS)

Wang Jun; Chao Yan; Fu Junjie; Wang Jianping

2001-01-01

A new technology is introduced to dry food products by hot-air after pretreated by irradiation. The influence of different dosage of irradiation, temperature of hot air, thickness of the slice potato on the rate of dehydration temperature of irradiated potato were studied. A conclusion is reached that the 3 factors, irradiation dosage, hot-air temperature and thickness of slice potato, affect the rate of dehydration and temperature of slice potato. The higher the dosage is, the greater the rate of dehydration of potato becomes, and the higher the temperature of the slice potato gets. (authors)

Enhanced cycle stability of micro-sized Si/C anode material with low carbon content fabricated via spray drying and in situ carbonization

Energy Technology Data Exchange (ETDEWEB)

Wang, Dingsheng; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Pan, Hongge; Liu, Yongfeng; Wang, Junhua; Li, Shouquan; Ge, Hongwei

2014-08-01

Highlights: • Micro-sized Si/C composites were fabricated via. spray drying and carbonization. • Multi-morphology carbon was formed in the Si/C composites. • Si/C composite with 5.6 wt.% C provides significant improved cycling stability. • Multi-morphology carbon plays effective role in improving the electrochemical property. • The method provides potential for mass production of superior Si-based anode materials. - Abstract: Micro-sized Si/C composites with in situ introduced carbon of multi-morphology were fabricated via spray drying a suspension of commercial micro-sized Si and citric acid followed by a carbonization. Different ratios of Si to citric acid were used to optimize the composition and structure of the composites and thus the electrochemical performance. Carbon flakes including crooked and flat ones were well dispersed in between the Si particles, forming Si/C composites. Floc-like carbon layers and carbon fragments were also found to cover partially the Si particles. The Si/C composite with a low carbon content of 5.6 wt.% provides an initial reversible capacity of 2700 mA h/g and a capacity of 1860 mA h/g after 60 cycles at a current density of 100 mA/g as anode material for lithium-ion batteries (LIBs), which are much higher than those of pristine Si and the Si/C composites with higher carbon content. The mechanism of the enhancement of electrochemical performance of the micro-sized Si/C composite is discussed. The fabrication method and the structure design of the composites offer valuable potential in developing adaptable Si-based anode materials for industrial applications.

Effect of Drying Method on the Permeability Coefficient of Oak Wood (Quercus infactoria

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Shuboo Salehpour

2014-05-01

Full Text Available In this study, the effect of drying method on the permeability coefficient of the oak wood (Quercus infectoria Oliv was studied. Freshly-cut logs of oak were prepared from Oureman, the east area of Kourdistan in Iran. Then, boards with nominal thickness of 6 cm were cut. The boards were dried using two methods. In the first method, the boards were air dried to the moisture content close to FSP for 45 days and then they were kiln dried using T5-D1 schedule. In the second method, the boards were dried from green condition to the final moisture content of 10% using T5-D1 schedule. Then, the permeability coefficient in the transverse and longitudinal directions in both heartwood and sapwood regions was measured, separately. Results showed that the permeability of oak boards dried by kiln drying method both in the transverse and longitudinal directions and also in the heartwood and sapwood regions was greater than that of those dried by the combined method (air drying + kiln drying.

Explore the influence of agglomeration on electrochemical performance of an amorphous MnO2/C composite by controlling drying process

Science.gov (United States)

Cui, Mangwei; Kang, Litao; Shi, Mingjie; Xie, Lingli; Wang, Xiaomin; Zhao, Zhe; Yun, Shan; Liang, Wei

2017-09-01

Amorphous MnO2/C composite is prepared by a facile redox reaction between potassium permanganate (KMnO4) and commercial black pen ink. Afterwards, two different drying processes, air drying or freeze drying, are employed to adjust the agglomeration state of particles in samples and explore its influence on capacitive performance. Experimental results indicate that the air-dried sample demonstrates much better cycling stability than the freeze-dried one (capacity retention at 5000 cycles: 70.9 vs. 60.7%), probably because of the relatively strong agglomeration between particles in this sample. Nevertheless, strong agglomeration seems to deteriorate the specific capacitance (from 492 down to 440.5 F/g at 1 A/g) due to the decrease of porosity and specific surface area. This study suggests that agglomeration of primary particles plays an important role to balance the specific capacitance and cycling stability for electrode materials.

[Psychosomatic aspects of dry eye syndrome].

Science.gov (United States)

Nepp, J

2016-02-01

Patients with dry eye syndrome are known to suffer from anxiety and depression. Analysis of psychological disorders in therapy-resistant dry eye syndrome. A retrospective analysis of the training for interactive psychiatric screening (TRIPS) questionnaire from 110 patients with therapy-resistant dry eye syndrome was carried out. The results of the questionnaire allow the diagnosis of psychological disorders and vegetative disorders. Patients were divided into groups with anxiety, depression, mixed diagnoses, vegetative disorders and no diagnosis. A sicca score was used for assessment of dryness comprising the Schirmer test, measurement of tear meniscus, break up time, lipid layer thickness, the use of fluorescein and rose bengal staining tests and the subjective visual analogue scale. The diagnosis of dry eye syndrome was compared with the psychological disorders of anxiety and depression. Of the patients 52.7 % had psychological disorders with anxiety in 21.8 %, depression in 15.3 %, mixed diagnoses in 14.5 %, dystonia in 25.4 % and in 22.7 % no psychological disorders were diagnosed. General anxiety was frequent and panic disorders were often associated with other kinds of anxiety. Severe depression, such as bipolar disorder was rare. Dry eye scores were highest in the mixed group (0.59), and lowest in the group with mild anxiety (0.38). No single sicca phase disorder could be correlated with any of the psychological diagnoses. Patients with therapy-resistant dry eye syndrome often suffer from anxiety and depression. The psychological stress acts on the nervous system to suppress lacrimal gland function. Further investigation of the correlation between the lacrimal tear film phase and psychological disorders is recommended. Knowledge of personality disorders may allow psychological support that would improve the treatment options for dry eye syndrome.

Ester-Mediated Amide Bond Formation Driven by Wet-Dry Cycles: A Possible Path to Polypeptides on the Prebiotic Earth.

Science.gov (United States)

Forsythe, Jay G; Yu, Sheng-Sheng; Mamajanov, Irena; Grover, Martha A; Krishnamurthy, Ramanarayanan; Fernández, Facundo M; Hud, Nicholas V

2015-08-17

Although it is generally accepted that amino acids were present on the prebiotic Earth, the mechanism by which α-amino acids were condensed into polypeptides before the emergence of enzymes remains unsolved. Here, we demonstrate a prebiotically plausible mechanism for peptide (amide) bond formation that is enabled by α-hydroxy acids, which were likely present along with amino acids on the early Earth. Together, α-hydroxy acids and α-amino acids form depsipeptides-oligomers with a combination of ester and amide linkages-in model prebiotic reactions that are driven by wet-cool/dry-hot cycles. Through a combination of ester-amide bond exchange and ester bond hydrolysis, depsipeptides are enriched with amino acids over time. These results support a long-standing hypothesis that peptides might have arisen from ester-based precursors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thick-shelled, grazer-protected diatoms decouple ocean carbon and silicon cycles in the iron-limited Antarctic Circumpolar Current

Science.gov (United States)

Assmy, Philipp; Smetacek, Victor; Montresor, Marina; Klaas, Christine; Henjes, Joachim; Strass, Volker H.; Arrieta, Jesús M.; Bathmann, Ulrich; Berg, Gry M.; Breitbarth, Eike; Cisewski, Boris; Friedrichs, Lars; Fuchs, Nike; Herndl, Gerhard J.; Jansen, Sandra; Krägefsky, Sören; Latasa, Mikel; Peeken, Ilka; Röttgers, Rüdiger; Scharek, Renate; Schüller, Susanne E.; Steigenberger, Sebastian; Webb, Adrian; Wolf-Gladrow, Dieter

2013-01-01

Diatoms of the iron-replete continental margins and North Atlantic are key exporters of organic carbon. In contrast, diatoms of the iron-limited Antarctic Circumpolar Current sequester silicon, but comparatively little carbon, in the underlying deep ocean and sediments. Because the Southern Ocean is the major hub of oceanic nutrient distribution, selective silicon sequestration there limits diatom blooms elsewhere and consequently the biotic carbon sequestration potential of the entire ocean. We investigated this paradox in an in situ iron fertilization experiment by comparing accumulation and sinking of diatom populations inside and outside the iron-fertilized patch over 5 wk. A bloom comprising various thin- and thick-shelled diatom species developed inside the patch despite the presence of large grazer populations. After the third week, most of the thinner-shelled diatom species underwent mass mortality, formed large, mucous aggregates, and sank out en masse (carbon sinkers). In contrast, thicker-shelled species, in particular Fragilariopsis kerguelensis, persisted in the surface layers, sank mainly empty shells continuously, and reduced silicate concentrations to similar levels both inside and outside the patch (silica sinkers). These patterns imply that thick-shelled, hence grazer-protected, diatom species evolved in response to heavy copepod grazing pressure in the presence of an abundant silicate supply. The ecology of these silica-sinking species decouples silicon and carbon cycles in the iron-limited Southern Ocean, whereas carbon-sinking species, when stimulated by iron fertilization, export more carbon per silicon. Our results suggest that large-scale iron fertilization of the silicate-rich Southern Ocean will not change silicon sequestration but will add carbon to the sinking silica flux. PMID:24248337

Formation and Characterization of TiO2/CNT Nanomaterials Dried under Supergravity Conditions

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Minerva Vargas

2009-01-01

Full Text Available The elaboration of bilayer TiO2/CNT films dried under terrestrial gravity conditions (g and on a centrifuge with 1.3g and 7g is reported. The changes in microstructure and thickness of these coatings under supergravity environment cause a red-shift tendency in the optical properties at increasing values of acceleration. Experiments of a drop under enhanced gravity force in the range of 3.7 < Bo (bond number < 51.5 suggest the incomplete elimination of surfactant-water molecules in the TiO2/CNT bilayer film. Increasing acceleration up to 14g will widen the optical differences found, proving the layer-by-layer solution-chemical method in combination with these drying protocols, an alternative to produce thickness-sensitive solar-selective absorbing coatings.

Determination of carbon-reduction-cycle intermediates in leaves of Arbutus unedo L. suffering depressions in photosynthesis after application of abscisic acid or exposure to dry air.

Science.gov (United States)

Loske, D; Raschke, K

1988-02-01

Gas exchange and contents of photosynthetic intermediates of leaves of Arbutus unedo L. were determined with the aim of recognizing the mechanisms of inhibition that were responsible for the "midday depression" of photosynthesis following exposure to dry air, and the decline in photosynthetic capacity following application of abscisic acid (ABA). Rapidly killed (<0.1 s) leaf samples were taken when gas analysis showed reduced CO2 assimilation. Determination of the contents of 3-phosphoglyceric acid (PGA), ribulose 1,5-bisphosphate (RuBP), triose phosphates, fructose 1,6-bisphosphate and hexose phosphates in the samples showed that significant variation occurred only in the level of PGA. As a result, the ratio PGA/RuBP decreased with increasing inhibition of photosynthesis, particularly when application of ABA had been the cause. A comparison of metabolite patterns did not bring out qualitative differences that would have indicated that effects of ABA and of dry air had been caused by separate mechanisms. Depression of photosynthesis occurred in the presence of sufficient RuBP which indicated that the carboxylation reaction of the carbon-reduction-cycle was inhibited after application of ABA or exposure to dry air.

Influence of steaming on drying quality and colour of beech timber

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Milić Goran

2015-01-01

Full Text Available This paper presents the results of an analysis of influence of the “light” steaming process on conventional drying and colour of beech timber. A stack consisting of steamed and unsteamed boards was dried. Moisture content and moisture content profiles were recorded, and at the end of drying final moisture content, moisture content difference across thickness, case-hardening and colour were determinated. No statistically significant difference between steamed and unsteamed timber was established in any of the examined parameters (MC, ΔMC, gap. The results indicate that equal (or even better drying quality can be expected with steamed beech timber than with unsteamed timber, given the same drying schedule. Dry steamed timber was darker and more reddish than the unsteamed one. An imprecision of measurement by probes in the kiln was noticed in measuring steamed and unsteamed beech timber having a moisture content of between 7% and 15%, and a solution for overcoming this problem was given. [Projekat Ministarstva nauke Republike Srbije, br. TR 31041

Efeitos de ciclos de umedecimento e secagem na reorganização da estrutura microgranular de latossolos Effects of wetting and drying cycles on the reorganization of the microgranular structure of latosols

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J. H. M. Viana

2004-02-01

Full Text Available Um experimento foi realizado em casa de vegetação com o objetivo de examinar as modificações provocadas por ciclos de umedecimento e secagem em amostras de Latossolos com diferentes mineralogias, em agregados integrais ou quando destruídos por moagem. Amostras de terra fina seca ao ar foram passadas em peneira de 1,0 mm e subdivididas em grupos: solo integral não moído e solo moído em almofariz e passado em peneira de 0,105 mm. O solo moído foi ainda subdividido em solo moído puro ou adicionado de ácido húmico purificado. Os materiais foram montados em cilindro de alumínio e submetidos a dez ciclos sucessivos de umedecimento e secagem, realizados por ascensão capilar, seguidos por secagem ao ar, com intervalo de sete dias entre cada ciclo. Após o término dos ciclos, os solos foram impregnados com resina de poliéster, montando-se seções finas para microscopia, as quais foram levadas para observação em microscópio ótico e fotografadas. As imagens obtidas foram digitalizadas, analisadas e quantificadas por meio do programa QUANTIPORO, desenvolvido no Departamento de Solos/Universidade Federal de Viçosa. Os resultados mostraram completa modificação na forma e no padrão da estrutura após a aplicação dos ciclos nos tratamentos que sofreram destruição de agregados por moagem. Essas mudanças foram atribuídas a uma reacomodação dos agregados fragmentados com a retração do plasma, que se seguiu ao processo de secagem. Todos os materiais estudados mostraram uma estrutura bem diferente da estrutura primária original destes solos. Não se observou qualquer tendência à reversão da estrutura após os dez ciclos, demonstrando que outros fatores, além dos físico-químicos e mineralógicos, devem ser invocados para explicar a gênese de microagregados em Latossolos.A greenhouse experiment was conducted to examine the structural modifications engendered by wetting-drying cycles in Latosol samples (Oxisols with different

Experiment Analysis of Concrete’s Mechanical Property Deterioration Suffered Sulfate Attack and Drying-Wetting Cycles

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Wei Tian

2017-01-01

Full Text Available The mechanism of concrete deterioration in sodium sulfate solution is investigated. The macroperformance was characterized via its apparent properties, mass loss, and compressive strength. Changes in ions in the solution at different sulfate attack periods were tested by inductively coupled plasma (ICP. The damage evolution law, as well as analysis of the concrete’s meso- and microstructure, was revealed by scanning electron microscope (SEM and computed tomography (CT scanning equipment. The results show that the characteristics of concrete differed at each sulfate attack period; the drying-wetting cycles generally accelerated the deterioration process of concrete. In the early sulfate attack period, the pore structure of the concrete was filled with sulfate attack products (e.g., ettringite and gypsum, and its mass and strength increased. The pore size and porosity decreased while the CT number increased. As deterioration progressed, the swelling/expansion force of products and the salt crystallization pressure of sulfate crystals acted on the inner wall of the concrete to accumulate damage and accelerate deterioration. The mass and strength of concrete sharply decreased. The number and volume of pores increased, and the pore grew more quickly resulting in initiation and expansion of microcracks while the CT number decreased.

New approaches and potential treatments for dry age-related macular degeneration

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Francisco Max Damico

2012-02-01

Full Text Available Emerging treatments for dry age-related macular degeneration (AMD and geographi c atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

Annotated Bibliography for Drying Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Rebecca E. Smith

2011-09-01

Internationally, the nuclear industry is represented by both commercial utilities and research institutions. Over the past two decades many of these entities have had to relocate inventories of spent nuclear fuel from underwater storage to dry storage. These efforts were primarily prompted by two factors: insufficient storage capacity (potentially precipitated by an open-ended nuclear fuel cycle) or deteriorating quality of existing underwater facilities. The intent of developing this bibliography is to assess what issues associated with fuel drying have been identified, to consider where concerns have been satisfactorily addressed, and to recommend where additional research would offer the most value to the commercial industry and the U. S. Department of Energy.

Drying wood waste with a pulse combustion dryer

Energy Technology Data Exchange (ETDEWEB)

Buchkowski, A.G. [Spectrum Engineering Corp., Ltd., Peterborough, Ontario (Canada); Kitchen, J.A. [John A. Kitchen, Ltd., Hastings, Ontario (Canada)

1993-12-31

There is a vast amount of wood waste available to be used as an alternate fuel if its moisture could be reduced efficiently. Tests have been conducted to assess an industrial dryer using pulse combustion as a heating source for drying wood waste; specifically sawdust and pulverized wet hog fuel. Pulse combustion offers the advantage of high heat transfer, efficient combustion, and low NO{sub x} emissions. The material is injected into the exhaust gases in the tailpipe of the combustor which uses natural gas or propane as a fuel. The turbulence created by the pulsations enhance the drying process by reducing the boundary layer thicknesses. The materials is further dried in a rotary drum. The material has been dried without scorching or burning in tests where the inlet moisture content has been as high as 60% on a wet basis. The outlet moisture contents achieved have typically been 10%. Analysis of the test data and cost estimates of the equipment indicate that the pulse combustion drying system is at least comparable to existing systems in terms of operating costs, and offers very significant savings in capital costs. Testing with various other materials such as wood pulp, sludges and peat is continuing to further assess the equipment`s performance.

Future directions and cycles for electricity production from geothermal resources

International Nuclear Information System (INIS)

Michaelides, Efstathios E.

2016-01-01

Graphical abstract: 25% more power may be produced using binary-flashing geothermal cycles. - Highlights: • Power from geothermal power plants is continuously available and “dispatchable.” • The next generation of geothermal will include more binary plants. • Lower temperature geothermal resources will be utilized in the future. • Dry rock resources may produce a high fraction of electricity in several countries. - Abstract: Geothermal power production is economically competitive and capable to produce a high percentage of the electric power demand in several countries. The currently operating geothermal power plants utilize water from an aquifer at relatively higher temperatures and produce power using dry steam, flashing or binary cycles. A glance at the map of the global geothermal resources proves that there is a multitude of sites, where the aquifer temperature is lower. There are also many geothermal resources where a high geothermal gradient exists in the absence of an aquifer. It becomes apparent that the next generation of geothermal power plants will utilize more of the lower-temperature aquifer resources or the dry resources. For such power plants to be economically competitive, modified or new cycles with higher efficiencies must be used. This paper presents two methods to increase the efficiency of the currently used geothermal cycles. The first uses a binary-flashing system to reduce the overall entropy production, thus, producing more electric power from the resource. The second describes a heat extraction system to be used with dry hot-rock resources.

Note: Influence of rinsing and drying routines on growth of multilayer thin films using automated deposition system.

Science.gov (United States)

Gamboa, Daniel; Priolo, Morgan A; Ham, Aaron; Grunlan, Jaime C

2010-03-01

A versatile, high speed robot for layer-by-layer deposition of multifunctional thin films, which integrates concepts from previous dipping systems, has been designed with dramatic improvements in software, positioning, rinsing, drying, and waste removal. This system exploits the electrostatic interaction of oppositely charged species to deposit nanolayers (1-10 nm thick) from water onto the surface of a substrate. Dip times and number of deposited layers are adjustable through a graphical user interface. In between dips the system spray rinses and dries the substrate by positioning it in the two-tiered rinse-dry station. This feature significantly reduces processing time and provides the flexibility to choose from four different procedures for rinsing and drying. Assemblies of natural montmorillonite clay and polyethylenimine are deposited onto 175 microm poly(ethylene terephthalate) film to demonstrate the utility of this automated deposition system. By altering the type of rinse-dry procedure, these clay-based assemblies are shown to exhibit variations in film thickness and oxygen transmission rate. This type of system reproducibly deposits films containing 20 or more layers and may also be useful for other types of coatings that make use of dipping.

Model for economical analysis of oil and gas deepwater production concepts : Comparisons of life cycle cost of subsea production systems vs. floating structures with dry wellheads.

OpenAIRE

Romero Mata, Omar

2010-01-01

Master's thesis in Offshore technology The scope of the work was to create a model that will allow the comparison of Life Cycle Costs (LCC) for subsea production systems and floating structures with dry wellheads for the Mexican territorial waters of the Gulf of Mexico. To give validity to the model, an empirical comparison on the resulting recovery factor based on data of the US Gulf of Mexico was included. This comparison is intended to answer ¿Is there a significant diffe...

Effect of human milk as a treatment for dry eye syndrome in a mouse model.

Science.gov (United States)

Diego, Jose L; Bidikov, Luke; Pedler, Michelle G; Kennedy, Jeffrey B; Quiroz-Mercado, Hugo; Gregory, Darren G; Petrash, J Mark; McCourt, Emily A

Dry eye syndrome (DES) affects millions of people worldwide. Homeopathic remedies to treat a wide variety of ocular diseases have previously been documented in the literature, but little systematic work has been performed to validate the remedies' efficacy using accepted laboratory models of disease. The purpose of this study was to evaluate the efficacy of human milk and nopal cactus (prickly pear), two widely used homeopathic remedies, as agents to reduce pathological markers of DES. The previously described benzalkonium chloride (BAK) dry eye mouse model was used to study the efficacy of human milk and nopal cactus (prickly pear). BAK (0.2%) was applied to the mouse ocular surface twice daily to induce dry eye pathology. Fluorescein staining was used to verify that the animals had characteristic signs of DES. After induction of DES, the animals were treated with human milk (whole and fat-reduced), nopal, nopal extract derivatives, or cyclosporine four times daily for 7 days. Punctate staining and preservation of corneal epithelial thickness, measured histologically at the end of treatment, were used as indices of therapeutic efficacy. Treatment with BAK reduced the mean corneal epithelial thickness from 36.77±0.64 μm in the control mice to 21.29±3.2 μm. Reduction in corneal epithelial thickness was largely prevented by administration of whole milk (33.2±2.5 μm) or fat-reduced milk (36.1±1.58 μm), outcomes that were similar to treatment with cyclosporine (38.52±2.47 μm), a standard in current dry eye therapy. In contrast, crude or filtered nopal extracts were ineffective at preventing BAK-induced loss of corneal epithelial thickness (24.76±1.78 μm and 27.99±2.75 μm, respectively), as were solvents used in the extraction of nopal materials (26.53±1.46 μm for ethyl acetate, 21.59±5.87 μm for methanol). Epithelial damage, as reflected in the punctate scores, decreased over 4 days of treatment with whole and fat-reduced milk but continued to

A present status for dry storage of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Bang, K. S.; Lee, J. C.; Park, H. Y.; Seo, K. S

2003-04-01

National policy for management of a spent nuclear fuel does not establish in Korea yet. A storage capacity of a storage pool that is to store the spent nuclear fuel will be exceeded an amount of accumulation from the first Woljin nuclear power plant in 2007. Therefore it is necessary that dry storage facility is secured to store safely the spent nuclear fuel on site of the nuclear power plant until national policy for a back-end spent nuclear fuel cycle is established. In order to store safely spent nuclear fuel, it is important that the present status and technology on dry storage of spent nuclear fuel is looked over. Therefore, the present status on dry storage of spent nuclear fuel was analyzed so as to develop dry storage system and choose a proper dry storage method domestic.

Wearable carbon nanotube based dry-electrodes for electrophysiological sensors

Science.gov (United States)

Kang, Byeong-Cheol; Ha, Tae-Jun

2018-05-01

In this paper, we demonstrate all-solution-processed carbon nanotube (CNT) dry-electrodes for the detection of electrophysiological signals such as electrocardiograms (ECG) and electromyograms (EMG). The key parameters of P, Q, R, S, and T peaks are successfully extracted by such CNT based dry-electrodes, which is comparable with conventional silver/chloride (Ag/AgCl) wet-electrodes with a conducting gel film for the ECG recording. Furthermore, the sensing performance of CNT based dry-electrodes is secured during the bending test of 200 cycles, which is essential for wearable electrophysiological sensors in a non-invasive method on human skin. We also investigate the application of wearable CNT based dry-electrodes directly attached to the human skins such as forearm for sensing the electrophysiological signals. The accurate and rapid sensing response can be achieved by CNT based dry-electrodes to supervise the health condition affected by excessive physical movements during the real-time measurements.

Comparison of drying characteristic and uniformity of banana cubes dried by pulse-spouted microwave vacuum drying, freeze drying and microwave freeze drying.

Science.gov (United States)

Jiang, Hao; Zhang, Min; Mujumdar, Arun S; Lim, Rui-Xin

2014-07-01

To overcome the flaws of high energy consumption of freeze drying (FD) and the non-uniform drying of microwave freeze drying (MFD), pulse-spouted microwave vacuum drying (PSMVD) was developed. The results showed that the drying time can be dramatically shortened if microwave was used as the heating source. In this experiment, both MFD and PSMVD could shorten drying time by 50% as compared to the FD process. Depending on the heating method, MFD and PSMVD dried banana cubes showed trends of expansion while FD dried samples demonstrated trends of shrinkage. Shrinkage also brought intensive structure and highest fracturability of all three samples dried by different methods. The residual ascorbic acid content of PSMVD dried samples can be as high as in FD dried samples, which were superior to MFD dried samples. The tests confirmed that PSMVD could bring about better drying uniformity than MFD. Besides, compared with traditional MFD, PSMVD can provide better extrinsic feature, and can bring about improved nutritional features because of the higher residual ascorbic acid content. © 2013 Society of Chemical Industry.

Future of lignite resources: a life cycle analysis.

Science.gov (United States)

Wang, Qingsong; Liu, Wei; Yuan, Xueliang; Zheng, Xiaoning; Zuo, Jian

2016-12-01

Lignite is a low-quality energy source which accounts for 13 % of China's coal reserves. It is imperative to improve the quality of lignite for large-scale utilization. To further explore and analyze the influence of various key processes on the environment and economic costs, a lignite drying and compression technology is evaluated using an integrated approach of life cycle assessment and life cycle costs. Results showed that lignite mining, direct air emissions, and electricity consumption have most significant impacts on the environment. An integrated evaluation of life cycle assessment and life cycle costs showed that the most significant contributor to the environmental impacts and economic costs was the lignite mining process. The impact of transportation and wastewater treatment process on the environment and economic costs was small enough to be ignored. Critical factors were identified for reducing the environmental and economic impacts of lignite drying and compression technology. These findings provide useful inputs for both industrial practice and policy making for exploitation, processing, and utilization of lignite resources.

Inadequate thickness of the weight-bearing surface of claws in ruminants : clinical review

Directory of Open Access Journals (Sweden)

A.S. Shakespeare

2009-05-01

Full Text Available The term 'thin soles' refers to the suboptimal thickness of the weight-bearing surface of claws in ruminants. These palmar / plantar surfaces of the claws support the weight of the animal and consist of the distal wall horn, the sole proper, the heel and the minute white line area. The sole should normally only bear weight on uneven or undulating surfaces. A decrease in the thickness of the weight-bearing claw surface will decrease the protective function of this structure and may alter the proportion of weight-bearing by each section with possible detrimental effects on hoof function. Horn tissue readily absorbs water and becomes softer which can lead to increased wear rates. Growth rates normally match wear rates but, unlike the latter, time is needed for the growth rate response to adapt to changes in wear rate. Concrete surfaces can be abrasive and dairy cows that spend their lactation cycle on these floors should be let out to pasture in the dry period so that their claws can recoup lost horn. Frictional coefficient is a measure of the 'slipperiness' of hooves on various surfaces. Newly laid or fresh concrete is not only abrasive but the thin surface suspension of calcium hydroxide that forms has a very alkaline pH which causes keratin degradation and is mostly responsible for the excessive claw wear that occurs. Four case studies are used to illustrate the importance of the distal wall horn, the dangers of over-trimming and the effects of disease and concrete on horn growth and wear rates.

Biomass fueled closed cycle gas turbine with water injection

Energy Technology Data Exchange (ETDEWEB)

Bardi, Silvia [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

2001-01-01

Direct water injection has been studied for a small scale ({approx} 8 MW fuel input) closed cycle gas turbine coupled to a biomass fueled CFB furnace. Two different working fluids have been considered (helium-water mixture and nitrogen-water mixture). The water injection could take place between the compressor stages, as an intercooler, or after the high pressure compressor, as an aftercooler. Both this options have been studied, varying the relative humidity levels after the injection and the temperatures of the injected water. The effect of water injection on thermodynamic properties of the working fluids has been studied, together with its effect on turbomachinery isentropic efficiency. A sensitivity analysis on turbomachinery efficiency and cycle base pressure has been included. The results from this study have been compared to the performance of a dry closed cycle without water injection. The wet cycle shows an electric efficiency in the range 29-32% with helium-water mixture as working fluid and 30-32% with nitrogen-water mixture as working fluid, while the total efficiency (referring to the fuel LHV) is always higher than 100%. In the non-injected cycle the electric efficiency is 30-35% with helium and 32-36 with nitrogen. The total efficiency in the dry case with two level intercooling and postcooling is 87-89%, while is higher than 100% when only one stage inter- and postcooling is present. Aside from this, the study also includes a sizing of the heat exchangers for the different cycle variations. The heat transfer area is very sensible to the working fluid and to the amount of injected water and it's always higher when a nitrogen-water mixture is used. Compared to the cycle without water injection, by the way, the number of heat exchangers is reduced. This will lead to a lower pressure drop and a simpler plant layout. The total heat transfer area, however, is higher in the wet cycle than in the dry cycle.

Sensitivity Variation on Low Cycle Fatigue Cracks Using Level 4/Method B Penetrant

Energy Technology Data Exchange (ETDEWEB)

FULWOOD,HARRY; MOORE,DAVID G.

1999-09-02

The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently conducting experiments with Level 4, Method B penetrant on low cycle fatigue specimens. The main focus of these experiments is to document the affect on penetrant brightness readings by varying inspection parameters. This paper discusses the results of changing drying temperature, drying time, and dwell time of both penetrant and emulsifier on low cycle fatigue specimens.

Thermal stability of double-ceramic-layer thermal barrier coatings with various coating thickness

International Nuclear Information System (INIS)

Dai Hui; Zhong Xinghua; Li Jiayan; Zhang Yanfei; Meng Jian; Cao Xueqiang

2006-01-01

Double-ceramic-layer (DCL) coatings with various thickness ratios composed of YSZ (6-8 wt.% Y 2 O 3 + ZrO 2 ) and lanthanum zirconate (LZ, La 2 Zr 2 O 7 ) were produced by the atmospheric plasma spraying. Chemical stability of LZ in contact with YSZ in DCL coatings was investigated by calcining powder blends at different temperatures. No obvious reaction was observed when the calcination temperature was lower than 1250 deg. C, implying that LZ and YSZ had good chemical applicability for producing DCL coating. The thermal cycling test indicate that the cycling lives of the DCL coatings are strongly dependent on the thickness ratio of LZ and YSZ, and the coatings with YSZ thickness between 150 and 200 μm have even longer lives than the single-layer YSZ coating. When the YSZ layer is thinner than 100 μm, the DCL coatings failed in the LZ layer close to the interface of YSZ layer and LZ layer. For the coatings with the YSZ thickness above 150 μm, the failure mainly occurs at the interface of the YSZ layer and the bond coat

Research of selection seeds drying in dense layer

Directory of Open Access Journals (Sweden)

S. A. Pavlov

2018-01-01

Full Text Available At the choice of the mode of safe drying of grain mass it is necessary to consider its heterogeneity on moisture content. It is an undesirable factor of which it is necessary to get rid. When increase in moisture inconstant the stability of grain mass at storage decreases, there is a danger of emergence of heating, the overall performance of dryers and other processing equipment decreases, energy costs for seeds production rise. To eliminate this shortcoming located in a grain layer or grain stream the dried-up product should be mixed carefully for the best uniformity. However not uniformity on individual moisture content of separate grains will remain. For its decrease combination of lying with material concitation is used. Researches were conducted in batch-operated laboratory machine. The humidified seeds of sugar beet were blowed-through with the drying agent speed of 0.5 m/s and temperature of 45 degrees Celsius. Moisture removal between concitations did not exceed 2.5 percent for selection seeds and 3.0 percent for ordinary ones. Duration of the periods between concitations can be determined in the analytical way. Thickness of a layer of seeds allowing drying without concitation decreases on square dependence on increase in moisture content. A contact moisture exchange between the damp and dried caryopsides for 30 min and more make it possibledrop-off in the unevenness of drying up to 0.5 percent.

Review of the Drying Kinetics of Olive Oil Mill Wastes: Biomass Recovery

Directory of Open Access Journals (Sweden)

Francisco J. Gómez-de la Cruz

2015-06-01

Full Text Available The drying kinetics of olive oil mill wastes was analyzed based on experiments carried out by various researchers utilizing different drying systems. A critical review of the literature was done, and mathematical models of drying curves proposed by investigators were evaluated. A comparison between the best mathematical models of fit in the drying curves used in past experiments and a two-term Gaussian model was performed. This model improved all the results of fit in each experiment. Drying rates and drying stages were obtained and discussed. An average drying rate for each experiment from the two-term Gaussian model was calculated. This value allowed for visualizing and comparing the average speed of evaporated water in each experiment for the different dryers. Finally, and after having verified that almost all drying occurs mainly by a diffusion phenomenon, an analysis on the effective moisture diffusivity and activation energy values was performed. The results indicated that there was no dependency of these quantities on independent variables such as the drying air temperature, the drying air velocity, and the sample thickness. It follows that drying of olive oil mill wastes is a very complex physical process that depends heavily on aspects such as pieces of pit, pulp, skin, vegetation water, olive oil content, sugars and organics compounds of different nature.

Effect of Sb thickness on the performance of bialkali-antimonide photocathodes

Energy Technology Data Exchange (ETDEWEB)

Mamun, Md Abdullah A., E-mail: mmamu001@odu.edu; Elmustafa, Abdelmageed A. [Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, Virginia 23529 and The Applied Research Center, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Hernandez-Garcia, Carlos; Mammei, Russell; Poelker, Matthew [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

2016-03-15

The alkali species Cs and K were codeposited using an effusion source, onto relatively thick layers of Sb (50 nm to ∼7 μm) grown on GaAs and Ta substrates inside a vacuum chamber that was baked and not-vented, and also baked and vented with clean dry nitrogen but not rebaked. The characteristics of the Sb films, including sticking probability, surface roughness, grain size, and crystal properties were very different for these conditions, yet comparable values of photocathode yield [or quantum efficiency (QE)] at 284 V were obtained following codeposition of the alkali materials. Photocathodes manufactured with comparatively thick Sb layers exhibited the highest QE and the best 1/e lifetime. The authors speculate that the alkali codeposition enabled optimized stoichiometry for photocathodes manufactured using thick Sb layers, which could serve as a reservoir for the alkali materials.

Evolution of spent fuel dry storage

Energy Technology Data Exchange (ETDEWEB)

Standring, Paul Nicholas [International Atomic Energy Agency, Vienna (Austria). Div. of Nuclear Fuel Cycle and Waste Technology; Takats, Ferenc [TS ENERCON KFT, Budapest (Hungary)

2016-11-15

Around 10,000 tHM of spent fuel is discharged per year from the nuclear power plants in operation. Whilst the bulk of spent fuel is still held in at reactor pools, 24 countries have developed storage facilities; either on the reactor site or away from the reactor site. Of the 146 operational AFR storage facilities about 80 % employ dry storage; the majority being deployed over the last 20 years. This reflects both the development of dry storage technology as well as changes in politics and trading relationships that have affected spent fuel management policies. The paper describes the various approaches to the back-end of the nuclear fuel cycle for power reactor fuels and provides data on deployed storage technologies.

The study of some physical properties and energy aspects of potatoes drying process by the infrared-vacuum method

Directory of Open Access Journals (Sweden)

N Hafezi

2016-09-01

laboratory scale vacuum-infrared dryer, developed at the Agricultural Machinery and Mechanization Engineering Laboratory of Shahid Chamran University of Ahvaz has been used. The dryer consists of a stainless steel drying chamber; a laboratory type piston vacuum pump, which was used to maintain vacuum in the drying chamber; an infrared lamp with power of 250 W which was used to supply thermal radiation to a drying product; and a control system for the infrared radiator. Sample Preparation Fresh potatoes were purchased from a local market in Hamadan province. Potatoes were peeled, washed, and cut into sliced with thickness of 1, 2 and 3 mm by a manual slicer. Drying experiments of potato slices were performed in a vacuum chamber with absolute pressure levels of 20, 80, 140 and 760 mmHg; and radiation intensity of infrared lamp was 0.2, 0.3 and 0.4 W cm-2. The mass change of the sample during drying was detected continuously using an electronic weight scale (Lutron, GM- 1500P, Taiwan with the accuracy of ±0.05 g. Evaluation of rehydration capacity of dried potato slices The rehydration tests measured the gain in weight of dehydrated samples (~5 g, dehydrated samples were rehydrated in 200 cc of distilled water at 100°C for 3 minutes. Evaluation of color The color of potatoes was measured on five slices selected randomly, and was described by three coordinates in the RGB color space using computer vision. Evaluation of specific energy consumption Energy consumption of dying process came from the electrical energy consumed by the operation of the vacuum pump and the infrared lamp. Specific energy consumption was defined as the energy required for removing a unit mass of water in drying the potato slice. Evaluation of thermal utilization efficiency Thermal utilization efficiency is defined as the latent heat of vaporization of moisture of sample to the amount of energy required to evaporate moisture from free water. The latent heat of vaporization of water at the evaporating

Modeling of dimensional changes of spent WWER fuel rods during dry storage

International Nuclear Information System (INIS)

Aliev, T.; Evdokimov, I.; Likhanskii, V.; Sorokin, A.; Kolesnik, M.; Kozhakin, A.; Zborovskii, V.; Zvir, E.; Ilyin, P.

2015-01-01

The engineering model of anisotropic creep is developed to predict the behavior of WWER fuel rods in dry storage of spent fuel. The model considers several deformation mechanisms, the main one being the dislocation creep. The effects of radiation defects accumulation and its partial annealing during storage, as well as work hardening are taken into account. Based on the available experimental data preliminary verification of the developed model is performed. The model adequately describes the data set used. Conditions of experiments conducted up to date are more severe in temperature and stresses than ones in dry storage. It is shown that in dry storage additional deformation mechanisms play an important role. One such mechanism is the creep induced by temperature cycling that occurs during the experiments. Thermal cycles produce internal stresses caused by thermal expansion anisotropy in α-Zr crystallites. This mechanism makes a significant contribution to the experimentally measured strain at stresses characteristic for spent fuel claddings. Additional experimental research is planned to expand the range of Verification Matrix to the prototype conditions for dry storage and to improve prediction accuracy of the model. (author)

Simulation of energetic- and exergetic performance of microwave-assisted fluidized bed drying of soybeans

International Nuclear Information System (INIS)

Ranjbaran, M.; Zare, D.

2013-01-01

The performance of microwave-assisted fluidized bed drying of soybeans was simulated (using a previously validated mathematical model) and analyzed based on the first- and second law of thermodynamics. The energy and exergy analysis were carried out for several drying conditions. The effects of inlet air temperature, microwave power density, bed thickness and inlet air velocity on the efficiencies and inefficiencies of drying process have been simulated and discussed. Generally, application of microwave energy during fluidized bed drying enhanced the exergy efficiency of drying process. However, the results showed that it was more efficient not to apply microwave energy at the first stage of fluidized bed drying process. The application of higher levels of drying air temperature led in higher exergy efficiencies. The values of mean relative deviations for the predictions of efficiencies and inefficiencies of drying process were less than 14%, compared with those calculated using experimental data. - Highlights: • Introducing a mathematical model to predict the efficiency of microwave-assisted fluidized bed dryers. • Energy and exergy analysis in microwave-assisted fluidized bed drying of grains. • Providing practical recommendations for efficient use of microwave power during drying

Al2O3 Coated Concentration-Gradient Li[Ni0.73Co0.12Mn0.15]O2 Cathode Material by Freeze Drying for Long-Life Lithium Ion Batteries

International Nuclear Information System (INIS)

Wang, Jingpeng; Du, Chunyu; Yan, Chunqiu; He, Xiaoshu; Song, Bai; Yin, Geping; Zuo, Pengjian; Cheng, Xinqun

2015-01-01

Highlights: • Al 2 O 3 -coated concentration-gradient oxide is synthesized by a freeze drying method. • The effect of Al 2 O 3 -coating on concentration-gradient cathode is firstly studied. • Al 2 O 3 -coated sample exhibits high capacity and significantly enhanced cyclability. • Improved cyclability is ascribed to the effective protection of uniform Al 2 O 3 layer. - Abstract: In order to enhance the electrochemical performance of the high capacity layered oxide cathode with a Ni-rich core and a concentration-gradient shell (NRC-CGS), we use a freeze drying method to coat Al 2 O 3 layer onto the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, charge-discharge measurements and electrochemical impedance spectroscopy. It is revealed that an amorphous Al 2 O 3 layer of about 5 nm in thickness is uniformly formed on the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material by the freeze drying procedure. The freeze drying Al 2 O 3 -coated (FD-Al 2 O 3 -coated) sample demonstrates similar discharge capacity and significantly enhanced cycling performances, in comparison to the pristine and conventional heating drying Al 2 O 3 -coated (HD-Al 2 O 3 -coated) samples. The capacity decay rate of FD-Al 2 O 3 -coated Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material is 1.7% after 150 cycles at 55 °C, which is 9 and 12 times lower than that of the pristine and HD-Al 2 O 3 -coated samples. The superior electrochemical stability of the FD-Al 2 O 3 -coated sample is attributed to the synergistic protection of CGS and high-quality Al 2 O 3 coating that effectively protect the active material from electrolyte attack. The freeze drying process provides an effective method to prepare the high performance surface-coated electrode materials

The effect of wet-dry weathering on the rate of bedrock river channel erosion by saltating gravel

Science.gov (United States)

Inoue, Takuya; Yamaguchi, Satomi; Nelson, Jonathan M.

2017-01-01

Previous work has shown that the bedrock erosion rate E because of collisions of saltating bedload can be expressed by E = βqb(1-Pc), where qb is the sediment transport rate, Pc is the extent of alluvial cover, and β is the abrasion coefficient. However, the dependence of the abrasion coefficient on the physical characteristics of the bedrock material is poorly known, and in particular, the effects of wet-dry weathering on the saltation-abrasion bedrock incision has not been specifically characterized. Observation suggests that the typical wet-dry cycling of exposed bedrock in river beds gives rise to cracks and voids that are likely to alter the incision rate of the material when subjected to impacts of moving sediment. In this study, flume experiments are performed to develop an understanding of how wet-dry cycling affects the rock tensile strength and the bedrock erosion rate. To represent the physical effects of weathering, boring cores taken from natural bedrock channel are exposed to artificial wet-dry cycles. The experimental results suggest the following: (1) the abrasion coefficient for fresh bedrock is estimated by β = 1.0 × 10− 4σT− 2(d/ksb)0.5, where σT is the tensile strength, d is the diameter of colliding gravel, and ksb is the hydraulic roughness height of bedrock; (2) the tensile strength of the bedrock decreases exponentially as a result of repeated wet-dry cycles, σT/σT0 = exp (-CTNWa0/σT0), where σT0 is the initial tensile strength, Wa0 is the initial normalized rate of water absorption., N is the number of wet-dry cycles, and CT is a constant; (3) the erosion rate of fresh bedrock depends on the inverse of the square of tensile strength, but the erosion rate of weathered bedrock depends on the − 1.5 power of tensile strength.

Dynamic Analysis of the Thorium Fuel Cycle in CANDU Reactors

International Nuclear Information System (INIS)

Jeong, Chang Joon; Park, Chang Je

2006-02-01

The thorium fuel recycle scenarios through the Canada deuterium uranium (CANDU) reactor have been analyzed for two types of thorium fuel: homogeneous ThO 2 UO 2 and ThO 2 UO 2 -DUPIC fuels. The recycling is performed through the dry process fuel technology which has a proliferation resistance. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 0%. After setting up the once-through fuel cycle model, the thorium fuel CANDU reactor was modeled to investigate the fuel cycle parameters. In this analysis, the spent fuel inventory as well as the amount of plutonium, minor actinides and fission products of the multiple recycling fuel cycle were estimated and compared to those of the once-through fuel cycle. From the analysis results, it was found that the closed or partially closed thorium fuel cycle can be constructed through the dry process technology. Also, it is known that both the homogeneous and heterogeneous thorium fuel cycles can reduce the SF accumulation and save the natural uranium resource compared with the once-through cycle. From the material balance view point, the heterogeneous thorium fuel cycle seems to be more feasible. It is recommended, however, the economic analysis should be performed in future

Dynamic Analysis of the Thorium Fuel Cycle in CANDU Reactors

Energy Technology Data Exchange (ETDEWEB)

Jeong, Chang Joon; Park, Chang Je

2006-02-15

The thorium fuel recycle scenarios through the Canada deuterium uranium (CANDU) reactor have been analyzed for two types of thorium fuel: homogeneous ThO{sub 2}UO{sub 2} and ThO{sub 2}UO{sub 2}-DUPIC fuels. The recycling is performed through the dry process fuel technology which has a proliferation resistance. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 0%. After setting up the once-through fuel cycle model, the thorium fuel CANDU reactor was modeled to investigate the fuel cycle parameters. In this analysis, the spent fuel inventory as well as the amount of plutonium, minor actinides and fission products of the multiple recycling fuel cycle were estimated and compared to those of the once-through fuel cycle. From the analysis results, it was found that the closed or partially closed thorium fuel cycle can be constructed through the dry process technology. Also, it is known that both the homogeneous and heterogeneous thorium fuel cycles can reduce the SF accumulation and save the natural uranium resource compared with the once-through cycle. From the material balance view point, the heterogeneous thorium fuel cycle seems to be more feasible. It is recommended, however, the economic analysis should be performed in future.

INFLUENCE OF EMBRYO IMPLANTATION ON ENDOMETRIUM IN LUTEAL PHASE OF MENSTRUAL CYCLE

Directory of Open Access Journals (Sweden)

Romana Dmitrović

2018-02-01

Full Text Available Background: Based on the facts known from embryology, rapid endometrial growth during late luteal phase of the cycle could be expected. In this research, we sought to establish if normal intrauterine pregnancy could be confirmed before gestational sac vizualization, by trans- vaginal ultrasound and hormonal tests. The primary hypothesis was that the endometrial thickness and/or volume in the luteal phase of the cycle, in cycles resulting in normal intra- uterine pregnancy, is significantly different compared to non-conception cycles. We also hypothesized that endometrial thickness and/or volume are different in cycles resulting in normal intrauterine pregnancy compared to cycles resulting in abnormal pregnancy, namely biochemical and ectopic pregnancy, and spontaneous abortion. Additionally, next to endometrial volumes, we decided to measure the endometrium in three planes (thick- ness, length and width, to see if the hypothesized endometrial volume differences could be approximated by this simple surrogate technique, which is available in most parts of the world. Methods: This was a prospective observational study of women enrolled in an assisted reproduction program. Patients were stimulated with standard stimulation protocols. The oocyte retrieval was performed 36 hours after the hCG administration and the embryo was transferred 3 or 5 days later. Patients were first seen on day 20–24 of the cycle , and then on day 27–30 of the cycle. A blood sample was taken, and 3D transvaginal ultrasound was done. Following the completion of study visits, patients with a positive HCG test received phone call check- ups until week 12 of pregnancy, and were stratified according to pregnancy outcome. Results: 80 subjects signed the informed consent form. 4 patients had the IUI in the stimulated cycle, one had ET in spontaneous cycle, and 74 patients had undergone IVF/ET in the stimulated cycle. 63 patients in the stimulated cycles completed the study and

Dry syngas purification process for coal gas produced in oxy-fuel type integrated gasification combined cycle power generation with carbon dioxide capturing feature.

Science.gov (United States)

Kobayashi, Makoto; Akiho, Hiroyuki

2017-12-01

Electricity production from coal fuel with minimizing efficiency penalty for the carbon dioxide abatement will bring us sustainable and compatible energy utilization. One of the promising options is oxy-fuel type Integrated Gasification Combined Cycle (oxy-fuel IGCC) power generation that is estimated to achieve thermal efficiency of 44% at lower heating value (LHV) base and provide compressed carbon dioxide (CO 2 ) with concentration of 93 vol%. The proper operation of the plant is established by introducing dry syngas cleaning processes to control halide and sulfur compounds satisfying tolerate contaminants level of gas turbine. To realize the dry process, the bench scale test facility was planned to demonstrate the first-ever halide and sulfur removal with fixed bed reactor using actual syngas from O 2 -CO 2 blown gasifier for the oxy-fuel IGCC power generation. Design parameter for the test facility was required for the candidate sorbents for halide removal and sulfur removal. Breakthrough test was performed on two kinds of halide sorbents at accelerated condition and on honeycomb desulfurization sorbent at varied space velocity condition. The results for the both sorbents for halide and sulfur exhibited sufficient removal within the satisfactory short depth of sorbent bed, as well as superior bed conversion of the impurity removal reaction. These performance evaluation of the candidate sorbents of halide and sulfur removal provided rational and affordable design parameters for the bench scale test facility to demonstrate the dry syngas cleaning process for oxy-fuel IGCC system as the scaled up step of process development. Copyright © 2017 Elsevier Ltd. All rights reserved.

High speed dry machining of MMCs with diamond tools

International Nuclear Information System (INIS)

Collins, J.L.

2001-01-01

The increasing use of metal matrix composites (MMCs) has raised new issues in their machining. Industrial demands for higher speed and dry machining of MMCs with improved component production to closer tolerances have driven the development of new tool materials. In particular, the wear characteristics of synthetic diamond tooling satisfy many of the requirements imposed in cutting these highly abrasive workpieces. The use of diamond tool materials, such as polycrystalline diamond (PCD), has resulted in tool life improvements which, allied with environmental considerations, show great potential for the development of dry cutting. This paper explores the wear characteristics of PCD, which is highly suited to the dry machining of particulate silicon carbide MMCs. Also, two further diamond tool materials are evaluated - chemical vapor deposition (CVD) thick layer diamond and synthetic single crystal diamond. Their suitability for the efficient machining of high volume fraction MMC materials is shown and their potential impact an the subsequent acceptance and integration of MMCs into engineering components is discussed. (author)

Power generation from a 7700C heat source by means of a main steam cycle, a topping closed gas cycle and a ammonia bottoming cycle

International Nuclear Information System (INIS)

Tilliette, Z.P.

1981-03-01

For power generation, steam cycles make an efficient use of medium temperature heat sources. They can be adapted to dry cooling, higher power ratings and output increase in winter by addition of an ammonia bottoming cycle. Active development is carried out in this field by 'Electricite de France'. As far as heat sources at higher temperatures are concerned, particularly related to coal-fired or nuclear power plants, a more efficient way of converting energy is at first to expand a hot working fluid through a gas turbine. It is shown in this paper that a satisfactory result, for heat sources of about 770 0 C, is obtained with a topping closed gas cycle of moderate power rating, rejecting its waste heat into the main steam cycle. Attention has to be paid to this gas cycle waste heat recovery and to the coupling of the gas and steam cycles. This concept drastically reduces the importance of new technology components. The use and the significance of an ammonia bottoming cycle in this case are investigated

Dry Refabrication Technology Development of Spent Nuclear Fuel

International Nuclear Information System (INIS)

Lee, Jung Won; Park, G. I.; Park, C. J.

2010-04-01

Key technical data on advanced nuclear fuel cycle technology development for the spent fuel recycling have been produced in this study. In the frame work of DUPIC, dry process oxide products fabrication, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remote modulated welding equipment has been designed and fabricated. In the area of advanced pre-treatment process development, a rotary-type oxidizer and spherical particle fabrication process were developed by using SIMFUEL and off-gas treatment technology and zircalloy tube treatment technology were studied. In the area of the property characteristics of dry process products, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data

Cradle-to-gate life cycle assessment of the dry etching step in the manufacturing of photovoltaic cells

Directory of Open Access Journals (Sweden)

Otto Andersen

2014-11-01

Full Text Available A new photovoltaic silicon crystalline solar cell dry chemical etching process (DCEP is developed. It is an alternative to the current State-of-the-Art (SoA wet chemical etching process (WCEP, associated with relatively large environmental loadings in the form of high water consumption and emissions of greenhouse gases with high Global Warming Potential (GWP. In order to compare the environmental impacts of DCEP to the corresponding impacts from WCEP, a comparative attributional life cycle assessment (LCA is conducted. From the LCA it can be concluded that the DCEP will lead to 86% reduction in water consumption compared to WCEP (acidic, and 89% reduction compared to WCEP (alkaline. The emissions of greenhouse gases, as expressed by the GWP100 indicator of the etching step, are also reduced with 63% and 20% respectively, when compared with current SoA acidic and alkaline WCEP. The toxicity impacts are also assessed to be lower for the DCEP compared to WCEP technologies, although the uncertainty is relatively high for the applied toxicity indicators. All in all, DCEP can reduce the CO2eq emissions of solar photovoltaic systems production by 5-10%.

Review of the literature for dry reprocessing oxide, metal, and carbide fuel: The AIROX, RAHYD, and CARBOX pyrochemical processes

Energy Technology Data Exchange (ETDEWEB)

Hoyt, R.C.; Rhee, B.W. [Rockwell International Corp., Canoga Park, CA (United States). Energy Systems Group

1979-09-30

The state of the art of dry processing oxide, carbide, and metal fuel has been determined through an extensive literature review. Dry processing in one of the most proliferation resistant fuel reprocessing technologies available to date, and is one of the few which can be exported to other countries. Feasibility has been established for oxide, carbide, and metal fuel on a laboratory scale, and large-scale experiments on oxide and carbide fuel have shown viability of the dry processing concept. A complete dry processing cycle has been demonstrated by multicycle processing-refabrication-reirradiation experiments on oxide fuel. Additional experimental work is necessary to: (1) demonstrate the complete fuel cycle for carbide and metal fuel, (2) optimize dry processing conditions, and (3) establish fission product behavior. Dry process waste management is easier than for an aqueous processing facility since wastes are primarily solids and gases. Waste treatment can be accomplished by techniques which have been, or are being, developed for aqueous plants.

Effect of simultaneous infrared dry-blanching and dehydration on quality characteristics of carrot slices

Science.gov (United States)

This study investigated the effects of various processing parameters on carrot slices exposed to infrared (IR) radiation heating for achieving simultaneous infrared dry-blanching and dehydration (SIRDBD). The investigated parameters were product surface temperature, slice thickness and processing ti...

Interim dry fuel storage for magnox reactors

Energy Technology Data Exchange (ETDEWEB)

Bradley, N [National Nuclear Corporation, Risley, Warrington (United Kingdom); Ealing, C [GEC Energy Systems Ltd, Whetstone, Leicester (United Kingdom)

1985-07-01

In the UK the practice of short term buffer storage in water ponds prior to chemical reprocessing had already been established on the early gas cooled reactors in Calder Hall. Thus the choice of water pond buffer storage for MGR power plants logically followed the national policy decision to reprocess. The majority of the buffer storage period would take place at the reprocessing plant with only a nominal of 100 days targeted at the station. Since Magnox clad fuel is not suitable for long term pond storage, alternative methods of storage on future stations was considered desirable. In addition to safeguards considerations the economic aspects of the fuel cycle has influenced the conclusion that today the purchase of a MGR power plant with dry spent fuel storage and without commitment to reprocess would be a rational decision for a country initiating a nuclear programme. Dry storage requirements are discussed and two designs of dry storage facilities presented together with a fuel preparation facility.

Interim dry fuel storage for magnox reactors

International Nuclear Information System (INIS)

Bradley, N.; Ealing, C.

1985-01-01

In the UK the practice of short term buffer storage in water ponds prior to chemical reprocessing had already been established on the early gas cooled reactors in Calder Hall. Thus the choice of water pond buffer storage for MGR power plants logically followed the national policy decision to reprocess. The majority of the buffer storage period would take place at the reprocessing plant with only a nominal of 100 days targeted at the station. Since Magnox clad fuel is not suitable for long term pond storage, alternative methods of storage on future stations was considered desirable. In addition to safeguards considerations the economic aspects of the fuel cycle has influenced the conclusion that today the purchase of a MGR power plant with dry spent fuel storage and without commitment to reprocess would be a rational decision for a country initiating a nuclear programme. Dry storage requirements are discussed and two designs of dry storage facilities presented together with a fuel preparation facility

Dry refabrication technology development of spent nuclear fuel

International Nuclear Information System (INIS)

Park, Geun Il; Lee, J. W.; Song, K. C.

2012-04-01

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed

Dry refabrication technology development of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Park, Geun Il; Lee, J. W.; Song, K. C.; and others

2012-04-15

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed.

Fuzzy Rule Suram for Wood Drying

Science.gov (United States)

Situmorang, Zakarias

2017-12-01

Implemented of fuzzy rule must used a look-up table as defuzzification analysis. Look-up table is the actuator plant to doing the value of fuzzification. Rule suram based of fuzzy logic with variables of weather is temperature ambient and humidity ambient, it implemented for wood drying process. The membership function of variable of state represented in error value and change error with typical map of triangle and map of trapezium. Result of analysis to reach 4 fuzzy rule in 81 conditions to control the output system can be constructed in a number of way of weather and conditions of air. It used to minimum of the consumption of electric energy by heater. One cycle of schedule drying is a serial of condition of chamber to process as use as a wood species.

Effect of thickness on electrical properties of SILAR deposited SnS thin films

Science.gov (United States)

Akaltun, Yunus; Astam, Aykut; Cerhan, Asena; ćayir, Tuba

2016-03-01

Tin sulfide (SnS) thin films of different thickness were prepared on glass substrates by successive ionic layer adsorption and reaction (SILAR) method at room temperature using tin (II) chloride and sodium sulfide aqueous solutions. The thicknesses of the films were determined using spectroscopic ellipsometry measurements and found to be 47.2, 65.8, 111.0, and 128.7nm for 20, 25, 30 and 35 deposition cycles respectively. The electrical properties of the films were investigated using d.c. two-point probe method at room temperature and the results showed that the resistivity was found to decrease with increasing film thickness.

Reproductive cycles in tropical intertidal gastropods are timed around tidal amplitude cycles.

Science.gov (United States)

Collin, Rachel; Kerr, Kecia; Contolini, Gina; Ochoa, Isis

2017-08-01

Reproduction in iteroparous marine organisms is often timed with abiotic cycles and may follow lunar, tidal amplitude, or daily cycles. Among intertidal marine invertebrates, decapods are well known to time larval release to coincide with large amplitude nighttime tides, which minimizes the risk of predation. Such bimonthly cycles have been reported for few other intertidal invertebrates. We documented the reproduction of 6 gastropod species from Panama to determine whether they demonstrate reproductive cycles, whether these cycles follow a 2-week cycle, and whether cycles are timed so that larval release occurs during large amplitude tides. Two of the species ( Crepidula cf. marginalis and Nerita scabricosta ) showed nonuniform reproduction, but without clear peaks in timing relative to tidal or lunar cycles. The other 4 species show clear peaks in reproduction occurring every 2 weeks. In 3 of these species ( Cerithideopsis carlifornica var. valida, Littoraria variegata , and Natica chemnitzi ), hatching occurred within 4 days of the maximum amplitude tides. Siphonaria palmata exhibit strong cycles, but reproduction occurred during the neap tides. Strong differences in the intensity of reproduction of Cerithideopsis carlifornica , and in particular, Littoraria variegata , between the larger and smaller spring tides of a lunar month indicate that these species time reproduction with the tidal amplitude cycle rather than the lunar cycle. For those species that reproduce during both the wet and dry seasons, we found that reproductive timing did not differ between seasons despite strong differences in temperature and precipitation. Overall, we found that most (4/6) species have strong reproductive cycles synchronized with the tidal amplitude cycle and that seasonal differences in abiotic factors do not alter these cycles.

Structure modification of Mg-Nb films under hydrogen sorption cycles

Energy Technology Data Exchange (ETDEWEB)

Mengucci, P., E-mail: p.mengucci@univpm.it [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita Politecnica delle Marche, Via Brecce Bianche, I-60131 Ancona (Italy); Barucca, G.; Majni, G. [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita Politecnica delle Marche, Via Brecce Bianche, I-60131 Ancona (Italy); Bazzanella, N.; Checchetto, R.; Miotello, A. [Dipartimento di Fisica, Universita di Trento, Via Sommarive, I-38123 Povo (Italy)

2011-09-15

Research highlights: > Influence of Nb additions on the hydrogen kinetics of Mg layers. > Structure modification of the Mg matrix during hydrogen cycling. > Lattice strains induced by Nb tends to decrease during hydrogen cycling. > Nb nanoparticles form during hydrogen cycling. > Nb enhances the porous structure of the Mg layer formed during hydrogen cycling. - Abstract: In the present work we focus our attention on the structural modifications induced by repeated absorption/desorption cycles on Mg-Nb layers. Samples consisting of a 30 {mu}m thick pure Mg or Mg-5 at.% Nb doped films, coated with a 20 nm thick Pd layer were submitted to repeated H{sub 2} sorption cycles in a volumetric apparatus. Isothermal desorption analysis at 350 deg. C was performed to evaluate the amount of absorbed hydrogen. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and electron microscopy techniques (SEM and TEM) were used for the structural characterisation of the samples. Analyses show a deep modification of the material upon cycling. The presence of Nb enhances the structural modifications and induces an initial lattice contraction of the Mg matrix that tends to decrease on cycling via the formation of Nb nanoparticles (with average size of {approx}10 nm). SEM and TEM observations performed in cross section evidenced the formation of a porous structure.

Effect of harvest period on foliage production and dry matter distribution in five cassava cultivars during the second plant cycle

Directory of Open Access Journals (Sweden)

Edvaldo Sagrilo

2006-11-01

Full Text Available The objective of this work was to study the leaf production pattern and dry matter distribution in cassava during the second plant cycle. The completely randomized experimental design with four replications was used, with five cultivars in the main plots and ten harvest times in the sub-plots. Foliage production was affected by plant age, being higher in hot periods. Leaf blades and petioles dry matter content presented a linear increase due to a progressive decrease in the amount of young leaves and ontogenetic factors. The stems provided, temporarily, carbohydrates to the plant re-growth, delaying the availability and use of storage roots dry matter. The dry matter content in the storage roots was lower during the vegetative and higher during rest period. The storage roots diameter increased considerably when the amount of leaves was higher, indicating the importance of leaf area in the cassava plant production.O experimento foi conduzido de outubro de 1997 a maio de 1999, no Noroeste do Paraná, Brasil, com o objetivo de avaliar o padrão de produção de folhas e distribuição de massa seca em 5 cultivares de mandioca, durante o segundo ciclo vegetativo. Utilizou-se o delineamento experimental em blocos casualizados, com 4 repetições, no esquema de parcelas subdivididas, estando as cultivares nas parcelas e as épocas de colheita nas subparcelas. A produção de folhas foi afetada pela idade das plantas, sendo maior nos períodos de temperatura elevada. Os teores de massa seca nos limbos foliares e pecíolos aumentaram linearmente com a idade das plantas, devido à menor proporção de folhas jovens e a fatores ontogênicos inerentes à planta. As hastes proporcionaram, temporariamente, os assimilados necessários para a reestruturação vegetativa das plantas, protelando a disponibilidade e uso dos carboidratos armazenados nas raízes. O teor de massa seca nas raízes foi menor durante o período de crescimento vegetativo e maior

Modelling and experimental validation of thin layer indirect solar drying of mango slices

Energy Technology Data Exchange (ETDEWEB)

Dissa, A.O.; Bathiebo, J.; Kam, S.; Koulidiati, J. [Laboratoire de Physique et de Chimie de l' Environnement (LPCE), Unite de Formation et de Recherche en Sciences Exactes et Appliquee (UFR/SEA), Universite de Ouagadougou, Avenue Charles de Gaulle, BP 7021 Kadiogo (Burkina Faso); Savadogo, P.W. [Laboratoire Sol Eau Plante, Institut de l' Environnement et de Recherches Agricoles, 01 BP 476, Ouagadougou (Burkina Faso); Desmorieux, H. [Laboratoire d' Automatisme et de Genie des Procedes (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bat.308G, 43 bd du 11 Nov. 1918 Villeurbanne, Universite Claude Bernard Lyon1, Lyon (France)

2009-04-15

The thin layer solar drying of mango slices of 8 mm thick was simulated and experimented using a solar dryer designed and constructed in laboratory. Under meteorological conditions of harvest period of mangoes, the results showed that 3 'typical days' of drying were necessary to reach the range of preservation water contents. During these 3 days of solar drying, 50%, 40% and 5% of unbound water were eliminated, respectively, at the first, second and the third day. The final water content obtained was about 16 {+-} 1.33% d.b. (13.79% w.b.). This final water content and the corresponding water activity (0.6 {+-} 0.02) were in accordance with previous work. The drying rates with correction for shrinkage and the critical water content were experimentally determined. The critical water content was close to 70% of the initial water content and the drying rates were reduced almost at 6% of their maximum value at night. The thin layer drying model made it possible to simulate suitably the solar drying kinetics of mango slices with a correlation coefficient of r{sup 2} = 0.990. This study thus contributed to the setting of solar drying time of mango and to the establishment of solar drying rates' curves of this fruit. (author)

Water level fluctuations in a tropical reservoir: the impact of sediment drying, aquatic macrophyte dieback, and oxygen availability on phosphorus mobilization.

Science.gov (United States)

Keitel, Jonas; Zak, Dominik; Hupfer, Michael

2016-04-01

Reservoirs in semi-arid areas are subject to water level fluctuations (WLF) that alter biogeochemical processes in the sediment. We hypothesized that wet-dry cycles may cause internal eutrophication in such systems when they affect densely vegetated shallow areas. To assess the impact of WLF on phosphorus (P) mobilization and benthic P cycling of iron-rich sediments, we tested the effects of (i) sediment drying and rewetting, (ii) the impact of organic matter availability in the form of dried Brazilian Waterweed (Egeria densa), and (iii) alternating redox conditions in the surface water. In principle, drying led to increased P release after rewetting both in plant-free and in plant-amended sediments. Highest P mobilization was recorded in plant amendments under oxygen-free conditions. After re-establishment of aerobic conditions, P concentrations in surface water decreased substantially owing to P retention by sediments. In desiccated and re-inundated sediments, P retention decreased by up to 30% compared to constantly inundated sediments. We showed that WLF may trigger biochemical interactions conducive to anaerobic P release. Thereby, E. densa showed high P release and even P uptake that was redox-controlled and superimposed sedimentary P cycling. Macrophytes play an important role in the uptake of P from the water but may be also a significant source of P in wet-dry cycles. We estimated a potential for the abrupt release of soluble reactive phosphorus (SRP) by E. densa of 0.09-0.13 g SRP per m(2) after each wet-dry cycle. Released SRP may exceed critical P limits for eutrophication, provoking usage restrictions. Our results have implications for management of reservoirs in semi-arid regions affected by WLF.

Dry Deposition from Sahara Sources Regions of Western Africa

Directory of Open Access Journals (Sweden)

B. Douaiba

2014-01-01

Full Text Available Sahara dust storms during March 2004 have attracted much attention from the dust-research community due to their intensity, wide coverage, and endurance. In the present work, the dry deposition mechanisms of mineral dust are analysed during an event on the 3 March 2004 over the Northwest African coast. This particular case was chosen based on the strong dry removal that occurred, rendering it ideal for examining the deposition processes. The simulation of synoptic conditions and dry deposition of four dust particles including clay, small silt, large silt, and sand was performed with Eta model, coupled with a desert dust cycle module. The results have been compared with surface data from weather stations in North Africa, data of dry metals from stations located in Gran Canaria, and various satellite images such as European Organization for the Exploitation of Meteorological Satellites and Moderate Resolution Imaging Spectroradiometer for the period in question.

Characterization of transfer layers on steel surfaces sliding against diamondlike carbon in dry nitrogen

Energy Technology Data Exchange (ETDEWEB)

Erdemir, A.; Bindal, C.; Pagan, J. [Argonne National Lab., IL (United States); Wilbur, P. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Mechanical Engineering

1995-03-01

Transfer layers on sliding steel surfaces play important roles in tribological performance of diamondlike carbon films. This study investigated the nature of transfer layers formed on M50 balls during sliding against diamondlike carbon (DLC) films (1.5 {mu}m thick) prepared by ion-beam deposition. Long-duration sliding tests were performed with steel balls sliding against the DLC coatings in dry nitrogen at room temperature and zero humidity. Test results indicated that the friction coefficients of test pairs were initially 0.12 but decreased steadily with sliding distance to 0.02-0.03 and remained constant throughout the tests, which lasted for more than 250,000 sliding cycles (30 km). This low-friction regime appeared to coincide with the formation of a carbon-rich transfer layer on the sliding surfaces of M50 balls. Micro-laser-Raman spectroscopy and electron microscopy were used to elucidate the structure and chemistry of these transfer layers and to reveal their possible role in the wear and friction behavior of DLC-coated surfaces.

Refractance Window™ drying of haskap berry--preliminary results on anthocyanin retention and physicochemical properties.

Science.gov (United States)

Celli, Giovana Bonat; Khattab, Rabie; Ghanem, Amyl; Brooks, Marianne Su-Ling

2016-03-01

The goal of this work was to determine the anthocyanin retention and physicochemical properties of haskap powder prepared by Refractance Window™ (RW) drying. In general, the RW-dried powder particles had a smooth surface with similar thickness, consistent with the preparation method, and had a solubility of 75.63% in water. The RW-dried powder (consisting of 98% haskap berries) retained approximately 93.8% of anthocyanins from the original frozen fruits, as assessed by the pH-differential method. This result is in good agreement with HPLC analysis that indicated 92.9% retention. Three anthocyanins were identified in frozen berries and RW-dried powder: cyanidin 3-glucoside, cyanidin 3-rutinoside, and peonidin 3-glucoside. Surprisingly, cyanidin 3-rutinoside exhibited the lowest retention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems

OpenAIRE

Rabidin Zairul Amin; Seng Gan Kee; Wahab Mohd Jamil Abdul

2017-01-01

Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be ac...

Symbiotic potential: the integration of preheating and dry cooling in cokemaking

Energy Technology Data Exchange (ETDEWEB)

Barker, J E [British Carbonization Research Association, England; Bruce, J M; Kemmetmueller, R

1978-06-01

The expression closed energy cycle has become popular in the last decade as descriptive of industrial systems in which exhaust heat is recovered from a primary energy-conversion stage and utilized either recuperatively or regeneratively within the overall complex. An old and well-proven means of utilizing the sensible heat of the incandescent coke discharged from coke ovens is known as dry cooling. This is being practiced widely in the USSR and Japan, but not yet to any significant extent in the western world. The waste heat recovered by this system is normally used to raise steam for power generation and process use. A recent advance in the carbonization of coal for the manufacture of metallurgical coke has been the application of the technique of coal drying and preheating as a means of improving both coke quality and oven productivity, and this is usually energized by burning gas as a fuel. An alternative configuration, having practical advantages in relation to efficiency of utilization of recovered energy and to safety in operation, is represented by a combination of coal drying and preheating with dry cooling of the coke. This paper is concerned with the case for this combination and the means whereby it may be effected in practice. The energy cycle of cokemaking would thus be more nearly closed.

Plasma Rich in Growth Factors for the Treatment of Dry Eye after LASIK Surgery.

Science.gov (United States)

Sanchez-Avila, Ronald Mauricio; Merayo-Lloves, Jesus; Fernandez, Maria Laura; Rodriguez-Gutierrez, Luis Alberto; Jurado, Nancy; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

2018-06-08

The aim of this study was to evaluate the use of plasma rich in growth factors (PRGF) eye drops in patients with dry eye disease after laser-assisted in situ keratomileusis (LASIK) surgery. This is a longitudinal, retrospective, comparative, and descriptive study of 77 eyes of 42 patients with dry eye disease following LASIK surgery. This study was designed to evaluate the efficacy of PRGF treatment compared to conventional therapy (control group). Outcome measures including signs and symptoms of dry eye disease were evaluated before and after treatment. The percentage of change before and after treatment for each clinical variable measured was compared between both groups. There were 1-4 treatment cycles with PRGF eye drops (1 cycle = 6 weeks). Results showed a statistically significant improvement in the Ocular Surface Disease Index (38.12%), visual analogue scale scores for frequency (41.89%) and severity (42.47%), and the Schirmer test scores (88.98%) after PRGF treatment (p eye drops are effective for the improvement of dry eye symptoms in patients who underwent LASIK surgery in comparison to the conventional therapy. The treatment with PRGF is an alternative for patients who suffer from postoperative dry eye. © 2018 S. Karger AG, Basel.

Investigation of a carbon fiber/epoxy prepreg curing behavior for thick composite materials production: An industrial case-study

Science.gov (United States)

Giorgini, Loris; Mazzocchetti, Laura; Minak, Giangiacomo; Dolcini, Enrico

2012-07-01

A case-study is presented, in cooperation with RI-BA Composites srl, where the industrial production of a thick part for primary structural application is analysed. The final product is a bulk carbon fiber reinforced object characterized by great dimensions, with thickness ranging between 10mm and 35mm and obtained by Hand-Lay-Up of prepregs. The study shows that prepregs age along the time required for the process work up. Moreover, the isothermal curing investigation of the prepreg used in the production gives some useful hint for the design of a new thermal curing cycle, in order to avoid exotherm problems along the thickness of the object. The effect of the applied curing cycle on thermal properties of the object are reported.

Efficacy of the drug Vitalux Plus of patients with dry form of age-related macular degeneration

Directory of Open Access Journals (Sweden)

I. R. Gazizova

2014-07-01

Full Text Available Purpose: To analyze the data, visometry and the thickness of the fovea, patients with dry form of age-related macular degeneration (AMD after dosing Vitalux Plus.Methods: We observed 25 patients with dry form of AMD. Visometry and optical coherence tomography of the macula was assessed at 1 and 3 months after treatment Vitalux Plus.Results: In the study group according to visometry and optical coherence tomography was found a positive trend. In the course of our research in 65.3 % of the thickness of the fovea increased, probably by increasing the layer of pigment epithelium. Improvement in the layer of pigment epithelium was observed mainly in patients with early-stage AMD, and in this group also found improvement in visual acuity and more motivated to treatment and further outpatient observation.Conclusion: During the observation period, all patients with dry form of AMD, the stabilization of visual acuity. In the main group on the background of the drug Vitalux Plus objective indicators showed improvement according to retinal optical coherence tomography.In the analysis of the results showed a positive therapeutic effect in patients Vitalux Plus, especially with early dry form of AMD.

Efficacy of the drug Vitalux Plus of patients with dry form of age-related macular degeneration

Directory of Open Access Journals (Sweden)

I. R. Gazizova

2013-01-01

Full Text Available Purpose: To analyze the data, visometry and the thickness of the fovea, patients with dry form of age-related macular degeneration (AMD after dosing Vitalux Plus.Methods: We observed 25 patients with dry form of AMD. Visometry and optical coherence tomography of the macula was assessed at 1 and 3 months after treatment Vitalux Plus.Results: In the study group according to visometry and optical coherence tomography was found a positive trend. In the course of our research in 65.3 % of the thickness of the fovea increased, probably by increasing the layer of pigment epithelium. Improvement in the layer of pigment epithelium was observed mainly in patients with early-stage AMD, and in this group also found improvement in visual acuity and more motivated to treatment and further outpatient observation.Conclusion: During the observation period, all patients with dry form of AMD, the stabilization of visual acuity. In the main group on the background of the drug Vitalux Plus objective indicators showed improvement according to retinal optical coherence tomography.In the analysis of the results showed a positive therapeutic effect in patients Vitalux Plus, especially with early dry form of AMD.

A low-cost, high-yield fabrication method for producing optimized biomimetic dry adhesives

International Nuclear Information System (INIS)

Sameoto, D; Menon, C

2009-01-01

We present a low-cost, large-scale method of fabricating biomimetic dry adhesives. This process is useful because it uses all photosensitive polymers with minimum fabrication costs or complexity to produce molds for silicone-based dry adhesives. A thick-film lift-off process is used to define molds using AZ 9260 photoresist, with a slow acting, deep UV sensitive material, PMGI, used as both an adhesion promoter for the AZ 9260 photoresist and as an undercutting material to produce mushroom-shaped fibers. The benefits to this process are ease of fabrication, wide range of potential layer thicknesses, no special surface treatment requirements to demold silicone adhesives and easy stripping of the full mold if process failure does occur. Sylgard® 184 silicone is used to cast full sheets of biomimetic dry adhesives off 4'' diameter wafers, and different fiber geometries are tested for normal adhesion properties. Additionally, failure modes of the adhesive during fabrication are noted and strategies for avoiding these failures are discussed. We use this fabrication method to produce different fiber geometries with varying cap diameters and test them for normal adhesion strengths. The results indicate that the cap diameters relative to post diameters for mushroom-shaped fibers dominate the adhesion properties

Emergence of nutrient limitation in tropical dry forests: hypotheses from simulation models

Science.gov (United States)

Medvigy, D.; Waring, B. G.; Xu, X.; Trierweiler, A.; Werden, L. K.; Wang, G.; Zhu, Q.; Powers, J. S.

2017-12-01

It is unclear to what extent tropical dry forest productivity may be limited by nutrients. Direct assessment of nutrient limitation through fertilization experiments has been rare, and paradigms pertaining to other ecosystems may not extend to tropical dry forests. For example, because dry tropical forests have a lower water supply than moist tropical forests, dry forests can have lower decomposition rates, higher soil carbon and nitrogen concentrations, and a more open nitrogen cycle than moist forests. We used a mechanistic, numerical model to generate hypotheses about nutrient limitation in tropical dry forests. The model dynamically couples ED2 (vegetation dynamics), MEND (biogeochemistry), and N-COM (plant-microbe competition for nutrients). Here, the MEND-component of the model has been extended to include nitrogen (N) and phosphorus (P) cycles. We focus on simulation of sixteen 25m x 25m plots in Costa Rica where a fertilization experiment has been underway since 2015. Baseline simulations are characterized by both nitrogen and phosphorus limitation of vegetation. Fertilization with N and P increased vegetation biomass, with N fertilization having a somewhat stronger effect. Nutrient limitation was also sensitive to climate and was more pronounced during drought periods. Overflow respiration was identified as a key process that mitigated nutrient limitation. These results suggest that, despite often having richer soils than tropical moist forests, tropical dry forests can also become nutrient-limited. If the climate becomes drier in the next century, as is expected for Central America, drier soils may decrease microbial activity and exacerbate nutrient limitation. The importance of overflow respiration underscores the need for appropriate treatment of microbial dynamics in ecosystem models. Ongoing and new nutrient fertilization experiments will present opportunities for testing whether, and how, nutrient limitation may indeed be emerging in tropical dry

Effects of buffer thickness on ATW blanket performances

International Nuclear Information System (INIS)

Yang, Won Sik

2001-01-01

This paper presents the preliminary results of target and buffer design studies for a lead-bismuth eutectic (LBE) cooled accelerator transmutation of waste (ATW) system, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using an 840 MWt LBE cooled ATW design, the effects of buffer thickness on the blanket performances have been studied. Varying the buffer thickness for a given blanket configuration, system performances have been estimated by a series of calculations using MCNPX and REBUS-3 codes. The effects of source importance change are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. As the irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. The results show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable

Full reflector thickness and isolation thickness on neutron transport

International Nuclear Information System (INIS)

Sakai, Tomohiro; Naito, Yoshitaka; Komuro, Yuichi.

1988-08-01

A method to determine ''full reflector thickness'' and ''isolation thickness'', which is utilized for criticality safety evaluation on nuclear fuel facilities, was proposed in this paper. Firstly, a calculation was tryed to obtain the two kinds of thicknesses from the result of criticality calculations for a specific case. Then, two simple equations which calculates the two kinds of thicknesses were made from the relation between reflector (or isolator) thickness and k eff , and one-group diffusion theory. Finally, we proposed a new method to determine the thicknesses. From the method we proposed, ''full reflector thickness'' and ''isolation thickness'' can be obtain using the equations and migration length of the reflector (or isolator) and infinite and effective multiplication factor of the fuel. (author)

Surface ozone seasonality under global change: Influence from dry deposition and isoprene emissions at northern mid-latitudes

Science.gov (United States)

Clifton, O.; Paulot, F.; Fiore, A. M.; Horowitz, L. W.; Malyshev, S.; Shevliakova, E.; Correa, G. J. P.; Lin, M.

2017-12-01

Identifying the contributions of nonlinear chemistry and transport to observed surface ozone seasonal cycles over land using global models relies on an accurate representation of ozone uptake by vegetation (dry deposition). It is well established that in the absence of ozone precursor emission changes, a warming climate will increase surface ozone in polluted regions, and that a rise in temperature-dependent isoprene emissions would exacerbate this "climate penalty". However, the influence of changes in ozone dry deposition, expected to evolve with climate and land use, is often overlooked in air quality projections. With a new scheme that represents dry deposition within the NOAA GFDL dynamic vegetation land model (LM3) coupled to the NOAA GFDL atmospheric chemistry-climate model (AM3), we simulate the impact of 21st century climate and land use on ozone dry deposition and isoprene emissions. This dry deposition parameterization is a version of the Wesely scheme, but uses parameters explicitly calculated by LM3 that respond to climate and land use (e.g., stomatal conductance, canopy interception of water, leaf area index). The parameterization includes a nonstomatal deposition dependence on humidity. We evaluate climatological present-day seasonal cycles of ozone deposition velocities and abundances with those observed at northern mid-latitude sites. With a set of 2010s and 2090s decadal simulations under a high climate warming scenario (RCP8.5) and a sensitivity simulation with well-mixed greenhouse gases following RCP8.5 but air pollutants held at 2010 levels (RCP8.5_WMGG), we examine changes in surface ozone seasonal cycles. We build on our previous findings, which indicate that strong reductions in anthropogenic NOx emissions under RCP8.5 cause the surface ozone seasonal cycle over the NE USA to reverse, shifting from a summer peak at present to a winter peak by 2100. Under RCP8.5_WMGG, we parse the separate effects of climate and land use on ozone dry

The Effect of Drying-Wetting Cycle’s Repetition to the Characteristic of Natural and Stabilization Residual Soils Jawa Timur - Indonesia

Science.gov (United States)

Muntaha, M.

2017-11-01

Indonesia, which located in tropical region, continuously undergoes wetting and drying cycles due to the changeable seasons. An important role in activating the clay minerals on tropical residual soils is the main factor that affects the static and dynamic properties, such as: volume change, soil suction and dynamic modulus. The purpose of this paper is to evaluate the effect of drying-wetting cycles repetition on volume change, soil suction and mechanical characteristics of natural and stabilization of residual soils from Jawa Timur - Indonesia. The natural undisturbed and stabilized residual soil sample was naturally and gradually dried up with air to 25%, 50%, 75%, and 100 % of the initial water content. The wetting processes were carried out with the gradual increment water content of 25 %(wsat - wi), 50 %(wsat - wi), 75 %(wsat - wi), up to 100 %(wsat - wi). The Direct Shear test is used to measure the mechanic properties, and Whatman filter paper No. 42 is used to measure the soil suction. The drying-wetting processes were carried out for 1, 2, 4, and 6 cycles. The laboratory test results showed that, the void ratio decreased, the unit weight, cohesion and the internal friction angle were increasing due to stabilization. Drying-wetting cycle repetition reduces void ratio, negative pore-water pressure, cohesion and internal friction angle of natural and stabilized soils. Briefly, the decreased of mechanical soil properties was proven from the physical properties change observation.

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. (TECOGEN, Inc., Waltham, MA (United States))

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. [TECOGEN, Inc., Waltham, MA (United States)

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg{sub evap} to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Former land-use and tree species affect nitrogen oxide emissions from a tropical dry forest.

Science.gov (United States)

Heather Erickson; Eric A. Davidson; Michael Keller

2002-01-01

Species composition in successional dry forests in the tropics varies widely, but the effect of this variation on biogeochemical processes is not well known. We examined fluxes of N oxides (nitrous and nitric oxide), soil N cycling, and litter chemistry (C/N ratio) in four successional dry forests on similar soils in western Puerto Rico with differing species...

Bark traits and life-history strategies of tropical dry- and moist forest trees

NARCIS (Netherlands)

Poorter, L.; McNeil, A.; Hurtado, V.H.; Prins, H.H.T.; Putz, F.E.

2014-01-01

1.Bark is crucial to trees because it protects their stems against fire and other hazards and because of its importance for assimilate transport, water relationships and repair. We evaluate size-dependent changes in bark thickness for 50 woody species from a moist forest and 50 species from a dry

Serving the fuel cycle: preparing tomorrow's packagings

International Nuclear Information System (INIS)

Roland, V.

2001-01-01

The main fleet of transport packagings serving today the fuel cycle was born more than 20 years ago. Or was it they? The present paper will show that serving the fuel cycle by preparing tomorrow's logistics is actually an on-going process, rather than a rupture. We shall review the great packagings of the fuel cycle: In the front end, the major actors are the UF 4 , UF 6 , enriched UF 6 , UO 2 powders, fresh fuel packagings. In the back end of the fuel cycle, we find the dry transport casks of the TN-12, TN-17, TN-13, family and also the Excellox wet flasks. In the waste management, a whole fleet of containers, culminating in the TN Gemini, are available or being created. (author)

Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

Energy Technology Data Exchange (ETDEWEB)

Chen Libao [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Xie Xiaohua [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wang Baofeng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang Ke [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xie Jingying [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China) and Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)]. E-mail: jyxie@mail.sim.ac.cn

2006-07-15

Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g{sup -1} and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly.

Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

International Nuclear Information System (INIS)

Chen Libao; Xie Xiaohua; Wang Baofeng; Wang Ke; Xie Jingying

2006-01-01

Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g -1 and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly

Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.

Science.gov (United States)

Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu

2016-05-01

The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

Directory of Open Access Journals (Sweden)

Aysun Şanal Doğan

2018-04-01

Full Text Available Objectives: The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Materials and Methods: Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy. Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Results: Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198 and gender (M/F: 4/29 vs. 8/32, p=0.366. Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90. Conclusion: The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

Science.gov (United States)

Doğan, Aysun Şanal; Gürdal, Canan; Köylü, Mehmet Talay

2018-04-01

The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy). Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198) and gender (M/F: 4/29 vs. 8/32, p=0.366). Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90). The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

Dry oxidation behaviour of metallic containers during long term interim storages

International Nuclear Information System (INIS)

Desgranges, C.; Terlain, A.; Bertrand, N.; Gauvain, D.

2004-01-01

Low-alloyed steels or carbon steels are considered candidate materials for the fabrication of some nuclear waste package containers for long term interim storage. The containers are required to remain retrievable for centuries. One factor limiting their performance on this time scale is corrosion. The estimation of the metal thickness lost by dry oxidation over such long periods requires the construction of reliable models from short-time experimental data. Two complementary approaches for modelling dry oxidation have been considered. First, basic models following simple analytical laws from classical oxidation theories have been adjusted on the apparent activation energy of oxidation deduced from experimental data. Their extrapolation to long oxidation periods confirms that the expected damage due to dry oxidation could be small. Second, a numerical model able to take in consideration several mechanisms controlling the oxide scale growth is under development. Several preliminary results are presented. (authors)

Effect of Firing Temperature on Humidity Sensing Properties of SnO2 Thick Film Resistor

Directory of Open Access Journals (Sweden)

R. Y. Borse

2009-12-01

Full Text Available Thick films of SnO2 were prepared using standard screen printing technique. The films were dried and fired at different temperatures. Tin-oxide is an n-type wide band gap semiconductor, whose resistance is described as a function of relative humidity. An increasing firing temperature on SnO2 film increases the sensitivity to humidity. The parameters such as sensitivity, response times and hysteresis of the SnO2 film sensors have been evaluated. The thick films were characterized by XRD, SEM and EDAX and grain size, composition of elements, relative phases are obtained.

Performance of a fiber optic sensor for online measurement of coating thickness

Science.gov (United States)

D'Emilia, Giulio

1999-01-01

Some aspects concerning a methodology for the measurement of thickness of dry and wet coatings which is based on a fiber optic probe are discussed in order to verify the feasibility of this approach and the capability of such a probe of on- line measuring. In this preliminary step of the research some problems discussed mainly concerning the methodology which has been proposed and which is based on the measuring of the reflectance of the coating plated on thin steel sheets for use in the food industry. Furthermore the effect of the main interfering and modifying quantities is discussed both theoretically and experimentally when the measurement has to be carried out in order to allow on-line coating thickness measurements with satisfactory accuracy.

Assessment of a combined dry anaerobic digestion and post-composting treatment facility for source-separated organic household waste, using material and substance flow analysis and life cycle inventory

DEFF Research Database (Denmark)

Jensen, Morten Bang; Møller, Jacob; Scheutz, Charlotte

2017-01-01

with low uncertainties for non-volatile substances, while balances for nitrogen, carbon, volatile solids and total organic carbon showed larger but reasonable uncertainties, due to volatilisation and emissions into the air. Material and substance flow analyses were performed in order to obtain transfer...... to the biogas, 24% to the compost, 13% to residues and 40% into the atmosphere. For nitrogen, 69% was transferred to the compost, 10% volatilised to the biofilter, 11% directly into the atmosphere and 10% to residues. Finally, a full life cycle inventory was conducted for the combined dry anaerobic digestion...

Safeguards and nonproliferation aspects of a dry fuel recycling technology

International Nuclear Information System (INIS)

Pillay, K.K.S.

1993-01-01

Los Alamos National Laboratory undertook an independent assessment of the proliferation potentials and safeguardability of a dry fuel recycling technology, whereby spent pressurized-water reactor (PWR) fuels are used to fuel canadian deuterium uranium (CANDU) reactors. Objectives of this study included (1) the evaluation of presently available technologies that may be useful to safeguard technology options for dry fuel recycling (2) and identification of near-term and long-term research needs to develop process-specific safeguards requirements. The primary conclusion of this assessment is that like all other fuel cycle alternatives proposed in the past, the dry fuel recycle entails prolfferation risks and that there are no absolute technical fixes to eliminate such risks. This study further concludes that the proliferation risks of dry fuel recycling options are relatively minimal and presently known safeguards systems and technologies can be modified and/or adapted to meet the requirements of safeguarding such fuel recycle facilities

Direct spray drying and microencapsulation of probiotic Lactobacillus reuteri from slurry fermentation with whey.

Science.gov (United States)

Jantzen, M; Göpel, A; Beermann, C

2013-10-01

Formulations of dietary probiotics have to be robust against process conditions and have to maintain a sufficient survival rate during gastric transit. To increase efficiency of the encapsulation process and the viability of applied bacteria, this study aimed at developing spray drying and encapsulation of Lactobacillus reuteri with whey directly from slurry fermentation. Lactobacillus reuteri was cultivated in watery 20% (w/v) whey solution with or without 0·5% (w/v) yeast extract supplementation in a submerged slurry fermentation. Growth enhancement with supplement was observed. Whey slurry containing c. 10(9)  CFU g(-1) bacteria was directly spray-dried. Cell counts in achieved products decreased by 2 log cycles after drying and 1 log cycle during 4 weeks of storage. Encapsulated bacteria were distinctively released in intestinal milieu. Survival rate of encapsulated bacteria was 32% higher compared with nonencapsulated ones exposed to artificial digestive juice. Probiotic L. reuteri proliferate in slurry fermentation with yeast-supplemented whey and enable a direct spray drying in whey. The resulting microcapsules remain stable during storage and reveal adequate survival in simulated gastric juices and a distinct release in intestinal juices. Exploiting whey as a bacterial substrate and encapsulation matrix within a coupled fermentation and spray-drying process offers an efficient option for industrial production of vital probiotics. © 2013 The Society for Applied Microbiology.

Development of Simple Drying Model for Performance Prediction of Solar Dryer: Theoretical Analysis

DEFF Research Database (Denmark)

Singh, Shobhana; Kumar, Subodh

2012-01-01

An analytical moisture diffusion model which considers the influence of external resistance to mass transfer is developed to predict thermal performance of dryer system. The moisture diffusion coefficient, Deff that is necessary to evaluate the prediction model has been determined in terms...... of experimental drying parameters. A laboratory model of mixed-mode solar dryer system is tested with cylindrical potato samples of thickness 5 and 18 mm under simulated indoor conditions. The potato samples were dried at a constant absorbed thermal energy of 750 W/m2 and air mass flow rate of 0.011 kg...

Improvement in greenhouse solar drying using inclined north wall reflection

Energy Technology Data Exchange (ETDEWEB)

Sethi, V.P. [Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India); Arora, Sadhna [Department of Processing and Food Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India)

2009-09-15

A conventional greenhouse solar dryer of 6 m{sup 2} x 4 m{sup 2} floor area (east-west orientation) was improved for faster drying using inclined north wall reflection (INWR) under natural as well as forced convection mode. To increase the solar radiation availability onto the product (to be dried) during extreme summer months, a temporary inclined wall covered with aluminized reflector sheet (of 50 {mu}m thickness and reflectance 0.93) was raised inside the greenhouse just in front of the vertical transparent north wall. By doing so, product fully received the reflected beam radiation (which otherwise leaves through the north wall) in addition to the direct total solar radiation available on the horizontal surface during different hours of drying. The increment in total solar radiation input enhanced the drying rate of the product by increasing the inside air and crop temperature of the dryer. Inclination angle of the reflective north wall with vertical ({beta}) was optimized for various selective widths of the tray W (1.5, 2, 2.5 and 3 m) and for different realistic heights of existing vertical north wall (h) at 25 N, 30 N and 35 N latitudes (hot climatic zones). Experimental performance of the improved dryer was tested during the month of May 2008 at Ludhiana (30.56 N) climatic conditions, India by drying bitter gourd (Momordica charantia Linn) slices. Results showed that by using INWR under natural convection mode of drying, greenhouse air and crop temperature increased by 1-6.7 C and 1-4 C, respectively, during different drying hours as compared to, when INWR was not used and saved 13.13% of the total drying time. By using INWR under forced convection mode of drying, greenhouse air and crop temperature increased by 1-4.5 C and 1-3 C, respectively, during different drying hours as compared to, when INWR was not used and saved 16.67% of the total drying time. (author)

Geomorphological evidence of warm-humid and cold-dry glaciations in the dry western Cordillera of the tropical Peruvian Andes

Science.gov (United States)

Mächtle, B.; Hein, A. S.; Dunai, T.; Eitel, B.

2012-04-01

The western Cordillera of the Andes (14°30'S, 74°W) is characterized by high altitudes, strong radiation and semi-arid conditions. Therefore, glacial processes and resulting landforms differ markedly from these of the outer-tropics. However, under sub-arctic conditions similar glacial landforms occur. This congruence can be explained by comparable environmental conditions, which determine the dynamics of ice flow, glacial erosion, debris production as well as moraine deposition. Outside the higher latitudes, typical sub-arctic glacial landforms as controlled moraines and trimline moraines (Evans 2009, Ó Cofaigh et al. 2005) remained undescribed until now. These landforms result from polythermal or cold-basal ice flow, respectively, which is typical for polar conditions. Beside this, we also found steep lateral moraines, which give evidence of increased ice thickness, debris production and deposition and warm-basal ice flow, which is conceivable only for alpine-type valley glaciers. Striations of the bedrock give evidence of accompanied basal erosion. Coexisting trimline moraines and steep lateral moraines rule out the influence of topography on ice thickness and the resulting thermal regime. Therefore, we match the different moraine types to changes in ice thickness, which was controlled by considerable precipitation changes during the last glaciation. An erroneous classification of the observed boulder associations as trimline moraine due to selective erosion after deposition can be excluded due to general arid conditions, slow weathering and the chronological proximity of only a few millennia between both landforms, determined from cosmogenic nuclides. Therefore, the occurrence of different thermal regimes gives evidence of considerable changes in precipitation during the last glaciation - but furthermore requires an associated change in the thermal conditions to explain the very close spatial position of both ice margins. Changes in ice volume must have

Drum drying of banana pulp on the sorption isotherm and flexible ...

African Journals Online (AJOL)

The dried product had moisture content of approximately 2.0% which was equivalent to (aw)of 5.11 of 38.5 oC. The storage condition should be such that does not go beyond 0.15 which is equivalent to about 2.5% moisture. In this range of (aw), Polyethylene (density 0.954) of thickness more than 5 mil or saran 517 of 1 mil ...

Contrasted response of colloidal, organic and inorganic dissolved phosphorus forms during rewetting of dried riparian soils

Science.gov (United States)

Gu, Sen; Gruau, Gérard; Malique, François; Dupas, Rémi; Gascuel-Odoux, Chantal; Petitjean, Patrice; Bouhnik-Le Coz, Martine

2017-04-01

Riparian vegetated buffer strip (RVBS) are currently used to protect surface waters from phosphorus (P) emissions because of their ability to retain P-enriched soil particles. However, this protection role may be counterbalanced by the development in these zones of conditions able to trigger the release of highly mobile dissolved or colloidal P forms. Rewetting after drying is one of these conditions. So far, the potential sources of P mobilized during rewetting after drying are not clearly identified, nor are clearly identified the chemical nature of the released dissolved P species, or the role of the soil P speciation on these forms. In this study, two riparian soils (G and K) showing contrasting soil P speciation (65% of inorganic P species in soil G, as against 70% of organic P) were submitted to three successive dry/wet cycles in the laboratory. Conventional colorimetric determination of P concentrations combined with ultrafiltration, and measurements of iron (Fe) and aluminum (Al) and dissolved organic carbon (DOC) contents using ICP-MS and TOC analyzers, respectively, were used to study the response of the different P forms to rewetting after drying and also their release kinetics during soil leaching. For both soils, marked P release peaks were observed at the beginning of each wet cycles, with the organic-rich K soils giving, however, larger peaks than the inorganic one (G soil). For both soils also, concentrations in molybdate reactive P (MRP) remained quite constant throughout each leaching episode, contrary to the molybdate unreactive P (MUP) concentrations which were high immediately after rewetting and then decreased rapidly during leaching. A speciation change was observed from the beginning to the end of all leaching cycles. Colloidal P was found to be a major fraction of the total P immediately after rewetting (up to 50-70%) and then decreased to the end of each wet cycle where most of the eluted P was true dissolved inorganic P. Colloidal

Dry and Semi-Dry Tropical Cyclones

Science.gov (United States)

Cronin, T.; Chavas, D. R.

2017-12-01

Our understanding of dynamics in our real moist atmosphere is strongly informed by idealized dry models. It is widely believed that tropical cyclones (TCs) are an intrinsically moist phenomenon - relying fundamentally on evaporation and latent heat release - yet recent numerical modeling work has found formation of dry axisymmetric tropical cyclones from a state of dry radiative-convective equilibrium. What can such "dry hurricanes" teach us about intensity, structure, and size of real moist tropical cyclones in nature? Are dry TCs even stable in 3D? What about surfaces that are nearly dry but have some latent heat flux - can they also support TCs? To address these questions, we use the SAM cloud-system resolving model to simulate radiative-convective equilibrium on a rapidly rotating f-plane, subject to constant tropospheric radiative cooling. We use a homogeneous surface with fixed temperature and with surface saturation vapor pressure scaled by a factor 0-1 relative to that over pure water - allowing for continuous variation between moist and dry limits. We also explore cases with surface enthalpy fluxes that are uniform in space and time, where partitioning between latent and sensible heat fluxes is specified directly. We find that a completely moist surface yields a TC-world where multiple vortices form spontaneously and persist for tens of days. A completely dry surface can also yield a parallel dry TC-world with many vortices that are even more stable and persistent. Spontaneous cyclogenesis, however, is impeded for a range of low to intermediate surface wetness values, and by the combination of large rotation rates and a dry surface. We discuss whether these constraints on spontaneous cyclogenesis might arise from: 1) rain evaporation in the subcloud layer limiting the range of viable surface wetness values, and 2) a natural convective Rossby number limiting the range of viable rotation rates. Finally, we discuss simulations with uniform surface enthalpy

Simulation of potential standalone liquid desiccant cooling cycles

International Nuclear Information System (INIS)

Das, Rajat Subhra; Jain, Sanjeev

2015-01-01

LDCS (Liquid desiccant cooling systems), capable of achieving dehumidification and cooling with low-grade heat input, can be effectively used for treating fresh air in hot and humid regions. These can also be operated using non-concentrating solar collectors. The present study is concerned with the evaluation of various potential liquid desiccant cycles for tropical climatic conditions. Six potential standalone liquid desiccant cycles are identified and analyzed to select the best configuration for achieving thermal comfort. A computer simulation model is developed in EES (Equation Solver) software platform to evaluate the performance of all the cycles at various operating conditions. Aqueous solution of LiCl (lithium chloride) is used as desiccant. Mass and energy balance equations of all the components along with their effectiveness and LiCl property correlation equations are solved simultaneously for given ambient conditions. As the desiccant circuit is a closed loop, no assumptions are made about its concentration and temperature in the algorithm. Supply air conditions, cooling capacity, COP (capacity and coefficient of performance) and CR (circulation rate) per unit cooling capacity and hot water temperature requirement are used as a measure for analyzing the performance of the different cycles. The effect of hot water temperature on the performance of the cycles is evaluated at ARI conditions. The performances of the cycles are also evaluated for cities selected from each of the climatic zone of India that represent typical tropical climates. Although all the cycles are feasible at ARI and hot and dry conditions, only two cycles can achieve the selected indoor conditions in the peak humid conditions. The results would be useful for selecting suitable liquid desiccant cycle for a given climate. - Highlights: • Six potential standalone liquid desiccant cycles identified and analyzed to select best configuration. • A computer simulation model is developed in

Decoupled responses of soil bacteria and their invertebrate consumer to warming, but not freeze-thaw cycles, in the Antarctic Dry Valleys.

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Knox, Matthew A; Andriuzzi, Walter S; Buelow, Heather N; Takacs-Vesbach, Cristina; Adams, Byron J; Wall, Diana H

2017-10-01

Altered temperature profiles resulting in increased warming and freeze-thaw cycle (FTC) frequency pose great ecological challenges to organisms in alpine and polar ecosystems. We performed a laboratory microcosm experiment to investigate how temperature variability affects soil bacterial cell numbers, and abundance and traits of soil microfauna (the microbivorous nematode Scottnema lindsayae) from McMurdo Dry Valleys, Antarctica. FTCs and constant freezing shifted nematode body size distribution towards large individuals, driven by higher mortality among smaller individuals. FTCs reduced both bacterial and nematode abundance, but bacterial cell numbers also declined under warming, demonstrating decoupled consumer-prey responses. We predict that higher occurrence of FTCs in cold ecosystems will select for large body size within soil microinvertebrates and overall reduce their abundance. In contrast, warm temperatures without FTCs could lead to divergent responses in soil bacteria and their microinvertebrate consumers, potentially affecting energy and nutrient transfer rates in soil food webs of cold ecosystems. © 2017 John Wiley & Sons Ltd/CNRS.

Smoking Decreases Endometrial Thickness in IVF/ICSI Patients.

Science.gov (United States)

Heger, Anna; Sator, Michael; Walch, Katharina; Pietrowski, Detlef

2018-01-01

Smoking is a serious problem for the health care system. Many of the compounds identified in cigarette smoke have toxic effects on the fertility of both females and males. The purpose of this study was to determine whether smoking affects clinical factors during IVF/ICSI therapy in a single-center reproductive unit. In a retrospective study of 200 IVF/ICSI cycles, endometrial thickness and the outcome of IVF/ICSI therapy were analyzed. Endometrial thickness was significantly lower in smoking patients than in non-smoking patients (10.4 ± 1.5 mm vs. 11.6 ± 1.8 mm). Age was significantly higher in women who failed to conceive. The total dose of gonadotropins administered was significantly lower in pregnant patients and the highest pregnancy rate was achieved with an rFSH protocol. BMI and number of cigarettes smoked did not influence treatment outcomes in this study. We showed that smoking has a negative effect on endometrial thickness on the day of embryo transfer. This may help to further explain the detrimental influence of tobacco smoke on implantation and pregnancy rates during assisted reproduction therapy.

Ion Diffusion-Directed Assembly Approach to Ultrafast Coating of Graphene Oxide Thick Multilayers.

Science.gov (United States)

Zhao, Xiaoli; Gao, Weiwei; Yao, Weiquan; Jiang, Yanqiu; Xu, Zhen; Gao, Chao

2017-10-24

The layer-by-layer (LbL) assembly approach has been widely used to fabricate multilayer coatings on substrates with multiple cycles, whereas it is hard to access thick films efficiently. Here, we developed an ion diffusion-directed assembly (IDDA) strategy to rapidly make multilayer thick coatings in one step on arbitrary substrates. To achieve multifunctional coatings, graphene oxide (GO) and metallic ions were selected as the typical building blocks and diffusion director in IDDA, respectively. With diffusion of metallic ions from substrate to negatively charged GO dispersion spontaneously (i.e., from high-concentration region to low-concentration region), GO was assembled onto the substrate sheet-by-sheet via sol-gel transformation. Because metallic ions with size of subnanometers can diffuse directionally and freely in the aqueous dispersion, GO was coated on the substrate efficiently, giving rise to films with desired thickness up to 10 μm per cycle. The IDDA approach shows three main merits: (1) high efficiency with a μm-scale coating rate; (2) controllability over thickness and evenness; and (3) generality for substrates of plastics, metals and ceramics with any shapes and morphologies. With these merits, IDDA strategy was utilized in the efficient fabrication of functional graphene coatings that exhibit outstanding performance as supercapacitors, electromagnetic interference shielding textiles, and anticorrosion coatings. This IDDA approach can be extended to other building blocks including polymers and colloidal nanoparticles, promising for the scalable production and application of multifunctional coatings.

Disinfestation studies on dried fish of Bangladesh. Part of a coordinated programme on radiation preservation of Asian fish and fishery products

International Nuclear Information System (INIS)

Ahmed, M.

1978-07-01

A survey of major fish drying areas, storage facilities and dried fish markets in Bangladesh showed that blow fly, house fly and fruit flies are destructive insects infesting fish during the process of drying. Dermestes maculatus, Necrobia rupifes and earwigs were the most predominant insects infesting dried fish during storage. The effect of irradiation on different developmental stages of D. maculatus was investigated. Results on radiation disinfestation of D. maculatus, the most serious pest during storage, showed that a dose of 30 krad and above would be sufficient to control infestation of dried fish. No changes on organoleptic properties of dried mackerel irradiated with doses up to 400 krad could be detected. Polyethylene bags with a thickness of 0.075 mm and above appeared to be suitable for packaging of dried fish

Construction of JRR-3 spent fuel dry storage facility

International Nuclear Information System (INIS)

Adachi, M.

1982-01-01

To store the JRR-3 metallic natural uranium spent fuel elements, dry storage facility has been constructed in JAERI. This facility has a capacity of about 30T of uranium. The elements are placed in encapsulated canister, then stored in drywell in the store. The store is basically an ordinary concrete box, about 12m long, 13m wide, and 5m deep. The store comprises a 10 x 10 lattice array of the drywells. The drywell consists of a stainless steel liner which is 2.5m deep, 36cm ID and 0.8cm thickness. A drywell also has an air inlet, outlet pipe for radiation monitoring and a shield plug in carbon steel for radiation protection. A canister which consists of stainless steel with 0.5cm thickness contains 36 elements. Sealing of the canister is accomplished by fusion welding

Microalgal drying and cell disruption--recent advances.

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Show, Kuan-Yeow; Lee, Duu-Jong; Tay, Joo-Hwa; Lee, Tse-Min; Chang, Jo-Shu

2015-05-01

Production of intracellular metabolites or biofuels from algae involves various processing steps, and extensive work on laboratory- and pilot-scale algae cultivation, harvesting and processing has been reported. As algal drying and cell disruption are integral processes of the unit operations, this review examines recent advances in algal drying and disruption for nutrition or biofuel production. Challenges and prospects of the processing are also outlined. Engineering improvements in addressing the challenges of energy efficiency and cost-effective and rigorous techno-economic analyses for a clearer prospect comparison between different processing methods are highlighted. Holistic life cycle assessments need to be conducted in assessing the energy balance and the potential environmental impacts of algal processing. The review aims to provide useful information for future development of efficient and commercially viable algal food products and biofuels production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of a combined dry anaerobic digestion and post-composting treatment facility for source-separated organic household waste, using material and substance flow analysis and life cycle inventory.

Science.gov (United States)

Jensen, Morten Bang; Møller, Jacob; Scheutz, Charlotte

2017-08-01

The fate of total solids, volatile solids, total organic carbon, fossil carbon, biogenic carbon and 17 substances (As, Ca, CaCO 3 , Cd, Cl, Cr, Cu, H, Hg, K, Mg, N, Ni, O, P, Pb, S, Zn) in a combined dry anaerobic digestion and post-composting facility were assessed. Mass balances showed good results with low uncertainties for non-volatile substances, while balances for nitrogen, carbon, volatile solids and total organic carbon showed larger but reasonable uncertainties, due to volatilisation and emissions into the air. Material and substance flow analyses were performed in order to obtain transfer coefficients for a combined dry anaerobic digestion and post-composting facility. All metals passed through the facility and ended up in compost or residues, but all concentrations of metals in the compost complied with legislation. About 23% of the carbon content of the organic waste was transferred to the biogas, 24% to the compost, 13% to residues and 40% into the atmosphere. For nitrogen, 69% was transferred to the compost, 10% volatilised to the biofilter, 11% directly into the atmosphere and 10% to residues. Finally, a full life cycle inventory was conducted for the combined dry anaerobic digestion and post-composting facility, including waste received, fuel consumption, energy use, gaseous emissions, products, energy production and chemical composition of the compost produced. Copyright © 2017. Published by Elsevier Ltd.

Gene Expression, Bacteria Viability and Survivability Following Spray Drying of Mycobacterium smegmatis

Directory of Open Access Journals (Sweden)

Elizabeth Hunter Lauten

2010-04-01

Full Text Available We find that Mycobacterium smegmatis survives spray drying and retains cell viability in accelerated temperature stress (40 °C conditions with a success rate that increases with increasing thermal, osmotic, and nutrient-restriction stresses applied to the mycobacterium prior to spray drying. M.smegmatis that are spray dried during log growth phase, where they suffer little or no nutrient-reduction stress, survive for less than 7 days in the dry powder state at accelerated temperature stress conditions, whereas M. smegmatis that are spray dried during stationary phase, where cells do suffer nutrient reduction, survive for up to 14 days. M. smegmatis that are spray dried from stationary phase, subjected to accelerated temperature stress conditions, regrown to stationary phase, spray dried again, and resubmitted to this same process four consecutive times, display, on the fourth spray drying iteration, an approximate ten-fold increase in stability during accelerated temperature stress testing, surviving up to 105 days. Microarray tests revealed significant differences in genetic expression of M. smegmatis between log phase and stationary phase conditions, between naïve (non spray-dried and multiply cycled dried M. smegmatis (in log and stationary phase, and between M. smegmatis in the dry powder state following a single spray drying operation and after four consecutive spray drying operations. These differences, and other phenotypical differences, point to the carotenoid biosynthetic pathway as a probable pathway contributing to bacteria survival in the spray-dried state and suggests strategies for spray drying that may lead to significantly greater room-temperature stability of mycobacteria, including mycobacterium bovis bacille Calmette-Guerin (BCG, the current TB vaccine.

Low-temperature technique for thick film resist stabilization and curing

Science.gov (United States)

Minter, Jason P.; Wong, Selmer S.; Marlowe, Trey; Ross, Matthew F.; Narcy, Mark E.; Livesay, William R.

1999-06-01

For a range of thick film photoresist applications, including MeV ion implant processing, thin film head manufacturing, and microelectromechanical systems processing, there is a need for a low-temperature method for resist stabilization and curing. Traditional methods of stabilizing or curing resist films have relied on thermal cycling, which may not be desirable due to device temperature limitations or thermally-induced distortion of the resist features.

Sonomyography Analysis on Thickness of Skeletal Muscle During Dynamic Contraction Induced by Neuromuscular Electrical Stimulation: A Pilot Study.

Science.gov (United States)

Qiu, Shuang; Feng, Jing; Xu, Jiapeng; Xu, Rui; Zhao, Xin; Zhou, Peng; Qi, Hongzhi; Zhang, Lixin; Ming, Dong

2017-01-01

Neuromuscular electrical stimulation (NMES) that stimulates skeletal muscles to induce contractions has been widely applied to restore functions of paralyzed muscles. However, the architectural changes of stimulated muscles induced by NMES are still not well understood. The present study applies sonomyography (SMG) to evaluate muscle architecture under NMES-induced and voluntary movements. The quadriceps muscles of seven healthy subjects were tested for eight cycles during an extension exercise of the knee joint with/without NMES, and SMG and the knee joint angle were recorded during the process of knee extension. A least squares support vector machine (LS-SVM) LS-SVM model was developed and trained using the data sets of six cycles collected under NMES, while the remaining data was used to test. Muscle thickness changes were extracted from ultrasound images and compared between NMES-induced and voluntary contractions, and LS-SVM was used to model a relationship between dynamical knee joint angles and SMG signals. Muscle thickness showed to be significantly correlated with joint angle in NMES-induced contractions, and a significant negative correlation was observed between Vastus intermedius (VI) thickness and rectus femoris (RF) thickness. In addition, there was a significant difference between voluntary and NMES-induced contractions . The LS-SVM model based on RF thickness and knee joint angle provided superior performance compared with the model based on VI thickness and knee joint angle or total thickness and knee joint angle. This suggests that a strong relation exists between the RF thickness and knee joint angle. These results provided direct evidence for the potential application of RF thickness in optimizing NMES system as well as measuring muscle state under NMES.

Accelerating Thick Aluminum Liners Using Pulsed Power

International Nuclear Information System (INIS)

Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

1999-01-01

The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane

Drying of α-amylase by spray drying and freeze-drying - a comparative study

Directory of Open Access Journals (Sweden)

S. S. de Jesus

2014-09-01

Full Text Available This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

Ovarian cycle of southern brown howler monkey (Alouatta guariba clamitans) through fecal progestin measurement.

Science.gov (United States)

Silvestre, Thiago; Zanetti, Eveline S; Duarte, José M B; Barriento, Fernando G; Hirano, Zelinda M B; Souza, Júlio C; Passos, Fernando C

2017-01-01

The ovarian cycle in howler monkeys (genus Alouatta) has beean investigated through several biological parameters (ranging between 16.3 and 29.5 days); however, no data exist concerning the ovarian activity of the southern brown howler monkey (Alouatta guariba clamitans). This study aimed to describe the ovarian cycle of A. g. clamitans by profiling fecal progestin concentrations. Over 20 weeks, fecal samples of eight captive adult females of A. g. clamitans were collected. The collections were made at dawn, 5 days a week, and the samples were frozen immediately following collection. Next, they were dried, pulverized and hormonal metabolites were extracted to determine progestin concentrations by enzyme immunoassay. Of the 758 samples tested, the mean concentration of fecal progestins was 2866.40 ± 470.03 ng/g of dry feces, while the mean concentration at baseline was 814.47 ± 164.36 ng/g of dry feces. Among the eight females, one showed no ovarian cyclicity and three presented periods of probable absence of cyclicity and low progestin concentrations. A mean duration of 16 ± 0.52 days was observed for the 35 cycles studied. The interluteal phase lasted 4 ± 0.37 days on average, with a mean concentration of fecal progestins of 467.98 ± 29.12 ng/g of dry feces, while the luteal phase lasted 11 ± 0.50 days, with a mean concentration of 4283.27 ± 193.31 ng/g of dry feces. Besides describing the characteristics of the ovarian cycle, possible causes for the low concentrations of fecal progestins and periods of absence of cyclicity are also discussed.

Efficacy of dry-ice blasting in preventive maintenance of auto robotic assemblies

Science.gov (United States)

Baluch, Nazim; Mohtar, Shahimi; Abdullah, Che Sobry

2016-08-01

Welding robots are extensively applied in the automotive assemblies and `Spot Welding' is the most common welding application found in the auto stamping assembly manufacturing. Every manufacturing process is subject to variations - with resistance welding, these include; part fit up, part thickness variations, misaligned electrodes, variations in coating materials or thickness, sealers, weld force variations, shunting, machine tooling degradation; and slag and spatter damage. All welding gun tips undergo wear; an elemental part of the process. Though adaptive resistance welding control automatically compensates to keep production and quality up to the levels needed as gun tips undergo wear so that the welds remain reliable; the system cannot compensate for deterioration caused by the slag and spatter on the part holding fixtures, sensors, and gun tips. To cleanse welding robots of slag and spatter, dry-ice blasting has proven to be an effective remedy. This paper describes Spot welding process, analyses the slag and spatter formation during robotic welding of stamping assemblies, and concludes that the dry ice blasting process's utility in cleansing of welding robots in auto stamping plant operations is paramount and exigent.

Characterization and drying of caja bagasse (Spondias mombin L. in a tray dryer using a factorial planning

Directory of Open Access Journals (Sweden)

Andréia Souto da Silva

2012-03-01

Full Text Available The caja (Spondias mombin L. is used in the manufacture of ice-cream, jams, pulps, beverages being also consumed in natura. One of the most important procedures in food conservation is drying, considering that most fresh fruits contain approximately 80% of water. Food drying is used to obtain two basic aspects: (1 the economic factor; in the shipping and handling of the product; (2 at the manipulation; once dried and grinded, the material is rehydrated, at desirable levels, to formulate a new product as in ice cream, jams, yoghurts and drinks and may also be added to pasta, biscuits and other industrialized products. The aim of this study was to investigate the kinetics of caja bagasse drying in a fixed-bed tray dryer, using central composite factorial planning. The following factors were evaluated: temperature (55, 65 and 75 ºC, dryer inlet air velocity (3.2, 4.6 and 6.0 m.s-1 and cake thickness (0.8, 1.2 and 1.6 cm where the response of the considered variable was caja bagasse moisture content (b.s. and the results showed that the main effects and their interactions were significant at a 95% confidence level being the best condition obtained at temperature of 75 ºC, velocity of 6.0 m.s-1 and cake thickness of 0.8 cm.

Modification of the solid-state nature of sulfathiazole and sulfathiazole sodium by spray drying.

Science.gov (United States)

Bianco, Stefano; Caron, Vincent; Tajber, Lidia; Corrigan, Owen I; Nolan, Lorraine; Hu, Yun; Healy, Anne Marie

2012-06-01

Solid-state characterisation of a drug following pharmaceutical processing and upon storage is fundamental to successful dosage form development. The aim of the study was to investigate the effects of using different solvents, feed concentrations and spray drier configuration on the solid-state nature of the highly polymorphic model drug, sulfathiazole (ST) and its sodium salt (STNa). The drugs were spray-dried from ethanol, acetone and mixtures of these organic solvents with water. Additionally, STNa was spray-dried from pure water. The physicochemical properties including the physical stability of the spray-dried powders were compared to the unprocessed materials. Spray drying of ST from either acetonic or ethanolic solutions with the spray drier operating in a closed cycle mode yielded crystalline powders. In contrast, the powders obtained from ethanolic solutions with the spray drier operating in an open cycle mode were amorphous. Amorphous ST crystallised to pure form I at ≤35 % relative humidity (RH) or to polymorphic mixtures at higher RH values. The usual crystal habit of form I is needle-like, but spherical particles of this polymorph were generated by spray drying. STNa solutions resulted in an amorphous material upon processing, regardless of the solvent and the spray drier configuration employed. Moisture induced crystallisation of amorphous STNa to a sesquihydrate, whilst crystallisation upon heating gave rise to a new anhydrous polymorph. This study indicated that control of processing and storage parameters can be exploited to produce drugs with a specific/desired solid-state nature.

Oral omega-6 essential fatty acid treatment in contact lens associated dry eye.

Science.gov (United States)

Kokke, Karolien H; Morris, Judith A; Lawrenson, John G

2008-06-01

Symptoms of dry eye are commonly reported in contact lens wearers and are a frequent cause of non-tolerance. The purpose of the present study is to evaluate the effects of oral treatment with particular omega-6 fatty acids in the form of evening primrose oil (EPO) on subjective symptoms, ocular surface signs and tear film characteristic in patients with contact lens associated dry eye. The study design was randomised, double-masked and placebo controlled. 76 female soft contact lens wearers were treated for 6 months with either EPO or placebo (olive oil). Subjects underwent three examinations (baseline, 3 and 6 months). At each examination subjects were given a questionnaire relating to lens comfort and dry eye symptoms and underwent a series of tests of tear film characteristics (tear meniscus height, break-up time), meibomian gland function (lipid layer thickness and quality) and ocular surface parameters (hyperaemia and staining). The EPO group showed a significant improvement in the specific symptom of 'dryness' at 3 and 6 months (porally administered omega-6 fatty acids in alleviating dry eye symptoms and improving overall lens comfort in patients suffering from contact lens associated dry eye.

Psychrophilic dry anaerobic digestion of cow feces and wheat straw: Feasibility studies

International Nuclear Information System (INIS)

Massé, Daniel I.; Saady, N.M.C.; Gilbert, Yan

2015-01-01

This paper reports a novel psychrophilic dry anaerobic digestion (PDAD) of cow feces (feces) and wheat straw (WS). Three feeding strategies (WS, feces, and feces plus WS) were assessed in pseudo sequential batch reactors (PSBR) during three successive cycles of around 21 days hydraulic retention time (HRT). Average specific methane yields on VS fed (L kg −1 ) of 129 ± 17 (WS only), 164 ± 23 (feces only (10–11% TS)) and 152 ± 6 (a mixture of feces plus WS (16% TS)) were obtained during the last three successive cycles. The average methane production rates on VS fed were 3.5 ± 1.5 and 3.6 ± 1.3 and 4.1 ± 0.4 L kg −1  d −1 for the three feeding strategies, respectively. The successive cycles revealed that the psychrophilic anaerobic digestion of high-solid content of cow feces and wheat straw is a reproducible process, practically feasible, and as efficient as mesophilic dry anaerobic digestion given that a well-adapted inoculum is developed and maintained. - Highlights: • Cow feces and wheat straw (CFWS) psychrophilic dry anaerobic digestion (PDAD). • PDAD of CFWS (TS 16% mass fraction) is feasible and as efficient as mesophilic DAD. • VS OLR 1.5 g kg −1  d −1 produced VS-based SMY of 152 ± 6 L kg −1 • Inoculum adaptation is a prerequisite to a stable PDAD

DEVELOPMENT OF MATHEMATICAL MODEL OF PROCESS OF BLACK CURRANT BERRIES DRYING IN VACUUMDEVICE WITH THE MICROWAVE POWER SUPPLY

Directory of Open Access Journals (Sweden)

S. T. Antipov

2014-01-01

Full Text Available Summary. The mathematical model allowed to reproduce and study at qualitative level the change of berries form and the structure of the berries layer in the course of drying. The separate berry in the course of drying loses gradually its elasticity, decreases in volume, the peel gathers in folds, there appear internal emptiness. In the course of drying the berries layer decreases in thickness, contacting berries stick strongly with each other due to the coordinated folds of peel appearing, the layer is condensed due to penetration of the berries which have lost elasticity into emptiness between them. The model with high specification describes black currant drying process and therefore has a large number of the parameters available to change. Among them three most important technological parameters, influencing productivity and the drying quality are chosen: the power of microwave radiation P, thickness of the berries layer h, environmental pressure p. From output indicators of the model the most important are three functions from time: dependence of average humidity of the layer on time Wcp (t, dependence of the speed of change of average humidity on time dWcp (t/dt, dependence of the layer average temperature on time Tср (t. On the standard models classification the offered model is algorithmic, but not analytical. It means that output characteristics of model are calculated with the entrance ones, not by analytical transformations (it is impossible principally for the modeled process, but by means of spatial and temporary sampling and the corresponding calculation algorithm. Detailed research of the microwave drying process by means of the model allows to allocate the following stages: fast heating, the fast dehydration, the slowed-down dehydration, consolidation of a layer of a product, final drying, heating after dehydration.

Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant

International Nuclear Information System (INIS)

Li, Xiaoxiao; Duniam, Sam; Gurgenci, Hal; Guan, Zhiqiang; Veeraragavan, Anand

2017-01-01

Highlights: • A 20 m high natural draft dry cooling tower is designed and tested. • The cooling tower model is refined and validated with the experimental data. • The performance of the cooling tower utilized in a CST power plant is investigated. • Ambient temperature effect on Rankine cycle and Brayton cycle is discussed. - Abstract: Concentrating solar thermal power system can provide low carbon, renewable energy resources in countries or regions with strong solar irradiation. For this kind of power plant which is likely to be located in the arid area, natural draft dry cooling tower is a promising choice. To develop the experimental studies on small cooling tower, a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence. The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 °C to 32 °C. The cooling tower numerical model was refined and validated with the experimental data. The model of 1 MW concentrating solar thermal supercritical CO_2 power cycle was developed and integrated with the cooling tower model. The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated. The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO_2 Brayton cycle were analysed and discussed.

Genetic and Developmental Basis for Increased Leaf Thickness in the Arabidopsis Cvi Ecotype

Directory of Open Access Journals (Sweden)

Viktoriya Coneva

2018-03-01

Full Text Available Leaf thickness is a quantitative trait that is associated with the ability of plants to occupy dry, high irradiance environments. Despite its importance, leaf thickness has been difficult to measure reproducibly, which has impeded progress in understanding its genetic basis, and the associated anatomical mechanisms that pattern it. Here, we used a custom-built dual confocal profilometer device to measure leaf thickness in the Arabidopsis Ler × Cvi recombinant inbred line population and found statistical support for four quantitative trait loci (QTL associated with this trait. We used publically available data for a suite of traits relating to flowering time and growth responses to light quality and show that three of the four leaf thickness QTL coincide with QTL for at least one of these traits. Using time course photography, we quantified the relative growth rate and the pace of rosette leaf initiation in the Ler and Cvi ecotypes. We found that Cvi rosettes grow slower than Ler, both in terms of the rate of leaf initiation and the overall rate of biomass accumulation. Collectively, these data suggest that leaf thickness is tightly linked with physiological status and may present a tradeoff between the ability to withstand stress and rapid vegetative growth. To understand the anatomical basis of leaf thickness, we compared cross-sections of Cvi and Ler leaves and show that Cvi palisade mesophyll cells elongate anisotropically contributing to leaf thickness. Flow cytometry of whole leaves show that endopolyploidy accompanies thicker leaves in Cvi. Overall, our data suggest that mechanistically, an altered schedule of cellular events affecting endopolyploidy and increasing palisade mesophyll cell length contribute to increase of leaf thickness in Cvi. Ultimately, knowledge of the genetic basis and developmental trajectory leaf thickness will inform the mechanisms by which natural selection acts to produce variation in this adaptive trait.

Dynamic behavior of Rankine cycle system for waste heat recovery of heavy duty diesel engines under driving cycle

International Nuclear Information System (INIS)

Xie, Hui; Yang, Can

2013-01-01

Highlights: • Waste heat recovery behavior of the RCS during driving cycle was investigated. • Four operating modes were defined to describe the operating process of the RCS under driving cycle. • The operating mode switching is the crucial reason for on-road inefficiency. • The dry and isentropic fluids are superior to the wet ones on the adaptability to unsteady ExGE. • The effects of the vapor parameters on RCT-E and power mode percentage are opposite. - Abstract: The RCS (Rankine cycle system) used to recover the WHE (waste heat energy) from engines has been regarded as one of the most potential ways of achieving higher efficiency. However, it is of great challenge to keep the RCS still in good performance under driving cycle. This paper tries to reveal and explain its on-road inefficiency. The operating process of the RCS under driving cycle was analyzed in advance. Afterwards, four basic operating modes were defined, including startup mode, turbine turning mode, power mode and protection mode. Then, a RCS model was established and operating performances of the RCS under an actual driving cycle were discussed based on this model. The results indicate that the on-road RCS-E (Rankine cycle system efficiency) is as low as 3.63%, which is less than half of the design RCS-E (7.77%) at the rated operating point. Despite the inevitable vapor state fluctuation, it is the operating mode switching during the driving cycle that leads to the on-road inefficiency. Further investigations indicate that the expander safety temperature and its safety margin affected by the working fluids, designed superheat degree and evaporating pressure are the main factors determining the operating mode switching. Finally, the effects of the working fluids, designed superheat degree and evaporating pressure on the operating mode switching and RC (Rankine cycle) efficiencies were profoundly investigated. The study shows that the dry and isentropic fluids are superior to the wet

Highly durable and unidirectionally stooped polymeric nanohairs for gecko-like dry adhesive

International Nuclear Information System (INIS)

Im, Hyeon Seong; Kwon, Ki Yoon; Kim, Jong Uk; Kim, Tae-il; Kim, Kwang Su; Yi, Hoon; Jeong, Hoon Eui; Yoo, Pil J; Pang, Changhyun

2015-01-01

Gecko-like dry adhesive using high aspect ratio polymeric nanohairs has insuperable limitations, although it has huge potential in many applications. Repeated harsh contacts on a target substrate lead to physical collapse of nanohairs and significant degradation of the adhesion property, because the polymeric nanohairs are quite fragile due to poor mechanical robustness. Herein, we demonstrate a highly robust gecko-like dry adhesive with unidirectionally stooped polymeric nanohairs (diameter 100 nm) with a high aspect ratio (∼9) using an ultrathin metal coating. 100 cycles of repeated adhesion tests with 1 N preloading force did not significantly degrade adhesion or cause collapse of nanohairs. We believe that this approach allows gecko-like dry adhesive to be utilized in many related applications and diverse industry interests. (paper)

Cooling of nuclear power stations with high temperature reactors and helium turbine cycles

International Nuclear Information System (INIS)

Foerster, S.; Hewing, G.

1977-01-01

On nuclear power stations with high temperature reactors and helium turbine cycles (HTR-single circuits) the residual heat from the energy conversion process in the primary and intermediate coolers is removed from cycled gas, helium. Water, which is circulated for safety reasons through a closed circuit, is used for cooling. The primary and intermediate coolers as well as other cooling equipment of the power plant are installed within the reactor building. The heat from the helium turbine cycle is removed to the environment most effectively by natural draught cooling towers. In this way a net plant efficiency of about 40% is attainable. The low quantities of residual heat thereby produced and the high (in comparison with power stations with steam turbine cycles) cooling agent pressure and cooling water reheat pressure in the circulating coolers enable an economically favourable design of the overall 'cold end' to be expected. In the so-called unit range it is possible to make do with one or two cooling towers. Known techniques and existing operating experience can be used for these dry cooling towers. After-heat removal reactor shutdown is effected by a separate, redundant cooling system with forced air dry coolers. The heat from the cooling process at such locations in the power station is removed to the environment either by a forced air dry cooling installation or by a wet cooling system. (orig.) [de

Astronomical cycle origin of bedded chert: A middle Triassic bedded chert sequence, Inuyama, Japan

Science.gov (United States)

Ikeda, Masayuki; Tada, Ryuji; Sakuma, Hironobu

2010-09-01

Astronomical forcing is one of the main drivers of climate change, and astronomical cyclicity recorded in sediments provides a clue to understand the dynamics of the global climate system. Bedded cherts consist of rhythmic alternations of chert and shale beds. Although previous studies have hypothesized that the origin of bedded chert is related to astronomical cycles (e.g. Fischer, 1976; Hori et al., 1993), conclusive proof remains elusive. To explore this possibility, we established a continuous, high-resolution lithostratigraphy of middle Triassic bedded chert in Central Japan. The average duration of each chert-shale couplet is 20 kyr, similar to that of the precession cycle. Spectral analysis of a bed number series of thickness variations in chert beds was performed assuming that each chert-shale couplet represents a 20-kyr precession cycle. The results reveal cycles involving approximately 200, 20, 5, and 2-3 beds, corresponding to periodicities of approximately 4000, 400, 100, and 40-60 kyr, respectively. By further assuming that the 20-bed cycle represents a 405-kyr eccentricity cycle of constant and stable periodicity, we converted the bed number series to a time series. Spectral analysis of the time series revealed distinct periodicities of 3600, 117, 97, and 38 kyr, in addition to 405 kyr. Besides 3600 kyr, these periodicities agree well with the 120, 95, and 37 kyr periodicities for eccentricity cycles and the obliquity cycle during the Triassic. Moreover, we detected amplitude modulation of the approximately 100-kyr cycle of thickness variations in chert beds with a 405-kyr periodicity, which may correspond to amplitude modulation of 100-kyr climatic precession cycle with the 405-kyr periodicity. The approximately 3600-kyr periodicity described above and 1800-kyr periodicity manifested as the amplitude modulation of the 405-kyr cycle are correlated to present-day long-term eccentricity cycles of 2400 and 4800 kyr evolved by chaotic behavior of solar

Greenhouse Gas Induced Changes in the Seasonal Cycle of the Amazon Basin in Coupled Climate-Vegetation Regional Model

Directory of Open Access Journals (Sweden)

Flavio Justino

2016-01-01

Full Text Available Previous work suggests that changes in seasonality could lead to a 70% reduction in the extent of the Amazon rainforest. The primary cause of the dieback of the rainforest is a lengthening of the dry season due to a weakening of the large-scale tropical circulation. Here we examine these changes in the seasonal cycle. Under present day conditions the Amazon climate is characterized by a zonal separation of the dominance of the annual and semi-annual seasonal cycles. This behavior is strongly modified under greenhouse warming conditions, with the annual cycle becoming dominant throughout the Amazon basin, increasing differences between the dry and wet seasons. In particular, there are substantial changes in the annual cycle of temperature due to the increase in the temperature of the warmest month, but the lengthening of the dry season is believed to be particularly important for vegetation-climate feedbacks. Harmonic analysis performed to regional climate model simulations yields results that differ from the global climate model that it is forced from, with the regional model being more sensitive to changes in the seasonal cycle.

Electron irradiation of dry food products

Energy Technology Data Exchange (ETDEWEB)

Gruenewald, Th [Bundesbahn-Zentralamt, Minden (Germany, F.R.)

1983-01-01

The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10**4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50 deg C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the irradiation field in a closed conveyor system.

Electron irradiation of dry food products

International Nuclear Information System (INIS)

Gruenewald, Th.

1983-01-01

The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10**4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50 deg C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the irradiation field in a closed conveyor system. (author)

THE EFFECT OF A DYNAMIC INNER HELIOSHEATH THICKNESS ON COSMIC-RAY MODULATION

International Nuclear Information System (INIS)

Manuel, R.; Ferreira, S. E. S.; Potgieter, M. S.

2015-01-01

The time-dependent modulation of galactic cosmic rays in the heliosphere is studied over different polarity cycles by computing 2.5 GV proton intensities using a two-dimensional, time-dependent modulation model. By incorporating recent theoretical advances in the relevant transport parameters in the model, we showed in previous work that this approach gave realistic computed intensities over a solar cycle. New in this work is that a time dependence of the solar wind termination shock (TS) position is implemented in our model to study the effect of a dynamic inner heliosheath thickness (the region between the TS and heliopause) on the solar modulation of galactic cosmic rays. The study reveals that changes in the inner heliosheath thickness, arising from a time-dependent shock position, does affect cosmic-ray intensities everywhere in the heliosphere over a solar cycle, with the smallest effect in the innermost heliosphere. A time-dependent TS position causes a phase difference between the solar activity periods and the corresponding intensity periods. The maximum intensities in response to a solar minimum activity period are found to be dependent on the time-dependent TS profile. It is found that changing the width of the inner heliosheath with time over a solar cycle can shift the time of when the maximum or minimum cosmic-ray intensities occur at various distances throughout the heliosphere, but more significantly in the outer heliosphere. The time-dependent extent of the inner heliosheath, as affected by solar activity conditions, is thus an additional time-dependent factor to be considered in the long-term modulation of cosmic rays

Effect of paddy drying depth using open-sun drying on drying time ...

African Journals Online (AJOL)

The smallholder rice farmers in the Uganda dry their paddy using open-sun drying method. In most cases the paddy is badly dried and has very high fissure levels. Such paddy on milling contributes to low levels of mill recovery and whole grain in the milled rice. This study was therefore done to find a recommendable ...

Study of the flash drying of the residue from soymilk processing - "okara"

Directory of Open Access Journals (Sweden)

Regina Kitagawa Grizotto

2011-09-01

Full Text Available The objective of this research project was to study the drying of soymilk residue in a pneumatic flash dryer, using response Surface Methodology (RSM, and to evaluate the quality of the dried residue. Soymilk residue, also known as okara, was provided by a Brazilian soymilk factory. RSM showed that for a 120 second drying cycle, the lower the residue moisture contents (y obtained, the higher the recirculation rates (x1, regardless of the air drying temperature (x2, and it could be expressed by the equation y = 7.072 - 7.92x1, with R² = 92,92%. It is possible to obtain okara with 10% of moisture (dwb under the condition x1=1.25, equivalent to RR = 61%, with air drying temperatures ranging from 252 °C to 308 °C. The dried okara obtained through Central Compound Rotational Design (CCRD presented a centesimal composition similar to the okara dried in a tray dryer, known as the original okara. There were significant variations (p < 0.05 in the Emulsifying Capacity (EC, Emulsion Stability (ES and Protein Solubility (PS between the dehydrated residues obtained. It was concluded that the flash drying of okara is technically feasible and that the physicochemical composition of the residue was not altered; on the contrary, the process promoted a positive effect on the technological functional properties.

Plague cycles in two rodent species from China: Dry years might provide context for epizootics in wet years

Science.gov (United States)

Eads, David A.; Biggins, Dean E.; Xu, Lei; Liu, Qiyong

2016-01-01

Plague, a rodent-associated, flea-borne zoonosis, is one of the most notorious diseases in history. Rates of plague transmission can increase when fleas are abundant. Fleas commonly desiccate and die when reared under dry conditions in laboratories, suggesting fleas will be suppressed during droughts in the wild, thus reducing the rate at which plague spreads among hosts. In contrast, fleas might increase in abundance when precipitation is plentiful, producing epizootic outbreaks during wet years. We tested these hypotheses using a 27-yr data set from two rodents in Inner Mongolia, China: Mongolian gerbils (Meriones unguiculatus) and Daurian ground squirrels (Spermophilus dauricus). For both species of rodents, fleas were most abundant during years preceded by dry growing seasons. For gerbils, the prevalence of plague increased during wet years preceded by dry growing seasons. If precipitation is scarce during the primary growing season, succulent plants decline in abundance and, consequently, herbivorous rodents can suffer declines in body condition. Fleas produce more offspring and better survive when parasitizing food-limited hosts, because starving animals tend to exhibit inefficient behavioral and immunological defenses against fleas. Further, rodent burrows might buffer fleas from xeric conditions aboveground during dry years. After a dry year, fleas might be abundant due to the preceding drought, and if precipitation and succulent plants become more plentiful, rodents could increase in density, thereby creating connectivity that facilitates the spread of plague. Moreover, in wet years, mild temperatures might increase the efficiency at which fleas transmit the plague bacterium, while also helping fleas to survive as they quest among hosts. In this way, dry years could provide context for epizootics of plague in wet years.

A New Xeromorphic Species of Clusia em>(Clusiaceae) from Dry Valleys of Northern Peru

DEFF Research Database (Denmark)

Gustafsson, Mats

2010-01-01

Clusia magnoliiflora M. H. G. Gust. is described as new for the Clusiaceae. It grows in dry scrub in the river valleys of the Marañón and its tributaries in northern Peru, a kind of habitat that harbors very few Clusia species. The species is distinct on account of its extremely thick, obovate le...

Design of solar drying-plant for bulk material drying

Directory of Open Access Journals (Sweden)

Peter Horbaj

2008-11-01

Full Text Available A generally well-known high energy requirement for technological processes of drying and the fact that the world’s supplyof the conventional energy sources has considerably decreased are the decisive factors forcing us to look for some new, if possible,renewable energy sources for this process by emphasising their environmental reliability. One of the possibilities how to replace, atleast partly, the conventional energy sources – heat in a drying process is solar energy.Air-drying of bulk materials usually has a series of disadvantages such as time expenditure, drying defects in the bulk materialand inadequate final moisture content. A method that obviates or reduces the disadvantages of air-drying and, at the same time, reducesthe costs of kiln drying, is drying with solar heat. Solar energy can replace a large part of this depletable energy since solar energy cansupply heat at the temperatures most often used to dry bulk material. Solar drying-plant offer an attractive solution.

Life cycle analysis on fossil energy ratio of algal biodiesel: effects of nitrogen deficiency and oil extraction technology.

Science.gov (United States)

Jian, Hou; Jing, Yang; Peidong, Zhang

2015-01-01

Life cycle assessment (LCA) has been widely used to analyze various pathways of biofuel preparation from "cradle to grave." Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae.

Temperature distribution of thick thermoset composites

Science.gov (United States)

Guo, Zhan-Sheng; Du, Shanyi; Zhang, Boming

2004-05-01

The development of temperature distribution of thick polymeric matrix laminates during an autoclave vacuum bag process was measured and compared with numerically calculated results. The finite element formulation of the transient heat transfer problem was carried out for polymeric matrix composite materials from the heat transfer differential equations including internal heat generation produced by exothermic chemical reactions. Software based on the general finite element software package was developed for numerical simulation of the entire composite process. From the experimental and numerical results, it was found that the measured temperature profiles were in good agreement with the numerical ones, and conventional cure cycles recommended by prepreg manufacturers for thin laminates should be modified to prevent temperature overshoot.

A microfabricated nickel-hydrogen battery using thick film printing techniques

Science.gov (United States)

Tam, Waiping G.; Wainright, Jesse S.

To utilize the distinctive cycle life and safety characteristics of the nickel-hydrogen chemistry while eliminating the high pressure limitations of conventional nickel-hydrogen cells, a microfabricated nickel-hydrogen battery using a low-pressure metal hydride for hydrogen storage is being developed for powering micro-electromechanical systems (MEMS) devices and for biomedical applications where the battery would be implanted within the body. Thick film printing techniques which are simple and low cost were used to fabricate this battery. Inks were developed for each of the different battery components, including the electrodes, current collectors and separator. SEM images on these printed components showed the desired characteristics for each. Positive electrode cycling tests were performed on the printed positive electrodes while cyclic voltammetry was used to characterize the printed negative electrodes. Consistent charge and discharge performance was observed during positive electrode cycling. Full cells with printed positive and negative assemblies were assembled and tested.

A microfabricated nickel-hydrogen battery using thick film printing techniques

Energy Technology Data Exchange (ETDEWEB)

Tam, Waiping G.; Wainright, Jesse S. [Department of Chemical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States)

2007-02-25

To utilize the distinctive cycle life and safety characteristics of the nickel-hydrogen chemistry while eliminating the high pressure limitations of conventional nickel-hydrogen cells, a microfabricated nickel-hydrogen battery using a low-pressure metal hydride for hydrogen storage is being developed for powering micro-electromechanical systems (MEMS) devices and for biomedical applications where the battery would be implanted within the body. Thick film printing techniques which are simple and low cost were used to fabricate this battery. Inks were developed for each of the different battery components, including the electrodes, current collectors and separator. SEM images on these printed components showed the desired characteristics for each. Positive electrode cycling tests were performed on the printed positive electrodes while cyclic voltammetry was used to characterize the printed negative electrodes. Consistent charge and discharge performance was observed during positive electrode cycling. Full cells with printed positive and negative assemblies were assembled and tested. (author)

Oxide thickness measurement for monitoring fuel performance at high burnup

International Nuclear Information System (INIS)

Jaeger, M.A.; Van Swam, L.F.P.; Brueck-Neufeld, K.

1991-01-01

For on-site monitoring of the fuel performance at high burnup, Advanced Nuclear Fuels uses the linear scan eddy current method to determine the oxide thickness of irradiated Zircaloy fuel cans. Direct digital data acquisition methods are employed to collect the data on magnetic storage media. This field-proven methodology allows oxide thickness measurements and rapid interpretation of the data during the reactor outages and makes it possible to immediately reinsert the assemblies for the next operating cycle. The accuracy of the poolside measurements and data acquisition/interpretation techniques have been verified through hot cell metallographic measurements of rods previously measured in the fuel pool. The accumulated data provide a valuable database against which oxide growth models have been benchmarked and allow for effective monitoring of fuel performance. (orig.) [de

Impact of Pretreatment and Drying Methods on Quality Attributes of Onion Shreds

Directory of Open Access Journals (Sweden)

Nihar R. Sahoo

2015-01-01

Full Text Available Experiments were conducted on dry untreated onion shreds (2 mm thickness or treated with salt (5 % solution and potassium metabisulphite (0.5 % solution in convective drier at 50 °C ((46±4 % relative humidity (RH, 55 °C ((35±4 % RH, 60 °C ((28±4 % RH and 65 °C ((20±4 % RH, heat pump-assisted convective drier at 35 °C ((32±2 % RH, 40 °C ((26±2 % RH, 45 °C ((19±2 % RH and 50 °C ((15±2 % RH and microwave-assisted convective drier at four microwave power levels, i.e. 120, 240, 360 and 480 W. The quality parameters of the dried onion shreds, namely rehydration ratio, colour diff erence, pyruvic and ascorbic acid contents and sensory scores were evaluated. The quality of dehydrated onion shreds was observed to be comparatively better when treated in heat pump drier at 50 °C, followed by that in microwave-assisted convective drier at 240 W and 50 °C, and last in convective drier at 60 °C. The onion shreds pretreated with potassium metabisulphite retained better colour of the dried product irrespective of drying methods. Therefore, heat pump drying may be recommended as one of the best drying methods for onion shreds, because it maintains the fi nal product quality, which has practical importance for the food industry.

Isotope studies to determine dry deposition of sulfate to deciduous and coniferous trees: Final draft

International Nuclear Information System (INIS)

Garten, C.T. Jr.

1988-01-01

Experiments have been conducted at two locations near Oak Ridge, Tennessee, with radioactive 35 S (87 day half-life) to examine the cycling behavior of sulfur in yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and loblolly pine (Pinus taeda) trees. Some findings pertain to methods development for estimating dry deposition of sulfur to forest canopies and the magnitude of sulfur emissions from natural sources (Task II). We will determine through field studies, the internal cycling, storage, and biogenic emission of sulfur, as traced by 35 SO 4 2- , in environments impacted by atmospheric sulfate deposition; and will determine through isotope dilution studies, the contribution of foliar leaching and dry deposition to net throughfall (NTF) sulfate concentrations beneath deciduous and coniferous trees in such environments. 3 refs., 2 figs., 1 tab

Modeling of an industrial drying process by artificial neural networks

Directory of Open Access Journals (Sweden)

E. Assidjo

2008-09-01

Full Text Available A suitable method is needed to solve the nonquality problem in the grated coconut industry due to the poor control of product humidity during the process. In this study the possibility of using an artificial neural network (ANN, precisely a Multilayer Perceptron, for modeling the drying step of the production of grated coconut process is highlighted. Drying must confer to the product a final moisture of 3%. Unfortunately, under industrial conditions, this moisture varies from 1.9 to 4.8 %. In order to control this parameter and consequently reduce the proportion of the product that does not meet the humidity specification, a 9-4-1 neural network architecture was established using data gathered from an industrial plant. This Multilayer Perceptron can satisfactorily model the process with less bias, ranging from -0.35 to 0.34%, and can reduce the rate of rejected products from 92% to 3% during the first cycle of drying.

Lead Thickness Measurements

International Nuclear Information System (INIS)

Rucinski, R.

1998-01-01

The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in 3 , an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

The correlation between endometrial thickness and outcome of in vitro fertilization and embryo transfer (IVF-ET outcome

Directory of Open Access Journals (Sweden)

Al-Rejjal Rafat

2008-09-01

Full Text Available Abstract Background To evaluate the relationship between endometrial thickness on day of human chorionic gonadotrophin administration (hCG and pregnancy outcome in a large number of consecutive in vitro fertilization and embryo transfer (IVF-ET cycles. Methods A retrospective cohort study including all patients who had IVF-ET from January 2003–December 2005 conducted at a tertiary center. Results A total of 2464 cycles were analysed. Pregnancy rate (PR was 35.8%. PR increased linearly (r = 0.864 from 29.4% among patients with a lining of less than or equal to 6 mm, to 44.4% among patients with a lining of greater than or equal to 17 mm. ROC showed that endometrial thickness is not a good predictor of PR, so a definite cut-off value could not be established (AUC = 0.55. Conclusion There is a positive linear relationship between the endometrial thickness measured on the day of hCG injection and PR, and is independent of other variables. Hence aiming for a thicker endometrium should be considered.

Infrared Drying as a Quick Preparation Method for Dried Tangerine Peel

Directory of Open Access Journals (Sweden)

Mingyue Xu

2017-01-01

Full Text Available To establish the most convenient and effective method to dry tangerine peels, different methods (sun drying, hot-air drying, freeze drying, vacuum drying, and medium- and short-wave infrared drying were exploited. Our results indicated that medium- and short-wave infrared drying was the best method to preserve nutraceutical components; for example, vitamin C was raised to 6.77 mg/g (D.W. from 3.39 mg/g (sun drying. Moreover, the drying time can be shortened above 96% compared with sun drying. Importantly, the efficiency of DPPH radical scavenging was enhanced from 26.66% to 55.92%. These findings would provide a reliable and time-saving methodology to produce high-quality dried tangerine peels.

Environmental improvement in drying process of plastics part paint; Jushi buhin toso kanso kotei no kankyo kaizen

Energy Technology Data Exchange (ETDEWEB)

Nakamura, T.; Horii, H.; Kobayashi, T.; Hayashida, T. [Hino Motors, Ltd., Tokyo (Japan)

1998-07-01

A method is developed of applying near infrared rays to the drying of paint coatings on resin-made automobile parts, and its environment improving effects are described. Using the conventional hot-air dryer for the drying of such coatings, the portion near the top surface is hardened prior to the other portions because the heat is absorbed near the top surface. Using an infrared drying system, however, defects in the product surface attributable to the lack of uniformity in the hardening of paint or to the splashing of solvent are remedied because deeper portions are hardened first. Experiment and study are conducted for the purpose of applying a near infrared drying method to an ABS (acrylonitrile butadiene styrene) coating. It is found that the near infrared drying method takes only seven minutes to dry a paint coating for which a hot-air furnace will take 20 minutes, thus shortening the drying time a great deal. Defects of gas hole of coatings are generally dealt with by changing the setting time and drying conditions for example by increasing the amount of the diluting thinner. When an near infrared drying method is used, the amount of the diluting thinner is reduced approximately 50% from the amount required using the hot-air drying method in case of the thickness of 60{mu}m. 2 refs., 9 figs., 2 tabs.

Bacterial regrowth potential in alkaline sludges from open-sun and covered sludge drying beds

Energy Technology Data Exchange (ETDEWEB)

Alkan, U.; Topac, F.O.; Birden, B.; Baskaya, H.S. [Uludag University, Gorukle (Turkey). Dept. of Environmnetal Engineering

2007-10-15

The aim of this study was to compare the regrowth potentials of wastewater sludges dried in two pilot-scale drying processes namely, Open-Sun Sludge Drying Bed (OSDB) and Covered Sludge Drying Bed (CSDB). Quicklime and/or coal fly ash were added to raw sludge samples prior to drying processes in order to enhance bacterial inactivation. Following three drying cycles (March-April, June-July and August-October), sludge samples were taken from the beds for the regrowth experiments. Addition of alkaline materials prevented the regrowth of faecal coliforms in all rewetted samples except for the samples obtained after the rainfall events in OSDB. Rewetting of these samples in the regrowth experiments increased faecal coliform numbers by 3.5-7 log units. In contradiction, the observed bacterial numbers in rewetted alkaline samples from CSDB were below the EPA Class B criterion (2 million MPN g{center_dot} 1) dry sludge). The combination of additional heat from solar collectors, protection from the rain and the unfavourable living conditions owing to alkaline materials appeared to inactivate bacteria more effectively in CSDB and hence eliminated regrowth potential more efficiently.

Sedimentological analysis and bed thickness statistics from a Carboniferous deep-water channel-levee complex: Myall Trough, SE Australia

Science.gov (United States)

Palozzi, Jason; Pantopoulos, George; Maravelis, Angelos G.; Nordsvan, Adam; Zelilidis, Avraam

2018-02-01

This investigation presents an outcrop-based integrated study of internal division analysis and statistical treatment of turbidite bed thickness applied to a Carboniferous deep-water channel-levee complex in the Myall Trough, southeast Australia. Turbidite beds of the studied succession are characterized by a range of sedimentary structures grouped into two main associations, a thick-bedded and a thin-bedded one, that reflect channel-fill and overbank/levee deposits, respectively. Three vertically stacked channel-levee cycles have been identified. Results of statistical analysis of bed thickness, grain-size and internal division patterns applied on the studied channel-levee succession, indicate that turbidite bed thickness data seem to be well characterized by a bimodal lognormal distribution, which is possibly reflecting the difference between deposition from lower-density flows (in a levee/overbank setting) and very high-density flows (in a channel fill setting). Power law and exponential distributions were observed to hold only for the thick-bedded parts of the succession and cannot characterize the whole bed thickness range of the studied sediments. The succession also exhibits non-random clustering of bed thickness and grain-size measurements. The studied sediments are also characterized by the presence of statistically detected fining-upward sandstone packets. A novel quantitative approach (change-point analysis) is proposed for the detection of those packets. Markov permutation statistics also revealed the existence of order in the alternation of internal divisions in the succession expressed by an optimal internal division cycle reflecting two main types of gravity flow events deposited within both thick-bedded conglomeratic and thin-bedded sandstone associations. The analytical methods presented in this study can be used as additional tools for quantitative analysis and recognition of depositional environments in hydrocarbon-bearing research of ancient

Effects of Long-Term Simulated Martian Conditions on a Freeze-Dried and Homogenized Bacterial Permafrost Community

Science.gov (United States)

Hansen, Aviaja A.; Jenson, Lars L.; Kristoffersen, Tommy; Mikkelsen, Karina; Merrison, Jonathan; Finster, Kai W.; Lomstein, Bente Aa.

2009-03-01

Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core, while the number of viable cells was reduced in the upper 15 mm. The number of cultured aerobic bacteria was reduced in the upper 6 mm of the soil core, whereas the community structure of cultured anaerobic bacteria was relatively unaffected by the exposure conditions. As explanations for the observed changes, we propose three causes that might have been working on the biological material either individually or synergistically: (i) UV radiation, (ii) UV-generated reactive oxygen species, and (iii) freeze-thaw cycles. Currently, the production and action of reactive gases is only hypothetical and will be a central subject in future investigations. Overall, we conclude that in a stable environment (no wind-/pressure-induced mixing) biological material is efficiently shielded by a 2 cm thick layer of dust, while it is relatively rapidly destroyed in the surface layer, and that biomolecules like proteins and polynucleotides are more resistant to destruction than living biota.

Microwave wood strand drying: energy consumption, VOC emission and drying quality

Energy Technology Data Exchange (ETDEWEB)

Wang, S.; Du, G.; Zhang, Y. [Tennessee Univ., Knoxville, TN (United States). Dept. of Forestry, Wildlife and Fisheries

2005-07-01

The objective of this research was to develop microwave drying technology for wood strand drying for oriented strand board (OSB) manufacturing. The advantages of microwave drying included a reduction in the drying time of wood strands and a reduction in the release of volatile organic compounds (VOC) through a decrease in the thermal degradation of the wood material. Temperature and moisture content changes under different microwave drying conditions were investigated. The effects of microwave drying on VOC emissions were evaluated and analyzed using gas chromatography and mass spectrometry. Microwave power input and the mass of drying materials in the microwave oven were found to have a dominant effect on drying quality. Results indicated that an increase in microwave power input and a decrease in sample weights resulted in high drying temperatures, short drying times and a high drying rate. The effect of microwave drying on the strand surfaces was also investigated. Different strand geometries and initial moisture content resulted in varying warm-up curves, but did not influence final moisture content. VOC emissions were quantified by comparing alpha-pinene concentrations. The microwave drying resulted in lower VOC emissions compared with conventional drying methods. It was concluded that the microwave drying technique provided faster strand drying and reduced energy consumption by up to 50 per cent. In addition, the surface wettability of wood strands dried with microwaves was better than with an industrial rotary drum drier. 12 refs., 3 tabs., 5 figs.

A Comparative Study of Spiral Tomograms with Different Slice Thicknesses in Dental Implant Planning

International Nuclear Information System (INIS)

Yoon Sook Ja

1999-01-01

To know whether there would be a difference among spiral tomograms of different slice thicknesses in the measurement of distances which are used for dental implant planning. 10 dry mandibules and 40 metal balls are used to take total 120 Scanora tomograms with the slice thickness of 2 mm, 4 mm and 8 mm. 3 oral radiologists interpreted each tomogram to measure the distances from the mandibular canal to the alveoalr crest and buccal, lingual and inferior borders of mandible. 3 observers recorded grades of 0, 1 or 2 to evaluate the perceptibility of alveolar crest and the superior border of mandibular canal. For statistical analysis, ANOVA with repeated measure, Chi-square tests and intraclass correlation coefficient (R2, alpha) were used. There was not a statistically significant difference among spiral tomograms with different slice thicknesses in the measurement of the distances and in the perceptibility of alveolar crest and mandibular canal (p>0.05). All of them showed a good relationship in the reliability analysis. The perceptibility of alveolar crest and mandibular canal was almost similar and an excellent relationship was seen on all of them. There would be no significant difference, no matter which spiral tomogram of any slice thickness may be used in dental implant planning, considering the thickness of dental implant fixture.

The potential of computer vision, optical backscattering parameters and artificial neural network modelling in monitoring the shrinkage of sweet potato (Ipomoea batatas L.) during drying.

Science.gov (United States)

Onwude, Daniel I; Hashim, Norhashila; Abdan, Khalina; Janius, Rimfiel; Chen, Guangnan

2018-03-01

Drying is a method used to preserve agricultural crops. During the drying of products with high moisture content, structural changes in shape, volume, area, density and porosity occur. These changes could affect the final quality of dried product and also the effective design of drying equipment. Therefore, this study investigated a novel approach in monitoring and predicting the shrinkage of sweet potato during drying. Drying experiments were conducted at temperatures of 50-70 °C and samples thicknesses of 2-6 mm. The volume and surface area obtained from camera vision, and the perimeter and illuminated area from backscattered optical images were analysed and used to evaluate the shrinkage of sweet potato during drying. The relationship between dimensionless moisture content and shrinkage of sweet potato in terms of volume, surface area, perimeter and illuminated area was found to be linearly correlated. The results also demonstrated that the shrinkage of sweet potato based on computer vision and backscattered optical parameters is affected by the product thickness, drying temperature and drying time. A multilayer perceptron (MLP) artificial neural network with input layer containing three cells, two hidden layers (18 neurons), and five cells for output layer, was used to develop a model that can monitor, control and predict the shrinkage parameters and moisture content of sweet potato slices under different drying conditions. The developed ANN model satisfactorily predicted the shrinkage and dimensionless moisture content of sweet potato with correlation coefficient greater than 0.95. Combined computer vision, laser light backscattering imaging and artificial neural network can be used as a non-destructive, rapid and easily adaptable technique for in-line monitoring, predicting and controlling the shrinkage and moisture changes of food and agricultural crops during drying. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Curing of Thick Thermoset Composite Laminates: Multiphysics Modeling and Experiments

Science.gov (United States)

Anandan, S.; Dhaliwal, G. S.; Huo, Z.; Chandrashekhara, K.; Apetre, N.; Iyyer, N.

2017-11-01

Fiber reinforced polymer composites are used in high-performance aerospace applications as they are resistant to fatigue, corrosion free and possess high specific strength. The mechanical properties of these composite components depend on the degree of cure and residual stresses developed during the curing process. While these parameters are difficult to determine experimentally in large and complex parts, they can be simulated using numerical models in a cost-effective manner. These simulations can be used to develop cure cycles and change processing parameters to obtain high-quality parts. In the current work, a numerical model was built in Comsol MultiPhysics to simulate the cure behavior of a carbon/epoxy prepreg system (IM7/Cycom 5320-1). A thermal spike was observed in thick laminates when the recommended cure cycle was used. The cure cycle was modified to reduce the thermal spike and maintain the degree of cure at the laminate center. A parametric study was performed to evaluate the effect of air flow in the oven, post cure cycles and cure temperatures on the thermal spike and the resultant degree of cure in the laminate.

An experimental study on the application of polyalcohol solid-solid phase change materials in solar drying with cross-corrugated solar air collectors

Science.gov (United States)

Gao, W. F.; Lin, W. X.; Liu, T.; Li, M.

2017-11-01

In this paper, two identical solar driers with the same cross-corrugated solar air collectors and drying chamber were developed, one with phase-change materials (PCMs) and the other without PCMs. These two solar drying systems were tested in typical sunny and cloudy days in Kunming and their thermal performances were analyzed. The experimental results show that the temperature changing is smoother in the collector with the PCMs, which is beneficial for the drying as the useful drying time was prolonged. The same trend was also found in the chamber with the PCMs. The PCMs in solar drying system was found to play a role in temperature regulating. There were several cycles of heat charging-discharging in a cloudy testing day while the temperatures on collectors and in chambers with the polyalcohol PCMs is higher than each phase-change temperature. Nevertheless, there was only one cycle of heat charging-discharging in a sunny testing day. The collector with PCMs has higher daily useful heat gain than the collector without PCMs.

Effect of Porosity on the Thick Electrodes for High Energy Density Lithium Ion Batteries for Stationary Applications

Directory of Open Access Journals (Sweden)

Madhav Singh

2016-11-01

Full Text Available A series of 250–350 μ m-thick single-sided lithium ion cell graphite anodes and lithium nickel manganese cobalt oxide (NMC cathodes with constant area weight, but varying porosity were prepared. Over this wide thickness range, micron-sized carbon fibers were used to stabilize the electrode structure and to improve electrode kinetics. By choosing the proper porosities for the anode and cathode, kinetic limitations and aging losses during cell cycling could be minimized and energy density improved. The cell (C38%-A48% exhibits the highest energy density, 441 Wh/L at the C/10 rate, upon cycling at elevated temperature and different C-rates. The cell (C38%-A48% showed 9% higher gravimetric energy density at C/10 in comparison to the cell with as-coated electrodes.

High-frequency thermal-electrical cycles for pyroelectric energy conversion

International Nuclear Information System (INIS)

Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna; Martin, Lane W.; King, William P.

2014-01-01

We report thermal to electrical energy conversion from a 150 nm thick BaTiO 3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10 5  kV/cm-s, and temperature change rates as high as 6 × 10 5  K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems

Drying and decontamination of pistachios with sequential infrared drying, tempering and hot air drying

Science.gov (United States)

The pistachio industry is in need of improved drying technology as the current hot air drying has low energy efficiency and drying rate and high labor cost and also does not produce safe products against microbial contamination. In the current study, dehulled and water- sorted pistachios with a mois...

Excavation and drying of compressed peat; Tiivistetyn turpeen nosto ja kuivaus

Energy Technology Data Exchange (ETDEWEB)

Erkkilae, A.; Frilander, P.; Hillebrand, K.; Nurmi, H.

1996-12-31

The target of this three year (1993 - 1995) project was to improve the peat product-ion efficiency by developing an energy economical excavation method for compressed peat, by which it is possible to obtain best possible degree of compression and load from the DS-production point of view. It is possible to improve the degree of utilization of solar radiation in drying from 30 % to 40 %. The main research areas were drying of the compressed peat and peat compression. The third sub-task for 1995 was demonstration of the main parts of the method in laboratory scale. Experimental compressed peat (Compeat) drying models were made for peats Carex-peat H7, Carex-peat H5 and Carex-Sphagnum-peat H7. Compeat dried without turning in best circumstances in 34 % shorter time than milled layer made of the same peat turned twice, the initial moisture content being 4 kgH2OkgDS-1. In the tests carried out in 1995 with Carex-peat the compression had not corresponding effect on intensifying of the drying of peat. Compression of Carex-Sphagnum peat H7 increased the drying speed by about 10 % compared with the drying time of uncompressed milled layer. In the sprinkling test about 30-50 % of the sprinkled water was sucked into the compressed peat layer, while about 70 % of the rain is sucked into the corresponding uncompressed milled layer. Use of vibration decreased the energy consumption of the steel-surfaced nozzles about 20 % in the maximum, but the effect depend on the rotation speed of the macerator and the vibration power. In the new Compeat method (production method for compressed peat), developed in the research, the peat is loosened from the field surface by milling 3-5 cm thick layer of peat of moisture content 75-80 %

Dual-objective optimization of organic Rankine cycle (ORC) systems using genetic algorithm: a comparison between basic and recuperative cycles

Science.gov (United States)

Hayat, Nasir; Ameen, Muhammad Tahir; Tariq, Muhammad Kashif; Shah, Syed Nadeem Abbas; Naveed, Ahmad

2017-08-01

Exploitation of low potential waste thermal energy for useful net power output can be done by manipulating organic Rankine cycle systems. In the current article dual-objectives (η_{th} and SIC) optimization of ORC systems [basic organic Rankine cycle (BORC) and recuperative organic Rankine cycle (RORC)] has been done using non-dominated sorting genetic algorithm (II). Seven organic compounds (R-123, R-1234ze, R-152a, R-21, R-236ea, R-245ca and R-601) have been employed in basic cycle and four dry compounds (R-123, R-236ea, R-245ca and R-601) have been employed in recuperative cycle to investigate the behaviour of two systems and compare their performance. Sensitivity analyses show that recuperation boosts the thermodynamic behaviour of systems but it also raises specific investment cost significantly. R-21, R-245ca and R-601 show attractive performance in BORC whereas R-601 and R-236ea in RORC. RORC, due to higher total investment cost and operation & maintenance costs, has longer payback periods as compared to BORC.

Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

Energy Technology Data Exchange (ETDEWEB)

Roh, Gyu Hong; Choi, Hang Bok

2005-09-15

The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology.

Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

International Nuclear Information System (INIS)

Roh, Gyu Hong; Choi, Hang Bok

2005-09-01

The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology

Analysis of Drying Process Quality in Conventional Dry-Kilns

OpenAIRE

Sedlar Tomislav; Pervan Stjepan

2010-01-01

This paper presents testing results of drying quality in a conventional dry kiln. Testing is based on a new methodology that will show the level of success of the drying process management by analyzing the quality of drying process in a conventional dry kiln, using a scientifi cally improved version of the check list in everyday practical applications. A company that specializes in lamel and classic parquet production was chosen so as to verify the new testing methodology. A total of 56 m3 of...

Micro-Spherical Sulfur/Graphene Oxide Composite via Spray Drying for High Performance Lithium Sulfur Batteries

Science.gov (United States)

Tian, Yuan; Sun, Zhenghao; Zhang, Yongguang; Yin, Fuxing

2018-01-01

An efficient, industry-accepted spray drying method was used to synthesize micro-spherical sulfur/graphene oxide (S/GO) composites as cathode materials within lithium sulfur batteries. The as-designed wrapping of the sulfur-nanoparticles, with wrinkled GO composites, was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The unique morphological design of this material enabled superior discharge capacity and cycling performance, demonstrating a high initial discharge capacity of 1400 mAh g−1 at 0.1 C. The discharge capacity remained at 828 mAh g−1 after 150 cycles. The superior electrochemical performance indicates that the S/GO composite improves electrical conductivity and alleviates the shuttle effect. This study represents the first time such a facile spray drying method has been adopted for lithium sulfur batteries and used in the fabrication of S/GO composites. PMID:29346303

Dry aerosol jet printing of conductive silver lines on a heated silicon substrate

Science.gov (United States)

Efimov, A. A.; Arsenov, P. V.; Protas, N. V.; Minkov, K. N.; Urazov, M. N.; Ivanov, V. V.

2018-02-01

A new method for dry aerosol jet printing conductive lines on a heated substrate is presented. The method is based on the use of a spark discharge generator as a source of dry nanoparticles and a heating plate for their sintering. This method allows creating conductive silver lines on a heated silicon substrate up to 300 °C without an additional sintering step. It was found that for effective sintering lines of silver nanoparticles the temperature of the heated substrate should be about more than 200-250 °C. Average thickness of the sintered silver lines was equal to ∼20 µm. Printed lines showed electrical resistivity equal to 35 μΩ·cm, which is 23 times greater than the resistivity of bulk silver.

Comparative study of the luminescence of structures with Ge nanocrystals formed by dry and wet oxidation of SiGe films

International Nuclear Information System (INIS)

RodrIguez, A; Ortiz, M I; Sangrador, J; RodrIguez, T; Avella, M; Prieto, A C; Torres, A; Jimenez, J; Kling, A; Ballesteros, C

2007-01-01

The luminescence emission of structures containing Ge nanocrystals embedded in a dielectric matrix obtained by dry and wet oxidation of polycrystalline SiGe layers has been studied as a function of the oxidation time and initial SiGe layer thickness. A clear relationship between the intensity of the luminescence, the structure of the sample, the formation of Ge nanocrystals and the oxidation process parameters that allows us to select the appropriate process conditions to get the most efficient emission has been established. The evolution of the composition and thickness of the growing oxides and the remaining SiGe layer during the oxidation processes has been characterized using Raman spectroscopy, x-ray diffraction, Fourier-transform infrared spectroscopy, Rutherford backscattering spectrometry and transmission electron microscopy. For dry oxidation, the luminescence appears suddenly, regardless of the initial SiGe layer thickness, when all the Si of the SiGe has been oxidized and the remaining layer of the segregated Ge starts to be oxidized forming Ge nanocrystals. Luminescence is observed as long as Ge nanocrystals are present. For wet oxidation, the luminescence appears from the first stages of the oxidation, and is related to the formation of Ge-rich nanoclusters trapped in the mixed (Si and Ge) growing oxide. A sharp increase of the luminescence intensity for long oxidation times is also observed, due to the formation of Ge nanocrystals by the oxidation of the layer of segregated Ge. For both processes the luminescence is quenched when the oxidation time is long enough to cause the full oxidation of the Ge nanocrystals. The intensity of the luminescence in the dry oxidized samples is about ten times higher than in the wet oxidized ones for equal initial thickness of the SiGe layer

Dry Eye

Science.gov (United States)

... Eye » Facts About Dry Eye Listen Facts About Dry Eye Fact Sheet Blurb The National Eye Institute (NEI) ... and their families search for general information about dry eye. An eye care professional who has examined the ...

Thermodynamic analysis of a simple Organic Rankine Cycle

International Nuclear Information System (INIS)

Javanshir, Alireza; Sarunac, Nenad

2017-01-01

Thermodynamic performance (thermal efficiency and net power output) of a simple subcritical and supercritical Organic Rankine Cycle (ORC) was analyzed over a range of operating conditions for a number of working fluids to determine the effect of operating parameters on cycle performance and select the best working fluid. The results show that for an ORC operating with a dry working fluid, thermal efficiency decreases with an increase in the turbine inlet temperature (TIT) due to the convergence of the isobaric lines with temperature. The results also show that efficiency of an ORC operating with isentropic working fluids is higher compared to the dry and wet fluids, and working fluids with higher specific heat capacity provide higher cycle net power output. New expressions for thermal efficiency of a subcritical and supercritical simple ORC are proposed. For a subcritical ORC without the superheat, thermal efficiency is expressed as a function of the Figure of Merit (FOM), while for the superheated subcritical ORC thermal efficiency is given in terms of the modified Jacob number. For the supercritical ORC, thermal efficiency is expressed as a function of dimensionless temperature. - Highlights: • Analyzing thermodynamic performance of ORC over a range of operating conditions. • Selecting the best working fluid suitable for a simple ORC. • Proposing new expressions for thermal efficiency of a simple ORC.

[Fundus autofluorescence in dry AMD - impact on disease progression].

Science.gov (United States)

Vidinova, C N; Gouguchkova, P T; Vidinov, K N

2013-11-01

Fundus autofluorescence is a novel technique that gives us information about the RPE cells by evaluating the distribution of lipofuscin in the retina. The purpose of our study was to evaluate the diagnostic abilities of OCT, RTVue and fundus autofluorescence in predicting the progression of dry AMD. In our study 37 dry AMD patients were enrolled: 22 of them with druses and 15 with developed geographic atrophy. They all underwent complete ophthalmological examinations including OCT and autofluorescence. We used the RTVue OCT programmes HD line, Cross line, EMM5 and EMM5 progression in all cases. The autofluorescence was recorded with the help of the Canon CX1 fundus camera. OCT images in the AMD patients with dry AMD and large druses showed typical undulations in the RPE/choroid line and occasionally drusenoid detachment of the RPE. Autofluorescence showed different patterns. The confluent reticular autofluorescence was associated with the development of neovascular membranes. In geographic atrophy patient OCTs showed diminished retinal thickness measured with EMM5. On autofluorescence the findings at the border zone atrophic/normal retina were of particular importance. The diffuse increased autofluorescence in that area was considered to be a sign for further atrophy progression. Our results point out that OCT in combination with autofluorescence is important in following the progression of dry AMD. Pathological autofluorescence at the border of atrophic lesions is an important sign for disease activity. Although both OCT and autofluorescence visualise the changes in RPE, autofluorescence is of key importance in predicting the development of the disease. Georg Thieme Verlag KG Stuttgart · New York.

Rewetting of semi-dried ink patterns by vapour annealing for developing a reflow process in reverse offset printing

International Nuclear Information System (INIS)

Kusaka, Yasuyuki; Ushijima, Hirobumi; Sugihara, Kazuyoshi; Koutake, Masayoshi

2017-01-01

A process for reflowing patterned materials for reverse offset printing was developed, with the aim of mitigating the step-coverage problem in multilayered devices. The proposed reflow process involves a single step of vapour annealing at moderate temperatures ranging from 60 to 70 °C. This step successfully changes the height profile of semi-dried ink patterns formed on a silicone blanket, from an initially rectangular shape to a rounded shape. A systematic investigation on the effects of various vapour species and vapour temperatures on the reflow process revealed that the miscibility between the vapour and the ink, and a low boiling point of the respective solvent (high vapour pressure) are the prerequisites for successful reflows of semi-dried ink layers patterned on a silicone blanket. The results suggested that the rewetting of previously semi-dried patterns is the main mechanism in the reflow process, which led to a change in the height profile. Furthermore, the reflowed patterns demonstrated almost identical peak-height thicknesses, irrespective of the width of the patterns. This is a unique property that is unattainable by other printing methods, including gravure offset printing and microcontact printing, wherein printed patterns have rounded shapes without a reflow process, but their thickness inevitably depends on the pattern sizes. (technical note)

Seasonal variability in physiological and anatomical traits contributes to invasion success of Prosopis juliflora in tropical dry forest.

Science.gov (United States)

Oliveira, Marciel T; Souza, Gustavo M; Pereira, Silvia; Oliveira, Deborah A S; Figueiredo-Lima, Karla V; Arruda, Emília; Santos, Mauro G

2017-03-01

We investigated whether there were consistent differences in the physiological and anatomical traits and phenotypic variability of an invasive (Prosopis juliflora (Sw.) DC.) and native species (Anadenanthera colubrina (Vell.) Brenan) in response to seasonality in a tropical dry forest. The water potential, organic solutes, gas exchange, enzymes of the antioxidant system, products of oxidative stress and anatomical parameters were evaluated in both species in response to seasonality. An analysis of physiological responses indicated that the invasive P. juliflora exhibited higher response in net photosynthetic rate to that of the native species between seasons. Higher values of water potential of the invasive species than those of the native species in the dry season indicate a more efficient mechanism for water regulation in the invasive species. The invasive species exhibits a thicker cuticle and trichomes, which can reduce transpiration. In combination, the increased epidermal thickness and the decreased thickness of the parenchyma in the dry season may contribute to water saving. Our data suggest a higher variability in anatomical traits in the invasive species as a response to seasonality, whereas physiological traits did not present a clear pattern of response. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Electrical and Gas Sensing Properties of SnO2 Thick Film Resistors Prepared by Screen-printing Method

Directory of Open Access Journals (Sweden)

R. Y. BORSE

2008-10-01

Full Text Available Thick films of tin-oxide (SnO2 were deposited on alumina substrates employing screen-printing technique. The films were dried and fired at 680 0C for 30 minutes. The variation of D.C. resistance of thick films was measured in air as well as in H2S gas atmosphere as a function of temperature. The SnO2 films exhibit semiconducting behaviour. The SnO2 thick films studied were also showing decrease in resistance with increase of concentration of H2S gas. The film resistors showed the highest sensitivity to H2S gas at 350 0C. The XRD studies of the thick film indicate the presence of different phases of SnO2. The elemental analysis was confirmed by EDX spectra. The surface morphological study of the films was analyzed by SEM. The microstructure of the films was porous resulting from loosely interconnected small crystallites. The parameters such as grain size, activation energy, sensitivity and response time were described.

Choroidal thickness in Malaysian eyes with full-thickness macular holes

Directory of Open Access Journals (Sweden)

Chew Y Tan

2018-02-01

Full Text Available AIM: To compare choroidal thickness at the macula in eyes with unilateral idiopathic full-thickness macular holes(FTMHwith that of unaffected fellow eyes, and eyes of normal control patients.METHODS: Cross-sectional study. Thirty patients with unilateral idiopathic FTMH and thirty age, sex, and race-matched controls were recruited. Axial lengths were measured using laser interferometry. Enhanced depth imaging optical coherence tomography images were obtained using Heidelberg spectral-domain optical coherence tomography. Choroidal thickness was measured at the fovea, and at 1 mm and 2 mm nasally, temporally, superiorly and inferiorly from the center of the fovea. Statistical analysis was performed using independent and paired t-tests, chi-square tests, and Pearson correlation tests(PRESULTS: The mean subfoveal choroidal thickness was 201.0±44.0 μm in the FTMH group, 225.3±51.4 μm in the fellow eye group and 262.3±70.3 μm in the control group. The choroid was thinner in FTMH eyes at all locations when compared to control eyes(PPP>0.05. Choroidal thickness was generally highest subfoveally and lowest nasally. Subfoveal choroidal thickness was negatively correlated with age(r=-0.278, P=0.032, and axial length(r=-0.328, P=0.011.CONCLUSION: Choroidal thickness is lower in both eyes of patients with unilateral FTMH compared to healthy control eyes.

Effects of buffer thickness on ATW blanket performance

International Nuclear Information System (INIS)

Yang, W. S.; Mercatali, L.; Taiwo, T. A.; Hill, R. N.

2001-01-01

This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy ( and lt; 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level

Effects of Buffer Thickness on ATW Blanket Performance

International Nuclear Information System (INIS)

Yang, W.S.; Mercatali, L.; Taiwo, T.A.; Hill, R.N.

2002-01-01

This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level. (authors)

Study on Gas Sensing Performance of In2O3 Thick Film Resistors Prepared by Screen Printing Technique

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S. C. KULKARNI

2011-02-01

Full Text Available Indium Oxide (In2O3 thick films were prepared on alumina substrate by using standard screen printing technique. These films were dried and fired at temperatures between 750 0C to 950 0C for two hours in air atmosphere. The compositional, morphological and structural properties of In2O3 films were performed by Energy Dispersive Spectroscopy (EDX, XRD, and Scanning electron Microscopy respectively. We explore the various gases to study sensing performance of In2O3 thick films. The maximum response was reported to film fired at 750 0C for H2S gas at 150 0C operating temperature.

Spray Drying Processing: granules production and drying kinetics of droplets

International Nuclear Information System (INIS)

Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.

2013-01-01

Spray drying is a unit operation very common in many industrial processes. For each particular application, the resulting granulated material must possess determined properties that depend on the conditions in which the spray drying processing has been carried out, and whose dependence must be known in order to optimize the quality of the material obtained. The large number of variables that influence on the processes of matter and energy transfer and on the formation of granular material has required a detailed analysis of the drying process. Over the years there have been many studies on the spray drying processing of all kind of materials and the influence of process variables on the drying kinetics of the granulated material properties obtained. This article lists the most important works published for both the spray drying processing and the drying of individual droplets, as well as studies aimed at modeling the drying kinetics of drops. (Author)

Preparation and Study the Electrical, Structural and Gas Sensing Properties of ZnO Thick Film Resistor

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M. K. DEORE

2010-08-01

Full Text Available Thick films of AR grade ZnO were prepared on glass substrate by screen-printing technique. These films were dried and fired at different temperatures between 550 oC, 600 oC and 650 oC for one hour in air atmosphere. The gas sensing performance of thick films was tested for various gases. ZnO films showed larger response (sensitivity to H2S gas (100 ppm at 250 oC for firing temperature 650 oC. The Morphological, Compositional and Structural properties of the ZnO thick films were performed by Scanning electron microscopy (SEM, Energy dispersive spectroscopy (EDX and XRD technique respectively. Chemical composition of ZnO film samples changes with firing temperature showing non-stoichiometric behaviours. XRD study indicated the formation of polycrystalline ZnO films with hexagonal wurtzite structure. The gas response (sensitivity, selectivity, response and recovery time of the sensor were measured and presented.

Effects of repeated cycles of starvation and refeeding on lungs of growing rats.

Science.gov (United States)

Sahebjami, H; Domino, M

1992-12-01

Adult male rats were subjected to four cycles of mild starvation (2 wk) and refeeding (1 wk) and were compared with a fed group. Starvation was induced by giving rats one-third of their measured daily food consumption. During each starvation cycle, rats lost approximately 20% of their body weight. Despite catch-up growth and overall weight gain, starved rats had lower final body weight than fed rats. Lung dry weight and lung volumes were also reduced in the starved group. The mechanical properties of air- and saline-filled lungs did not change significantly with repeated cycles of starvation. Mean linear intercept was similar in the two groups, but alveolar surface area was reduced in the starved rats. Total content of crude connective tissue and concentration per lung dry weight of hydroxyproline and crude connective tissue were reduced in starved rats. We conclude that lung growth is retarded in growing rats subjected to repeated cycles of mild starvation and refeeding, as manifested by smaller lung volume and reduced alveolar surface area. Because alveolar size is unchanged, a reduced number of alveoli is most likely responsible for decreased lung volumes.

Polymer degradation in reactive ion etching and its possible application to all dry processes

International Nuclear Information System (INIS)

Hiraoka, H.; Welsh, L.W. Jr.

1981-01-01

Dry etching processes involving CF 4 -plasma and reactive ion etching become increasingly important for microcircuit fabrication techniques. In these techniques polymer degradation and etch resistance against reactive species like F atoms and CF 3 + ions are the key factors in the processes. It is well-known that classical electron beam resists like poly(methyl methacrylate) and poly(1-butene sulfone) are not suitable for dry etching processes because they degrade rapidly under these etching conditions. In order to find a correlation of etching rate and polymer structures the thickness loss of polymer films have been measured for a variety of polymer films in reactive ion etching conditions, where CF 3 + ions are the major reactive species with an accelerating potential of 500 volts. Because of its high CF 4 -plasma and reactive ion etch resistance, and because of its high electron beam sensitivity, poly(methacrylonitrile) provides a positive working electron beam resist uniquely suited for all dry processes. (author)

Intensifying drying process with creation of functional plant compositions

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Zh. Petrova

2015-05-01

Full Text Available Introduction. The process of drying agricultural raw products is associated with loss of bioactive substances by the products exposed to heat, light, oxygen, or рН medium. It is reasonable to enhance the table beet processing technology in order to achieve maximum betanin conservation at lower energy consumption. Materials and methods. Table beets, rhubarbs, lemons, and tomatoes were dried at temperature of 50 to 100 ºС, air speed of 1.5 to 3.5 m/s, heat carrier water content of 7 to 15 g/kg, and layer thickness of 2 to 20 mm. The betanіn content was determined via absorption spectra, using the optical density value at 540 nm wavelength. A differential microcalorimeter was used for measuring evaporation heat consumption. Results and discussion.The effect of raw product pre-drying preparation was studied. With no preliminary preparation, the loss of betanin after drying reaches 66 %. The preliminary preparation technology we have developed includes boiling whole root crops with optimal selection of acid medium and allows us to reduce the betanin loss down to 6 %. Regretfully, the process requires large energy consumption. Low energy consumption pre-drying preparation method was developed for antioxidant raw products with thermal processing replaced by blending. The betanin loss, in this case, does not exceed 5 %. Optimal drying temperature of betanin-containing raw stock, after its preliminary processing, is 60 °С. It allows to keep up to 95 % of betanіn. Specific heat consumption for water evaporation out of the developed table beet based antioxidant plant compositions, with addition of rhubarb and lemon, is less by 4 to 5 % as compared to the initial components. Conclusions. Dependence of betanin loss in plant raw stock on the material temperature and composition components, in the course of their pre-drying preparation, was found. It was also found that water evaporation heat, for some antioxidant plant compositions developed, is less

Drying hardwood lumber

Energy Technology Data Exchange (ETDEWEB)

Chow, A T

1988-11-14

Dried lumber is a high-value-added product, especially when it is of high quality. Lumber damaged during the drying operation can represent substantial lost revenue. It has been demonstrated that dehumidification kilns can improve lumber quality, and reduce energy consumption over conventional drying methods. A summary of the literature on drying hardwood lumber, particularly using heat pump dehumidification, has been prepared to allow the information to be readily accessible to Ontario Hydro personnel who work with customers in the lumber industry. For that purpose, this summary has been prepared from the perspective of the customer, a dry kiln operator. Included are brief descriptions of drying schedules, precautions needed to minimize drying defects in the lumber, and rules-of-thumb for selecting and estimating the capital cost of the drying equipment. A selection of drying schedules and moisture contents of green lumber, a glossary of lumber defects and brief descriptions of the possible preventive measures are also included. 10 refs., 8 figs., 4 tabs.

HYBRID LAYER THICKNESS IN PRIMARY AND PERMANENT TEETH – A COMPARISON BETWEEN TOTAL ETCH ADHESIVES

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Natalia Gateva

2012-05-01

Full Text Available Purpose: The aim this study is to compare the hybrid layer thickness and its micromorphological characteristics in samples from primary and permanent teeth following application of total etch adhesives.Materials and methods: On intact specimens of 20 primary and 10 permanent teeth was created flat dentin surfaces. The patterns were divided in 6 groups. Two different total etch adhesive systems were used – one tree steps (OptiBond, Kerr and one two steps (Exite, VivaDent. In groups 3, 4, 5 and 6 recommended etching time was used - 15 s, in groups 1 and 2 the etching time was reduced to 7 s. After applying the adhesive, resin composite build-ups were constructed. Thus restored samples are stored in saline solution for 24 hours at temperature 37 C. Then they are subjected to thermal stress in temperature between 5 C to 55 C for 1,500 cycles and to masticatory stress – 150,000 cycles with force 100 N in intervals of 0.4 s. After that the teeth are cut through the middle in medio-distal direction with a diamond disc. SEM observation was done to investigate the thickness of the hybrid layer and the presence of microgaps. Statistical analysis was performed with ANOVA and Tukey׳s tests.Results: SEM observation showed significant differences of the hybrid layer thickness between primary and permanent teeth under equal conditions and after different etching time. Group 6 presented the highest average thickness 8.85 μ and group 1 the lowest average in hybrid layer 3.74 μ.Conclusion: In primary teeth the hybrid layer thickness increases with the increased etching time. The hybrid layer thickness in primary teeth is greater than that of the hybrid layer in permanent teeth under equal conditions. For primary teeth it is more appropriate to reduce the etching time to 7s to obtain a hybrid layer with better quality

Effect of Autologous Serum Eye Drops in Patients with Sjögren Syndrome-related Dry Eye: Clinical and In Vivo Confocal Microscopy Evaluation of the Ocular Surface.

Science.gov (United States)

Semeraro, Francesco; Forbice, Eliana; Nascimbeni, Giuseppe; Taglietti, Marco; Romano, Vito; Guerra, Germano; Costagliola, Ciro

To evaluate in vivo changes after therapy using autologous serum (AS) eye drops in Sjögren's syndrome (SS)-related dry eyes by confocal microscopy. In this study, 24 patients with SS-related dry eyes [12 in AS eye drop therapy and 12 in artificial tear (AT) therapy] and 24 healthy volunteers were recruited. Ocular Surface Disease Index (OSDI), central corneal thickness, tear film, break-up time, corneal and conjunctival staining, Schirmer's test and corneal confocal microscopy were investigated. Tear production, tear stability, corneal staining, inflammation, and central corneal thickness, Langherans cells, activated keratocytes, intermediate epithelial cell density, nerve tortuosity, number of sub-basal nerve branches, and number of bead-like formations differed between patients and controls (peye drops improve symptoms and confocal microscopy findings in SS-related dry eyes. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Study on the fuel cycle cost of gas turbine high temperature reactor (GTHTR300). Contract research

Energy Technology Data Exchange (ETDEWEB)

Takei, Masanobu; Katanishi, Shoji; Nakata, Tetsuo; Kunitomi, Kazuhiko [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Oda, Takefumi; Izumiya, Toru [Nuclear Fuel Industries, Ltd., Tokyo (Japan)

2002-11-01

In the basic design of gas turbine high temperature reactor (GTHTR300), reduction of the fuel cycle cost has a large benefit of improving overall plant economy. Then, fuel cycle cost was evaluated for GTHTR300. First, of fuel fabrication for high-temperature gas cooled reactor, since there was no actual experience with a commercial scale, a preliminary design for a fuel fabrication plant with annual processing of 7.7 ton-U sufficient four GTHTR300 was performed, and fuel fabrication cost was evaluated. Second, fuel cycle cost was evaluated based on the equilibrium cycle of GTHTR300. The factors which were considered in this cost evaluation include uranium price, conversion, enrichment, fabrication, storage of spent fuel, reprocessing, and waste disposal. The fuel cycle cost of GTHTR300 was estimated at about 1.07 yen/kWh. If the back-end cost of reprocessing and waste disposal is included and assumed to be nearly equivalent to LWR, the fuel cycle cost of GTHTR300 was estimated to be about 1.31 yen/kWh. Furthermore, the effects on fuel fabrication cost by such of fuel specification parameters as enrichment, the number of fuel types, and the layer thickness were considered. Even if the enrichment varies from 10 to 20%, the number of fuel types change from 1 to 4, the 1st layer thickness of fuel changes by 30 {mu}m, or the 2nd layer to the 4th layer thickness of fuel changes by 10 {mu}m, the impact on fuel fabrication cost was evaluated to be negligible. (author)

Cyclic changes of the junctional zone on 3 T MRI images in young and middle-aged females during the menstrual cycle

International Nuclear Information System (INIS)

He, Y.L.; Ding, N.; Li, Y.; Li, Z.; Xiang, Y.; Jin, Z.Y.; Xue, H.D.

2016-01-01

Aim: To evaluate the cyclic changes of the junctional zone in different age groups during the menstrual cycle using 3 T magnetic resonance imaging (MRI), and to investigate the correlation with basic female hormone levels. Materials and methods: Thirty-eight normal volunteers (age range, 20–40 years; mean age, 29 years: 20–30 years, n=22; 31–40 years, n=16) with regular menstrual cycles underwent a pelvic 3 T MRI examination on the 2nd or 3rd days of their menstrual phase (MP), follicular phase (FP), peri-ovulatory phase (OP), and luteal phase (LP), respectively, including a T2-weighted three-dimensional (3D) turbo spin-echo (TSE) with variable flip angle (“SPACE”) sequence, a T2-weighted mapping sequence, and diffusion tensor imaging (DTI). The thickness, T2, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) values of the junctional zone on mid-sagittal images were separately measured by two radiologists on the post-processed workstation. The linear mixed model and one-way analysis of variance were used to evaluate the differences between the two age groups during the four phases. The serum levels of oestradiol (E), progesterone (P), luteinising hormone (LH), and follicle-stimulating hormone (FSH) were measured during the MP and compared with anatomical and functional MRI values using Pearson's correlation analysis. Results: The thickness of the anterior and posterior junctional zone increased with age (p<0.05). In the 20–30 year age group, during the MP the junctional zone was significantly thicker than at the other three phases (p<0.05). Serum E levels correlated moderately with variation in thickness during the menstrual cycle. In the 30–40 year age group, no statistical difference in the thickness was found during the menstrual cycle. As age increased, the ADC values of the junctional zone decreased (p=0.02). In both groups, the ADC and T2 values of the junctional zone showed significant differences between the MP and LP (p<0

Drying behaviour, effective diffusivity and energy of activation of olive leaves dried by microwave, vacuum and oven drying methods

Science.gov (United States)

Elhussein, Elaf Abdelillah Ali; Şahin, Selin

2018-01-01

Drying is the crucial food processing for bioactive components from plant materials before strating extraction in addition to preservation of raw plant materials during storage period. Olive leaves were dried by various methods such as microwave drying (MD), oven drying (OD) and vacuum drying (VD) at several temperature values in the present study. Mathematical models allow to develop, design and control the processes. 14 emprical equations were used to estimate the drying behaviour and the time required for drying. Convenience of the models were evaluated according to the correlation coefficient (R 2 ), varience (S 2 ) and root mean square deviation (D RMS ). On the other hand, the effective diffusion coefficient and energy for activation were also calculated. Effects of the drying methods on the total phenolic (TPC), flavonoid (TFC) and oleuropein contents and free radical scavenging activity (FRSA) of the olive leaves were also investigated to take into considiration the quality of the dried product. MD has proved to be the fastest drying method having the highest effective diffusivity and the lowest activation energy with a more qualitive product.

Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry

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Andres D. Sola

2018-01-01

Full Text Available Nitrogen (N and phosphorus (P concentrations and N:P ratios critically influence periphyton productivity and nutrient cycling in aquatic ecosystems. In coastal wetlands, variations in hydrology and water source (fresh or marine influence nutrient availability, but short-term effects of drying and rewetting and long-term effects of nutrient exposure on periphyton nutrient retention are uncertain. An outdoor microcosm experiment simulated short-term exposure to variation in drying-rewetting frequency on periphyton mat nutrient retention. A 13-year dataset from freshwater marshes of the Florida Everglades was examined for the effect of long-term proximity to different N and P sources on mat-forming periphyton nutrient standing stocks and stoichiometry. Field sites were selected from one drainage with shorter hydroperiod and higher connectivity to freshwater anthropogenic nutrient supplies (Taylor Slough/Panhandle, TS/Ph and another drainage with longer hydroperiod and higher connectivity to marine nutrient supplies (Shark River Slough, SRS. Total P, but not total N, increased in periphyton mats exposed to both low and high drying-rewetting frequency with respect to the control mats in our experimental microcosm. In SRS, N:P ratios slightly decreased downstream due to marine nutrient supplies, while TS/Ph increased. Mats exposed to short-term drying-rewetting had higher nutrient retention, similar to nutrient standing stocks from long-term field data. Periphyton mat microbial communities may undergo community shifts upon drying-rewetting and chronic exposure to nutrient loads. Additional work on microbial species composition may further explain how periphyton communities interact with drying-rewetting dynamics to influence nutrient cycling and retention in wetlands.

Large-scale freestanding nanometer-thick graphite pellicles for mass production of nanodevices beyond 10 nm.

Science.gov (United States)

Kim, Seul-Gi; Shin, Dong-Wook; Kim, Taesung; Kim, Sooyoung; Lee, Jung Hun; Lee, Chang Gu; Yang, Cheol-Woong; Lee, Sungjoo; Cho, Sang Jin; Jeon, Hwan Chul; Kim, Mun Ja; Kim, Byung-Gook; Yoo, Ji-Beom

2015-09-21

Extreme ultraviolet lithography (EUVL) has received much attention in the semiconductor industry as a promising candidate to extend dimensional scaling beyond 10 nm. We present a new pellicle material, nanometer-thick graphite film (NGF), which shows an extreme ultraviolet (EUV) transmission of 92% at a thickness of 18 nm. The maximum temperature induced by laser irradiation (λ = 800 nm) of 9.9 W cm(-2) was 267 °C, due to the high thermal conductivity of the NGF. The freestanding NGF was found to be chemically stable during annealing at 500 °C in a hydrogen environment. A 50 × 50 mm large area freestanding NGF was fabricated using the wet and dry transfer (WaDT) method. The NGF can be used as an EUVL pellicle for the mass production of nanodevices beyond 10 nm.

Assessment of the dry process fuel sodium-cooled fast reactors

Energy Technology Data Exchange (ETDEWEB)

Roh, Gyu Hong; Choi, Hang Bok

2004-04-01

The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed.

Assessment of the dry process fuel sodium-cooled fast reactors

International Nuclear Information System (INIS)

Roh, Gyu Hong; Choi, Hang Bok

2004-04-01

The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed

Drying Kinetics Analysis of Seaweed Gracilaria changii using Solar Drying System

International Nuclear Information System (INIS)

Mohd Yusof Othman; Ahmad Fudholi; Kamaruzzaman Sopian; Mohd Hafidz Ruslan; Muhammad Yahya

2012-01-01

A solar drying system suitable for agricultural and marine products have been designed, constructed and evaluated under Malaysia climatic conditions. The solar drying system has been constructed and evaluated for the drying of seaweed Gracilaria changii. The initial and final moisture content of seaweed are 95 % (wet basis) and 10 % (product basis), respectively. The drying time was about 7 hours at average solar radiation of 593 W/ m 2 and air flow rate of 0.0613 kg/ s. Three different thin-layer drying models were compared with experimental data, during the drying of seaweed using the solar drying system at average temperature and humidity of about 50 degree Celsius and 20 %, respectively. The one with highest R2 and lowest MBE and RMSE was selected to better estimate the drying curves. The study showed that the Page model was better fit to drying seaweed compared to the other models (Newton model, and Henderson and Pabis model). (author)

Visual acuity loss associated with excessive “dry macula” in exudative age-related macular degeneration

Directory of Open Access Journals (Sweden)

Takahashi H

2018-02-01

Full Text Available Hidenori Takahashi,1–3 Yuji Inoue,1,2 Xue Tan,2,3 Satoru Inoda,1 Shinichi Sakamoto,1 Yusuke Arai,1 Yasuo Yanagi,4–6 Yujiro Fujino,2,3 Hidetoshi Kawashima1 1Department of Ophthalmology, Jichi Medical University, Shimotsuke, 2Department of Ophthalmology, The University of Tokyo, Bunkyo, 3Department of Ophthalmology, Japan Community Health Care Organization Tokyo Shinjuku Medical Center, Shinjuku, Japan; 4Medical Retina, Singapore National Eye Centre, 5Medical Retina, Singapore Eye Research Institute, 6Eye-ACP, Duke NUS Medical School, National University of Singapore, Singapore Purpose: To investigate the correlation between visual acuity and central macular thickness (CMT and choroidal thickness (CCT in patients with wet age-related macular degeneration (AMD. Methods: In this retrospective analysis, 14 eyes that received >10 ranibizumab injections (based on pro re nata [PRN] regimen and maintained initial visual acuity gain were analyzed. The following 5 parameters were measured at the foveal center: CMT (distance from the inner limiting membrane [ILM] to Bruch’s membrane; central retinal thickness (CRT; distance from the ILM to the inner limit of the retinal pigment epithelium or subretinal fluid [SRF]; SRF thickness (SRFT; pigment epithelium detachment thickness (PEDT; and CCT. The correlation between the logarithm of the minimum angle of resolution (logMAR best-corrected visual acuity (BCVA and the 5 parameters was examined with generalized estimating equations. Results: CMT, CRT, and CCT were negatively correlated with logMAR BCVA (P=0.031, 0.023, and 0.036, respectively when only CMT values less than the thickness that maximized visual acuity for each eye were used for the analysis. Each 100-µm reduction in CMT, CRT, or CCT improved logMAR BCVA by -0.1, -0.08, or -0.07, respectively. SRFT and PEDT were not correlated with BCVA. The median CMT that maximized the visual acuity was 230 µm. Conclusion: Dry macula with CMT <230 µm was

Underwater cutting of reactor core internals by CO laser using local-dry-zone creating nozzle

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Osa (Mitsubishi Heavy Industries Ltd., Takasago, Hyogo (Japan). Takasago Research and Development Center); Sugihara, Masaaki; Miya, Kenzo

1992-11-01

With a view to practical application of the CO laser to underwater cutting of thick steel plates, a nozzle for creating a local dry zone on the workpiece has been developed and tested. The nozzle directed against the workpiece surface discharges a jet of air, which forms the local dry zone, bounded by a cone of high-speed water jet discharged from a concentric annular outlet. Preliminary tests were performed to optimize the nozzle shape and operating conditions. The resulting nozzle was used with a 5 kW CO laser for actual underwater cutting tests on stainless steel plates: Entirely satisfactory cutting performance was confirmed on various workpiece geometries and working positions. (author).

Graphene and maghemite composites based supercapacitors delivering high volumetric capacitance and extraordinary cycling stability

International Nuclear Information System (INIS)

Zhang, Haitao; Zhang, Xiong; Lin, He; Wang, Kai; Sun, Xianzhong; Xu, Nansheng; Li, Chen; Ma, Yanwei

2015-01-01

Metal oxides (like MnO 2 , Fe 2 O 3 , and Co 3 O 4 , etc) based supercapacitors have disadvantages, such as low volumetric capacitance for thick-film electrodes, or short cycling life because a Faradaic process involves chemical changes of state of the reactant species. In the present work, we report that supercapacitors based on reduced graphene oxide and maghemite (γ-Fe 2 O 3 ) composites (GγM) exhibit superior performance. GγM electrodes with average electrode thickness up to ∼60 μm have a high volumetric capacitance of 230 F cm −3 , together with an outstanding electrode package density of 1.44 g cm −3 . Particularly, the GγM electrodes have excellent cycling performance of ∼90% capacitance retention over 100,000 galvanostatic charge–discharge cycles or voltage floating at 0.9 V for 300 h. No detectable change in phase and an effective inhibition of γ-Fe 2 O 3 refinement after cycle-life test are confirmed by X-ray diffraction and transmission electron microscopy

Process integration of organic Rankine cycle

International Nuclear Information System (INIS)

Desai, Nishith B.; Bandyopadhyay, Santanu

2009-01-01

An organic Rankine cycle (ORC) uses an organic fluid as a working medium within a Rankine cycle power plant. ORC offers advantages over conventional Rankine cycle with water as the working medium, as ORC generates shaft-work from low to medium temperature heat sources with higher thermodynamic efficiency. The dry and the isentropic fluids are most preferred working fluid for the ORC. The basic ORC can be modified by incorporating both regeneration and turbine bleeding to improve its thermal efficiency. In this paper, 16 different organic fluids have been analyzed as a working medium for the basic as well as modified ORCs. A methodology is also proposed for appropriate integration and optimization of an ORC as a cogeneration process with the background process to generate shaft-work. It has been illustrated that the choice of cycle configuration for appropriate integration with the background process depends on the heat rejection profile of the background process (i.e., the shape of the below pinch portion of the process grand composite curve). The benefits of integrating ORC with the background process and the applicability of the proposed methodology have been demonstrated through illustrative examples.

Variation of Drying Strains between Tangential and Radial Directions in Asian White Birch

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Zongying Fu

2016-03-01

Full Text Available In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk logs were dried at a constant temperature (40 °C. The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were measured both tangentially and radially. The effects of moisture content and radial position on each strain were also discussed qualitatively. Overall, the difference of the practical shrinkage strain between the tangential and radial directions was proportional to the distance from the pith. The tangential elastic strain and viscoelastic creep strain were higher than these strains in a radial direction, and they all decreased with the decrease of moisture content. Additionally, there were opposite mechano-sorptive creep between tangential and radial directions.

Determination of drying characteristics and quality properties of eggplant in different drying conditions

Directory of Open Access Journals (Sweden)

Gözde Bayraktaroglu Urun

2015-12-01

Full Text Available Drying is the most traditional process used for preserving eggplant a long time. The aim of this study was to determining drying characteristics and quality properties of eggplant dried by sun drying, hot air convective drying and infrared assisted convective drying. Convective drying and infrared assisted convective were carried out in a convective dryer at three different temperatures(40°, 50°, 60°C and air velocity at 5 m/s.The increasing of temperatures during the drying of eggplant led to a significant reduction of the drying time. However loss of nutrition was observed in eggplant samples dried at higher temperature.The biggest change in colour parameters was observed in samples dried with sun drying.So it was thought that sun drying had a negative effect on quality properties of eggplant samples.

Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices.

Science.gov (United States)

Esparza, Eliana; Hadzich, Antonella; Kofer, Waltraud; Mithöfer, Axel; Cosio, Eric G

2015-08-01

Maca, Lepidium meyenii Walpers (Brassicaceae), is an annual herbaceous plant native to the high plateaus of the Peruvian central Andes. Its underground storage hypocotyls have been a traditional medicinal agent and dietary staple since pre-Columbian times. Reported properties include energizing and fertility-enhancing effects. Published reports have focused on the benzylalkamides (macamides) present in dry hypocotyls as one of the main bioactive components. Macamides are secondary amides formed by benzylamine and a fatty acid moiety, with varying hydrocarbon chain lengths and degree of unsaturation. Although it has been assumed that they are usually present in fresh undamaged tissues, analyses show them to be essentially absent from them. However, hypocotyls dried by traditional Andean postharvest practices or industrial oven drying contain up to 800μgg(-1) dry wt (2.3μmolg(-1) dry wt) of macamides. In this study, the generation of macamides and their putative precursors were studied during nine-week traditional drying trials at 4200m altitude and in ovens under laboratory conditions. Freeze-thaw cycles in the open field during drying result in tissue maceration and release of free fatty acids from storage and membrane lipids up to levels of 1200μgg(-1) dry wt (4.3μmolg(-1) dry wt). Endogenous metabolism of the isothiocyanates generated from glucosinolate hydrolysis during drying results in maximal benzylamine values of 4300μgg(-1) dry wt (40.2μmolg(-1) dry wt). Pearson correlation coefficients of the accumulation profiles of benzylamine and free fatty acid to that of macamides showed good values of 0.898 and 0.934, respectively, suggesting that both provide sufficient substrate for amide synthesis during the drying process. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The menstrual cycle and the skin.

Science.gov (United States)

Raghunath, R S; Venables, Z C; Millington, G W M

2015-03-01

Perimenstrual exacerbations of dermatoses are commonly recognized, yet our knowledge of the underlying pathophysiological mechanisms remains imperfect. Research into the effects of oestrogen on the skin has provided evidence to suggest that oestrogen is associated with increases in skin thickness and dermal water content, improved barrier function, and enhanced wound healing. Research into the effects of progesterone suggests that the presence of various dermatoses correlates with peak levels of progesterone. Dermatoses that are exacerbated perimenstrually include acne, psoriasis, atopic eczema and irritant dermatitis, and possibly also erythema multiforme. Exacerbations occur at the peak levels of progesterone in the menstrual cycle. Underlying mechanisms include reduced immune and barrier functions as a result of cyclical fluctuations in oestrogen and/or progesterone. Autoimmune progesterone and oestrogen dermatitis are the best-characterized examples of perimenstrual cutaneous reactions to hormones produced during the menstrual cycle. In this review, we describe the current understanding of the menstrual cycle, and its effect on the skin and cutaneous disorders. © 2015 British Association of Dermatologists.

Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO3@C composites as anode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Fan, Fuqiang; Fang, Guoqing; Zhang, Ruixue; Xu, Yanhui; Zheng, Junwei; Li, Decheng

2014-01-01

Highlights: • The thickness of carbon coating layers can be successfully controlled through varying molar concentration of aqueous glucose solution. • Coating carbon thickness and carbon content are two important factors on the electrochemical performances of CoSnO3@C. • CoSnO 3 @C under optimized conditions exhibits the optimal balance between the volume buffering effect and reversible capacity. • As-prepared CoSnO 3 @C under optimized conditions shows excellent electrochemical performances, whose reversible capacity could reach 491 mA h g −1 after 100 cycles. - Abstract: A series of core–shell carbon coated amorphous CoSnO 3 (CoSnO 3 @C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge–discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO 3 @C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g −1 after 100 cycles

What Is Dry Eye?

Medline Plus

Full Text Available ... Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué es el ojo seco? ...

Economic aspects of Dukovany NPP fuel cycle

International Nuclear Information System (INIS)

Vesely, P.; Borovicka, M.

2001-01-01

The paper discusses some aspects of high burnup program implementation at Dukovany NPP and its influence on the fuel cycle costs. Dukovany internal fuel cycle is originally designed as a three years cycle of the Out-In-In fuel reloading patterns. These reloads are not only uneconomical but they additionally increased the radiation load of the reactor pressure vessel due to high neutron leakage typical for Out-In-In loading pattern. To avoid the high neutron leakage from the core a transition to 4-year fuel cycle is started in 1987. The neutron leakage from the core is sequentially decreased by insertion of older fuel assemblies at the core periphery. Other developments in fuel cycle are: 1) increasing of enrichment in control assemblies (3.6% of U-235); 2) improvement in fuel assembly design (reduce the assembly shroud thickness from 2.1 to 1.6 mm); 3) introduction of Zr spacer grid instead of stainless steel; 4) introduction of new type of assembly with profiled enrichment with average value of 3.82%. Due to increased reactivity of the new assemblies the transition to the partial 5-year fuel cycle is required. Typical fuel loading pattern for 3, 3.5, 4 and 5-year cycles are shown in the presented paper. An evaluation of fuel cost is also discussed by using comparative analysis of different fuel cycle options. The analysis shows that introduction of the high burnup program has decrease relative fuel cycle costs

Measurement of the through thickness compression of a battery separator

Science.gov (United States)

Yan, Shutian; Huang, Xiaosong; Xiao, Xinran

2018-04-01

The mechanical integrity of the separator is critical to the reliable operation of a battery. Due to its minimal thickness, compression experiments with a single/a few layers of separator are difficult to perform. In this work, a capacitance based displacement set-up has been developed for the measurement of the through thickness direction (TTD) compression stress-strain behavior of the separator and the investigation of its interaction with the electrode. The experiments were performed for a stack of two layers of Celgard 2400 separator, NMC cathode, and separator/NMC cathode/separator stack in both dry and wet (i.e. submersed in dimethyl carbonate DMC) conditions. The experimental results reveal that the separator compression modulus can be significantly affected by the presence of DMC. The iso-stress based rule of mixtures was used to compute the compressive stress-strain curve for the stack from that of the separator and NMC layer. The computed curve agreed with the experimental curve reasonably well up to about 0.16 strain but deviated significantly to a softer response at higher strains. The results suggest that, in the stack, the TTD compressive deformation of the separator is influenced by the NMC cathode.