Conventional Strip Research Articles

Solvent regeneration by novel direct non-aqueous gas stripping process for post-combustion CO2 capture

Using an inert, immiscible organic component as the purging gas is an innovative technology in the CO2 stripping process. It allows stripping at a lower temperature and overcomes the inherent problem of high energy consumption in steam-based CO2 stripping processes. This work focused on developing a novel, direct non-aqueous gas stripping process and exploiting its potential for energy saving through experiments. An elaborate pre-screening of carrier gases was conducted through hydrocarbon, alcohols, aldehydes, ketones, and their isomers, etc. Pentane, hexane, and cyclohexane were selected as the carrier candidates for their good immiscibility with water/amine, low vaporization energy, mild condensation conditions, and low toxicity. The effects of carrier gas category, carrier gas flow rate, and rich solvent feeding temperature on the stripping performance were investigated. Pentane was found to be the superior carrier gas due to its low heat of vaporization, high regeneration rate, and low energy requirement. A unique phenomenon of water evaporation from the solvent was discovered in the organic gas stripping process, providing a promising approach to break the gas-liquid interface for enhanced diffusion kinetics. The feasibility of low temperature CO2 stripping was analyzed by varying the rich solvent feeding temperature (70–100°C). With pentane as the stripping gas, it was interesting to find an optimum rich-feed temperature lower than 90°C, indicating great potential for a reduction in the overall energy requirement. Under the optimal conditions, the energy consumption during CO2 regeneration, using pentane as the carrier gas, was 2.38GJ/tCO2, 38.8% lower than that of the conventional stripping process. Furthermore, parasitic issues, such as water loss and solvent loss, were discussed. An improved direct non-aqueous gas stripping process with two-stage compression was used to tackle the carrier gas recovery problem. The simulation results show that more than 98% of the carrier gas can be recovered through preliminary separation approaches.

Preliminary Performance Assessment of Intensified Stripper in Post-combustion Carbon Capture through Modelling and Simulation

Intensified stripper used in chemical absorption process based on rotating packed bed (RPB) technology was studied through modelling and simulation in this paper. The model was developed by dynamically linking Aspen Plus® rate-based model with visual Fortran. Suitable correlations for RPB were implemented in Fortran to replace the default correlations in Aspen Plus® rate-based model. The standalone stripper model was validated with experimental data. The paper compared standalone intensified stripper with conventional stripper using MEA solvent. The result shows 9.69 times size reduction. Therefore PI has great potential for use in carbon capture application.

Stripping of CO2 in Post-combustion Capture with Chemical Solvents: Intensification Potential of Hollow Fiber Membrane Contactors

The implementation of hollow fiber membrane contactors (HFMC) in the stripping of CO2 within the PCC context was addressed in this paper. Two stripping techniques were studied by modelling and simulation: high and low temperature stripping. These processes where compared against the conventional CO2 stripping process using packed columns. The latter was also modelled and simulated and good agreement between experimental data and model predictions was obtained. The stripping step is constituted by a whole set of unit operations thus making the modelling more difficult than that used for absorption. HFMC implementation for high temperature stripping is a promising technology, provided that membranes can resist high temperatures and are equally resistant to wetting. Composite membranes currently represent the best candidates. Low temperature stripping requires more energy if similar volumetric contactor reduction factors to those of high temperature stripping using HFMC are desired. It is worth noting that these results are based on the performance of a given packed column, i.e. IMPT-50 packing. Advancements in packed bed technology are also expected, thus the intensification potentials identified here may be affected.

Sediment-bound total organic carbon and total organic nitrogen losses from conventional and strip tillage cropping systems

Global carbon (C) and nitrogen (N) cycles are closely linked to erosion and hydrologic processes. By reducing tillage erosion and runoff, sediment-bound C and N losses can be reduced. Published studies represent only a few soil types and regions and rarely directly compare tillage practices. The objective of this study was to quantify concentrations and sediment-bound total organic carbon (TOC) and nitrogen (TON) loads and enrichment ratios in runoff from 0.2-ha fields in rotational cotton (Gossypium hirsutum L.)-peanut (Arachis hypogea L.) production during a 7-yr study within a southeastern USA coastal plain landscape. The Ultisoils at the study site have loamy sand to sandy loam texture surface horizons. The fields were in either continuous conventional tillage (CT) or strip tillage (ST) and were at upper, middle, and lower landscape positions. Sediment-bound TON and TOC concentrations were significantly greater from ST than CT fields as were the TOC and TON enrichment ratios. However, due to greater surface runoff and sediment loss, TON and TOC loads were significantly greater from CT than ST fields. The CT and ST loads were significantly different at the upper and middle but not at the lower landscape position. Enrichment ratios, 14 to 19 for TON and 8 to 12 for TOC, were several-fold greater than reported in the limited available literature, where studies focused on finer textured surface soils. Our findings have highlighted the site-specific nature of erosion processes, how they affect sediment-bound C and N loss in agricultural landscapes, and how reducing tillage may impact sediment C and N dynamics. The observed enrichment ratios can be used to modify or adjust values used in current erosion models and improve their suitability for use in the region and elsewhere where surface soils have sandy texture and when practices like ST are implemented.

Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators.

Compared to the conventional strip waveguide microring resonators, subwavelength grating (SWG) waveguide microring resonators have better sensitivity and lower detection limit due to the enhanced photon-analyte interaction. As sensors, especially biosensors, are usually used in absorptive ambient environment, it is very challenging to further improve the detection limit of the SWG ring resonator by simply increasing the sensitivity. The high sensitivity resulted from larger mode-analyte overlap also brings significant absorption loss, which deteriorates the quality factor of the resonator. To explore the potential of the SWG ring resonator, we theoretically and experimentally optimize an ultrasensitive transverse magnetic mode SWG racetrack resonator to obtain maximum quality factor and thus lowest detection limit. A quality factor of 9800 around 1550 nm and sensitivity of 429.7 ± 0.4nm/RIU in water environment are achieved. It corresponds to a detection limit (λ/S·Q) of 3.71 × 10-4 RIU, which marks a reduction of 32.5% compared to the best value reported for SWG microring sensors.

Pulse Reverse Electrolytic Stripping of Chrome Plate

A strong desire exists from an environmental, health and safety perspective to eliminate hexavalent chromium during electroplating of protective hard chrome coatings used to enhance component wear resistance. However, toxic hexavalent chromium waste streams are also generated during repair and refurbishment of chrome components as the parts are electrolytically stripped of the existing chrome before being recoated and reinstalled into various systems. Furthermore, the chromate formed during stripping accumulates in the electrolyte, interfering with the process efficiency and damaging the base metal. Faraday is working to develop an electrolytic stripping process intended as a drop-in replacement for the conventional stripping process. The process seeks to eliminate the formation of hexavalent chromium while maintaining the material properties of the underlying substrate. Faraday will present work that demonstrates removal of chrome from high strength steel substrates using a weak acid electrolyte that doesn’t produce hexavalent chromium or adversely affect the substrate properties. Furthermore, the effect of pulse and pulse/reverse electric fields on the efficacy of the stripping process will be presented.

Lanthanide-Labeled Immunochromatographic Strip Assay for the On-Site Identification of Ancient Silk.

The on-site identification of ancient silks has long been a key challenge in archeology. Therefore, a rapid, cost-effective, sensitive analytical approach is highly desirable. In this paper, a lanthanide-labeled immunochromatographic strip which is suitable for the on-site identification of ancient silks is described. Compared with the conventional colloidal gold-based immunochromatographic strip, this strip shows much higher analytical sensitivity and better quantitative discrimination. The limit of detection (LOD) of the strip for silk fibroin (SF) was calculated as 8.09 ng/mL, approximately 185 times lower than that of the colloidal gold-based immunochromatographic strip. No cross-reactions with other possible interfering antigens were observed. Moreover, the strip also shows good reproducibility, with a mean recovery of 94.15-102.55% and coefficient of variation of 5.22-17.57% in the repeated tests. Based on the advantages of portability and cost-effectiveness, as well as sensitivity, specificity, and reproducibility, the lanthanide-labeled immunochromatographic strip is a promising tool for on-site detection of ancient relics in archeological fieldwork.

Simultaneous monitoring of glucose and uric acid on a single test strip with dual channels

The conventional test strip has usually only one electrochemical reaction channel, which requires two times figure punctures for the self-management of patients suffering from both diabetes and gout. Considering the large number of such patients and for the sake of reducing their pains, we report an enzymatic test strip which can simultaneously monitor glucose and uric acid (UA) with only one fingertip blood droplet. The proposed test strip is composed of dual channels. The glucose in blood is detected in the 1st channel above on the substrate and the UA is characterized in the 2nd channel located at the bottom of the substrate. The proposed design intensively matches the requirement of those patients simultaneously suffering from diabetes and gout. We carried out comparative investigations on the proposed test strip and clinical biochemical analyser, which indicates a good agreement and proved the reliability and accuracy of the proposed test strip, as promising solution for the fast growth of family health management market.

Electroabsorption modulator based on inverted-rib-type silicon waveguide including double graphene layers

We investigate, theoretically, a compact graphene-based electroabsorption modulator (EAM). The compactness of the EAM arises from an inverted-rib-type (IRT) silicon waveguide including a graphene–oxide–graphene stack. The EAM consists of input and output waveguides, which are conventional silicon strip waveguides, and the IRT waveguide efficiently connected to them through tapering regions. The stack is located in the region where the fundamental transverse electric mode of the IRT waveguide is mainly confined. Hence, the IRT waveguide mode strongly interacts with the graphene layers. Moreover, the IRT waveguide can be realized without complex high-precision processes. The calculated modulation depth of the IRT waveguide is 0.41 dB μm−1 when the chemical potential of graphene is tuned between 0.2 and 0.6 eV. It is more than two times larger than those of previous graphene-covered silicon waveguides. The EAM, with a 3 dB extinction ratio, employs an IRT waveguide of length 7–8 μm. This EAM is analyzed and found to have an optical bandwidth of 100 nm, an electrical bandwidth of up to 46.4 GHz, and energy consumption smaller than 630 fJ bit−1. Such EAMs based on IRT waveguides may play an important role in off-chip optical interconnection.

Enhancing evaporative mass transfer and steam stripping using microwave heating

The effect of microwave heating on evaporative mass transfer of hydrocarbons was investigated for a number of contaminated solid materials. The rate of oil removal could be rationalised by the velocity of steam that was created by selective heating of water within the solid. A single correlation was found to fit 45 independent experiments across 10 separate variables, and the correlation was consistent with the physics of evaporative mass transfer. It is shown for the first time that steam stripping is the dominant mechanism that governs hydrocarbon removal during microwave processing. It was further discovered that mass transfer is enhanced due to microwave heating when compared to conventional stripping processes, with this improvement in efficiency due to the ability of the microwave process to overcome the channelling effects that limit conventional mass transfer processes.

The Effect of Compacting Rolling on the Properties of Titanium Powder Mill Products

The effect of deformation stress on the consolidating of titanium powder strips obtained by symmetrical and asymmetrical rolling is analyzed. It is determined, that the strength of green strips after asymmetrical rolling is substantially higher than that of conventional strips: for low and medium deformation stress (by a factor of 3–5) and for high deformation stress (by a factor of >10). The repeated rolling improves the mechanical properties of sintered strips. Titanium powder strips produced through optimal asymmetrical rolling possess better mechanical properties than conventional titanium strips.

Hollow Au-Ag Nanoparticles Labeled Immunochromatography Strip for Highly Sensitive Detection of Clenbuterol

The probe materials play a significant role in improving the detection efficiency and sensitivity of lateral-flow immunochromatographic test strip (ICTS). Unlike conventional ICTS assay usually uses single-component, solid gold nanoparticles as labeled probes, in our present study, a bimetallic, hollow Au-Ag nanoparticles (NPs) labeled ICTS was successfully developed for the detection of clenbuterol (CLE). The hollow Au-Ag NPs with different Au/Ag mole ratio and tunable size were synthesized by varying the volume ratio of [HAuCl4]:[Ag NPs] via the galvanic replacement reaction. The surface of hollow Ag-Au NPs was functionalized with 11-mercaptoundecanoic acid (MUA) for further covalently bonded with anti-CLE monoclonal antibody. Overall size of the Au-Ag NPs, size of the holes within individual NPs and also Au/Ag mole ratio have been systematically optimized to amplify both the visual inspection signals and the quantitative data. The sensitivity of optimized hollow Au-Ag NPs probes has been achieved even as low as 2 ppb in a short time (within 15 min), which is superior over the detection performance of conventional test strip using Au NPs. The optimized hollow Au-Ag NPs labeled test strip can be used as an ideal candidate for the rapid screening of CLE in food samples.

Early experience of transilluminated cryosurgery for varicose vein with saphenofemoral reflux: review of 84 patients (131 limbs).

PurposeVaricose veins with great saphenous vein (GSV) insufficiency is prevalent. Among various surgical treatments for varicose veins, cryosurgery of GSV is an alternative minimally invasive technique that could leave fewer scars and replace conventional stripping with ambulatory phlebectomy. This study sought to assess outcomes including efficacy and safety of cryosurgery for varicose veins.MethodsOne hundred thirty-one limbs in 84 patients (37 male, 47 female; mean age, 53.3 years) with varicose veins were treated with cryosurgery over a 2-year period. The patients were followed for postoperative complication with surveillance of recurrence. The analyzed variables included age, sex, symptom, operative time (from skin incision to the application of elastic bandages on the legs for compression purposes), and postoperative complications including bruising, hematoma, superficial thrombophlebitis, cellulitis, seroma, cutaneous nerve damage, and wound complication.ResultsThe mean operative time was 64.7 minutes for both limbs and 44 minutes for single limbs. The median number of incisions was 2. For stripping of GSV, one incision at the groin was necessary. Postoperative complications included an episode of hematoma in 3 limbs (2.3%), cutaneous nerve damage in 3 limbs (2.3%), cellulitis in 2 patients (1.5%), and seroma in 1 limb (0.8%). No wound infection, thrombophlebitis or deep venous thrombosis was observed. During follow-up (mean follow-up period, 13.5 months; range, 3–28 months), there was no recurrence.ConclusionCryosurgery to treat varicose veins is an effective and safe treatment modality in terms of postoperative complication, cosmetic result, and recurrence.

Unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating waveguides.

In this paper, unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating (SWG) waveguides are studied and demonstrated. The SWG structure consists of periodic silicon pillars in the propagation direction with a subwavelength period. Effective sensing region in the SWG microring resonator includes not only the top and side of the waveguide, but also the space between the silicon pillars on the light propagation path. It leads to greatly increased sensitivity and a unique surface sensing property in contrast to common evanescent wave sensors: the surface sensitivity remains constantly high as the surface layer thickness grows. Microring resonator biosensors based on both SWG waveguides and conventional strip waveguides were compared side by side in surface sensing experiment and the enhanced surface sensing capability in SWG based microring resonator biosensors was demonstrated.

Dispersion characteristics of nanometer-scaled silicon nitride suspended membrane waveguides**Project supported by the National Natural Science Foundation of China (Nos. 61435002, 61527823 61321063).

We investigate the dispersion properties of nanometer-scaled silicon nitride suspended membrane waveguides around the communication wavelength and systematically study their relationship with the key structural parameters of the waveguide. The simulation results show that a suspended membrane waveguide can realize anomalous dispersion with a relatively thinner silicon nitride thickness in the range of 400 to 600 nm, whereas, for the same membrane thickness, a conventional rib or strip silicon nitride waveguide cannot support anomalous dispersion. In particular, a waveguide with 400 nm silicon nitride thickness and deep etch depth (r = 0.05) exhibits anomalous dispersion around the communication wavelength when the waveguide width ranges from 990 to 1255 nm, and the maximum dispersion is 22.56 ps/(nm·km). This specially designed anomalous dispersion silicon nitride waveguide is highly desirable for micro-resonator based optical frequency combs due to its potential to meet the phase-matching condition required for cascaded four-wave-mixing.

Colour stripping of reactive‐dyed cotton by ozone treatment

Trials have been carried out to investigate the efficiency of ozone treatment in the colour stripping of reactive‐dyed cotton fabrics. The trials were performed on a specially designed apparatus to inject ozone gas into the liquor passing through a perforated beam with fabric rolls on it, just like a beam dyeing machine with ozone venturi injection. Conventional reductive colour stripping was applied as the control treatment, and ozone treatment was applied for three different application times (15, 30, and 45 min). Trials were performed with seven selected reactive dyes having various chromophores and reactive groups. The results indicate that 45 min ozone treatment yielded the best colour stripping results among the three application times. Furthermore, the colour stripping percentages of the 45 min ozone treatment were higher for four of the tested dyes, the same for one of the tested dyes, and lower for two of the tested dyes compared with the control treatment, which consisted of conventional reductive colour stripping. Colour stripping of 90% and above was achieved for all samples of the 45 min ozone treatment. The chemical oxygen demand values of the colour stripping baths were compared: the average value of the 45 min ozone application baths was 105 mg l−1, and it was 1993 mg l−1 for the conventional reductive treatment baths. Consequently, a reduction in chemical oxygen demand of almost 94% was achieved by ozone treatment compared with conventional reductive treatment. The strength values of the fabrics after the respective treatments were similar, with a difference of only 3%.

Vertical wicking tester for monitoring water transportation behavior in fibrous assembly.

An instrument based on the principle of change of resistance of fibrous assembly on wetting has been developed for precise monitoring of the water transportation behaviour in the fibrous assemblies. The conducting probes sense the change in resistance of a dry fibrous assembly on wetting. This change in resistance generates analog signals which trigger an amplifying circuit. This circuit produces an enlarged copy of the received signals which are further converted to digital signals by a Darlington pair and are encoded to measurable quantity with the help of a microcontroller. The data thus obtained are displayed on a suitable display device. Comparison between conventional strip test and experimental results obtained by the developed instrument shows its reliability. The developed instrument measures the initial rate of water transport with increased precision and hence could be used for detailed study of fluid flow in the fibrous structure.

Profitability of Organic Vegetable Production via Sod Based Rotation and Conventional Versus Strip Tillage in the Southern Coastal Plain

<p class="sar-body"><span lang="EN-US">There are little economic data concerning the profitability of organic vegetable crops in the Southern Coastal Plain, especially in reference to sod-based rotation and tillage alternatives. A three-year experiment was conducted at the North Florida Research and Education Center-Quincy involving a crop rotation sequence of oats and rye (winter), bush beans (spring), soybean (summer) and broccoli (fall). Bush beans and broccoli were the cash crops. This paper presents analyses of the riskiness of organic production utilizing years in bahiagrass prior to initiating the crop rotation sequence and conventional tillage (CT) versus strip tillage (ST). Methods of “Risk-rated enterprise budget” and “Analyses of Variance-Covariance Matrix (ANOVA)” were utilized for determining relative profitability, and coefficient of variation was applied for measuring riskiness of each treatment. Three years of bahiagrass prior to initiating the crop rotation sequence, in combination with conventional tillage, had the highest profitability and ranked as the least risky scenario. The second most profitable treatment was conventional tillage with four years of bahiagrass. Focusing on strip tillage, four years of bahiagrass with strip-tillage ranked third in term of profitability.</span></p>

Efficacy of Nanostructures as Preservation Carriers of Bacillus atrophaeus in the Preparation of Sterilization Bioindicators

The spores of Bacillus atrophaeus are used to monitor the efficacy of disinfection and sterilization processes, particularly in dry heat and ethylene oxide sterilization processes. The production process of biological sterilization indicators of this bacterium includes bacterial sporulation, which leads to a dormant structure with extreme resistance to heat stresses. In this study, the efficacy of the application of nanomaterials as alternative carriers instead of regular paper strips in the recovery of spores and the stability of the prepared bioindicator was investigated. For this purpose, the structural types of nanomaterials applied as carriers on D values and spore absorption were evaluated and compared. The results suggest the nanomaterial’s potential to be used as the supports of bioindicators. Among the evaluated nanomaterials adsorbents, including nanocellulose, lignocellulose, chitin, gamma alumina and silica, silica and gamma alumina illustrated the highest spore absorption potency (107 CFU/mL) and highest spore resistance by the D value of 6.5 min. The results of this study suggest that nanomaterials can be a suitable replacement for conventional strips due to their higher perdurability.

Foundations for low cost buildings

Abstract Attaining an economical and safe design of structures is regarded as a prerequisite for the structural engineer. The market prices of reinforcing steels have dramatically soared in recent years internationally. Therefore, the purpose of the current paper is not just reducing the ratio of reinforcing steel in the foundations for skeleton structures, but rather minimizing this ratio through choosing the most effective footing shape (folded strip footings). Folded footings have been used as an alternative to the conventional rectangular strip footings. The height of the studied model is ten floors. Two different foundation systems are used in the analysis namely; rectangular strip footings, and folded strip footings respectively. Both footing shapes will be designed as continuous footings with grid shape under the building. Comparison between the two systems is also presented regarding the concrete sections and reinforcement ratio under the same applied loads. The finite element analysis software ADINA is used in modeling and analysis of the structural and geotechnical behavior of both types of footings, with emphasis on the effect of changing the footing shape on the stresses in the footing concrete body and the underlying soils. Research results presents the internal stresses within the footing and soil domains, as well as the contact pressure distribution for a reinforced folded strip footing resting on different soil types. The influence of folding inclination angle, and soil type on the results are also studied. Results showed that folded strip footings are efficient in reducing the amount of needed reinforcements, and such efficiency in reducing the required steel reinforcement in the footings is depending on the applied footing loads, and to some degree on the soil type and properties. Reduction in the reinforcement ratio between the rectangular and folded footing types is about 26% in favor of the folded strip footings. A comparative economical study shows that the total cost of the reinforced concrete section for the folded strip footings is less than the traditional one by about 18%. This difference in cost of both types of footings is mainly due to the relatively smaller in steel reinforcement ratio needed for the folded type as compared with the rectangular ones. So, the folded strip footing is more economical than the rectangular strip footing. Highlights Two different foundation systems are used in the analysis namely; rectangular strip footings, and folded strip footings respectively. The finite element analysis software ADINA is used in modeling and analysis of structural and geotechnical behavior of both types of footings with emphasis on the effect of changing the footing shape and soil type (Ks) on the stresses and soil settlement. Results showed that the maximum value of contact pressure decreased by about 38% for folded strip footing when compared with the traditional strip footing in stiff clay soil, and by about 25% in dense sand soil when increasing vertical static load to its peak value. The reduction in the reinforcement ratio between the two types of footings is about 26% in favor of the folded strip footings. While the total cost of the concrete for the folded strip footings is less than the rectangular one by about 18%. So, the folded shape is more economical than the ordinary rectangular strip footing.