Characterization of ultrafiltration of undiluted and diluted stored urine

2016 ◽  
Vol 74 (9) ◽  
pp. 2105-2114 ◽  
Author(s):  
J. Ouma ◽  
S. Septien ◽  
K. Velkushanova ◽  
J. Pocock ◽  
C. Buckley

Urine ultrafiltration (UF) was studied in terms of flux, permeability, resistance and fouling. Two types of samples were used: stored urine representing the feedstock obtained from urine diversion dry toilets; and diluted stored urine representing the feedstock obtained from urinals. Three different filtration experiment sets were adopted in this study. For the first case, pressure was set in an ascending order, i.e. from 10 to 60 kPa during filtration of stored urine. For the second case, pressure was set in a descending order, i.e. from 60 to 10 kPa for the same feed stream. The third case involved filtration of diluted urine with pressure in ascending order, i.e. from 10 to 60 kPa. The results indicated that diluted urine had higher flux than undiluted urine with maximum values of 43 and 26 L·m−2·h−1 respectively. Cake formation was the dominating fouling mechanism during urine filtration with a contribution of about 90% to the total hydraulic resistance. The contribution of chemically irreversible fouling was low (−2%), unless operating from high to low pressures. Indeed, irreversible fouling appeared to be greater during the experiments starting at higher pressure. Although undiluted urine had a higher fouling potential compared to diluted urine, the specific cake resistance was higher for diluted urine, probably due to a denser cake caused by lower particle sizes in that sample. The permeate obtained after urine filtration had much lower suspended solids content compared to the feedstock, with rejections up to 99%. The concentration of the ionic species remained unchanged, and 75% of the organic compounds and dissolved solids remained in the permeate. Urine UF could then be used as pre-treatment to remove suspended solids.

2016 ◽  
Vol 12 (30) ◽  
pp. 127
Author(s):  
Mohammed Izougarhane ◽  
Dalale Mansouri ◽  
Hamid El Ibaoui1 ◽  
Said Chakiri ◽  
Mohamed Fadli

This work focuses on the physical, chemical and metal characterization of the estuary waters of Oued Sebou during a long period of sand dredging. To do this, several physicochemical parameters were evaluated during periods 2007 and 2014-2016. The results showed that this estuary has a significant degree of pollution. The source of this pollution is diverse: urban waste, industrial waste, agricultural activities. This pollution is accentuated by the action of repeated dredging that increases the turbidity and the suspended solids content which covers the seabed during immersions that are covering the sediment and disturbs the physicochemical equilibrium of the estuary. So, indirectly this operation of dredging influences the parameters that are related to the amount and quality of materials suspended such as the dissolved oxygen content and orthophosphates and the brightness level in the water and over up the sediment.Indeed, for the majority of the physicochemical parameters assessed, the water of the estuary was belonging to a middle class, poor class or very poor class. Thus, the operation of dredging should consider the ecological balance of the coastal zone. Note also that the contents of assessed heavy metals are not worrisome. However, their risks might be amplified by the dredging operations.


Author(s):  
Dirk Doyle ◽  
Lawrence Benedict ◽  
Fritz Christian Awitan

Abstract Novel techniques to expose substrate-level defects are presented in this paper. New techniques such as inter-layer dielectric (ILD) thinning, high keV imaging, and XeF2 poly etch overflow are introduced. We describe these techniques as applied to two different defects types at FEOL. In the first case, by using ILD thinning and high keV imaging, coupled with focused ion beam (FIB) cross section and scanning transmission electron microscopy (STEM,) we were able to judge where to sample for TEM from a top down perspective while simultaneously providing the top down images giving both perspectives on the same sample. In the second case we show retention of the poly Si short after removal of CoSi2 formation on poly. Removal of the CoSi2 exposes the poly Si such that we can utilize XeF2 to remove poly without damaging gate oxide to reveal pinhole defects in the gate oxide. Overall, using these techniques have led to 1) increased chances of successfully finding the defects, 2) better characterization of the defects by having a planar view perspective and 3) reduced time in localizing defects compared to performing cross section alone.


2017 ◽  
Vol 2017 (7) ◽  
pp. 4255-4262
Author(s):  
Elena Torfs ◽  
Julie Doucet ◽  
Domenico Santoro ◽  
Dang Ho ◽  
Medhavi Gupta ◽  
...  

Author(s):  
Marie Doussiere ◽  
Morgane Choquet ◽  
Franck Grados ◽  
François Peltier ◽  
Jean-Philippe Lanoix ◽  
...  

Author(s):  
A. Brown ◽  
K. Krishnan ◽  
L. Wayne ◽  
P. Peralta ◽  
S. N. Luo ◽  
...  

Global and local microstructural weak links for spall damage were investigated using 3-D characterization in polycrystalline (PC) and multicrystalline (MC) copper samples, respectively. All samples were shocked via flyer-target plate experiments using a laser drive at low pressures (2–6 GPa). The flyer plates measured approximately 500 μm thick and 8 mm in diameter and the target plates measured approximately 1000 μm thick and 10 mm in diameter. Electron Backscattering Diffraction (EBSD) and optical microscopy were used to determine to presence of voids and relate them to the surrounding microstructure. Statistics on the strength of grain boundaries (GBs) was conducted by analyzing PC samples and collecting the misorientation across GBs with damage present, and it was found that a misorientation range of 25–50° is favorable for damage. Statistics were also taken of copper PC samples that had undergone different heat treatments and it was found that although the 25–50° range is less dominant, it is still favorable for damage nucleation. Removal of initial plastic strain via heat treatments and an increase in Σ3 CSL boundaries, indicative of strong annealing twins, also led to an increased amount of transgranular damage. 3-D X-ray tomography data were used to investigate the shape of the voids present in untreated, as received and heat treated samples. It was found that the as received sample contained a higher amount of “disk”, or, “sheet-like” voids indicative of intergranular damage, whereas the heat treated samples had a higher fraction of spherical shaped voids, indicative of transgranular damage. MC samples were used to study microstructural weak links for spall damage because the overall grain size is much larger than the average void size, making it possible to determine which GBs nucleated damage. Simulations and experimental analysis of damage sites with large volumes indicate that high Taylor factor mismatches with respect to the crystallographic grain GB normal is the primary cause for the nucleation of damage at a GB interface and a low Taylor factor along the shock direction in either grain drives void growth perpendicular to the GB. Cases where experimental results show damage and simulation results show no damage are attributed to the presence of an intrinsic microstructural weak link, such as an incoherent twin boundary.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Megan H. Trager ◽  
Emanuelle Rizk ◽  
Sharon Rose ◽  
Kuixi Zhu ◽  
Branden Lau ◽  
...  

AbstractThe presence of actinic keratoses (AKs) increases a patient’s risk of developing squamous cell carcinoma by greater than six-fold. We evaluated the effect of topical treatment with imiquimod on the tumor microenvironment by measuring transcriptomic differences in AKs before and after treatment with imiquimod 3.75%. Biopsies were collected prospectively from 21 patients and examined histologically. RNA was extracted and transcriptomic analyses of 788 genes were performed using the nanoString assay. Imiquimod decreased number of AKs by study endpoint at week 14 (p < 0.0001). Post-imiquimod therapy, levels of CDK1, CXCL13, IL1B, GADPH, TTK, ILF3, EWSR1, BIRC5, PLAUR, ISG20, and C1QBP were significantly lower (adjusted p < 0.05). Complete responders (CR) exhibited a distinct pattern of inflammatory gene expression pre-treatment relative to incomplete responders (IR), with alterations in 15 inflammatory pathways (p < 0.05) reflecting differential expression of 103 genes (p < 0.05). Presence of adverse effects was associated with improved treatment response. Differences in gene expression were found between pre-treatment samples in CR versus IR, suggesting that higher levels of inflammation pre-treament may play a part in regression of AKs. Further characterization of the immune micro-environment in AKs may help develop biomarkers predictive of response to topical immune modulators and may guide therapy.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Uasmim Lira Zidanes ◽  
Matheus Cordazzo Dias ◽  
Mário Sérgio Lorenço ◽  
Elesandra da Silva Araujo ◽  
Maryella Júnnia Ferreira e Silva ◽  
...  

AbstractAdhesives based on vegetable tannins are already a reality in the market. However, their use is still limited due to their low mechanical resistance and weak humidity resistance. Cellulose nanofibrils (CNFs) are being used as reinforcing materials in various composites, resulting in an improvement of mechanical proprieties in general. The objective of this work was to evaluate the incorporation of CNFs in adhesives made of tannins obtained from the Angico tree (Anadenanthera peregrine). Concentrations of nanofibrils at 1, 5, and 10% were added to the adhesives on a dry basis. Tests of viscosity, pH, solids content, and gel time were performed to determine the physical proprieties of the adhesives. The Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Raman spectra measurements were also determined to understand the interaction between tannins and CNFs. Thermogravimetric analyses (TGA) were carried out to determine the thermal resistance of the composite. The FTIR and Raman characterization identified some differences in the peaks in the chemical composition of the adhesives with different percentages of CNFs. The adhesives showed no different decomposition in the thermogravimetric analyses. The shear strength in the glue line of the adhesive with 5% of CNFs in Toona ciliata woods was determined. Among all the adhesives analyzed, the one with 5% of CNFs produced an improvement in the mechanical resistance and humidity resistance on the glue line.


Author(s):  
C Honey ◽  
M Morrison

Background: We published the world’s first case of hemi-laryngpharyngeal spasm (HELPS) syndrome cured by microvascular decompression (MVD) of the Xth cranial nerve in 2016. We now present a small cohort of patients (n=3) successfully treated with surgery in order to better delineate the common characteristics of this syndrome, diagnostic tests of choice, nuances of their surgical care and outcomes of their treatment. Methods: The history and physical examination of three patients with HELPS syndrome are presented. Pre-operative laryngoscopy, neuroimaging, response to botox and intra-operative videos are detailed. Post-operative outcome and complications are presented. Results: Each patient reported similar motor (choking) and sensory (coughing) features in their history. Episodic choking relentlessly progressed over the years until it occurred while sleeping and with frightening severity prompting tracheostomy in one patient and intubation in another. A “tickling” sensation deep in the throat triggered episodic coughing that worsened over the years until it occurred while sleeping and with frightening severity (syncope and incontinence). Conclusions: A review of the literature suggests that patients with similar symptoms, often called episodic laryngospasm in the past, have been treated with psychotherapy or antacids. With the recognition that a clearly defined subset of these patients have HELPS syndrome, we can offer them the potential of a neurosurgical cure.


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