• Membrane and Water Treatment
• /
• v.7 no.2
• /
• pp.155-173
• /
• 2016

The present work has been focused on the development of polysulfone (PSf) ultrafiltration membrane via blending by sulfonated polyethersulfone (SPES) in order to permeability enhancement for ultrafiltration of cheese whey. In this regards, sulfonation of polyethersulfone was carried out and the degree of sulfonation was estimated. The effect of blend ratio on morphology, porosity, permeation and fouling of PSf / SPES membranes was investigated. Filtration experiments of whey were conducted for separation of macromolecules and proteins from the lactose enrichment phase. The morphology and performance of membranes were evaluated using different techniques such SEM, AFM, and contact angle measurements. The contact angle measurement showed that the hydrophilicity of membrane was increased by adding SPES. According to AFM images, PSf / SPES membranes exhibited lower roughness compared to neat PSf membrane. The water and whey flux of these membranes were higher than neat membrane. However, flux was decreased when the PSf / SPES blend ratio was 0/100. It can be attributed to pore size and morphology changes. Further, fouling parameters of PSf membrane were improved after blending. The blend membranes show a great potential to be used practically in proteins separation from cheese whey.

• Nuclear Engineering and Technology
• /
• v.55 no.1
• /
• pp.378-390
• /
• 2023

The SPES (Selective Production of Exotic Species) facility, currently under development at Legnaro National Laboratories of INFN, aims at the production of intense RIB (Radioactive Ion Beams) employing the Isotope Separation On-Line (ISOL) technique for interdisciplinary research. The radioactive isotopes of interest are produced by the interaction of a multi-foil uranium carbide target with a 40 MeV 200 μA proton beam generated by a cyclotron proton driver. The Target Ion Source (TIS) is the core of the SPES project, here the radioactive nuclei, mainly neutron-rich isotopes, are stopped, extracted, ionized, separated, accelerated and delivered to specific experimental areas. Due to efficiency reasons, the TIS unit needs to be replaced periodically during operation. In this highly radioactive environment, the employment of autonomous systems allows the manipulation, transport, and storage of the TIS unit without the need for human intervention. A dedicated remote handling infrastructure is therefore under development to fulfill the functional and safety requirement of the project. This contribution describes the layout of the SPES target area, where all the remote handling systems operate to grant the smooth operation of the facility avoiding personnel exposure to a high dose rate or contamination issues.

• Bulletin of the Korean Space Science Society
• /
• 2010.04a
• /
• pp.38.2-38.2
• /
• 2010

We have examined the occurrence probability of solar proton events (SPEs) and their peak fluxes depending three flare parameters (X-ray peak flux, longitude, and impulsive time). For this we used NOAA SPEs from 1976 to 2006, and their associated X-ray flare data. As a result, we selected 166 proton events that were associated with major flares; 85 events associated with X-class flares and 81 events associated with M-class flares. Especially the occurrence probability strongly depends on these three parameters. In addition, the relationship between X-ray flare peak flux and proton peak flux as well as its correlation coefficient are strongly dependent on longitude and impulsive time. Among NOAA SPEs from 1997 to 2006, most of the events are related to both flares and CMEs but a few fraction of events (5/93) are only related with CMEs. We carefully identified the sources of these events using LASCO CME catalog and SOHO MDI data. Specifically, we examined the directions of CMEs related with the events and the history of active regions. As a result, we were able to determine active regions which are likely to produce SPEs without ambiguity as well as their longitudes at the time of SPEs by considering solar rotation rate. From this study, we found that the longitudes of five active regions are all between $90^{\circ}W$ and $120^{\circ}W$. When the flare peak time is assume to be the CME event time, we confirmed that the dependence of their rise times (proton peak time - flare peak time) on longitude are consistent with the previous empirical formula. These results imply that five events should be also associated with flares which were not observed because they occurred from back-side. Now we are examining the occurrence probability of SPEs depending on CME parameters. Finally, we will discuss the future prospects on the development of an empirical SPE forecast model based on the information of flares and CMEs.

• Journal of Periodontal and Implant Science
• /
• v.33 no.4
• /
• pp.585-597
• /
• 2003

Porphyromonas gingivalis has been implicated as an important periodontophathic bacterium in the etiology and progression of periodontal diseases. It has been reported that P.gingivalis may mediate periodontal destruction not only directly through its virulence factors, but also indirectly by including complex host mediated inflammatory reponses. The purpose of this study was t o evaluate the effects of P.gingivalis on the bone formation and resorption by osteoblasts. For this purpose, after determining the concentration below which sonicated P.gingivalis extracts (SPEs) have no cytotoxicity on mouse calvarial primary osteoblastic (POB) cells, we investigated the effects of SPEs on the alkaline phosphatase (ALP) activity, matrix metalloproteinase (MMP) expression (MMP-2, -9, 13), and prostaglandin $E_2$ ($PGE_2$) release in POB cells by treatment with SPEs below that concentration. The results were as follows; 1. SPEs showed no cytotoxic effect on POB cells up to a concentration of 1 ${\mu}m$/ml. 2. The treatment with SPEs reduced ALP activity in a dose-dependent manner in POB cells, In addition, when we investigated the effect of SPEs (1 ${\mu}m$/ml) on ALP activity for different exposure periods, statistically significant inhibition of ALP activity was shown at 2 days of exposure, and further significant inhibition occurred by extending the periods of exposure. 3. The treatment with SPEs stimulated the gene expression of MMP-9 in POB cells. 4. The pre-treatment with SPEs increased the amount of $PGE_2$ released in POB cells. In summary, the present study shows that P.gingivalis could inhibit osteogenesis and stimulate bone resorption not only by reducing ALP activity but also by increasing MMP-9 mRNA expression in osteoblasts, possibly through an endogenous $PGE_2$ pathway. In addition, our results suggest that if P.gingivalis affects osteoblasts in early differentiation stage, such effects by P. gingivalis could be irreversible.

• Bulletin of the Korean Space Science Society
• /
• 2011.04a
• /
• pp.28.4-29
• /
• 2011

Solar Proton Events (SPEs, ${\geq}\;10\;cm^{-1}s^{-1}sr^{-1}$ with >10 MeV) are very important for space weather forecasting. It is well known that they are associated with solar flares and/or CME-driven shocks. Especially, the CME-driven shocks have been observed as solar and interplanetary type II bursts. In this study, we estimated the occurrence probability of SPEs depending on three groups: (1) metric, (2) decameter-hectometric (D-H), and (3) meter-to-kilometric (m-to-km) type II bursts. For this work, we used SPEs and all available type II burst data in 1996-2004. The primary findings of this study are as follows. First, the majority (77%) of the m-to-km type II bursts are associated with SPEs and its probability is noticeably higher than D-H type II bursts probability strongly depend on longitude: eastern (0%), center(45%), and western (33%) for X-class associated metric type II bursts, eastern (15%), center (55%), and western (50%) for X-class associated D-H type II bursts, eastern (17%), center (77%), and western (64%) for X-class associated m-to-km type II bursts. Third, for m-to-km type II bursts, the SPE probability increases with CME speed: 400km/s${\leq}$V <1000km/s (36%), 1000km/s ${\leq}$V<1500km/s (40%), 1500km/s${\leq}$V (66%). Finally, we expect that these results will be used for setting up more reasonable solar proton event forecasting models.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.63.3-64
• /
• 2015

In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (>5000pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low (~1Rs) and close to the western limb, while the latter has a relatively higher and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (<1000pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.1
• /
• pp.33.2-33.2
• /
• 2010

We have investigated a relationship among the solar proton events (SPEs), coronal mass ejections (CMEs) and solar flares during the solar cycle 23 (1997-2006). Using 63 SPE dataset, we found that SPE rise time, duration time, and decrease times depend on CME speed and SPE peak intensity depends on the CME earthward direction parameter as well as CME speed and x-ray flare intensity. While inspecting the relation between SPE peak intensity and the CME earthward direction parameter, we found that there are two groups: first group consists of large 6 SPEs (> 10,000 pfu at >10 MeV proton channel of GOES satellite) and shows a very good correlation (cc=0.65) between SPE peak intensity and CME earthward direction parameter. The second group has a relatively weak SPE peak intensity and shows poor correlation between SPE peak intensity and the CME earthward direction parameter (cc=0.01). By investigating characteristics of 6 SPEs in the first group, we found that there are special common conditions of the extremely large proton events (group 1); (1) all the SPEs are associated with very fast halo CME (>1400km/s), (2) they are almost located at disk region, (3) they also accompany large flare (>M7), (4) all they are preceded by another wide CMEs, and (5) they all show helmet streamer nearby the main CME. In this presentation, we will give details of the energy spectra of the 6 SPE events from the ERNE/HED aboard the Solar and Heliospheric Observatory (SOHO), and onset time comparison among the SPE, flare, type II burst, and CME.

• The Bulletin of The Korean Astronomical Society
• /
• v.36 no.2
• /
• pp.97.1-97.1
• /
• 2011

In this study we have examined the probability of solar proton events (SPEs) and their peak fluxes depending on flare (flux, longitude and impulsive time) and CME parameters (linear speed, longitude, and angular width). For this we used the NOAA SPE list and their associated flare data from 1976 to 2006 and CME data from 1997 to 2006. We find that about 3.5% (1.9% for M-class and 21.3% for X-class) of the flares are associated with SPEs. It is also found that this fraction strongly depends on longitude; for example, the fraction for $30W^{\circ}$ < L < $90W^{\circ}$ is about three times larger than that for $30^{\circ}E$ < L < $90^{\circ}E$. The SPE probability with long duration (${\geq}$ 0.3 hours) is about 2 (X-class flare) to 7 (M-class flare) times larger than that for flares with short duration (< 0.3 hours). In case of halo CMEs with V ${\geq}$ 1500km/s, 36.1% are associated with SPEs but in case of partial halo CME ($120^{\circ}$ ${\leq}$ AW < $360^{\circ}$) with 400 km/s ${\leq}$ V < 1000 km/s, only 0.9% are associated with SPEs. The relationships between X-ray flare peak flux and SPE peak flux are strongly dependent on longitude and impulsive time. The relationships between CME speed and SPE peak flux depend on longitude as well as direction parameter. From this study, we suggest a new SPE forecast method with three-steps: (1) SPE occurrence probability prediction according to the probability tables depending on flare and CME parameters, (2) SPE flux prediction from the relationship between SPE flux and flare (or CME) parameters, and (3) SPE peak time.

• Membrane Journal
• /
• v.8 no.4
• /
• pp.210-219
• /
• 1998

Sulfonated poly(ether sulfone)(SPES) of various ion exchange capacity (IEC) was prepared by heterogeneous sulfonation with chlorosulfonic acid (CSA) to make hydrophilic ultrafiltration membrane for reducing fouling. The effects of CSA concentration, reaction temperature and reaction time has been investigated. The reaction was effective when the temperature is above 10$\circ$C and the CSA concentration is over 0.05 mol, although polymer chain has been significantly degraded. The substitution of sulfonic acid groups was characterized by FTIR and $^1$H-NMR. Transport properties and fouling test have been conducted to the modified SPES ultrafiltration rnembranrs by heterogeneors method. Membranes were obtained using DCM and PVP as a non-solvent and pore forming agent, respectively. Flux reduced and rejection increased with ion exchange capacity. Finger-like structure was disappeared and the thickness of top layer was increased. Dense membrane by non-solvent DCM and porous membrane by pore forming agent PVP was prepared. Fouling was reduced with increasing ion exchange capacity because of hydrophilicity.

• Bulletin of the Korean Space Science Society
• /
• 2010.04a
• /
• pp.38.3-39
• /
• 2010

While major solar proton events (SPEs) come from the coronal mass eject (CME)-driven shocks in solar wind, there are many evidences that potentiality of CMEs to generate SPEs depends on its early evolution near the Sun and on different solar activities observed around the CME liftoff time. To decipher origin of SPE release, we have investigated onset time comparison of the SPE with CME, metric type II radio burst, and hard X-ray flare. For this, we select 30 SPEs observed from 1997 to 2006 by using the particle instrument ERNE onboard SOHO, which allows proton flux anisotropy measurement in the energy range ~10 - 50MeV. Onset time of the SPEs is inferred by considering the energy-dependent proton transport time. As results, we found that (1) SPE onset time is comparable to that of type II but later than type III onset time and HXR start time, (2) SPE onset time is mostly later than the peak time of HXR flare, (3) almost half of the SPE onsets occurred after the HXR emission, and (4) there are two groups of CME height at the onset time of SPE; one is the height below 5 Rs (low corona) and the other is above 5Rs (high corona). In this talk, we will present the onset time comparison and discuss about the origin of the SPE onset.