Earticle

Irradiation of egg white increased foaming ability significantly. To investigate the protein modification by irradiation responsible for the increase of foaming ability, 3 major egg white proteins were purchased and mixed(7.7g/L ovalbumin, 1.8g/L ovotransferrin, 0.5g/L lysozyme) as a model system and irradiated at 0, 2.5, and 5kGy. The different protein expressions were evaluated using 2-D electrophoresis and it was found that ovotransferrin was cleaved by irradiation and molecular weight and isoelectric point were changed. In addition, many uncharacterized proteins were found and it indicated that irradiation modified proteins randomly but mainly fragmentation was observed. Therefore, it can be concluded that protein fragmentation of 3 major egg white proteins responsible for foaming ability may be the main reason for the improvement of foaming ability.

고농도 질소를 함유하고 있는 하수는 하수처리장 처리 효율에 악영향을 미치는 것으로 알려져 있다. 따라서 고농도 질소를 함유한 하수를 처리하기 위한 다양한 연구가 이루어지고 있다. 본 연구에서는 대표적인 고농도 질소를 함유한 하수인혐기 소화 상징액과 가축분뇨를 대상으로 유기물 분석, foaming 실험 및 실험실 규모 아질산화 반응조 운전을 실시하였다. 유기물 분석 결과 혐기 소화 상징액은 용존성 불활성한 성분, 가축분뇨는 입자성 생물학적 분해가능한 성분이 가장큰 부분을 차지하는 것으로 나타났다. 아질산화 반응에 적합한 체류시간은 혐기소화 상징액 2일과 가축분뇨 6일이였으며,이와 같은 적정 체류시간에 차이는 암모니아성 질소 농도 및 유기물 성상차이에 의한 것으로 보인다. 또한 가축 분뇨 반응조 foam은 혐기 소화 상징액 반응조 foam과 비교하여 발생량은 많지만 빠르게 제거되는 특성을 보였다. 본 연구의 결과는 향 후 아질산화 반응의 하수처리장 적용 시 기초 자료로 이용할 수 있을 것으로 보인다.

It has been known that sewage containing high-concentration nitrogen affects the efficiency of municipal wastewatertreatment plants harmfully. Therefore, research has been actively conducted to treat sewage containing high-concentrationnitrogen. The current study has analyzed organic compounds, conducted foaming tests, and operated a laboratory-levelnitritation reactor with the subjects of anaerobic digester supernatant and livestock wastewater which are the typical kinds ofsewage containing high-concentration nitrogen. According to the results of analyzing organic compounds, soluble inertcomponents form the largest part of anaerobic digester supernatant while particle biodegradable components occupy the mostpart of livestock wastewater. About the retention time proper for the reaction of nitritation, anaerobic digester supernatantshows 2 days while livestock wastewater indicates 6 days. It seems that the difference in the proper retention time isresulted from the difference of properties in organic compounds and ammonium nitrogen concentration. In addition, livestockwastewater’s reactor foam is generated comparatively more than anaerobic digester supernatant’s, but it tends to beeliminated faster. It is expected that the findings of this study can be utilized as foundational data afterwards in applyingthe reaction of nitritation to municipal wastewater treatment plants.

합성섬유를 주 여재로 충진한 실험실 규모의 수직 지하흐름형 습지를 제작하여 인공축산단지 강우유출수 처리시험을 수행하 였다. 3개의 습지에 대하여 수리학적 체류시간은 각각 2, 4, 8일 로 운전하였으며 매일 1회씩 내부순환을 실시하였다. 운전 기간 동안에 매일 일반적인 수질인자에 대하여 모니터링을 실시하였으며 갑자기 HRT에 따라 순차적으로 거품이 발생되면 서 처리수의 COD가 증가하는 현상이 관찰되었다. 따라서 연구의 방향을 거품의 발생원인을 분석하는데 초점을 맞추게 되었 으며 거품의 출처 및 유기물질 농도의 증가는 습지에 충진한 폴리프로필렌 합성섬유가 분해되면서 방출된 것으로 분석되었 다. 거품의 발생 및 유기물질의 농도증가는 질소제거의 효율증가와 밀접한 관련이 있었으며 2가지의 중요한 역할을 수행한 것으로 밝혀졌다. 먼저 거품은 습지내부에서 질산화에 필요한 산소를 억류하면서(hold-up) 질산화를 촉진시키며 거품에 내 재된 유기물질은 탈질에 필요한 탄소원으로 작용한 것으로 판단된다. 따라서 거품발생시기와 질소제거효율이 증가한 시기가 일치한 것으로 보인다. 이후에 거품문제가 사라지면서 질소제거 수준은 서서히 감소하여 이전의 거품이 없던 시기로 회귀하 였다.

A lab-scale vertical flow subsurface (VFS) wetland composed of three parallel columns with polypropylene synthetic fiber as main substrate was operated. Piggery stormwater diluted from swine excreta was fed to the wetland on the basis of three different hydraulic regimes or hydraulic retention time (HRT) of 2, 4, and 8 days with daily internal recirculation. Then, monitoring of common water quality parameters was carried out. Unexpectedly, an increase of effluent COD concentration accompanying the appearance of foams was observed during a distinct period in the wetland with HRT 2, 4, and 8 days, successively. Subsequently, a series of experiments was conducted to investigate the origin of the foams. Foams and the increase of COD concentration were found to be induced by the release of organic matter from the synthetic polypropylene fiber which was fed with piggery stormwater. Meanwhile, nitrogen removal was found to be enhanced during a period which overlapped the distinct foaming period signifying that foaming played two important functions in biological nitrogen removal. Foams which form rapidly and then burst easily could hold up and then release oxygen for nitrification. Foams which contain organic surfactants could serve as carbon sources for denitrification as well. Hence, nitrogen removal was enhanced during the foaming stage. After that, COD concentration decreased slowly to a level prior to the foaming stage, and nitrogen removal efficiency declined as well.

일관제철소 제강공정의 전로 조업시 발생하는 슬래그 폼은 전로 외부로 슬래그가 용출되는 현상으로써 용강의 실수율 저하와 설비이상을 초래할 수 있다. 이러한 슬래그 폼을 억제시킬 수 있는 다양한 진정제가 사용중에 있는데, 본 보고에서는 제지산업에서 발생하는 폐기물인 제지슬러지를 이용하여 슬래그 폼 진정제를 제조하였고 그 효과를 확인하였다. CaO-SiO2-FeO계 슬래그 물성이 폼 발생에 미치는 영향을 모사 실험을 통해 관찰한 결과, 슬래그 염기도 및 슬래그중(FeO) 농도가 증가할수록 슬래그 표면장력 증가와 슬래그중(SiO2) 활량의 저하로 인해 폼 지수()는 감소하였다. 알루미늄 드로스, 코크스, 쌀겨 및 제지슬러지 등 4가지 종류의 슬래그 진정제를 실제 공정에 적용하여 슬래그 폼 진정효과를 관찰한 결과, 알루미늄 드로스가 슬래그 폼 진정효과가 가장 우수하였고 제지슬러지를 이용해 제조한 진정제도 우수한 효과를 나타내었다

Foaming of slag is a thermodynamically unstable phenomenon and has significant effects in iron and steelmaking processes.For better recycling method of pulp sludge, the application as an defoaming agent during steelmaking process was adopted andtested. The forming machine has been modified in order to produce the briquettes, which are made of pulp sludge and slag withfoaming phenomena. Experiments were carried out with CaO-FeO-SiO2 based slags with Ar gas injection and addition of cokeparticles. The slag basicity and (%FeO) contents adapted as major factors to measure foaming tendency of the slag system. Itwas found that foam index (Σ) gradually decreased as both the basicity and the (FeO) content increase. Four kinds of antifoamingagent such as aluminium dross, cokes, rice bran and pulp sludge with steelmaking slag have been tested in actual process. Alu-minium dross was the most effective, and pulp sludge with steelmaking slag also showed the desired results.

전기로 공정은 스크랩을 재활용하여 주원료로 사용하고 아크에 의해 용해하며, 전력을 주 에너지로 사용한다. 슬래그 포밍은 전력에너지 저감에 중요한 요소 기술이다. 투입되는 가탄재(분탄)와 슬래그 중 FeO와의 반응과 용강 중의 카본과 투입되는 산소와의반응에 의해 CO가스가 발생된다. 이러한 반응에 의해 발생된 CO가스는 슬래그에 포집되어 슬래그 포밍 현상이 일어난다. 전기로제강 공정에서 일반적으로 가탄재는 가공분탄(무연탄)과 cokes를 사용하고 있다. 본 연구는 전기로 제강 공정에 사용되는 가탄재에따른 슬래그 포밍의 영향을 조사하였다. 연구 결과 가공분탄 보다는 cokes에 의해 슬래그 포밍 높이가 증가 되었으며, 입도 500 µm 이하의 입자 함량이 증가할수록 포밍높이가 증가하는 결과를 나타내었다. 이러한 결과를 바탕으로 조업에 적용한 결과, 슬래그 포밍높이 증가와 가탄재 원단위 저감, 전력에너지 저감의 효과를 얻었다.

본 연구에서는 PBAT의 가교 개질을 위해 DCP를 도입 하였고 화학발포제인 ADC를 PBAT에 분산시킨 후 압축성형 공정으로 발포제의 분해를 통해 셀을 형성하여 시트 형태의 PBAT 발포체를 제작하였다. FT-IR 분석을 통해 DCP의 분해를 확인하였으며 DCP 함량에 따른 PBAT의 용융 흐름 지수를 비교하여 가교로 인한 용융 점도의 향상 을 확인할 수 있었다. DSC 분석을 통해 열적 특성을 비교 한 결과 Tc의 변화를 확인할 수 있었고 이를 통해 DCP 첨가로 인한 가교 반응의 결과를 확인할 수 있었다. TGA 분석 결과를 통해 DCP의 첨가가 열 안정성의 유의미한 차 이를 야기시키지 않는 것을 확인하였다. 발포 시트의 DCP 함량 별 기계적 물성은 유의미한 차이를 보이지 않았으나 PB_D3에서 다소 낮은 인장강도를 보였으며 PB_D3의 큰 셀 사이즈로 인해 응력 전달에 부정적으로 작용하여 인장 강도 및 연신율이 감소하였을 것으로 판단하였다. DCP 함 량 증가에 따라 발포 셀의 개수는 감소하였으나 평균 셀 사이즈는 증가하였고 가장 큰 PB_D3의 평균 셀 사이즈로 인해 발포 시트의 밀도가 가장 낮게 나타났다. 반면 이러한 큰 셀의 사이즈와 낮은 밀도는 열전도도를 감소시키는 요 인으로 작용하여 PB_D3 발포 시트의 경우 최대 0.066W/ mk 까지 감소시킬 수 있었기에, 단열 특성을 지닌 생분해 성 발포 시트로의 활용에 대한 가능성을 확인할 수 있었다.

Poly (butylene adipate-co-terephthalate) (PBAT) is one of the representative biodegradable polymers with high ductility and processability to replace petroleum-based polymers. Many investigations have been conducted to broaden the applications of PBAT in a variety of industries, including the food packaging, agricultural mulching film, and logistics and distribution fields. Foaming process is widely known technique to generate the cell structure within the polymer matrix, offering the insulation and light weight properties. However, there was no commercially feasible foam product based on biodegradable polymers, especially PBAT, and maintaining a proper melt viscosity of the polymer would be a key parameter for the foaming process. In this study, chemical foaming agent and cross-linking agent were introduced to PBAT, and a compression molding process was applied to prepare a foam sheet. The correlation between cell morphological structures and mechanical and physical properties was evaluated. It was found that PBAT with foam structures effectively reduced the density and thermal conductivity, allowing them to be suitable for applications such as insulation and lightweight packaging or cushion materials.

본 현대사회에서 스트레스는 신체의 항상성을 저해하며, 이로 인한 호르몬의 변화로 각종 피부 트러블이 발생 되고 있다. 그러나 바쁜 현대인들은 피부를 관리할 때 많은 시간을 투자하는 의학적 치료보다 즉각적인 커버 효과를 볼 수 있는 메이크업에 더 큰 관심을 보인다. 따라서 메이크업을 제거하기 위해 피부관리의 기초과정인 세안용 클렌징 제품은 필수 불가결한 품목으로 인식되고 있다. 선행연구에 따르면, 포밍클렌저의 사용률이 2010년 (49.1%), 2022년, (73.7%)로 포밍클렌저를 선호하는 경향이 더욱 강화되었음을 보여준다. Aroma Oil은 후각과 피부를 통해 흡수되어 신체 및 피부에 영향을 미치는 천연 성분으로, 심신안정 및 스트레스 완화와 피부 개선에 효과적이다. 이에 본 연구에서는 Aroma Oil을 함유한 포밍클렌저를 개발하고, EEG 분석을 통해 그 효과를 평가하 였다. 또한, 물리, 화학적 분석과 피부 분석을 통해 품질 및 안전성을 평가하였다. 연구 결과, 제조한 포밍클렌저는 멘탈케어와 피부 개선에 효과적임을 확인하였으며, 이에 본 연구는 향후 클렌징 제품의 기능적 확장을 위한 기초 자료를 제공한다.

Stress in modern society disrupts homeostasis, causing hormonal changes that lead to skin troubles.Busy individuals prefer makeup for quick coverage over medical treatments. Thus, cleansing products are essential for skincare. Studies show foaming cleanser usage increased from 49.1% (2010) to 73.7% (2022). Aroma oil, absorbed through skin and smell, aids relaxation, stress relief, and skin health. This study developed a foaming cleanser with aroma oil and analyzed its effects using EEG. Physical, chemical, and skin tests assessed its quality and safety. Results confirmed its benefits for mental care and skin health, supporting future product development.

Egg white powders (EWPs) were produced after pH adjustment (PH 6-9) of fresh egg white, followed by spray-drying, and foaming and gelling properties of EWPs were examined. EWP produced after pH adjustment to 6.5 (EWP-6.5) resulted in significantly higher foaming ability and gel hardness than control and other pH-adjusted EWP. Significant increases in surface -SH content and surface hydrophobicity of EWP-6.5 coincided with improved foaming ability and gel hardness. Significantly higher consistency index for reconstituted EWP-6.5 indicates unfolding of egg white protein was substantially increased in EWP-6.5. Decreased a-helix content in EWP-6.5 was confirmed by circular dichroism spectral analysis. These results indicate pH adjustment prior to spray-drying leads to structural changes in egg white proteins, significantly affecting major functionalities of EWP

Chestnut flours (CFs) were produced from 3 chestnut samples (Aydin, Kutahya, and Bursa) by 2 different methods (boiled and oven-dried: BOD-CF and freeze-dried: FD-CF). Functional properties and effects of CF addition (10, 20, and 30%) on the qualities of regular and low-fat cookie were investigated. The freeze drying significantly increased water solubility of CFs but decreased their water binding capacity. The emulsion capacity and stability of FD-CFs were higher than those of BOD-CFs. At pH 4, 6, 8, and 10 FD-CFs had better gelation properties. Spread ratio (SR) values of BOD-CF supplemented regular or low-fat cookies decreased with increasing CF levels. Hardness values of CF supplemented regular cookies were generally lower compared to control. SR and hardness values of FD-CF supplemented cookies were higher than those of BOD-CF supplemented ones. Surface colors of the cookies were darker with FD-CF addition as compared to BODCF addition. In low-fat cookies, the sample supplemented with 10% Kutahya FD-CF had the highest taste-flavor value. FDCF supplementation generally resulted in higher appearance and taste-flavor scores than BOD-CF supplementation in cookies.

본 연구에서는 난백의 거품형성능력 및 안정성을 간편하게 평가하기 위한 표준방법을 제시하고자 시료의 양, whipping 속도 및 시간이 거품형성에 미치는 영향을 조사하고 적합한 거품형성조건을 선정하였다. 선정된 조건(시료량 70g, 1,200rpm, 2분)으로 난백의 거품형성능력 및 안정성을 20회 반복 측정하여 평가한 결과 높은 재현성을 나타내었으며 시료의 변화(신선한 난백, 동결건조 난백분말, 상업용 난백분말) 및 계란의 저장기간에 따른 거품형성능력 및 안정성의 유의적 차이를 효과적으로 구별할 수 있었다.

Convenient method for determination of egg white foaming properties was suggested. Highly reproducible results were obtained when 70g egg white was whipped at 1,200 rpm for 2 min. Using standardized testing method, foaming capacity and stability of egg white samples including fresh egg white, freeze-dried egg white and commercial egg white powder were effectively differentiated. Foaming capacity of egg white was not affected during storage of fresh egg white up to 4 weeks at 4℃, whereas foaming stability significantly decreased after 2 weeks of storage.

Metal foam is one of the most interesting materials with various multi-functional properties such as light weight, energy absorption, high stiffness and damping capability. Among them, energy absorption property has keen interests in the field of automotives for passenger protection. Nowadays, researches about pore size and porosity control of the foam are increased to correspond them. However, though energy absorption properties are improved, these results are not cost-effective process. In present research, however, as a part of improving the energy absorption property of metallic foams, 606X aluminum alloy was used for cell wall material which has higher strength than pure aluminum. And its morphological features are characterized. As a results, porosity and pore size are uniformity distribution with increasing foaming temperature in the case of 6061 alloy foams. 6063 alloy foam specimens have opposite tendency because of the influence of alloying element and viscosity of the molten melt.

MIF (Molded-In Foaming) 공법의 발포 거동에 적합한 고분자 기재를 선정하기 위해 SBC (K-resin KK38)와 SBS (KTR 101와 KTR 301)의 유변물성을 측정하였다. SBS의 유변물성 ($G^{\prime}$, $G^{{\prime}{\prime}}$, ${\eta}^*$)은 $155^{\circ}C$와 $170^{\circ}C$의 경우 시간에 따라 유변물성 값의 변화가 거의 없으나, $185^{\circ}C$와 $200^{\circ}C$의 경우에는 시간에 따라 증가하는 것을 볼 수 있었다. 특히, KTR 301의 유변물성 값이 시간에 따라 큰 폭으로 증가하였다. 시간에 따른 유변물성 상승의 정확한 원인을 확인하기 위해 $155^{\circ}C$와 $200^{\circ}C$에서 1800 s 이후의 KTR 301의 비선형 유변물성을 진폭에 대해 측정하였다. $155^{\circ}C$에서는 일반적인 수지와 같은 한 번의 박화(thinning)현상이 관찰되나 $200^{\circ}C$에서는 두 번의 박화현상이 관찰되었고 (Payne effect), 이는 고온에서 SBS가 겔화에 의한 경화가 일어난다고 볼 수 있다. 따라서 이러한 유변물성으로부터 MIF 공법에 요구되는 특성(발포 초기 낮은 점도와 발포 완료 이후 높은 점도)에 적합한 고분자 기재는 SBS KTR 301임을 확인할 수 있었다.

In order to select polymer matrix for MIF (Molded-In Foaming) process, in this study, we investigated rheological properties of commercial polymers, SBC (Styrene-Butadiene Copolymers, K-resin KK38) and SBS (Styrene- Butadiene-Styrene, KTR 101 and KTR 301). In time sweep test, the rheological properties ($G^{\prime}$, $G^{{\prime}{\prime}}$, ${\eta}^*$) of SBS at 155 and $170^{\circ}C$ display almost constant value as a function of time from 0 s to 1800 s. On contrast, the rheological properties of SBS at 185 and $200^{\circ}C$ exponentially increase as a function of time. It could be due to gelation of SBS at high temperature conditions. These increment of rheological properties are not observed in SBC. From LAOS (large amplitude oscillatory shear) test, the nonlinear rheological properties of SBS at 155 and $200^{\circ}C$ after 1800 s are compared. The nonlinear rheological properties at $155^{\circ}C$ show simple strain thinning behavior such as linear homopolymer, however, the nonlinear rheological properties at $200^{\circ}C$ show 2 times strain thinning behavior (Payne effect). It well match with the gelation of SBS at $200^{\circ}C$. From rheological studies, it is confirmed that the proper polymer matrix for MIF process (low rheological properties at initial time and high rheological properties after process) is SBS KTR 301.

1l들이 mass cylinder에 200ml의 맥주를 넣고 질소가스로써 발포시킨 다음 거품이 사라지는 현상을 시간적으로 측정하는 방법을 이용하며 생산공정의 각 단계에서 채취한 맥주를 검사해 본 결과 chillproofing 공정 이후의 맥주에 foaming이 현저히 손상되고 있다는 것을 알았다.

In order to effectively reuse red mud and coal gangue, foam glass was successfully prepared by sintering. The foaming of foamglass is ensured by adding foaming agent, foam stabilizer and fluxing agent to the raw materials including red mud, coalgangue and waste glass. Furthermore, the defects in the foam glass are also reduced. The obtained powder was dried at 105ºC and characterized by XRF, DSC-TG analysis, etc. According to cellular structure, apparent density and water absorption,the optimal type and ratio of foaming agent, foaming stabilizer and fluxing agent were revealed. The results indicate that theoptimized formula of foaming agent, foaming stabilizer and fluxing agent is 3% MnO2-2% Na3PO4-2% borax. The foam glassprepared under optimized conditions exhibits uniform porous distribution and suitable pore size with an apparent density of0.575 g/cm3 and water absorption of 4.61%. The research in this work could establish the technical foundation of red mudbasedporous material for industrial production.

나노보강제의 하나인 아연 메타아크릴레이트 (ZMA)로 보강된 천연고무(NR)/부타디엔고무(BR) 블랜드에 발포제 함량을 달리하여 적용하여 발포거동을 관찰하였다. ZMA 첨가에 따라 전반적인 발포고무의 물성은 향상되었지만, 발포입자크기, 밀도, 발포도 등 발포입자의 모폴로지에는 크게 영향을 미치지 않았다. 발포제의 함량에 따라 발포고무의 기계적 물성은 크게 영향을 받는 것으로 나타났다. 발포제 함량 증가에 따라 발포도가 증가하였고, 이는 발포고무의 밀도감소로 나타났지만, 발포입자의 크기나 분산성은 크게 영향을 받지 않았다. 고함량 스티렌-부타디엔 고무(HSBR)의 영향도 함께 조사하였다. HSBR 함량 증가에 따라 발포입자의 크기는 작아졌고 분산성은 향상되었다. 발포고무는 대변형에서 에너지 흡수성이 뛰어난 것으로 나타났다.

Different amounts of foaming agents were employed in natural rubber(NR)/butadiene rubber(BR) blends to understand the foaming behavior in presence of nano-reinforcing agent, zinc methacrylate (ZMA). The ZMA greatly improved most of the mechanical properties of the rubber foams, however it did not show considerable effect on the cell morphology, such as cell size, density and porosity. It was also observed that the foaming agent concentration affected all the mechanical parameters. When the content of foaming agent was increased, the number of foams was increased leading to a decrease in density of the compounds. But the size and distribution of foams remained unchanged with increased foaming agent. The effect of high styrene-butadiene rubber (HSBR) was also studied. The size of cells became smaller and the cell uniformity was improved with increasing HSBR. The foam rubber compounds showed much efficient energy absorbing capability at higher strains.

Metal foam is one of the most interesting materials with various multi-functional properties such as light weight, energy absorption, high stiffness and damping capability. Among them, energy absorption property has keen interests in the field of automotives for passenger protection. Nowadays, researches about pore size and porosity control of the foam are increased to correspond them. However, though energy absorption properties are improved, these results are not cost-effective process. In present research, however, as a part of improving the energy absorption property of metallic foams, 606X aluminum alloy was used for cell wall material which has higher strength than pure aluminum. And its morphological features are characterized. As a results, porosity and pore size are uniformity distribution with increasing foaming temperature in the case of 6061 alloy foams. 6063 alloy foam specimens have opposite tendency because of the influence of alloying element and viscosity of the molten melt.