Ethanol production from various agricultural and forest residues has been widely researched, but there is limited information available on the use of mixed hardwood for ethanol production. The main objective of this study is to assess the impact of time on the steam explosion pretreatment of waste wood (mixed hardwood) and to determine the convenience of a delignification step with respect to the susceptibility to enzymatic hydrolysis of the cellulose residue and the recoveries of both cellulose and hemicellulosic sugars. Delignification did enhance enzymatic hydrolysis yields of steam exploded waste wood. For steam explosion pretreatment times of 3 and 5 min, the recovery yield of hemicellulosic-derived sugars decreased. The effective hemicellulose solubilization does not always result in high recoveries of hemicellulose-derived sugars in the liquid fractions due to sugar degradation. In the steam explosion pretreatment times of 3 and 5 min, where hemicellulose solubilization exceeded 95%, but sugar recoveries in the liquid fraction remained below 30%. Cellulose to glucose yield losses were less significant than hemicellulosic-sugar losses, with a maximum loss of 24% at 5 min. Up to 80% of the lignin in the original wood was solubilized, leaving a cellulose-rich residue that led to a concentrated cellulose to glucose yield solution (about 50 g/L after 72 h enzymatic hydrolysis in the best case). The maximum overall process yield, taking into account both sugars present in the liquid from steam explosion pretreatment and cellulose to glucose yield from the steam exploded, delignified and hydrolyzed solid was obtained at the lowest steam explosion pretreatment time assayed.
Hierarchically porous carbon foam composites with highly dispersed Fe2O3 nanoparticles confined in the foam pores, facilely fabricated by hydrolysis-driven emulsion polymerization strategy. The as-generated acidic conditions of Fe3+ hydrolysis could catalyze the polymerization of phenolic resin, and the carbon-based composite materials containing iron oxides were obtained in situ. The structural characterization results show that HCF@Fe2O3 NPs-2 electrode has the largest specific surface area (549 m2/ g) and pore volume (0.46 cm3/ g). Electrochemical results indicates that typical HCF@Fe2O3 NPs-2 electrode displays good capacitive properties. including high specific capacitance (225 F/g at 0.2 A/g current density). Excellent magnification performance (capacity retention rate 80% as current density increases from 0.2 to 10 A/g). At the same time, HCF@SnO2 NPs was successfully synthesized by replacing hydrolyzed tin tetrachloride with ferric chloride. This study provides a new idea for the preparation of metal oxide–carbon matrix composites, and also highlights the potential of such carbon foams in application of energy storage.
본 연구는 생후 12개월령의 염소를 사용하여 앞다리, 뒷 다리, 등심 및 갈비 부위로 분할하여 in vitro 소화실험을 통해 부위별 단백질 가수분해도 및 아미노산 조성을 조사 하였다. 이 때, 소고기 및 돼지고기의 분할육을 이용하여 염소고기와 비교, 분석하였다. 염소고기 분할육 중 뒷다리 (8.32%) 및 갈비(8.32%)가 가장 높게 단백질 가수분해도가 나타났으며, 염소고기의 갈비 부위는 갈비 분할육 중 가장 높은 단백질 가수분해율을 보였던 돼지고기(8.57%)와 유의 차가 없었다 (P>0.05). In vitro 소화 전에는 염소고기 분할 육 중 등심에서 글리신(11.03%)이, 앞다리에서 글루타민 (53.44%)이 다른 고기 종류 및 분할육들에 비해 유의적으 로 높은 비율로 포함된 것이 확인되었다(P<0.05). In vitro 소화 후에는 염소고기 갈비 부위에서 라이신(17.54%)이 가 장 높은 비율로 포함된 것으로 확인되었으며, 소 갈비 부 위보다 유의적으로 높았다(P<0.05). 본 연구는 염소고기 분 할육의 단백질 가수분해도 및 아미노산 조성을 제공하며 단백질 소화양상 및 생체 이용률을 평가하기 위한 기초 자 료로써 활용되어질 수 있을 것으로 사료된다.
With respect to the geologic repository, intrusion of groundwater has been considered as a major factor that can transfer radionuclides to the natural environment. Moreover, the migration of radionuclides in the natural groundwater system is significantly influenced by the interaction between the radionuclides and groundwater constituents. Among various hydrogeochemical reactions, hydrolysis is one of the major reactions that can affect the aqueous solubility of radionuclides. Therefore, a precise understanding of relevant chemical thermodynamic behavior is of cardinal importance for the reliable prediction of migration/retardation behavior of radionuclides in the natural groundwater system. The objective of the present work is to investigate the solubility behavior of Nd(OH)3(s) to provide relevant chemical thermodynamic data of Nd(III) as a chemical analogy of major radiotoxic elements such as Am(III) and Cm(III). All the experiments were performed with Ar gas-filled glovebox under inert atmospheric condition. The aqueous Nd(III) solution was prepared by dissolution of 0.5 g NdCl3·6H2O (Sigma-Aldrich) in 10 ml of deionized water. The Nd(III) solid phase was precipitated by dropwise addition of ca. 10 ml of 4 M NaOH (Sigma-Aldrich). The Nd(III) precipitate was identified to be crystalline Nd(OH)3(s) nanorod by using XRD and TEM. For the solubility experiment, the solid Nd(OH)3(s) was equilibrated at the pH range from 5.0 to 9.0 at 0.1 M NaCl condition. The total concentration of the Nd(III) was quantified by using UV/Vis absorption spectroscopy and ICP-MS after the phase separation. In the present work, the solubility behavior of the solid Nd(OH)3(s) phase was investigated by using colorimetric analysis. The chemical thermodynamic data obtained in this study are expected to enhance the reliability of solubility prediction for the trivalent lanthanides and actinides.
Fescues, which are widely cultivated as grasses and forages around the world, are often naturally infected with the endophyte, Epichloë. This fungus, transmitted through seeds, imparts resistance to drying and herbivorous insects in its host without causing any external damage, thereby contributing to the adaptation of the host to the environment and maintaining a symbiosis. However, some endophytes, such as E. coenophialum synthesize ergovaline or lolitrem B, which accumulate in the plant and impart anti-mammalian properties. For example, when livestock consume excessive amounts of grass containing toxic endophytes, problems associated with neuromuscular abnormalities, such as convulsions, paralysis, high fever, decreased milk production, reproductive disorders, and even death, can occur. Therefore, pre-inoculation with non-toxic endogenous fungi or management with endophyte-free grass is important in preventing damage to livestock and producing high-quality forage. To date, the diagnosis of endophytes has been mainly performed by observation under a microscope following staining, or by performing an immune blot assay using a monoclonal antibody. Recently, the polymerase chain reaction (PCR)-based molecular diagnostic method is gaining importance in the fields of agriculture, livestock, and healthcare given the method’s advantages. These include faster results, with greater accuracy and sensitivity than those obtained using conventional diagnostic methods. For the diagnosis of endophytes, the nested PCR method is the only available option developed; however, it is limited by the fact that the level of toxic alkaloid synthesis cannot be estimated. Therefore, in this study, we aimed to develop a triplex real-time PCR diagnostic method that can determine the presence or absence of endophyte infection using DNA extracted from seeds within 1 h, while simultaneously detecting easD and LtmC genes, which are related to toxic alkaloid synthesis. This new method was then also applied to real field samples.
Hydrolyzed proteins have an advantage over intact proteins in terms of their rate of digestion and absorption. The high-pressure enzymatic extraction (HPE) method has been shown to improve the quality characteristics of hydrolysates from Protaetia brevitarsis seulensis (Kolbe) larvae (PBSL). This study investigated the effects of the HPE treatment period, a key candidate factor, on the quality characteristics of PBSL HPE hydrolysates. The hydrolysates were prepared by HPE for 0, 12, 18, 24, 30, and 36 h under optimized conditions—solid:solvent ratio (1:14 [w/v]), using complex proteases (Alcalase:Flavorzyme:Bromelain = 1:1:1, 4%), treatment temperature (50oC), and pressure level (100 MPa). All quality characteristics tended to be superior with longer HPE treatment periods, most of which had the highest values at 30 h, with no significant difference or a slight decrease after that. The quality characteristics of the PBSL HPE hydrolysates were improved by 1.3-1.7 times under conditions of optimal HPE treatment period.
수산화인회석은 생체적합성이 뛰어나기 때문에 생체재료로 사용되고 있다. 본 연구에서는 온도, 농도, pH를 조절하여 인산수소칼슘 중간체의 가수분해반응을 통해 c면이 배향된 수산화인회석을 합성하였다. 염기조건에서 전구체의 농도가 낮을 경우 막대 형태의 수산화인회석 결정이 모여 불규칙한 형태의 입자를 만들었고 농도가 높을 경우 수산화인회석결정의 c면이 노출된 판 형태의 입자를 만들었으며 이에 따라 입자의 제타전위 차가 3 mV가 되었다. 생성물의 물리화학적 특성은 XRD, SEM, FT-IR, 제타전위측정기를 통해 평가하였다.
연료 전지 구동 시 전기화학적 활성은 촉매와 연료, 전해질이 만나는 삼상계면에서 일어나며 연료전지의 성능은 이 삼상계면의 수에 영향을 받는다. 인산이 도핑된 Polybenzimidazole (PA-doped PBI)을 기반으로 한 고온 고분자 전해질막 연료전지 (HT-PEMFC)의 경우 막 내의 인산이 전해질의 역할을 하며 삼상계면 및 연료전지의 성능에 영향을 끼친다. PBI 막 내의 인산은 고분자 합성 용매인 폴리인산의 가수분해에 의해 생성된다. 본 연구에서는 Sol-Gel 법(Direct casting 법)으로 제조된 PA-doped PBI 막의 가수분해 조건을 달리하여 이에 따른 연료전지의 성능을 비교하여 보았다.
The purpose of this study was that the optimal hydrolysis conditions of endo- and exo-type enzymes were selected to utilize organic cheese byproducts. Optimal substrate concentration and optimum enzyme ratio were measured by using 4 kinds of endo-type enzymes (alcalase, neutrase, protamex, and foodpro alkaline protease) and two exo-type enzymes (flavourzyme and prozyme 2000P) for whey protein hydrolysis were analyzed using liquid chromatography. As a result, the optimal endo-type enzyme through the first enzyme reaction was selected as alcalse, and as a result of the secondary enzyme reaction, flavourzme was selected as the Exo type enzyme. The concentration of whey protein substrate for optimal primary and secondary enzyme reactions was 10%. In addition, the optimum ratio of enzyme was 0.5% of alcalase and 0.2% of flavourzyme, which showed low molecular weight chromatography pattern compared to 2% of alcalase and 1% of flavourzyme hydrolyzate. Therefore, hydrolyzing the endo-type enzyme alcalase at a concentration of 0.5% for 10 hours and then hydrolyzing the exo-type enzyme flavouryme at a concentration of 0.2% for 4 hours was considered to be the optimum condition.
본 연구에서는 piperazine 기반 상용화 된 NE70 분리막 표면 성분인 아마이드기가, 산 가수분해 이후 생성된다고 알려져 있는 카르복실과 아민기에 대한 분석을 하고자 한다. 실험 방법으로 15 w/v% 황산 수용액 조건에서 7일간 노출 전/후의 NE70 분리막을 ToF-SIMS 기기를 이용하여 카르복실산과 아민기를 포함하는, Molecular weight이 120 미만인 이차이온들을 비교하였다. 또한, 상대적으로 내산성이 있는 m-phenylene diamine 기반 상용화 된 NE90 분리막을 15 w/v% 황산 수용액 조건에서 63일간 노출 전/후 샘플을 비교군으로 두어 NE70 분리막에서 발생 되는 peak intensity 차이는 산 가수분해로 인해 발생한 것임을 추가로 확인 하였다.
화석연료 사용에 의한 환경문제의 해결을 위한 방법의 하나로 수소에너지에 대한 연구가 활발히 진행되고 있다. 물을 분해에 의한 수소 제조는 전기분해, 광화학적, 열화학적, 생물학적 방법 등이 있다. 물의 전기분해 기술은 전기를 이용하여 수소를 물로부터 직접 제조하는 방법으로 지구오염물질인 이산화탄소의 배출이 없는 것이 특징이다. 특히, 물의 전기분해 방법 중에서 알칼리 수전해는 오래전부터 알려진 수소제조 방법으로 전해액으로 ∼30 wt%의 KOH수용액 또는 ∼20 wt%의 NaOH수용액을 사용하며, 셀은 수산화이온 (OH-) 만을 선택적으로 통과시키는 격막, 수소와 산소를 발생시키는 전극으로 구성된다. 최근에는 양.음이온교환막의 발 전과 더불어 전해효율이 60% 이상에 이를 만큼 분리막의 중요성이 부각되고 있다.