Short Aging Period Research Articles

Engineering crystal network of supramolecular Oleogel via kinetical regulation for improved lutein bioaccessibility

This study presented an approach for controlling supramolecular oleogel crystal network by regulating kinetical factors - specifically, a combination of cooling temperature and aging period. Results indicated that only under long aging period, supramolecular oleogels prepared at different cooling temperature exhibited distinct crystal morphology compared to those under short aging period. The physicochemical properties of oleogels were affected by different crystal networks. Therefore, further research on oleogels under longed aging was explored. For lutein encapsulation, it was observed that supramolecular oleogels with denser crystal network exhibited higher lutein bioaccessibility. This was probably because the denser crystal network providing a solid physical barrier that effectively protected lutein unaffected by gastric acid degradation. Additionally, the micellar capacity was also enhanced to accommodate lutein due to release of long chain fatty acid from the gelator glycerol monostearate (GMS). Collectively, kinetical factors regulation facilitated rational design of oleogels for delivery of lipid-soluble bioactive compounds.

Entry pathways determined the effects of MPs on sludge anaerobic digestion system: The views of methane production and antibiotic resistance genes fates

Sludge is one of the primary reservoirs of microplastics (MPs), and the effects of MPs on subsequent sludge treatment raised attention. Given the entry pathways, MPs would exhibit different properties, but the entry pathway-dependent effect of MPs on sludge treatment performance and the fates of antibiotic resistance genes (ARGs), another high-risk emerging contaminant, were seldom documented. Herein, MPs with two predominant entry pathways, including wastewater-derived (WW-derived) and anaerobic digestion-introduced (AD-introduced), were used to investigate the effects on AD performance and ARGs abundances. The results indicated that WW-derived MPs, namely the MPs accumulated in sludge during the wastewater treatment process, exhibited significant inhibition on methane production by 22.8%–71.6%, while the AD-introduced MPs, being introduced in the sludge AD process, slightly increased the methane yield by 4.7%–17.1%. Meanwhile, MPs were responsible for promoting transmission of target ARGs, and polyethylene terephthalate MPs (PET-MPs) showed a greater promotion effect (0.0154–0.0936) than polyamide MPs (PA-MPs) (0.0013–0.0724). Compared to size, entry pathways and types played more vital roles on MPs influences. Investigation on mechanisms based on microbial community structure revealed characteristics (aging degree and types) of MPs determined the differences of AD performance and ARGs fates. WW-derived MPs with longer aging period and higher aging degree would release toxics and decrease the activities of microorganisms, resulting in the negative impact on AD performance. However, AD-introduced MPs with short aging period exhibited marginal impacts on AD performance. Furthermore, the co-occurrent network analysis suggested that the variations of potential host bacteria induced by MPs with different types and aging degree attributed to the dissemination of ARGs. Distinctively from most previous studies, the MPs with different sizes did not show remarkable effects on AD performance and ARGs fates. Our findings benefited the understanding of realistic environmental behavior and effect of MPs with different sources.

Pilot plant study for management of toxic solid waste collected in landfill of spent lubricant oil refinery by conversion into zeolite packed bed via continuous extrusion and fusion techniques

The pilot plant extrusion was successfully utilized to manage a clay based solid waste deposited in the landfill of spent oil refinery through the conversion into the rod-like zeolite with LTA (Linde Type A) structure. The research was designed in combination with fusion, and hydrothermal processes to produce a packed bed with appropriate cation exchange capacity (CEC). However, the conversion of waste into the proper zeolite structure was the challenge of study due to lack of aluminum. To address this issue, boehmite, and sodium hydroxide were added to solid waste for compensation of aluminum lack before extrusion. The extrudates were further consolidated by fusion at 800 °C, and then were converted into zeolite LTA by control of aging, and reaction periods in the hydrothermal step. The crystallinity, microstructure, and textural characteristics of waste, and fabricated rods were studied to examine the capability of process. The results revealed that the rod fabricated through the short aging period, 3 h, and longer reaction time, 9 h, represents the minimal CEC due to the recrystallization of hydroxysodalite. Although the textural characteristics of zeolites were found to be slightly affected by extrusion, the aging, and reaction periods of 9, and 6 h are beneficial to produce a packed bed with proper CEC, 214 mg g−1, demonstrating the potential of innovated technique.

Evolution of UV/VIS Photoluminescence of Aged Zn(acac)2 Solutions in Correlation with Carbon Precipitation

Evolution of photoluminescence of ethanol solutions of Zn(acac) from near UV to VIS was monitored for time period of several months. It has been found that transparent solutions with time colored in light brown that is accompanied by development of strong visible photoluminescence. This phenomenon is analyzed and discussed in terms of carbon precipitation. It has been demonstrated that at short aging period the photoluminescence is observed as relatively narrow and excitation independent emission band centered at at about 400 nm. In course of aging period emission is converted from violet to blue and green with corresponding shift of excitation band from UV to VIS. Electron paramagnetic resonance spectroscopy allows to identify carbon precipitates in the solutions approving hypothesis on nanocarbon nature of the photoluminescence.

New insights into the effects of aging on Portland cement hydration and on retarder performance

To gain a better understanding of the aging impact on the mechanisms of cement hydration, a Portland cement was intentionally exposed to moist air under controlled conditions. This resulted in the formation of nanoscale ettringite needles on the particle surfaces which act as seeding materials, thereby accelerating setting. The subsequent ettringite overgrowth of cement particles slows water access to the silicate phases, thus retarding strength development. The effectiveness of gluconate and pyrophosphate retarders against this accelerated hydration is limited at short aging periods, but sharply increases towards prolonged aging times when the ettringite seeds are carbonated by atmospheric CO2.

Effect of Superpave Short-Term Aging on Binder and Asphalt Mixture Rheology

This study aimed to evaluate the effect of Superpave short term aging period length and type of additive used in modifying the asphalt binder on the creep behavior of asphalt binder and asphalt mix. Hot-mix asphalt (HMA) specimens were prepared at optimum asphalt content using unmodified asphalt, or asphalt with 4% by weight of SBS or PE. The Universal Testing Machine was used to conduct dynamic creep tests. Tests results indicated that the effect of extending the aging period on creep deformation is highly dependent on type of additive used in preparing the asphalt mix. Extending the aging period more than three hours caused insignificant effect of creep behavior of control asphalt mixes. On the other hand, extending the aging period more than one hour caused insignificant effect of creep behavior of asphalt mixes prepared using SBS additive. While for mixes prepared using PE, the creep deformation continues to decrease as aging period increase.

Legal control over substances that can have a significant impact on a person s life, body or health

위해성이 잠재된 위험물질들(한계물질)은 그 안전성이 완전하게 증명되지는 않았음에도 불구하고 필요에 의해서 허용될 수밖에 없지만 그 손해 위험성이 크기 때문에 일반적인 물질들과는 달리 취급되어야 한다. 첨단과학물질문명의 발달로부터 인간의 생명·신체·건강을 지키는 가장 현실적인 방법 중 하나는 사전에 그 물질에 대하여 잘 아는 사업자(개발특허권자, 생산자, 유통업자 등을 포함)로 하여금 공법상의 정보제공의무와 더불어 일반인이나 계약당사자에게 정보제공을 하도록 의무지우는 방법이다. 유럽연합은 소비자지침 등에서 구체적인 정보제공의무를 규율하기 시작하였는데, 최근에는 공통기준초안(DCFR)이나 유럽공통매매법(CESL)에서 소비자지침을 업그레이드하여 구체적인 규정을 마련하고 있다. 정보에 대한 권리는 소비자의 지위를 강화시키기 위해 사용되는 가장 중요한 도구들 중의 하나로 간주된다. 정보의무를 위반한 당사자 일방은 그 불이행으로 상대방 당사자에게 발생한 모든 손해에 대하여 책임이 있다. 규범목적설에 따르면 위법성요건은 손해배상책임을 획정하는데 기여할 뿐만 아니라 범위를 획정하는데 기여한다. 정보제공의무 위반은 발생된 손해에 대하여 위법성을 징표하고 이러한 위법성 징표는 위험책임론에 입각하여 인과관계의 명확한 증명이 없더라도 추정과 입증전환에 의하여 그 특별법의 규범취지를 달성할 수 있는 것이다. 잠재적 위험물질의 특성상 그 위험의 현실화로 인한 인신손해에 따른 손해배상청구권의 소멸시효기산점과 그 최장기간은 다른 재산상의 손해와 구별되어야 한다. 석면이나 의료과오에 의한 피해사건에서 학설은 이들 채권을 다른 것과 구별하는 것을 정당하다고 본다. 이러한 특별취급은 한계물질에 의한 손해가 명백해질 때까지 장기간을 경과하는 경우가 많은 점, 생명·신체·건강과 같은 신체적 완전성은 특히 법적보호에 가치가 있다는 점, 일반적으로 인신손해는 재산상의 손해에 비해서 훨씬 중대하다고 생각되고 있다는 점에서 그 정당성이 부여된다. 잠재적 손해 등의 기산점계산이 어렵다는 점을 고려하여 시효기간의 기산점을 손해의 발생과 상관없이 결정하는 방식을 생각할 수 있다. 여기서 생각할 수 있는 기준은 채권자의 인식가능이다. 채권자는 채권에 대하여 알고 있었든지 아니면 적어도 합리적으로 보아 알아야 했다고 할 수 없으면 안 된다. 인식가능성 기준의 중요성은 비교적 짧은 일반적 시효기간이 정해져 있는 경우에 더욱 두드러진다. 단기의 시효기간 및 채권의 소멸시효제도 자체는 주로 채무자의 보호를 의도한 것이지만, 인식가능성 기준은 채권자의 합리적인 이익을 고려하여 양당사자의 균형을 도모하는데 필수적이다. 어찌되었든 잠재적 위험물질로 인한 인신손해에 대해서는 30-40년의 최장상한기간을 생각하는 것이 합리적이라 판단된다.Although its safety has not been fully demonstrated, potentially hazardous substances is bound to be allowed by necessity and demand. But potentially hazardous substances should be handled differently from common materials bacuse the risk of its damage is large. One of effective way to protect human life, body, healthfrom the development of advanced scientific material civilization is that Operators(Including development patents, producers, distributors, etc.) who are familiar with the substance in advance are to oblige the public or contracting party to provide information. The European Union has begun to regulate specific information obligations in consumer guidelines and recently has set specific regulations in DCFR and CESL. The right to information is regarded as one of the most important tools used to enhance consumer status. A party who has violated information obligations is liable for any loss caused to the other party by such violate. By normative purpose theory illegality requirements contribute. Violation of the obligation to provide information marks the illegality of the damages incurred. This illegal token, even if there is no clear proof of causation, is possible to achieve the purpose of the special law by presumption and conversion of evidence with the help of risk accountability theory. The expiration date of the right to claim for damages due to the realization of the risk and the longest period of time should be distinguished from the damages on other property because of the nature of the potential hazardous materials. In the case of asbestos or medical malpractice, the doctrine justifies distinguishing these bonds from the others. The reason for treating them differently are that there is often a long latency period and that life, health and the bodily integrity in general are particularly valuable objects of legal protection and person injuries are generally regarded as more serious than property damage or economic harm. It is possible to consider the method of determining the starting point of the statute regardless of the occurrence of the damage considering that it is difficult to calculate the starting point of potential damage etc. The criteria we can think of here are creditor s perceptions. The creditor must be able to say that he knew about the bond or at least he should know it rationally. The importance of the recognizability criterion is more pronounced when a relatively short general aging period is established. The short-term aging period and the statute of limitations of the bonds themselves are mainly intended to protect the debtor. But recognition criteria are essential to balance the two parties, taking into account the reasonable interests of creditors. In any way it is reasonable to think of the maximum period of 30-40 years for damage caused by potential hazardous materials.

Influences of humidity and temperature on oil contamination discharge of HV motor stator windings

The leaking oil, as one typical contamination in stator windings of high voltage motor, will corrode stator winding and be dissolved in the grounding insulation layer. The oil contamination could lead to the stratification of insulation, the reduction of dielectric strength and the occurrence of partial discharge. In order to investigate the influence rules of humidity and temperature on oil contamination discharge of stator windings, two discharge winding models with oil contamination were made. At twice the rated line-to-earth voltage of 6 kV, two windings were aged for 240 hours under different relative humidity and temperatures, respectively. The phase resolved partial discharge (PRPD) patterns were monitored and analyzed during the short aging period. The experiment results confirm that temperature and ambient humidity have a significant impact on the oil contamination discharge of winding. The PD intensity of oil contamination increases with the rise of temperature. The creeping phenomenon will take place at the higher relative humidity. In addition, it will provide a judging basis for the on-line monitoring and fault diagnosis of the 10 kV three-phase asynchronous motors.

Dynamic Interactions between a Silica Sphere and Deformable Interfaces in Organic Solvents Studied by Atomic Force Microscopy

Recent studies have successfully measured surface forces using atomic force microscope (AFM) and modeled surface deformations using the Stokes-Reynolds-Young-Laplace (SRYL) equations for particle-droplet, particle-bubble, droplet-droplet, and bubble-bubble systems in various solutions. The current work focuses on interactions between spherical silica particles and a viscoelastic interface of water droplets in crude oil. The self-assembly of surface active natural polyaromatic molecules (NPAMs) at the oil-water interface has previously been shown to change a viscous dominant oil-water interface to an elastic dominant interface upon aging, due to gradual formation of rigid interfacial networks. AFM was used to measure the interactions between a small silica sphere (D ≈ 8 μm) and a deformable water droplet (D ≈ 70 μm), which exhibits time-dependent interfacial viscoelasticity in NPAM solutions. Unlike the systems studied previously, the measured deformation shown as a repulsive force over the region of constant compliance could not be modeled adequately by the conventional SRYL equations which are applicable only to purely Laplacian interfaces. As the water droplet ages in NPAM solutions, a rigid "skin" forms at the oil-water interface, with the interface exhibiting increased elasticity. Over a short aging period (up to 15 min in NPAM-in-toluene solution), interfacial deformation is well predicted by the SRYL model. However, upon further exposure to the NPAM solution, droplet deformation is overpredicted by the model. Physical properties of this mechanical barrier as a function of interfacial aging were further investigated by measuring interfacial tension, dilatational rheology, and interfacial "crumpling" (non-smooth, non-Laplacian interface) upon droplet volume reduction. By introducing a viscoelasticity parameter to account for interfacial stiffening and using experimentally determined elasticity, we are able to correct this discrepancy and predict droplet deformation under AFM cantilever compression. This parameter appears to be important for modeling non-Laplacian systems of significant viscoelastic contributions, such as biological cell membranes or polymer blends.

Attaching Redox Proteins onto Electrode Surfaces by using bis‐Silane

AbstractImmobilization of redox proteins on electrode surfaces is of special interest for mechanistic studies and applications, because of the well‐controlled redox state of protein molecules at a polarized electrode and fast electron‐transfer kinetics that are free from diffusion limitation. Here, bis‐organosilane [1,2‐bis(trimethoxysilyl)ethane] was used as a fresh solution in a pH 7 phosphate buffer without the use of any organic solvent, sol‐gel, or mesoporous bulk matrix. A short aging period of 30 min before deposition on the electrodes was optimal for the immobilization of proteins. Three redox proteins (cytochrome c, neuroglobin, and GLB‐12) were confined to the gold surface of electrodes with high coverages and stabilities, indicating that the suggested technique is simple, efficient, and generic in nature.

Acidity and catalytic performance of Yb-doped [formula omitted]/Zr in comparison with [formula omitted]/Zr catalysts synthesized via different preparatory conditions for biodiesel production

Highly efficient, robust and mesoporous sulfated zirconia, SZ catalysts were prepared by co-precipitation and incipient-wetness routes with sufficient and in-excess acid. The study investigated the effect of pH, precursor type, and concentration, on SZ and compared their acidity and performance with ytterbium-doped SZ toward transesterification. N2 sorption, elemental analysis, XRD, and ammonia temperature-programmed desorption (NH3-TPD) revealed the properties of the catalytic materials. The specific surface area increases independently of the presence of Ti up to 60.33 m2/g, with increasing pH while pore size of the tetragonal crystallites decreases from 37.04 to 6.83 nm. Soaking the material in sufficient 0.5-M H2SO4 produced 37.04 nm SBET in contrast to 21.21 nm from soaking in excess. Double sulfation ensured sulfate incorporation while moderate precursor amounts enhanced activity of the materials. Interestingly, despite low specific surface area, which was due to short aging period, large mesoporosity, high amount, and dispersion of active sites on Yb-doped SZ, SZr-Ti-Yb-500-4/s ensured remarkable activity. The catalyst converted ca. 99% of used frying oil containing ca. 48 wt. % FFA. Consequently, this highlights the prospect of producing biodiesel at lower cost especially with current dwindling price of crude oil.

A novel conversion process for waste residue: Synthesis of zeolite from electrolytic manganese residue and its application to the removal of heavy metals

Abstract The zeolite material was first synthesized from electrolytic manganese residue (EMRZ), by a two-step synthetic procedure using NaOH and NaAlO2 within a short aging period. Based on the detailed analyses using XRD, FT-IR, FE-SEM, XRF, CEC and BET surface area measurement, the product synthesized at Si/Al ratio = 1.5 was mainly composed of Na-A zeolite with a specific surface area of 35.38 m2 g−1. Then, the removal characteristics of Mn2+ and Ni2+ ions by EMRZ were investigated under various operating variables like contact time, solution pH and initial metal concentration. The adsorption equilibrium for both Mn2+ and Ni2+ was best described by the Langmuir model, confirming the applicability of monolayer coverage of metal ions onto EMRZ particles. The maximum sorption capacities for Mn2+ and Ni2+ shown by EMRZ were 66.93 mg g−1 and 128.70 mg g−1, respectively. It was also found that adsorption of Mn2+ and Ni2+ by EMRZ followed second-order kinetics and rate constants for Mn2+ and Ni2+ sorption were found to be 0.001091 and 0.005668 g mg−1 min−1, respectively at 30 °C. These results indicate that the synthesized EMRZ is a promising and low-cost adsorbent for removing heavy metals from wastewater due to higher adsorption capacity than other adsorbents.

Advances in Wine Aging Technologies for Enhancing Wine Quality and Accelerating Wine Aging Process

Wine aging is an important process to produce high-quality wines. Traditionally, wines are aged in oak barrel aging systems. However, due to the disadvantages of the traditional aging technology, such as lengthy time needed, high cost, etc., innovative aging technologies have been developed. These technologies involve aging wines using wood fragments, application of micro-oxygenation, aging on lees, or application of some physical methods. Moreover, wine bottling can be regarded as the second phase of wine aging and is essential for most wines. Each technology can benefit the aging process from different aspects. Traditional oak barrel aging technology is the oldest and widely accepted technology. The application of wood fragments and physical methods are promising in accelerating aging process artificially, while application of micro-oxygenation and lees is reliable to improve wine quality. This paper reviews recent developments of the wine aging technologies. The impacts of operational parameters of each technology on wine quality during aging are analyzed, and comparisons among these aging technologies are made. In addition, several strategies to produce high-quality wines in a short aging period are also proposed.

RETRACTED ARTICLE: Precipitation behavior of Al-Ti-Ag alloy system

Transmission electron microscopy (TEM) examinations of Al3Ti with an L12-ordered structure have revealed the precipitation of D023-Al11Ti5 and L10-TiAl upon aging after quenching from higher temperatures. TEM observations revealed that fine uniform precipitation of Al2Ti occurs when the supersaturation is sufficiently high, and, a preferential precipitation at the antiphase boundaries can be observed in alloy with a low supersaturation. When L12-Al3Ti is supersaturated with DO22-Al3Ti, DO23-Al11Ti5 with a multidomain structure is formed during aging. On the other hand, plate-like L10-TiAl precipitates lie on the {001} planes of (Al,Ag)3Ti matrix in the short aging period and the habit plane changed from {001} to {hhl} after a long period aging or higher temperature aging and finally to {225} of the matrix lattice. The Ll2 phase field in the Al-Ti-Ag system is severely skewed with respect to the temperature axis and is restricted into a much smaller field at lower temperatures. Appreciable hardening and overage softening during aging can be explained in terms of microstructural variations.

Effects of high pressure on anhydrous milk fat crystallization in emulsion

Anhydrous milk fat crystallization was compared either in bulk phase or in oil in water emulsion by studying melting curves obtained by calorimetry measurements. Emulsions were submitted to a high pressure (HP) treatment (200 MPa/10 min). An aging period of 72 h was required to obtain the highest amount of crystallized fat at 4 °C. Emulsification promoted the crystallization of low melting point (LMP) triglycerides. The effect of HP on anhydrous milk fat crystallization depended on the aging time. For short aging periods (30 min and 1 h), HP treatment favored the crystallization of LMP triglycerides, thus amplifying the effect of emulsification compared with the crystallization in bulk phase. However, for a long aging time, i.e. 48 h, the amounts of crystallized matter in emulsion with or without HP treatment were comparable. This result was interpreted in terms of a different polymorphic form crystallizing under HP.

브랜드 한우고기 연도 조사 - 2007 : 육질등급 및 소분할 부위별 전단력 평가

본 연구는 시판중인 브랜드 한우고기의 연도 조사를 위하여 13개 브랜드 한우고기 판매점에서 3개 등급(육질 <TEX>$1^{++}$</TEX>, <TEX>$1^+$</TEX>, 1등급)과 8개 소분할 부위별로 구입한 한우고기의 전단력을 분석하였다. 브랜드 한우고기 육질 <TEX>$1^{++}$</TEX> 등급, <TEX>$1^+$</TEX> 등급, 1등급의 숙성기간 분포비율은 7일 미만이 37.5, 45.8, 36.4% 였고, 7일-13일이 26.6, 47.2, 36.4%였으며, 14일-20일이 31.3, 4.2, 25.8%였다. 브랜드 한우고기 판매장의 냉장고 온도는 평균 <TEX>$2.27-2.42^{\circ}C$</TEX> 범위였다. 안삼실, 윗등심살, 채끝살, 도가니살과 홍두께살에서 육질 <TEX>$1^{++}$</TEX>등급이 육질 1 등급보다 연하였다(p<0.05). 브랜드 한우고기 육질 <TEX>$1^{++}$</TEX> 등급, <TEX>$1^+$</TEX> 등급, 1 등급의 소분할 부위 중 안심살의 전단력가가 각각 2.56, 2.76, 3.10 kg로 가장 연하였고, 각 육질등급에서 도가니살이 4.76 kg,홍두께살이 4.96 kg, 보섭살이 5.66 kg로 가장 질긴 것으로 나타났다(p<0.05). 육질 <TEX>$1^{++}$</TEX> 등급의 브랜드 한우고기 소분할 부위에서 전단력가 3.9 kg 이하의 분포비율은 안심살과 채끝살이 100%, 윗등심살과 보섭살이 각각 87.5, 62.5%인 반면 전단력가 4.6 kg 이상 분포비율은 흥두께살과 도가니살이 각각 50%였다. 육질 <TEX>$1^+$</TEX> 등급의 브랜드 한우고기 소분할 부위에서 전단력가 3.9 kg 이하 분포비율이 안심살과 윗등심살이 100%, 채끝살과 꾸리살이 각각 44.4%였고, 전단력가 4.6 kg 이상 분포비율은 홍두께살, 도가니살, 보섭살이 각각 66.7, 55.6, 44.4%를 차지하였다. 육질 1등급의 브랜드 한우고기 소분할 부위에서 전단력가 3.9 kg 이하 분포비율은 안심살과 채끝살, 윗등심살이 각각 88.9, 62.5, 44.4%인 반면에 전단력가 4.6 kg 이상 분포비율은 도가니살이 100.0%, 홍두께살, 꾸리살, 뭉치사태가 각각 62.5, 62.5, 55.6%로 나타났다. 이상의 결과를 종합하면, 시판 브랜드 한우고기는 숙성기간이 짧고, 전단력가 4.6 kg 이상 분포비율이 높은 것으로 나타났다. Eight subprimal cuts purchased from the branded Hanwoo beef of 3 quality grades (<TEX>$1^{++}$</TEX>, <TEX>$1^+$</TEX>, 1) at 13 stores were evaluated the tenderness using Warner-Bratzler shear (WBS). The beef frequency ratio (%) depending on postmortem aging periods were investigated. The 37.5 (quality grade <TEX>$1^{++}$</TEX>), 45.8 (quality grade <TEX>$1^+$</TEX>), and 36.4% (quality grade <TEX>$1^{++}$</TEX>) of branded beef were aged for < 7 d, 26.6 (quality grade <TEX>$1^{++}$</TEX>), 47.2 (quality grade <TEX>$1^+$</TEX>) and 36.4% (quality grade 1) were aged for <TEX>$7{\sim}13$</TEX> d, and 31.3 (quality grade <TEX>$1^+$</TEX>), 4.2 (quality grade <TEX>$1^+$</TEX>) and 25.8% (quality grade <TEX>$1^+$</TEX>) were aged for 14 to 20 d. The temperature of cold room in stores was ranged average 2.27 to <TEX>$2.42^{\circ}C$</TEX>. WBS values for ansimsal (tenderloin), witdngsimsal (ribeye), cheggtsal (shortloin), doganisal (knuckle) and moongchisatae (hind shank) from branded Hanwoo beef of quality grade <TEX>$1^{++}$</TEX> were tender than those from branded Hanwoo beef of quality grade 1 (p<0.05). WBS values for ansimsal (tenderloin) were 2.56 (quality grade <TEX>$1^{++}$</TEX>), 2.76 (quality grade <TEX>$1^+$</TEX>) and 3.10 kg (quality grade 1), respectively, and those for doganisal (knuckle, quality grade <TEX>$1^{++}$</TEX>), hongdukesal (eye of round, quality grade <TEX>$1^+$</TEX>) and bosupsal (top sirloin, quality grade 1) were 4.76, 4.96 and 5.66kg, respectively (p<0.05). The frequency ratio (%) of WBS < 3.9 kg in the all subprimal cuts from branded Hanwoo beef of quality grade <TEX>$1^{++}$</TEX> were 100 [ansimsal (tenderloin) and cheggtsal (shortloin)], 87.5 [witdngsimsal (ribeye)] and 62.5% [bosupsal (top sirloin)], whereas that of WBS > 4.6 kg were 50.0% [hongdukesal (eye of round) and doganisal (knuckle)]. The frequency ratio of WBS < 3.9 kg in the an subprimal cuts of quality grade <TEX>$1^+$</TEX> were 100 [ansimsal (tenderloin) and witdngsimsal (ribeye)] and 44.4% [cheggtsal (shortloin) and gurisal (chuck tender)], whereas that of WBS > 4.6 kg were 66.7 [hongdukesal (eye of round)], 55.6 [doganisal (knuckle)] and 44.4% [bosupsal (top sirloin)]. The frequency ratio (%) of WBS < 3.9 kg in the all subprimal cuts of quality grade 1 were 88.9 [ansimsal (tenderloin)], 62.5 [cheggtsal (shortloin)] and 44.4% [witdngsimsal (ribeye)], whereas that of WBS > 4.6 kg were 100.0 [doganisal (knuckle)] 62.7 [hongdukesal (eye of round)], 62.5 [gurisal (chuck tender)] and 55.6% [moongchisatae (hind shank)]. From these results, subprimal cuts from branded Hanwoo beef were marketed with short aging periods and high frequency ratio (%) of WBS > 4.6 kg.

Improvement of Hydroxyapatite Sol–Gel Coating on Titanium with Ammonium Hydroxide Addition

Small amounts (1–5 vol%) of ammonium hydroxide (NH4OH) were added to the ethanol–water‐based hydroxyapatite (HA) sol–gel solution. After aging the sol, a Ti substrate was dip‐coated and heat‐treated at 500°C for 1 h in air. The sol properties were monitored in terms of pH, viscosity, and structure changes with aging time; also, the coating phase and structure on Ti were investigated. During aging, the viscosity of the sol increased while the pH decreased, confirming the polymerization and gelation of the sol. The addition of NH4OH altered the sol properties significantly. Increase in the NH4OH concentration increased the pH and viscosity of the sol considerably, especially at short aging period, followed by a saturation with further aging. The Fourier transformed‐infrared analysis also confirmed a gradual structure change of the sol with NH4OH addition. Such changes in pH, viscosity, and structure bands of the sol driven by the NH4OH addition were attributed to the improved polymerization and gelation of the sol. The improved gelation shortened the aging time needed for crystallization of the apatite coating, i.e., increase in the NH4OH addition improved the crystallization of the coatings. Within 24 h aging time, the coatings on Ti containing over 3.5 vol% NH4OH showed characteristic HA phase and structure bands, at which period no apatite peaks were observed on the HA coating obtained without NH4OH addition.

An Evaluation of the Thermal Conductivity of Extruded Polystyrene Foam Blown with HFC-134a or HCFC-142b

Insulation performance of extruded polystyrene (XPS) foams expanded with various halogenated blowing agents including HFC-134a or HCFC-142b was measured over time. Residual blowing agents were measured after aging up to 26 years. The diffusive transport properties of the blowing agents can be determined through the mathematical calculation of the heat transfer in the gas phase component of the foam thermal conductivity. These values are used in a Dow model which allows an accurate prediction of the long-term thermal resistance of extruded polystyrene foams blown with a variety of blowing agents including CFC-12, HCFC-142b, HCFC-22, HFC-134a, HFC-152a, and CO2. Excellent agreement was obtained between measured and predicted thermal conductivity values with samples stored in laboratory conditions, as well as samples extracted from field conditions, such as cellar and upside-down roof applications. The results confirm the slow diffusion rate of CFC-12, HCFC-142b and HFC-134a through extruded polystyrene foam, and demonstrate that HFC-134a or HCFC-142b-blown extruded polystyrene (XPS) foams meet the requirement for applications requiring excellent long-term insulation performance. HCFC-22 and HFC-152a are fugitive blowing agents in XPS foams, and the thermal performance of foams made with these blowing agents reach the thermal performance of CO2-blown foams after a short aging period.

Migration of Plasticizer between Bonded Propellant Interfaces

AbstractPlasticizer migration across bonded propellant interfaces during cure has been shown to have a measurable effect on propellant properties compared to each propellant by itself. This shows that the curing period is significant to the migration phenomenon. The plasticizer migration has been shown to have a direct influence on tensile strength for short aging periods up to the point the plasticizer reaches equilibrium. The tensile data for short aging periods have been shown to follow an empirical equation connecting the physical characteristics of plasticizer migration with increasing propellant tensile strength. The diffusion coefficient has been evaluated on the basis of this relation from a plot of σ$ ^{\it m}_{\rm t}$ versus t1/2 and was in good agreement with the diffusion coefficient from the plasticizer content data.

Morphology of L1 0-TiAl(Ag) precipitation in Ag-modified L1 2–Al 3Ti

Transmission electron microscopy (TEM) examinations of Ag-modified Al 3Ti with an L1 2-ordered structure have revealed the precipitation of L1 0–TiAl upon aging after quenching from higher temperatures. TEM observations revealed that plate-like L1 0–TiAl precipitates lie on {001} planes of (Al,Ag) 3Ti matrix in the short aging period and the habit plane changed from {001} to {hhl} after a long period aging or higher temperature aging and finally to {225} of the matrix lattice. A quantitative X-ray microanalysis for determining the chemical compositions of precipitate and matrix has been done by using an analytical electron microscope. The L1 2 phase field in the Ti–Al–Ag system is severely skewed with respect to the temperature axis and is restricted into a much smaller field at lower temperatures. The coherency stresses across the precipitate/matrix interface is considered to be the main factor controlling the precipitate morphology.