Evaluation of new and renewable energy technologies in Korea using real options

For several years recently, the price of oil has fluctuated due to the weak US dollar and financial risks. In particular, the WTI crude oil price reached $147 per barrel in July of 2008, which is the highest price thus far. An awareness of an impending crisis and concern over climate change are driving an increase in R&D for alternative energy sources instead of fossil‐based energy. However, the researches based on traditional method show negative options about the economic value of new and renewable energy. This paper evaluates the value of new and renewable energy through a real option method which considers the uncertainty associated with fossil energy and the uncertainty of the success of R&D. The evaluating model assumes that the fossil energy price follows a geometric mean reverting process and that the probability of success with R&D on renewal forms of energy follows a binomial probability model. The model considers four options: the option to continue R&D, the option to delay R&D, the option to deploy R&D, and the option to abandon R&D. Finally, the value of Korean R&D on renewal forms of energy is analyzed by the model. Copyright © 2012 John Wiley & Sons, Ltd.     

Crystal Growth of Thiol-Stabilized Gold Nanoparticles by Heat-Induced Coalescence

A monolayer of dodecanethiol-stabilized gold nanoparticles changed into two-dimensional and three-dimensional self-organized structures by annealing at 323 K. Subsequent crystal growth of gold nanoparticles occurred. Thiol molecules, although chemisorbed, form relatively unstable bonds with the gold surface; a few thiols desorbed from the surface and oxidized to disulfides at 323 K, because the interaction energy between thiol macromolecules is larger than that between a thiol and a nanoparticle. The gold nanoparticles approached each other and grew into large single or twinned crystals because of the van der Waals attraction and the heat generated by the exothermic formation of disulfides.     

Relationship between Texas Cone Penetrometer Tests and Axial Resistances of Drilled Shafts Socketed in Clay Shale and Limestone

Modern methods for designing drilled shafts in soft rock require knowledge of the compressive strength and modulus of the rock. However, rock jointing at many sites prohibits the recovery of samples of sufficient length and integrity to test rock cores in either unconfined or triaxial compression tests. Since rational design procedures usually require values of compressive strength, surrogate methods must be employed to estimate the compressive strength of the rock. The surrogate methods considered in this study was Texas cone penetrometer tests, and performed at several sites in North Central Texas. In order to develop the relationships between Texas cone penetrations and side and base resistances of rock socketed drilled shafts, three field load tests were conducted. Based on the field study and literature reviews, a relationship between Texas cone penetration tests and axial resistances of rock socketed drilled shafts was proposed.     

The pH effect for rare earth metals Nd, Pr and Y in aqueous solution dissolved Mg, Zn and Al

The pH variations of Mg, Zn and Al solutions to which had been added the rare earth metals Nd, Pr and Y were observed in 3.5 wt.% NaCl with respect to high energy mechanical ball milling effects. Mg was directly dissolved and exhibited a pH value of 10.5. On the other hand, Zn and Al needed to be saturated for a certain amount of time. The addition of rare earth metals played a role in increasing the pH with low reduction potentials. Additionally, mechanical ball milling provided high energy to Mg + x wt.% Zn + 0.5 wt.% Nd mixture by fracturing fragmentation of metals, which led to an increase in the pH when the mixture was immersed in 3.5 wt.% NaCl. The addition of Zn to Mg + 0.5 wt.% Nd caused a higher pH than when Mg + 0.5 wt.% Nd alone was added.     

Composition-dependent phase segregation and cocrystallization behaviors of blends of metallocene-catalyzed octene-LLDPE(D) and LDPE(H)

The morphological structures of slowly cooled blends of deuterated metallocene-catalyzed octene linear low-density polyethylene (O-mLLDPE(D)), and hydrogenous low-density polyethylene (LDPE(H)) were studied by using small angle neutron scattering in combination with complementary small angle X-ray scattering and differential scanning calorimetry. The phase segregation, which is more nanoscale than macroscale, and cocrystallization behaviors were found to vary with the blend composition. Phase-segregated O-mLLDPE(D) lamellae are predominantly formed in LDPE(H)-rich compositions. In contrast, few segregated O-mLLDPE(D) lamellae form in O-mLLDPE(D)-rich compositions, and instead O-mLLDPE(D) lamellar stacks are extensively cocrystallized with LDPE(H) mostly in the interlamellar amorphous region.     

Relationship of Carcass Weight to Muscle Fiber Characteristics and Pork Quality of Crossbred (Korean Native Black Pig × Landrace) F2 Pigs

A total of 168 carcasses of crossbred (Korean native black pig × Landrace) F₂ pigs were divided into four carcass weight groups (A, 70–79 kg; B, 80–89 kg; C, 90–99 kg; D, 100–109 kg). The influence of carcass weight on muscle fiber characteristics and meat quality traits of pork, from the longissimus dorsi, were investigated. Carcass traits such as loin-eye area and back-fat thickness were found to increase with increasing carcass weight. Fat content, sarcomere length, drip loss, and meat color values (L*, a*, and b*) also increased with increasing carcass weight. However, moisture content and Warner–Bratzler shear force decreased with increasing carcass weight. A decrease in the compositions of type I and IIA fibers and an increase in the composition of type IIB fibers were observed with increasing carcass weight. The heavier carcasses showed type I and IIB fibers of bigger size and a smaller size of type IIA fibers. Fiber number percentage and the diameter of type IIB showed a significant positive correlation with carcass weight, fat content, and lightness (p?<?0.05). Fiber diameter of type IIB was positively correlated with loin-eye area, but was negatively correlated with moisture content. However, muscle fiber characteristics had no correlation with back-fat thickness, ultimate pH, Warner–Bratzler shear force, and b* value. In conclusion, crossbred pig which has of high composition and size of type IIB has high lightness (L* value) and water-holding capacity (drip loss). Therefore, excessively high weight of carcass has influence on pale and exudative properties in pig because of muscle fiber characteristics, especially type IIB fiber.     

钢桁架筒结构基于刚度的设计方法——一种可持续的方法

桁架筒结构是高层建筑的一种高效的结构体系,该结构体系形式,自60年代末问世以来已广泛应用于大多数高层建筑中。提出基于刚度的设计方法,用以初步确定高层建筑桁架筒结构的构件尺寸。该方法适用于40～80层高的建筑物,并给出对应于代表性的设计荷载,使用材料最为经济的设计参数。就结构构件的不同几何配置对于设计经济性的影响进行了讨论,并对几何配置优化提出了建议。基于刚度的设计方法,只需较少迭代过程,非常适合于桁架筒结构的初步设计。对使用最少量的资源以满足构建建筑环境要求的设计,将具有推动和促进作用。     

摇滚彩虹 韩国ROCK IT SUDA度假屋

韩国建筑师Moon Hoon为大家所认识大概是因为他2005年获得韩国设计大奖的SangSang博物馆,从那座极富工业感和机械感的建筑设计中,我们不难感受到设计师不一样的设计理念与艺术感知。与其说他是一名建筑师,不如说是一个艺术家更为准确。     

Mechanical properties and durability of PMMA impregnated mortar

Polymer impregnated concrete (PIC) is known to exhibit better strength and durability characteristics than the other classes of polymer cement composites. In the work described herein the monomer was impregnated into cement mortar and polymerized by two methods — the conventional thermal method and using microwaves. The mechanical properties and durability characteristics of the samples and on exposure to chemical environments were then evaluated. The above studies revealed that the strengths of PIC specimens were almost 2–3 times better than those of conventional cement mortars. The chemical resistance was also found to be superior even on prolonged exposure to the chemical media. This may be attributed to the protective layer formed by the polymer on the cement mortar, which prevents the external chemical media from interacting with the cement particles. The properties of the PIC specimens prepared by both methods have also been compared and discussed in this paper.     

Effect of hydrogen partial pressure on a polymer electrolyte fuel cell performance

We first investigated the effect of partial pressure of hydrogen (H₂) on the performance of polymer electrolyte fuel cells (PEFCs) by controlling the ratio of hydrogen and nitrogen (N₂). The cell performance with Pt/C anode was significantly decreased with reduction of the partial pressure of H₂ in the presence of carbon monoxide (CO), while the performance variation was negligible in the absence of CO. Severe CO poisoning on Pt/C electrode at low partial pressure of H₂ might be attributed to the hindering effect by N₂ and CO. On the other hand, PtRu/C anode showed consistent power performance even at low partial pressure of H₂.