Prestressing steel is an effective means of increasing the load carrying capacity and control the deflection of structural steel members. Although the method of prestressing is not new, the application and development of the technique for steel members has been limited and not as advanced as prestressed concrete structures. Prestressing force is commonly introduced using hydraulic jacks and utilizes high strength tendons as the prestressing material. In this paper, a new method of applying prestressing force is introduced. The method involves a segmental beam consisting of three segments and a normal strength bottom plate (BP) as the pretressing material attached to the two initially inclined outer segments of the steel H-beam. Pretressing force is introduced by taking advantage of the geometry of the segmental assembly of the beam. Experiment, analytical studies, and finite element (FE) analysis using ABAQUS is performed to verify the feasibility and applicability of the method and to understand the behavior of a mechanically prestressed segmental steel beam. Results showed that the prestressing method significantly increases the load carrying capacity and at the same time reduces the deflection of the beam. The difficulties encountered in the method are the rigorous assembly and the introduction of the exact required amount of prestressing force. Overall, the method of prestressing performed in the study can be used to introduce pretressing force which improves the performance of steel beams, provided that proper detailing is implemented.
According to a recent analysis of NASA, the year 2014 now ranks as the warmest on record since 1880. Africa is widely held to be highly vulnerable to future climate change related hazards, and Ethiopia is often cited as one of the most extreme examples. The country’s economy is highly exposed to climate variability and extremes and the nature of agriculture, primarily rain-fed is sensitive to fluctuations in rainfall, which forms the basis of the economy supporting roughly 42% GDP and 85% employment. Wahlström M (2009) reported that over the last two decades (1988-2007), 76% of all disaster events were hydrological, meteorological or climatological in nature. In this review, a great concern is given for extreme conditions (flood and drought) particularly climate change related hazards and tries to look at the challenges, mitigation and policies. Climate change, drought and flood will continue to be a primary concern for many Ethiopian and even agricultural production and water supplies will become more severely diminished. Starting from 1970-1996 droughts and the resulting food shortage have affected millions and cause for the death of a significant number of people and in 2009 Ethiopia has experienced a delay in the main rainy season, particularly in northeastern areas, resulting in 50-70 % of agricultural land being sown for cropping. Ethiopia has also experienced a major flood in 1988, 1993, 1994, 1995, 1996 and 2006 and climate change, including extreme events like drought and flood affected areas will likely become more widely spread. Recently, flash floods affected big cities, including Addis Ababa and Dire Dawa (death of 300 people) and result in considerable damage to lives, livelihoods and property. Despite the hugely damaging effect that natural and man-made disasters have on Ethiopia’s economic development, little is done to prevent them. There are significant challenges to reduce climate change related hazards, but linking of climate change adaptation with disaster risk reduction and effective strategies to prevent hazards from becoming disasters and managing those disasters that do occur would make a lasting contribution to the quality of life and sustainable livelihoods. Several factors contribute to Ethiopia’s high vulnerability to disasters, but here the authors will focus on institutional frameworks and policy. There are several NGO and governmental climate change actors in Ethiopia. The country’s National Policy on Disaster Prevention and Management (NPDPM) was prepared in 1993. Ethiopia has also ratified the United Nations Framework Convention on Climate Change (UNFCCC) and under the mechanism, a National Adaptation Program of Action (NAPA) was produced in 2001 with an ambition to identify ‘immediate and urgent’ adaptation activities that address current and anticipated adverse effects of climate change and extreme climate events. The Environmental policy of Ethiopia indicates that environmental sustainability to be recognized in policies and strategies as a key prerequisite. In line with this the Environmental Protection Agency (EPA), was established and mainly assumes a regulatory role and coordinates various activities and included policy on climate change and pollution, particularly on promoting climate monitoring programs as the country is sensitive to changes in climate, identifying a firm and demonstrable commitment to the principle of containing climate change and fostering to use hydro, geothermal and solar energy to minimize an emission of greenhouse gases.
This study was initiated to examine the potential impacts on the environment during the management of food waste by anaerobic digestion in Daejeon Metropolitan City (DMC) that is built in 2017. The evaluation was based on both material flow analysis (MFA) and life cycle assessment (LCA). The MFA study was performed using STAN 2.5, while the LCA was conducted according to ISO standards by utilizing Total 4 LCA software with the incorporation of CML 2002 methodology. According to the LCA results, global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP) were found to be approximately 166 kg CO2-eq/ton of food waste, 0.43 kg SO2-eq/ton of food waste, 0.66 kg PO4 3−eq/ton of food waste, and 0.08 kg C2H4-eq/ ton of food waste, respectively. The disposal stage showed higher impact of GWP on the environment due to the landfilling of solid sludge and screening waste. In case of eutrophication potential, the treatment phase showed the highest impact on the environment, mainly because of the consumption of electricity. Based on the results of normalization, the highest environmental impacts was found in the treatment stage related to eutrophication potential. The results of LCA would provide policy-makers to identify and reduce potential environmental impacts associated with food waste to biogas conversion in DMC by life cycle.
Food waste, a putrescible form of waste, comprised of 30% of the total municipal solid waste stream in Daejeon Metropolitan City (DMC) in 2012. Proper management of food waste is a challenging task for local government. This study was conducted to determine material flows when treated food waste in various recycling facilities. Material flows in the recycling processes were collected by site surveys, field trips and discussion with operators and governmental employees. Material flow analysis (MFA) was conducted to quantify the flow of food waste from generation to disposal for the year 2012. MFA along with its mass transfer coefficients were determined based on the inputs, outputs and waste fluxes. According to the mass transfer coefficient results, treatment efficiency for the dry and wet feed manufacturing facility was found to be higher than other treatment facilities. Water consumption was higher for the composting site, resulting in large volume of wastewater (mass transfer coefficient 1.539). While large amounts of screening materials such as plastic, chopsticks, aluminum foils, and bottle caps were generated at the composting site, mass transfer coefficients (0.312) at the dry and wet feed facility were relatively high, implying effective treatment of food waste occurring. The results of this study help to facilitate waste management policy decision-makers in developing effective food waste management techniques in DMC.
Purpose – While studying the topic of seeking behavioral excellence (proactive and creative competence) in organization, scholars have presented a variety of literature sprinkled with countless theories on behavioral competence. Research design, data, and methodology - Foremost among the several theories on this topic are two distinct sets of behavioral theories: OCB (Organizational Citizenship Behavior) and Constructive Deviance. Both of these theories attempt to posit their usefulness in positive organizational outcomes (such as organizational effectiveness, quality, performance, and innovations). Results - However, their proposed constructs are opposing and studies are conducted in isolation, thereby creating a significant literature gap and omitting the possibility of being inclusive of the best that both OCB and constructive deviance have to offer. Conclusions - The article bridges the gap by critically examining OCB and constructive deviance and including a consideration of other empirical studies in an attempt to be comprehensive while, at the same time, seeking to find an effective behavioral construct that is both appropriate and conducive for positive organizational outcomes in the context of the current business environment
A ship-to-ship (STS) lightering operation takes place in order to transfer cargo (e.g. crude oil or petroleum products) between an ocean-going ship and a service ship alongside it. Instrumental measurements to accurately determine the relative speeds and distances during the approach between the vessels would benefit the operational safety and efficiency. A velocity information GPS (VI-GPS) system, which uses the instantaneous velocity measures from carrier-phase Doppler measurement, has been applied in a field observation onboard a service ship (Aframax tanker) approaching a ship-to-be-lightered (VLCC) in open waters. This article proposes to apply VI-GPS as the input sensor to a guidance and decision-support system aiming to provide accurate velocity information to the officer in charge of an STS operation. A method for precise velocity measurement using VI-GPS was described and the measurement results were compared each other with the results of Voyage Data Recorder (VDR) and VI-GPS that showed the concept of a guidance and decision-support system applying VI-GPS with the field test results during STS operations. Also, it turned out that VI-GPS has sufficient accuracy to serve as an input sensor from the field test results.
The uneven mass distribution of the Moon highly perturbs the lunar spacecrafts. This uneven mass distribution leads to peculiar dynamical features of the lunar orbiters. The critical inclination is the value of inclination which keeps the deviation of the argument of pericentre from the initial values to be zero. Considerable investigations have been performed for critical inclination when the gravity field is assumed to be symmetric around the equator, namely for oblate gravity field to which Earth’s satellites are most likely to be subjected. But in the case of a lunar orbiter, the gravity field of mass distribution is rather asymmetric, that is, sectorial, and tesseral, harmonic coefficients are big enough so they can’t be neglected. In the present work, the effects of the first sectorial and tesseral harmonic coefficients in addition to the first zonal harmonic coefficients on the critical inclination of a lunar artificial satellite are investigated. The study is carried out using the Hamiltonian framework. The Hamiltonian of the problem is cconstructed and the short periodic terms are eliminated using Delaunay canonical variables. Considering the above perturbations, numerical simulations for a hypothetical lunar orbiter are presented. Finally, this study reveals that the critical inclination is quite different from the critical inclination of traditional sense and/or even has multiple solutions. Consequently, different families of critical inclination are obtained and analyzed.
Autophagy is a homeostatic degradation process that is involved in tumor development and normal development. Autophagy is induced in cancer cells in response to chemotherapeutic agents, and inhibition of autophagy results in enhanced cancer cell death or survival. Chloroquine (CQ), an anti-malarial drug, is a lysosomotropic agent and is currently used as a potential anticancer agent as well as an autophagy inhibitor. Here, we evaluate the characteristics of these dual activities of CQ using human colorectal cancer cell line HCT15. The results show that CQ inhibited cell viability in doseand time-dependent manner in the range between 20 to 80 uM, while CQ did not show any antiproliferative activity at 5 and 10 uM. Cotreatment of CQ with antitumor agent NVP-BEZ235, a dual inhibitor of PI3K/mTOR, rescued the cell viability at low concentrations meaning that CQ acted as an autophagy inhibitor, but CQ induced the lethal effect at high concentrations. Acridine orange staining revealed that CQ at high doses induced lysosomal membrane permeabilization (LMP). High doses of CQ produced cellular reactive oxygen species (ROS) and cotreatment of antioxidants, such as NAC and trolox, with high doses of CQ rescued the cell viability. These results suggest that CQ may exert its dual activities, as autophagy inhibitor or LMP inducer, in concentration-dependent manner.
Osteosarcoma (OS) is one of the most common malignant primary bone tumors and NF-κB appears to play a causative role, but the mechanisms are poorly understood. OS is one of the pleomorphic, highly metastasized and invasive neoplasm which is capable to generate osteoid, osteoclast and osteoblast matrix. Its high incidence has been reported in adolescent and children. Cell signal cascade is the pivotal functional mechanism acquired during the differentiation, proliferation, growth and survival of the cells in neoplasm including OS. The major limitation to the success of chemotherapy in OS is the development of multidrug resistance (MDR). Answers to all such queries might come from the knock-in experiments in which the combined approach of miRNAs with NF-κB pathway is put into use. Abnormal miRNAs can modulate several epigenetical switching as a hallmark of number of diseases via different cell signaling. Studies on miRNAs have opened up the new avenues for both the diagnosis and treatment of cancers including OS. Collectively, through the present study an attempt has been made to establish a new systematic approach for the investigation of microRNAs, biophysiological factors and their target pairs with NF-κB to ameliorate oncogenesis with the “bridge between miRNAs and NF- κB”. The application of NF-κB inhibitors in combination with miRNAs is expected to result in a more efficient killing of the cancer stem cells and a slower or less likely recurrence of cancer.
국내 음식물류폐기물은 생활폐기물 발생량의 약 30%의 비율로 매우 많은 양 발생되고 있으며, 이러한 음식물류폐기물은 우리나라의 음식문화 특성으로 인한 높은 염분농도와 수분함량으로 침출수 및 악취문제 등 여러가지 환경문제를 야기해왔다. 이에 따라 2005년 이후 직매립을 금지시킴으로써 음식물류폐기물의 재활용 정책이 도입되고 자원화 시설이 설치되었다. 현재 국내에서는 습식 및 건식 사료화, 퇴비화, 탄화, 기계적 감량화 등 다양한 방법을 통하여 음식물류폐기물을 자원화 하고 있으며 그 중 사료화와 퇴비화 시설이 가장 보편적으로 운영되고 있다. 이와 같은 음식물류폐기물 재활용 정책의 적극적인 도입과 시설 증축으로 국내에서는 95%이상의 음식물류폐기물 재활용률을 달성 하였지만 실제 처리시설에서의 낮은 공정수율, 대량의 음폐수 발생, 악취, 운송과정에서의 부패 등 여러 가지 환경 문제점이 여전히 나타나고 있다. 따라서 본 연구에서는 실제 처리공정의 효율, 공정의 특징, 문제점 등을 파악하고자 하였으며, 이를 위하여 대전광역시 음식물류폐기물 처리시설 4곳(퇴비화 1곳, 사료화 3곳)을 중심으로 시설별 일반적 사항을 비롯한 투입 및 배출 물질의 종류와 양, 시설별 공정 주요 특징과 문제점 등을 조사하였다. 또한 조사 결과를 바탕으로 처리시설별 물질흐름분석을 통하여 물질수지를 마련함으로써 대전광역시 음식물류폐기물 처리시설의 운영 실태를 파악하고 문제점의 개선방안을 마련하였다. 본 연구에서는 대전광역시에서 발생하는 음식물류폐기물을 처리하는 시설을 바탕으로 현장조사를 실시하였다. 현장조사를 통해 확보된 투입 및 배출 물질에 대한 데이터를 바탕으로 시설별 물질흐름분석을 수행하고 물질전환계수를 산정하였다. 아울러 Stan 2.5 Software를 활용하여 분석을 실시하였다. 연구결과, 대전광역시 음식물류폐기물 처리 시설 중 반입 음식물류폐기물 대비 재활용 제품의 양의 비율은 건식 및 습식사료화 시설에서 가장 높은 것으로 나타났으며, 퇴비화 시설에서 가장 낮은 것으로 나타났다. 음폐수의 경우 퇴비화시설에서 반입되는 음식물류폐기물의 1.5배를 초과하는 대량의 음폐수가 발생되는 것으로 나타났으며, 이는 처리 공정 중 물질의 이동을 위하여 대량의 공정수가 불가피하게 투입되기 때문인 것으로 분석되었다. 이러한 낮은 공정수율, 대량의 음폐수 발생 등과 같은 문제점은 대부분 처리공정의 개선을 통하여 보완 가능한 사항들이기 때문에 보다 효율적이고 친환경적 관리를 위해서 스크류, 탈수기, 선별기 등의 시설개선이 반드시 필요할 것으로 분석되었다. 또한 적정 관리 방안 마련을 위해서는 보다 정밀한 관리시스템의 분석과 다양한 측면에서의 환경평가가 필요할 것으로 판단된다.
본 연구에서는 음식물 폐기물을 이용한 반탄화물의 고형연료로서 에너지 잠재성 평가를 위하여 반탄화시 특성 및 탄화물의 연소 특성에 관한 결과를 고찰하였으며, 이를 위하여 온도(150~600℃) 조건에서 에너지 수율 및 발열량, 회분 및 가연분, 발생가스 측정을 통한 분석을 하였고, TGA (Thermaogravimetric Analyzer)를 이용하여 음식물 폐기물의 반탄화 반응에 따른 활성화 에너지 변화를 속도론적 해석을 통해 고찰하였다. 또한 탄화물로부터 펠릿을 성형 제조한 후 고형연료화 시설에서 생산된 고형연료(SRF)와 등온, 승온 연소하여 발생되는 가스의 성분을 비교 분석 하였다. 본 연구로부터 반탄화 온도의 증가함에 따라 발열량과 회분함량은 증가 하였으며, 가연분 및 에너지 수율은 감소하였다. 또한 연소 배가스 중 CO2, CO, HCl의 경우 고형연료(SRF) 보다 낮게 발생함을 확인할 수 있었다.
Purpose – The study aims to investigate empirically the effects of the flow of an Internet shopping mall upon consumers' revisit intention and purchase intention. Research design, data, and methodology – The subjects comprised customers of Internet shopping malls. SPSS 19.0 for Windows was used to verify the models and hypotheses. Frequency, factors, reliability, and regression analysis were used. Results – This study classified flow behavior factors of Internet shopping malls into four categories-skills, convenience, design, and mutual reaction-to investigate their influence on flow. Skills and convenience had a greater influence than mutual reaction and design. The flow was most influenced by convenience, followed by skills. Conclusions – First, the subjects comprised those who had made purchases at least once at an Internet shopping mall. Second, the study applied the common flow attributes of past researchers to the Internet shopping mall environment, to gauge customers' e-commerce involvement. Third, skill, convenience, and shopping mall display design affirmatively influenced the computer-mediated environment from the Internet marketing control implications perspective regarding the contents of the marketer’s website.
This study aimed to simulate the complex behavior of structures and predict test results. For this, the leading nonlinear model ‘Bouc-wen model’ was used, and rubber bearing and MR-damper were investigated. While seismic load was being applied, complex behavior of continuous structures was simulated. To test simulation performances, in addition, a seismic response test of the model structure was conducted using shaking table. Then, each structure’s displacement data were compared to simulation results. This study found that nonlinear model-based simulation results were mostly matched with test results, and they are applicable to the prediction of test results.
In this work, the separation characteristics of CO2 from CO2 and CH4 mixed gas was studied using pressure swingadsorption (PSA) process. Zeolite 13X was used as an adsorbent to adsorb CO2 from gaseous stream in a fixed-bed ofadsorbent. The adsorption experiments were performed with various gas flow rates, adsorption pressures and temperatures.The deactivation model was used to analyze the adsorption kinetics of CO2 using the experimental breakthrough data.From this work, it was found that the activation energies of adsorption and deactivation were 29.15 and 13.0 kJ/mol,respectively. And the experimental breakthrough curves were agree very well with the adsorption isotherm models basedon Freundlich equation.
The isolated single coronary artery is a rare congenital anomaly, in which both coronary arteries arise from a solitary ostium. Diagnosis of coronary anomalies and identification of the exact anatomy of coronary arteries has significant clinical importance, hence, myocardial ischemia or sudden cardiac death is usually related to its course of anomalous coronary artery. Most patients with a single coronary artery are asymptomatic and have normal electrocardiogram and negative stress tests. However, if the patient has other structural abnormalities, for example, ventricular hypertrophy, the exam is determined. This report describes a case of single coronary artery, where the right coronary artery originated from the distal left circumflex artery in a patient with hypertrophic ardiomyopathy.
Dormant blastocysts during delayed implantation exhibit heightened autophagic activation. Activation of autophagy, the self-eating process within cells, was suggested as an adaptive response to unfavorable environment of prolonged survival in utero. During the course of this study, we observed by transmission electron microscopy that multivesicular bodies (MVBs) accumulate in the trophectoderm of dormant blastocysts upon activation of implantation by estrogen. MVBs are the late endosomes which are characterized by the presence of diverse internal vesicles within a large vesicle. Autophagosomes fuse with MVBs during autophagic activation, and efficient autophagic degradation requires functional MVBs. Biogenesis of MVBs depends on a dynamic network of ESCRT complexes 0, I, II, and III. Tsg101 (a component of the ESCRT-I complex) and CD63 are often used as a marker of MVBs. Lysobisphosphatidic acid (LBPA) is an abundant lipid in MVBs and required for the formation of MVBs. In this study, we performed immunofluorescence staining for detection of MVB makers in dormant and activated embryo. In dormant blastocysts, expression of Tsg101 and LBPA exhibited a uniform pattern throughout the trophectoderm. In contrast, expression of both markers prominently increased in the mural trophectoderm of activated blastocysts. To investigate the relationship with MVB formation and autophagy activation in activated blastocyst, 3-MA, a widely used inhibitor of autophagy, was daily injected intraperitoneally to ovx mice. Interestingly, 3-MA injection to block autophagy during delayed implantation led to a reduction of the signal of MVB markers, suggesting that prolonged activation of autophagy in dormant blastocysts is associated with MVB formation upon activation of implantation. Collectively, these results show that expression of MVB makers increase in the trophectoderm of blastocysts upon activation of implantation and that the formation of MVB is associated with heightened autophagy during delayed implantation.
A RPS (Renewable Portfolio Standard) for South Korea became effective in 2012 with a beginning renewable electricity quota of 2% of total generation of capacities exceeding 500 MW, increasing to 10% by 2022. However, almost of all the coal-fired power plant are not designed to co-firing large amount of biomass with coal. In practice, the biomass cofiring rate is commonly 5 -10% of total heat input. In the case of biomass import, it will cost a great deal on the transshipment, transportation and storage of biomass. Therefore new research and development on the biomass fuel with high energy density in needed to reduce logistics cost on transportation of the biomass fuel. Torrefaction is a thermochemical treatment process of biomass at temperatures ranging between 200 and 300oC. During this process, 70% of the mass is retained as a solid product, and retain 90% of the initial energy content. The physical and chemical properties of torrefied biomass are similar to those of coal. Therefore co-firing torrefied biomass could increase the co-firing percentages much further to even 40%. This review paper looks into the torrefaction technologies of biomass, the technical characteristic of torrefaction reactors, the overview of torrefaction project and the future prospects of torrefaction.
Purpose - This study is aimed at examining Indian consumers’ online shopping motivations, information search, and shopping intentions. The study intends to reveal the relationship between online shopping motivations, information search, and shopping intentions. Research design, data, and methodology - The study employs factor analysis to verify correct loading of items on corresponding factors, and to confirm the applicability of constructs in the Indian context. The model was verified using stepwise regression analysis. Results -The findings show that hedonic and utilitarian motivations significantly affect online information search and shopping intentions. The information search is a significant predictor of online purchase intention. Conclusions - Hedonic and utilitarian motivations are the salient factors affecting online information search and purchase intentions. Marketers are required to design websites that foster an enjoyable online experience. This will attract customers who will browse the website for a longer duration. More time devoted to information search will ensure brand building and loyalty.
Plant bZIP transcription factors play crucial roles in biological processes. In this study, 136 putative bZIP transcription members were identified in Brassica rapa. The bZIP family can be divided into nine groups according to the specific amino acid rich domain in Brassica rapa. To screen the cold stress responsive BrbZIP genes, we evaluated whether the transcription patterns of the BrbZIP genes were enhanced by cold treatment in the inbred lines, Chiifu and Kenshin, by microarray data analysis and qRT-PCR. The expression level of six genes increased significantly in Kenshin, but these genes were unchanged in Chiffu. Additionally, homo- and hetero-dimerization test between selected bZIP proteins indicated the Bra020735 is a key regulator in cold response. These findings suggest that the six genes that encoded proteins containing N-rich regions might be involved in cold stress response. These results presented herein provide valuable information regarding the molecular basis of the bZIP transcription factors and their potential function in regulation growth and development, particularly in cold stress response.