• 제목/요약/키워드: State of matter

검색결과 642건 처리시간 0.025초

식품보장과 수분활성에 관한 연구 1. 조절기류에 의한 건조말쥐치육의 등온흡습곡선의 측정 (Studies on Food Preservation by Controlling Water Activity 1. Measurement of Sorption Isotherm of Dried Filefish Muscle by Equilibration in Dynamic Stream of Conditioned Air)

  • 한봉호;최수일
    • 한국수산과학회지
    • /
    • 제14권4호
    • /
    • pp.189-193
    • /
    • 1981
  • 등온흡습곡선측정시의 건제품이 주어진 대상습도에서 평형에 이르는 시간을 단축시키기 위하여 조절기류를 이용하는 장치를 만들고, 이를 이용하여 $25^{\circ}C$에서 말쥐치 건제품의 등온흡습곡선을 측정하였다. 1. 조절기류를 이용함으로써 주어진 수분활성에서보다 높은 수분활성에 이르는 시간을 평균 45 시간으로 단축시킬 수 있었다. 2. 단분자의 수분함양은 고형물 1kg당 0.092kg이었으며, 건조말쥐치의 제품에 대하여 $8.42\%$였다. Symbols used in the text A : surface, $m^2$ $a_w$: water activity $A_s$ : specific surface, $m^2/kg$ dry matter C : constant related to the heat of adsorption $K_g$ : gas film coefficient of mass transfer, $kg water/hr{\cdot}Pa{\cdot}m^2$ n : number of molecular layers $n_s$ : moisture content, kg water /kg dry matter $n_{sa}$ : mean moisture content, kg water/kg dry matter $n_{se}$ : equilibrium moisture content, kg water/kg dry matter $n_{sm}$ : moisture content for monolayer, kg water/kg dry matter $P_g$ : saturated vapor pressure at wet-bulb temperature, Pa $P_a$ : partial vapor pressure of water in air, Pa $R_d$ : resistance factor against diffusion, $m^2{\cdot}hr/kg$ dry matter $R_s$ : resistance factor against drying, $m^2{\cdot}hr/kg$ dry matter R.H. : relative humidity, $\%$ $\varphi$ : R.H./100

  • PDF

해상보검에 있어서 항검증가의 교과에 관한 비교법적 고찰 (A Comparative Legal Study on the Effect of the Increase of Risk in Marine Insurance)

  • 김경식
    • 한국항해학회지
    • /
    • 제18권2호
    • /
    • pp.111-127
    • /
    • 1994
  • A Contract of marine insurance is a contract whereby the insurer undertakes to indemnity the assurd, in manner and to the extent thereby agreed, against marine losses that is to say, the losses incident to marine adventure. But the matter is that whether the problem of increased risk in insurance law should be understood by matching to nay state under general principle of contract law and whether that we should give any effect is more proper to the original object of the system. For this, it is understood that it is a case to be applied a "clausula rebus sic stantibus" in general today, but it is regarded as the matter that whether "clausula rebus sic stantibs" is charging any position in change of risk and whether we should understood the concept of the risk on the substance of the risk. Accordingly the recognition for the problem like this, study should examine closely into whether any system for the effect of increase in change of risk is more proper and rational system provide the supplementing points through our principle of insurance law and the study by comparing method.by comparing method.

  • PDF

막미생물과 부유미생물의 kinetics 비교 연구 (A Comparative Study on the Bio-kinetics of Suspended Sludge and Attached Sludge)

  • 이정수;이태규
    • 상하수도학회지
    • /
    • 제12권4호
    • /
    • pp.59-69
    • /
    • 1998
  • Biological treatment systems generally can be divided into two main classes of a suspended sludge process and attached one like a fluidized bed reactor. These process are considered to bring remarkable change in species composition of microorganisms, due to difference of a state of biofilm, a concentration and diffusion velocity of dissolved oxygen, a concentration and diffusion velocity of substance or poisonous matter. The change of species composition bring different treatment result for influence factors like F/M ratio, DO concentration, pH or poisonous matter. This study is to investigate the reaction characteristics of both microorganisms, namely, a suspended sludge and attached sludge, through the changes of pH, temperature and substance concentration.

  • PDF

Accumulated organic matter, litterfall production, and decomposition tell us the status of litter dynamics in forests

  • Kim, Jae-Geun
    • Journal of Ecology and Environment
    • /
    • 제35권2호
    • /
    • pp.99-109
    • /
    • 2012
  • Litterfall dynamics in forests are assessed by estimating biomass production and decomposition. However, there have been few studies on how litter dynamics impact the health and management of ecosystems. Here, a new approach to measure and assess ecosystem function is presented based on conventional methods using littertraps, litterbags, and the mass on the forest floor. To assess the status of litter dynamics, the decay rate (k) was estimated from a litterbag experiment, and removal rates ($k_i$) were determined from mass balance on the forest floor at 21 sites on three mountains in South Korea. The $k_3$ (organic mass ratio of $O_i$ and $O_e+O_a$ + A horizons in November) values in an equilibrium state in South Korea were within the range of $k{\pm}0.174$ when considering the annual variation of litterfall production. This study also suggests that sampling sites for these types of studies should be in the middle, not at the ends, of steady slopes on the forest floor.

초전도체와 d-wave 초전도체 근접효과 접합에서의 터널링 상태밀도함수 (Tunneling Density of States in Superconductor/d-wave Superconductor Proximity Junction)

  • Lee, H. J.;Yonuk Chong;J. I. Kye;Lee, S. Y.;Z.G. Khim
    • Progress in Superconductivity
    • /
    • 제2권2호
    • /
    • pp.57-64
    • /
    • 2001
  • We have calculated the tunneling density of states (TDOS) of a metal/d-wave superconductor proximity junction, where the metal stands fur the normal metal, 5-wave superconductor, and d-wave superconductor. The tunneling direction is through the ab-plane of the d-wave superconductor. Because of the sign change in the order parameter experienced in the multiple Andreev reflection, there appears a finite TDOS at zero bias for duty geometry, which results in the anomalous zero bias conductance peak(ZBCP). For $d_{x2-y2}$ geometry, however, no TDOS peak appears at zero bias. We have calculated TDOS for various crystal orientation of HTSC and compared with the experimental conductance.

  • PDF

Neutrino mass from cosmological probes

  • Rossi, Graziano
    • 천문학회보
    • /
    • 제39권2호
    • /
    • pp.42.1-42.1
    • /
    • 2014
  • Neutrino science has received a boost of attention quite recently in cosmology, since the outstanding discovery in particle physics over the last decade that neutrinos are massive: pinpointing the neutrino masses is one of the greatest challenges in science today, at the cross-road between particle-physics, astrophysics, and cosmology. Cosmology offers a unique 'laboratory' with the best sensitivity to the neutrino mass, as primordial massive neutrinos comprise a small portion of the dark matter and are known to significantly alter structure formation. I will first introduce a new suite of state-of-the-art hydrodynamical simulations with cold dark matter, baryons and massive neutrinos, specifically targeted for modeling the low-density regions of the intergalactic medium as probed by the Lyman-Alpha forest at high-redshift. I will then present and discuss how these simulations are used to constrain the parameters of the LCDM cosmological model in presence of massive neutrinos, in combination with BOSS data and other cosmological probes, leading to the strongest bound to date on the total neutrino mass.

  • PDF

Impact of Massive Neutrinos and Dark Radiation on the High-Redshift Cosmic Web

  • Rossi, Graziano
    • 천문학회보
    • /
    • 제43권1호
    • /
    • pp.38.1-38.1
    • /
    • 2018
  • With upcoming high-quality data from surveys such as eBOSS or DESI, improving the theoretical modeling and gaining a deeper understanding of the effects of neutrinos and dark radiation on structure formation at small scales are necessary, to obtain robust constraints free from systematic biases. Using a novel suite of hydrodynamical simulations that incorporate dark matter, baryons, massive neutrinos, and dark radiation, we present a detailed study of their impact on Lyman-Alpha forest observables. In particular, we accurately measure the tomographic evolution of the shape and amplitude of the small-scale matter and flux power spectra and search for unique signatures along with preferred scales where a neutrino mass detection may be feasible. We then investigate the thermal state of the intergalactic medium (IGM) through the temperature-density relation. Our results indicate that the IGM at z ~ 3 provides the best sensitivity to active and sterile neutrinos.

  • PDF

Transfer-learning-based classification of pathological brain magnetic resonance images

  • Serkan Savas;Cagri Damar
    • ETRI Journal
    • /
    • 제46권2호
    • /
    • pp.263-276
    • /
    • 2024
  • Different diseases occur in the brain. For instance, hereditary and progressive diseases affect and degenerate the white matter. Although addressing, diagnosing, and treating complex abnormalities in the brain is challenging, different strategies have been presented with significant advances in medical research. With state-of-art developments in artificial intelligence, new techniques are being applied to brain magnetic resonance images. Deep learning has been recently used for the segmentation and classification of brain images. In this study, we classified normal and pathological brain images using pretrained deep models through transfer learning. The EfficientNet-B5 model reached the highest accuracy of 98.39% on real data, 91.96% on augmented data, and 100% on pathological data. To verify the reliability of the model, fivefold cross-validation and a two-tier cross-test were applied. The results suggest that the proposed method performs reasonably on the classification of brain magnetic resonance images.

Application of sugarcane bagasse ash in the production of low cost soil-cement brick

  • Amaral, Mateus C.;Holanda, Jose N.F.
    • Advances in environmental research
    • /
    • 제6권4호
    • /
    • pp.255-264
    • /
    • 2017
  • This work investigated the use of sugarcane bagasse ash (SCBA) generated by an energy cogeneration process in sugarcane mill as an alternative raw material in soil-cement brick. The SCBA obtained from a sugarcane mill located in southeastern Brazil was characterized with respect to its chemical composition, organic matter content, X-ray diffraction, plasticity, and pozzolonic activity. Soil-cement bricks were prepared by pressing and curing. Later, they were tested to determine technical properties (e.g., volumetric shrinkage, apparent density, water absorption, and compressive strength), present crystalline phases, and microstructural evolution. It was found that the SCBA contains appreciable amounts of silica ($SiO_2$) and organic matter. The results showed that the SCBA could be used in soil-cement bricks, in the range up to 30 wt.%, as a partial replacement for Portland cement. These results suggest that the SCBA could be valorized for manufacturing low-cost soil-cement bricks.