Nonlinear boundary parameter identification of bridges based on temperature-induced strains

Zuo-Cai Wang,Guo-Peng Zha,Wei-Xin Ren,Ke Hu,Hao Yang 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.5

Temperature-induced responses, such as strains and displacements, are related to the boundary conditions. Therefore, it is required to determine the boundary conditions to establish a reliable bridge model for temperature-induced responses analysis. Particularly, bridge bearings usually present nonlinear behavior with an increase in load, and the nonlinear boundary conditions cause significant effect on temperature-induced responses. In this paper, the bridge nonlinear boundary conditions were simulated as bilinear translational or rotational springs, and the boundary parameters of the bilinear springs were identified based on the measured temperature-induced responses. First of all, the temperature-induced responses of a simply support beam with nonlinear translational and rotational springs subjected to various temperature loads were analyzed. The simulated temperature-induced strains and displacements were assumed as measured data. To identify the nonlinear translational and rotational boundary parameters of the bridge, the objective function based on the temperature-induced responses is then created, and the nonlinear boundary parameters were further identified by using the nonlinear least squares optimization algorithm. Then, a beam structure with nonlinear translational and rotational springs was simulated as a numerical example, and the nonlinear boundary parameters were identified based on the proposed method. The numerical results show that the proposed method can effectively identify the parameters of the nonlinear boundary conditions. Finally, the boundary parameters of a real arch bridge were identified based on the measured strain data and the proposed method. Since the bearings of the real bridge do not perform nonlinear behavior, only the linear boundary parameters of the bridge model were identified. Based on the bridge model and the identified boundary conditions, the temperature-induced strains were recalculated to compare with the measured strain data. The recalculated temperature-induced strains are in a good agreement with the real measured data.

Order parameter and crossover temperature from temperature-dependent refractive indices for low birefringence liquid crystals

Ranjkesh, Amid,Choi, Jun-Chan,Park, Ji-Sub,Park, Min-Kyu,Kiani, Somaye,Zakerhamidi, Mohammad Sadegh,Kim, Hak-Rin Elsevier 2017 Journal of molecular liquids Vol.230 No.-

<P>The temperature dependencies of three low birefringence (Delta n) liquid crystals (LCs) at similar clearing temperatures (T-NI) were investigated to characterize the order parameter S(T) and crossover temperature (T-co). Three different methods were used to determine the S(T) property, including the Vuks model, the Haller approximation model, and a model based on the effective geometry parameter (alpha(eg)). In our low Delta n LCs with relatively analogous T-NI, three parameters (B, (Delta n)(o), and beta) that originated from the modified four-parameter model were analyzed to increase the T-co condition. A larger absolute value for the B parameter and a smaller beta parameter were also needed to reduce the temperature dependence of Delta n. In particular, a lower (Delta n)(o) value was found to be beneficial for increasing the Too value, which resulted in a higher T-co value for the low Delta n LCs, compared with that of a high An LC with a similar T-NI value. This led to a narrower temperature range between T-co and T-NI for the low Delta n LCs compared to that of the high Delta n LC, which could result in appropriate temperature properties for LCs for practical display applications, including a lower temperature dependence of Delta n and wider operational temperature regime. (C) 2017 Published by Elsevier B.V.</P>

Optical anisotropy, order parameter and its critical behavior in temperature-dependent refractive indices of nematic liquid crystals

Ranjkesh, Amid,Kiani, Somaye,Strzeż,ysz, Olga,Zakerhamidi, Mohammad Sadegh,Yoon, Tae-Hoon Elsevier 2018 Journal of molecular liquids Vol.268 No.-

<P><B>Abstract</B></P> <P>The temperature dependence of optical birefringence, order parameter, effective geometry parameter, and normalized polarizability was determined for nematic liquid crystal mixtures by measuring the refractive indices. The effects of the adjustable parameters obtained from temperature-dependent refractive indices were analyzed appropriately for the crossover temperature and order parameter values. Besides, a four-parameter power law expression method was used for the optical birefringence measurement to address inappropriate fits in the weak first-order phase transition region. From this method, the effective second order phase transition temperature <I>T</I> <SUP>⁎⁎</SUP> was determined by showing the slightly higher values than phase transition temperature. The value of the order parameter critical exponent <I>λ</I> obtained from this method showed a good agreement with the mean field theory by demonstrating closeness to the tricritical hypothesis (<I>β</I> = 0.25). As a consequence, the measurement of the temperature-dependent optical birefringence was successfully verified the pre-transitional phenomena accurately, and it can facilitate an insightful description of that region.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Temperature dependence of high birefringence (∆<I>n</I>) liquid crystals was analyzed. </LI> <LI> The temperature dependent order parameter was sorted based on ∆<I>n</I> values. </LI> <LI> Lower (∆<I>n</I>)<SUB>o</SUB> and <I>β</I> values were valuable factors for increasing <I>T</I> <SUB>co</SUB> at the same <I>T</I> <SUB>NI</SUB>. </LI> <LI> A four-parameter power law expression shows the high critical exponent value. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

현장수준의 축산폐수처리에 있어서 계절별 농도 및 온도변화에 따른 분해반응계수 및 온도보정계수의 산정

박석환 한국환경보건학회 1996 한국환경보건학회지 Vol.22 No.2

This study was performed to calculate the degration rate coefficient, operating parameters to meet the effluent standards, and the temperature adjustment coefficients to each parameter of pollution by seasonal variation of concentration and temperature of influent in livestock wastewater treatment by sequencing batch reactor process in field scale. The followings are the conclusions that were derived from this study. 1. In the field, temperature of livestock wastewater in reactor was 20.3$\circ$C in summer and 6.0$\circ$C in winter. The ratio of BOD:TKN: T-P in influent was 100:80:7. BOD loadings in winter and spring were 0.26 and 0.43 kg $BOD/m^3$ day, respectively. Those in summer and fall were 0.25 and 0.13 kg $BOD/m^3$ day, respectively. 2. The degradation rate coefficient for TKN was larger in summer and fall in which temperature was high than that in which temperature was high than that in winter and spring in which concentration was high. On the contrary, the phosphorus uptake rate was larger in winter and spring than that in summer and fall. 3. The hydraulic retention time in winter and spring was longer than that in summer and fall. Especially, in order to meet the standard for TKN of 120 mg/l in winter in which temperature of wastewater was 6.0$\circ$C, as the MLSS concentration was increased from 4, 000 to 7, 000 mg/l, the hydraulic retention time was increased from 212 to 121 hours. But, in order to shorten that less than 121 hours for the economical wastewater treatment, countermeasure to increase temperature of wastewater in the reactor should be considered. 4. the temperature adjustment coefficients for BOD, $COD_{Mn}$, TKN and T-P were 1.0241, 1.0225, 1.0541 and 1.0495, respectively. Namely, the treatment of TKN was most sensitively affected by temperature. For the purpose of the effective removal of nitrogen and phosphorus which are sensitive to temperature, it is necessary to keep the temperature of livestock wastewater more than 20$\circ$C which is the temperature of it in summer.

고온 스트레스에 대한 배추의 생장과 광합성 및 엽록소형광 반응

오순자(Soonja Oh),문경환(Kyung Hwan Moon),손인창(In-Chang Son),송은영(Eun Young Song),문영일(Young Eel Moon),고석찬(Seok Chan Koh) 한국원예학회 2014 원예과학기술지 Vol.32 No.3

본 연구는 온도구배터널에서 자라는 배추의 잎에서 광합성적 CO₂ 교환과 엽록소형광을 분석함으로써 배추의 생장에 미치는 고온의 영향을 정량적으로 분석하였다. 결구가 형성되기 전의 생육초기에는 대기온도보다 대기온도 + 4℃와 대기온도 + 7℃ 조건에서 생장한 배추가 엽수의 증가와 엽길이의 신장이 두드러지게 나타났다. CO₂ 고정률은 대기온도 + 4℃에서 자란 배추의 잎에서 25.8μ㏖ㆍm<SUP>-2</SUP>ㆍs<SUP>-1</SUP>로 다소 높았으나, 생육 온도에 따라 통계적으로 유의한 차이는 없었다. 반면에 호흡률은 대기온도에서 다소 높았으며 대기온도 + 4℃와 대기온도 + 7℃ 조건에서는 낮았다. 기공전도도와 증산률은 대기온도에서보다 대기온도 + 4℃와 대기온도 + 7℃ 조건에서 증가하고 수분이용효율은 감소하였다. 그리고, OKJIP 곡선의 패턴에서도 상승온도에서 FJ, FI, FP가 크게 낮아지고, 고온에서 특이적으로 나타나는 FK의 증가와 FV/FO값의 감소 등을 확인할 수 있었다. RC/CS는 대조구에 비해 온도가 높아지면 크게 감소하였으며, ABS/CS, TRo/CS와 ETo/CS도 온도가 높아짐에 따라 점차 줄어들었다. 이에 반해 DIo/CS는 온도가 높아짐에 따라 증가하였다. 그리고 대조구인 대기온도에서는 정식 후 7주, 9주, 10주째에 수확한 배추 내부에서 병징이 나타나지 않았으나, 대기온도 + 4℃와 대기온도 + 7℃ 조건에서는 재배기간이 길어질수록 점차 무름병에 의한 피해가 두드러지게 나타났다. 이러한 결과는 급격하게 변화하는 미래의 기후 환경 하에서 배추가 고온 스트레스에 노출될 가능성을 암시하고 있다. 따라서 배추의 안정적인 생산을 위해서는 고온 적응성 품종, 특히 결구 시점에서 내고온성이 강한 품종을 육성하거나 고온의 피해를 최소화할 수 있는 재배기술이 확립되어야 할 것으로 보인다. 그리고 결구형성 시 고온 스트레스의 영향을 조기감별하기 위해서 OKJIP 곡선에서 FK의 증가를 비롯하여 기존에 사용되고 있는 변수인 FO, FV/FM와 FV/FO 이외에도 MO, SM, RC/CS, ETo/CS, PIabs, SFIabs 등의 형광변수들이 유용하게 활용될 수 있을 것으로 보인다. In order to gain insight into the physiological responses of plants to high temperature stress, the effects of temperature on Chinese cabbage (Brassica campestris subsp. napus var. pekinensis cv. Detong) were investigated through analyses of photosynthesis and chlorophyll fluorescence under 3 different temperatures in the temperature gradient tunnel. Growth (leaf length and number of leaves) during the rosette stage was greater at ambient + 4℃ and ambient + 7℃ temperatures than at ambient temperature. Photosynthetic CO₂ fixation rates of Chinese cabbage grown under the different temperatures did not differ significantly. However, dark respiration rate was significantly higher in the cabbage that developed under ambient temperature relative to elevated temperature. Furthermore, elevated growth temperature increased transpiration rate and stomatal conductance resulting in an overall decrease of water use efficiency. The chlorophyll a fluorescence transient was also considerably affected by high temperature stress; the fluorescence yield FJ, FI, and FP decreased considerably at ambient + 4℃ and ambient + 7℃ temperatures, with induction of FK and decrease of FV/FO. The values of RC/CS, ABS/CS, TRo/CS, and ETo/CS decreased considerably, while DIo/CS increased with increased growth temperature. The symptoms of soft-rot disease were observed in the inner part of the cabbage heads after 7, 9, and/or 10 weeks of cultivation at ambient + 4℃ and ambient + 7℃ temperatures, but not in the cabbage heads growing at ambient temperature. These results show that Chinese cabbage could be negatively affected by high temperature under a future climate change scenario. Therefore, to maintain the high productivity and quality of Chinese cabbage, it may be necessary to develop new high temperature tolerant cultivars or to markedly improve cropping systems. In addition, it would be possible to use the non-invasive fluorescence parameters FO, FV/FM, and FV/FO, as well as FK, MO, SM, RC/CS, ETo/CS, PIabs, and SFIabs (which were selected in this study), to quantitatively determine the physiological status of plants in response to high temperature stresses.

Temperature Dependence of Action Potential Parameters in <b><i>Aplysia</i></b> Neurons

Hyun, Nam Gyu,Hyun, Kwang-Ho,Lee, Kyungmin,Kaang, Bong-Kiun S. Karger AG 2012 Neuro-Signals Vol.20 No.4

<P>Abstract</P><P>Although the effects of temperature changes on the activity of neurons have been studied in <I>Aplysia</I>, the reproducibility of the temperature dependence of the action potential (AP) parameters has not been verified. To this end, we performed experiments using <I>Aplysia </I>neurons. Fourteen AP parameters were analyzed using the long-term data series recorded during the experiments. Our analysis showed that nine of the AP parameters decreased as the temperature increased: the AP amplitude (A<SUB>AP</SUB>), membrane potential at the positive peak (V<SUB>pp</SUB>), interspike interval, first half (Δt<SUB>r1</SUB>) and last half (Δt<SUB>r2</SUB>) of the temperature rising phase, first half (Δt<SUB>f1</SUB>) and last half (Δt<SUB>f2</SUB>) of the temperature falling phase, AP (Δt<SUB>AP, 1/2</SUB>), and differentiated signal (Δt<SUB>DS, 1/2</SUB>) half-width durations. Five of the AP parameters increased with temperature: the differentiated signal amplitude (A<SUB>DS</SUB>), absolute value of the membrane potential at negative peak (∣ V<SUB>np</SUB> ∣), absolute value of the maximum slope of the AP during the temperature rising (∣ –MSR ∣) and falling (∣–MSF∣) phases, and spiking frequency (Frequency). This work could provide the basis for a better understanding of the elementary processes underlying the temperature-dependent neuronal activity in <I>Aplysia.</I></P><P>Copyright © 2012 S. Karger AG, Basel</P>

Effect of water temperature on protein requirement of Heteropneustes fossilis (Bloch) fry as determined by nutrient deposition, hemato-biochemical parameters and stress resistance response

Shabihul Fatma,Imtiaz Ahmed 한국수산과학회 2020 Fisheries and Aquatic Sciences Vol.23 No.1

Background: Dietary protein requirements are dependent on a variety of factors and water temperature is one of the most important abiotic factors affecting protein requirement of fish. This study was, therefore, conducted to investigate effects of water temperature on dietary protein requirement of fry Heteropneustes fossilis which has high demand in most of the Asian markets. Methods: Quadruplicate groups of 30 fish per treatment (2.97 ± 0.65 cm; 5.11 ± 0.34 g) were fed seven isoenergetic diets (17.9 kJ g−1 gross energy; 14.99 kJ g−1 digestible energy) containing dietary protein levels ranging from 28 to 52% at two water temperatures (18 and 26 °C). Experimental diets were fed to apparent satiation as semi-moist cakes thrice daily at 17:00, 12:00, and 17:30 h for 12 weeks. For precise information, various growth parameters, protein deposition, hematological parameters, metabolic enzymes, and stress response were analyzed, and effects of water temperature on dietary protein requirement was recommended on the basis of response from above parameters. Results: Groups held at 26°C attained best growth, feed conversion, and protein deposition at 44% dietary protein indicating that temperature affected dietary protein requirement for optimum growth of H. fossilis fry and protein requirement seems to be satisfied with 44% dietary protein. Interestingly, interactive effects of both dietary protein levels and temperature were not found (P > 0.05). Fish reared at 18 °C had comparatively higher values for aspartate and alanine transferases than those reared at 26 °C water temperature which exhibited normal physiological value for these enzymes indicating that body metabolism was normal at this temperature. Hematological parameters also followed same pattern. Furthermore, fish reared at 26 °C water temperature exhibited more resistant to thermal stress (P < 0.05). The 95% maximum plateau of protein deposition data using second-degree polynomial regression analyses exhibited dietary protein requirement of fry H. fossilis between 40.8 and 41.8% of diet at 26 °C water temperature. The recommended range of dietary protein level and protein/digestible energy ratio for fry H. fossilis is 40.8–41.8% and 27.21–27.88 mg protein kJ−1 digestible energy, respectively. Conclusions: Information developed is of high significance for optimizing growth potential by making better utilization of nutrient at 26 °C and, to develop effective management strategies for mass culture of this highly preferred fish species.

전문가 경험치를 반영한 이력 온도 해석 시스템

이창근,구명모,김상복 한국지식정보기술학회 2014 한국지식정보기술학회 논문지 Vol.9 No.6

We proposes using a Time History of Temperature Analysis System by applying Expert Weight Value for obtaining a measurement of temperature with precision according to a temperature change due to external circumstances. It is not easy to precisely diagnose a normal temperature change using the existing system, which employs a fiber optic sensor. Only once a temperature has been accepted as normal, may it be considered valid Historical Information and be utilized for reference. When it exceeds a specified figure of Historical Temperature Information, it is rated to be a mistake. This paper applied Expert Weight Value to Historical Temperature Information of the temperature measured in real-time, specifically while diagnosing a normal and an abnormal temperature and the difference between the standard Historical Temperature Information and the measured temperature. In this paper, we improved the history information Data in our system for Historical Temperature and Alarm Temperature which are used in the history inquiry module in the simple typical Optical Temperature Distribution Sensor Measurement system. Simulations demonstrated that this system showed a relatively higher rate of diagnosis of a temperature change than the existing system that does not apply Expert Weight Value.

Correlation between the ash composition and melting temperature of waste incineration residue

이제근,Mi-Ran Kim,Jeong-Gook Jang,Sang-Keun Lee,Bu-Yeon Hwang 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.3

The correlation between the ash composition of various incinerated waste residues and their melting temperatures was examined by using their chemical composition parameters. There was a low correlation between the melting temperatures and the acidic oxide content in the ashes. However, the composition parameters derived from the basic oxides showed a good correlation with the ash melting temperature. The composition parameter, P7, which is defined as the ratio of basic oxides (CaO+MgO+K2O+Na2O) to acidic oxides (SiO2+Al2O3+Fe2O3), showed a strong correlation with the ash melting temperature. By fitting the composition parameter to the experimental data, the correlation equation for the half fluid temperature (HFT) was found to be HFT=426.77P72−736.76P7+1592.3 with a correlation coefficient of 0.91. The correlation equation could be used to predict the melting temperatures of various waste incineration residues. The relative error between the measured and predicted melting temperature was approximately 5%. Overall, these parameters and correlation equations can be used to predict and reduce the melting temperature of incineration residues.

Model based on temperature parameters predicts optimal harvest date for ‘Whasan’ Asian pear

서호진,Po-An Chen,Jang Hoon Song 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.5

The optimal harvest date for ‘Whasan’ pears ( Pyrus pyrifolia ‘Whasan’), which is diffi cult to predict, is currently determinedon the basis of fi eld observations of fruit quality. To create better models for predicting pear maturation, we utilized fl oweringperiod data from the Pear Research Institute, South Korea; commercial harvest data; and daily meteorological informationfrom 2007 to 2011 to assess fi ve temperature-related parameters for inclusion in the models: (1) daily mean temperature; (2)daily maximum temperature; (3) daily minimum temperature; (4) average of the daily mean temperature and daily maximumtemperature; and (5) average of the daily mean temperature, daily maximum temperature, and daily minimum temperature. We used these parameters and the minimum coeffi cient of variation method to estimate the base temperature and constructfi ve temperature-based models for predicting harvest date. Data from 2015 to 2016 were used to evaluate the performanceof these models, as assessed by average absolute deviation, average squared error, and average absolute percentage error. Using the average of the daily mean and maximum temperatures as the variable input temperature and 9.4 °C as the basetemperature, we obtained the most accurate prediction of the optimal pear harvest date. Our model indicates that the optimalharvest date for ‘Whasan’ pear occurs at 2370 accumulated growing-degree days after full bloom.