scholarly journals Effects of Temperature and Aeration on The Dissolved Oxygen (DO) Values in Freshwater Using Simple Water Bath Reactor: A Brief Report

2020 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
Febiyanto Febiyanto

<em>This work investigated the effect of temperature and aeration treatments on the dissolved oxygen (DO) values in freshwater. The study was carried out using a simple water bath reactor in room temperature condition. Based on the results, freshwater sample without the aeration and temperature treatments (control) indicates a fluctuating profile on which the obtained values of DO were 4.21-4.98 mg/L at T<sub>average </sub>= 27.7 °C. However, the aeration treatment was slightly able to enhance the DO value up to 8.12 mg/L from the initial concentration of 3.88 mg/L at T<sub>average </sub>= 27.4 °C. Compared to the aeration treatment, the addition of temperature treatment has extremely increased the DO value up to 21 mg/L from 6.6 mg/L (T<sub>0 minutes</sub> = 27 °C)  for 20 minutes of DO observation (T<sub>20 minutes</sub> = 12.4 °C). Hence, this brief report suggests that the addition of temperature treatment gave a significant effect on the DO value in freshwater than the aeration treatment and control.</em>

1997 ◽  
Vol 19 (2) ◽  
pp. 39-44 ◽  
Author(s):  
Júlia M. C. S. Magalhães ◽  
Adélio A. S. C. Machado

This paper describes an automatic system which measures the effect of temperature variations on the response of ion-selective electrodes (hysteresis curves). The system is managed by a computer program which plots hysteresis curves following a pre-established temperature cycle, from setting and controlling the temperature of the water-bath, to acquiring the response potentials of up to five electrodes after temperature stabilization.


2014 ◽  
Vol 39 (2) ◽  
pp. 247-257 ◽  
Author(s):  
Humayun Reza Khan ◽  
Md Mosarraf Hossain

The eggs of Culex quinquefasciatus Say (Diptera: Culicidae) were exposed to 40oC for different exposure periods (viz. half an hour, one, two and four hours) and control (room temperature, 28±6oC); the percentage of egg hatching ranged from 74.14 to 96.33 (F=215.593, P<0.05), larval mortalities were from 24.52 to 0.00% (F=73.287, P<0.05), pupal mortalities ranged from 10.2 to16.71% (F=34.056, P<0.05), mean larval periods ranged from 127.9 to 155.3 hours (F=124.002, P<0.05), mean pupal periods ranged from 30.5 to 36.1 hours (F=10.531, P<0.05), lengths of 2nd instar ranged from 3.82 to 4.67 mm (F=16.50, P<0.05), lengths of 3rd instar ranged from 6.195 to 7.195 mm (F=7.558, P<0.05), lengths of 4th instar ranged from 7.395 to 8.025 mm (F=3.961, P<0.05), mean diameter of the head capsule of 1st instar larvae was 0.316 to 0.384 mm (F=8.308, P<0.05), that of 2nd instar larvae was 0.395 to 0.468 mm (F=4.953, P<0.05), that of 3rd instar larvae was 0.652 to 0.71 mm (F=2.629, P>0.05), that of 4th instar larvae was 0.806 to 0.91 mm (F= 13.871, P<0.05), length of the cephalothorax of pupae ranged from 1.862 to 2.062 mm (F=0.662, P>0.05), body length of male adults ranged from 3.41 to 3.58 mm (F=0.59, P>0.05), and that of female ranged from 3.75 to 4.09 mm (F=1.98, P>0.05), mean egg- rafts laid per female ranged from 1.4 to 2.0 and mean numbers of eggs per raft were 230 to 260. DOI: http://dx.doi.org/10.3329/jasbs.v39i2.17864 J. Asiat. Soc. Bangladesh, Sci. 39(2): 247-257, December 2013


1948 ◽  
Vol 38 (1) ◽  
pp. 90-92 ◽  
Author(s):  
R. Gane

SUMMARYThe loss of viability of seeds of Chewing's Fescue Grass has been a serious problem to both the producers in New Zealand and the trade in the United Kingdom. It has been shown by Foy (1934) that seeds with a high moisture content (20 %) held at 30° C. deteriorated rapidly after 10–14 days and even more quickly at 40° and 50° C. Seeds with a water content of 13 % deteriorated more slowly but it was not until the water content was reduced to and maintained at 5 % that seeds retained their viability at 30°, 40° or 50° C. for 42 days. Even at room temperature (16–20° C.) the loss of viability occurred after 4–5 months at 20 % water content and after 8–9 months at 13 % but at 5 % water content there was no loss. Foy discusses the effects of temperature and humidity that may occur during transport; Hyde (1935) has examined the effect of heating seeds to 50°, 60°, 70°, 80° and 90° C. with a view to working out the conditions for artificial drying of the seeds before transport, and Lewis (1934) has found that, in some seasons, there was a marked loss of viability in storing these seeds in the United Kingdom.


Author(s):  
Shuosi Wang ◽  
Tim Langrish

The effects of temperature, relative humidity and molecular structure on the crystallization process within amorphous solids have been explored. Lactose and sucrose were spray dried, and the products were exposed to different and relative humidities. To investigate the effect of temperature, experiments were conducted at both room temperature and 40oC. The rate of the crystallization was more than doubled for every increase of temperature by 10oC, up to three times for the case of lactose. These results are consistent with the picture of the process as an activated rate one. The effect of increasing relative humidity (RH) was observed to increase the rate of crystallization up to a threshold value, after which the rate was no longer affected by relative humidity. This threshold was found to be 51% for sucrose, at room temperature, which was lowered to 32% at 40oC. Lactose and sucrose, which have the same molecular weight of 342 g/mol but different molecular structures and thus glass transition temperatures, were exposed to similar conditions. The difference in molecular structures had little effect on the overall rate of the crystallization process for the same material temperatures, in contrast with the predictions of the Williams Landel Ferry equation, which suggests that the rate of crystallization is a function of the difference between the material temperature and the glass transition temperature.


Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.


1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.


MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 299
Author(s):  
Reetika Singh ◽  
Christophe Hano ◽  
Gopal Nath ◽  
Bechan Sharma

Carissa carandas L. is traditionally used as antibacterial medicine and accumulates many antioxidant phytochemicals. Here, we expand this traditional usage with the green biosynthesis of silver nanoparticles (AgNPs) achieved using a Carissa carandas L. leaf extract as a reducing and capping agent. The green synthesis of AgNPs reaction was carried out using 1mM silver nitrate and leaf extract. The effect of temperature on the synthesis of AgNPs was examined using room temperature (25 °C) and 60 °C. The silver nanoparticles were formed in one hour by stirring at room temperature. In this case, a yellowish brown colour was developed. The successful formation of silver nanoparticles was confirmed by UV–Vis, Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The characteristic peaks of the UV-vis spectrum and XRD confirmed the synthesis of AgNPs. The biosynthesised AgNPs showed potential antioxidant activity through DPPH assay. These AgNPs also exhibited potential antibacterial activity against human pathogenic bacteria. The results were compared with the antioxidant and antibacterial activities of the plant extract, and clearly suggest that the green biosynthesized AgNPs can constitute an effective antioxidant and antibacterial agent.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu-An Chen ◽  
Yong-Da Sie ◽  
Tsung-Yun Liu ◽  
Hsiang-Ling Kuo ◽  
Pei-Yi Chou ◽  
...  

AbstractMetastatic cancer cells are frequently deficient in WWOX protein or express dysfunctional WWOX (designated WWOXd). Here, we determined that functional WWOX-expressing (WWOXf) cells migrate collectively and expel the individually migrating WWOXd cells. For return, WWOXd cells induces apoptosis of WWOXf cells from a remote distance. Survival of WWOXd from the cell-to-cell encounter is due to activation of the survival IκBα/ERK/WWOX signaling. Mechanistically, cell surface epitope WWOX286-299 (repl) in WWOXf repels the invading WWOXd to undergo retrograde migration. However, when epitope WWOX7-21 (gre) is exposed, WWOXf greets WWOXd to migrate forward for merge. WWOX binds membrane type II TGFβ receptor (TβRII), and TβRII IgG-pretreated WWOXf greet WWOXd to migrate forward and merge with each other. In contrast, TβRII IgG-pretreated WWOXd loses recognition by WWOXf, and WWOXf mediates apoptosis of WWOXd. The observatons suggest that normal cells can be activated to attack metastatic cancer cells. WWOXd cells are less efficient in generating Ca2+ influx and undergo non-apoptotic explosion in response to UV irradiation in room temperature. WWOXf cells exhibit bubbling cell death and Ca2+ influx effectively caused by UV or apoptotic stress. Together, membrane WWOX/TβRII complex is needed for cell-to-cell recognition, maintaining the efficacy of Ca2+ influx, and control of cell invasiveness.


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