scholarly journals Moisture Desorption Studies on Polymer Hydrated and Vacuum Extruded Bentonite Clay Mat

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Eric Wooi Kee Loh ◽  
Devapriya Chitral Wijeyesekera ◽  
Mihaela Anca Ciupala

Moisture desorption observations from two bentonite clay mats subjected to ten environmental zones with individually different combinations of laboratory-controlled constant temperatures (between 20 °C and 40 °C) and relative humidity (between 15% and 70%) are presented. These laboratory observations are compared with predictions from mathematical models, such as thin-layer drying equations and kinetic drying models proposed by Page, Wang and Singh, and Henderson and Pabis. The quality of fit of these models is assessed using standard error (SE) of estimate, relative percent of error, and coefficient of correlation. The Page model was found to better predict the drying kinetics of the bentonite clay mats for the simulated tropical climates. Critical study on the drying constant and moisture diffusion coefficient helps to assess the efficacy of a polymer to retain moisture and control desorption through water molecule bonding. This is further substantiated with the Guggenheim–Anderson–De Boer (GAB) desorption isotherm model which is presented.

2020 ◽  
Vol 12 (2) ◽  
pp. 165-176
Author(s):  
Sunday Samuel Sobowale ◽  
Oluwole Benjamin Omotoso ◽  
Yusuf Olamide Kewuyemi ◽  
Olawale Paul Olatidoye

Nonlinear regression analysis was conducted for thin layer drying characteristics of two onion varieties (white and red) and some quality characteristics were also examined. The experimental data obtained at drying temperatures of 40, 50, and 60 oC and thicknesses of 2, 4 and 6 mm, was subsequently fitted into four commonly used models (Henderson and Pabis, Lewis, Page, and logarithmic). Moisture diffusivity and activation energy ranged from 8.9 × 10-10 to 8.4 × 10-9 m2/s and 55.98 to 65.68 KJ/mol, respectively. Significant differences (p<0.05) were observed in the colour profile and rehydration ratio. The optimum desirable colour was obtained at 50 oC with 2 mm thick onion slices and the observed higher rehydration ratio indicates good quality of dried onions. Among the four selected drying models, the Page model predicted optimally (R2> 0.9) and was found to be better in describing dried onion varieties, while the Lewis model provided the least fit.


Author(s):  
Norliza Latiff ◽  
Luqman Abdullah ◽  
Pei Ong ◽  
Amin Mohd

Drying kinetic models and energy characteristics are well known as tools to evaluate and predict the most suitable drying physiochemical conditions for a particular product. In this study, a thin-layer drying model was developed to best describe the drying kinetic behaviour of Cosmos caudatus (C. caudatus). The drying experiments were conducted using a thermal convection oven and C. caudatus leaves were dried at five different temperatures (40, 50, 60, 70, 80?C). Six different thin-layer drying models were proposed and applied to select the best drying model by fitting to the experimental moisture ratio data. The proposed drying models included Page, Modified Page, Lewis, Henderson-Pabis, Two Term and Weibull and the results were statically compared and evaluated based on their goodness of fit. Among these, the Page model was found to best to represent the thin-layer drying behaviour of C. caudatus with 99.76 %, 5.93 x 10-5, 9.68 x 10-5 for the coefficients determination (R2), reduced chi-square (?2), and root mean square error (RMSE), respectively. The average effective moisture diffusion coefficient (Deff) for the temperature 40 to 80?C ranged from 4.12 x 10-12 to 24.71 x10-12 m2/s, while the activation energy (Ea) was calculated at 39.35 kJ/mol based on the Arrhenius?s equation.


Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.


Author(s):  
Margaret Jane Radin

Boilerplate—the fine-print terms and conditions that we become subject to when we click “I agree” online, rent an apartment, or enter an employment contract, for example—pervades all aspects of our modern lives. On a daily basis, most of us accept boilerplate provisions without realizing that should a dispute arise about a purchased good or service, the nonnegotiable boilerplate terms can deprive us of our right to jury trial and relieve providers of responsibility for harm. Boilerplate is the first comprehensive treatment of the problems posed by the increasing use of these terms, demonstrating how their use has degraded traditional notions of consent, agreement, and contract, and sacrificed core rights whose loss threatens the democratic order. This book examines attempts to justify the use of boilerplate provisions by claiming either that recipients freely consent to them or that economic efficiency demands them, and it finds these justifications wanting. It argues that our courts, legislatures, and regulatory agencies have fallen short in their evaluation and oversight of the use of boilerplate clauses. To improve legal evaluation of boilerplate, the book offers a new analytical framework, one that takes into account the nature of the rights affected, the quality of the recipient's consent, and the extent of the use of these terms. It goes on to offer possibilities for new methods of boilerplate evaluation and control, and concludes by discussing positive steps that NGOs, legislators, regulators, courts, and scholars could take to bring about better practices.


Author(s):  
V. V. Agafonov ◽  
V. Yu. Zalyadinov ◽  
M. E. Yusupov ◽  
N. S. Bikteeva

Sustainability of mining companies is of of high concern. The problem is specifically acute at companies that are monotownor monosettlement-forming. Sustainability of a mine depends in many ways on product quality and production resource-intensity. This article discusses formation of mineral quality indexes in terms of an open pit chrysotile mine. The studies took into account specific features of operation procedures implemented by each structural division of the mine. The analysis has found managerial and technological inconsistencies which affect quality and marketable product output, as well as efficiency of the mine in whole. The background for efficiency enhancement at a company is, by the authors’ opinion, consolidation of personnel subject to the single development strategy, namely: improvement of production and control efficiency, as well as use of available reserves and resources by means of better setup for production. The proposed approaches to planning mining operations and forming mineral quality allow higher quality of processing stock. In addition, a new model proposed for interaction between structural divisions of a mining company ensures improvement of general production indexes.


2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Vũ Xuân Hùng

In the process of teaching, technical teaching facilities are both a content and a means of conveying information, they help the lecturer organize and control the students' cognitive activities, in addition, they also help students be interested in learning, practice practical skills from which to form active and creative learning methods. Teaching technology is one of the necessary conditions to help teachers carry out their related work of educating, teaching and bringing up, and intellectual development, arouse the inherent intelligence qualities of students. Currently, the management of technical teaching facilities at the Central Kindergartens College has been carried out on a regular basis and achieved certain results, but in fact, there are still many inadequacies. Finding a number of limitations in the management of teaching technical facilities, thereby proposing solutions to overcome those limitations, improve the efficiency of investment, preservation and use of teaching technical facilities in the trend of Industry Revolution 4.0, improving the quality of teaching at Central Kindergarten Pedagogy colleges in the current period is a very important and urgent task.


2019 ◽  
Author(s):  
Nur Tsalits Fahman Mughni

Teaching materials by integrating local culture makes easier for students to understand the subject matter in the learning process. The aims of the study is to measure the effectiveness of teaching materials based on local wisdom of agriculture in Binjai in improving the students problem solving abilities. The research method was a quasi experimental which use non equivalent control group in the pretest posttest design. The sample of study were students of Senior High School grade X in Binjai that consisted of experiment group which used teaching materials based on local wisdom of agriculture in Binjai and control group that used student handbooks. Teaching materials are tested by material experts and technology experts to ensure the quality of teaching materials. Data collection was conducted through test. The results showed that the teaching materials based on local wisdom of agriculture in Binjai effective in improving students problem solving abilities in the experimental group students based on the results of N gain value was 0.67 which has medium criteria. It means teaching materials based on agricultural local wisdom of agriculture in Binjai can be used as one of the teaching materials in learning activities.


Author(s):  
Dheeraj Kumar Tyagi ◽  
Shivakumar .

Lifestyle disorders are one of the biggest threats for the population living unhealthy lifestyle. Sthoulya (Obesity) is one such disorder which creates lot of physical as well as mental disorder to the sufferer. Due to changing lifestyle, comforts and dietary habit lots of individuals changed their life totally. Obesity is a growing disease in developed and developing countries. Prevalence is drastically hike in past few years. Ayurveda, the science of life with which we can manage and control lots of lifestyle disorders. Focusing on dietary and lifestyle management along with treatment, we can overcome the hazards of obesity which is growing in a uncontrolled manner. The available data is based on the clinical findings only. Aim and objective: To assess the effect of “Guru Cha Atarpanam Chikitsa” in the management of Sthoulya. Setting: Swastharakshana evam Yoga, OPD and IPD, SDMCAH, Hassan. Method: Udwarthana, Parisheka, Shamana Aushadhis, Ahara, and Vihara was followed within the treatment duration and effect of treatment was assessed before and after treatment, advised for follow up. Results: The treatment adopted is effective in the management of Sthoulya and to improve the quality of life.


Author(s):  
Adeleh Sadeghloo ◽  
Parna Shamsaee ◽  
Elham Hesari ◽  
Golbanhar Akhondzadeh ◽  
Hamid Hojjati

Abstract Introduction Thalassemia, as the most common chronic hereditary blood disorder in humans, can impose many adverse effects on parents and their affected children. On the other hand, positive thinking is the method or the result of a positive focus on a constructive issue, so by teaching positive thinking, we can improve physical and social function, and promote emotional health and overall quality of life. The aim of this study was to determine the effect of positive thinking training on the quality of life of parents of adolescents with thalassemia. Methods This quasi-experimental study was performed on 52 parents of adolescents with thalassemia who attended Taleghani Hospital in Golestan province, Iran in 2017. Samples were randomly assigned into two groups of intervention and control. The positive thinking training (based on the theory of Martin Seligman) was carried out in the intervention group in 10 (45–60 min) sessions over a 5-week period. Data collection tools in this study were the World Health Organization (WHO) quality of life questionnaire (WHOQOL-BREF) and a demographic information questionnaire. Data were analyzed by SPSS-16 software using independent t-test, the paired t-test and a covariance test. Results The results of paired t-test showed a significant difference in the score of quality of life in intervention group before and after the intervention (p < 0.001). However, this test did not show any significant difference in the control group (p = 0.11). The covariance test, after removing the pre-test score, showed a significant difference between the intervention and control groups in terms of the score of quality of life, so that 13% of the changes after the intervention were due to the intervention (p = 0.009, η = 0.13). Conclusion The positive thinking training increased the quality of life of parents of adolescents with thalassemia. Therefore, using this program can be an effective way of improving the quality of life of parents. Thus, positive thinking training is suggested to be used as an effective strategy for increasing the quality of life of parents with ill children.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Adele Brunetti ◽  
Francesca Macedonio ◽  
Giuseppe Barbieri ◽  
Enrico Drioli

Abstract The recent roadmap of SPIRE initiative includes the development of “new separation, extraction and pre-treatment technologies” as one of the “key actions” for boosting sustainability, enhancing the availability and quality of existing resources. Membrane condenser is an innovative technology that was recently investigated for the recovery of water vapor for waste gaseous streams, such as flue gas, biogas, cooling tower plumes, etc. Recently, it has been also proposed as pre-treatment unit for the reduction and control of contaminants in waste gaseous streams (SOx and NOx, VOCs, H2S, NH3, siloxanes, halides, particulates, organic pollutants). This perspective article reports recent progresses in the applications of the membrane condenser in the treatment of various gaseous streams for water recovery and contaminant control. After an overview of the operating principle, the membranes used, and the main results achieved, the work also proposes the role of this technology as pre-treatment stage to other separation technologies. The potentialities of the technology are also discussed aspiring to pave the way towards the development of an innovative technology where membrane condenser can cover a key role in redesigning the whole upgrading process.


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