scholarly journals ELECTROPOLYMERISATION AND CHARACTERISATION OF DOPED-POLYPYRROLE AS HUMIDITY SENSOR

2010 ◽  
Vol 6 (2) ◽  
pp. 189-194
Author(s):  
Siswoyo Siswoyo ◽  
Trio F. Nugroho ◽  
Zulfikar Zulfikar ◽  
Agus Subekti
Keyword(s):  
Relative Humidity ◽  
Conducting Polymer ◽  
Humidity Sensor ◽  
Synthesis Process ◽  
Principal Characteristic ◽  
Volatile Chemicals ◽  
New Type ◽  
R Value ◽  
The Stability ◽  
Sensor Stability

A new type of sensing materials for humidity measurement has been developed based on conducting polymer polypyrrole synthesised from pyrrole by adding some dopant compounds, bromide and chloride, it is prepared by potentiodynamic-electropolymerisation technique. Variation of dopant types and concentration has been carried out in order to investigate the effect of this variation to the change of polymeric conductivity when interacting with water vapour. Polypyrrole-Cl (Ppy-Cl) and polypyrrole-Br (Ppy-Br) exhibit a good principal characteristic as sensor candidate namely responding proportionally to humidly variation ranging 30% - 90% relative humidity. Characterisation test for the sensor candidates has been carried out for evaluating their linearity respond toward humidity, their stability in certain period and their reproducibility in some tests. The results show that Ppy-Cl and Ppy-Br showing good linearity respond with R value in a range of 0.95 - 0.99. Their reproducibility and sensitivity were relatively good, however their respond stability were only last in few days. The stability probably is related to the stability of resulted polymeric structure that very affected by synthesis process and dopant used. It is necessary to extend the use of other dopant materials and changing the synthesis process in order to improve sensor stability. In other hand it is also necessary to characterise other performance characteristic of the sensor namely response time, and interference effect of some volatile chemicals and other gases.   Keywords: polypyrrole, potentiodynamic, electropolymerisation, humidity sensor and conducting polymer

Capacitive and Conductometric type Dual-Mode Relative Humidity Sensor based on 5,10,15,20-tetra phenyl porphyrinato nickel (II) (TPPNi)

2021 ◽  
Author(s):  
Rizwan Akram ◽  
Muhammad Yaseen ◽  
Zahid Farooq ◽  
Ayesha Rauf ◽  
Karwan Wasman Qadir ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Humidity Sensor ◽  
Dynamic Range ◽  
Layer Structure ◽  
Soret Band ◽  
Organic Polymer ◽  
Synthesis Process ◽  
Microwave Assisted Synthesis ◽  
Electrode Gap ◽  
Electron Microscopic

Abstract In the present study, TPPNi has been synthesized by using a microwave-assisted synthesis process. The layer structure of the fabricated humidity sensor (Al/TPPNi/Al) consists of pair of planar 120 nm thin Aluminium (Al) electrodes (deposited by thermal evaporation) and ~ 160 nm facile spin-coated solution-processable organic polymer TPPNi as an active layer between the ~ 40 µm electrode gap which was created through shadow mask process. Physical characterization showed that synthesized TPPNi thin films are very well suitable for their application as ambient sensors based on location and width for Soret band from optical characterization, amorphous structure from XRD, and most importantly the porous surface morphology from field emission scanning electron microscopic study. Electrical properties (capacitance and impedance) of sensors were found to be substantially sensitive not only on relative humidity but also on the frequency of the input bias signal. Our findings demonstrate that the TPPNi has higher humidity sensitivity at lower frequencies. The proposed sensor exhibits multimode (capacitive and conductometric) operation with significantly higher sensitivity ~ 146.17 pF/%RH at 500 Hz and 48.23 kΩ/%RH at 1 kHz. The developed Al/TPPNi/Al surface type humidity sensor's much-improved detecting properties along with reasonable dynamic range and response time suggest that it could be effective for continuous humidity monitoring in multi environmental applications.

scholarly journals Capacitive and Conductometric Type Dual-Mode Relative Humidity Sensor Based on 5,10,15,20-tetra Phenyl Porphyrinato Nickel (II) (TPPNi)

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3336
Author(s):  
Rizwan Akram ◽  
Muhammad Yaseen ◽  
Zahid Farooq ◽  
Ayesha Rauf ◽  
Ziyad M. Almohaimeed ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Humidity Sensor ◽  
Dynamic Range ◽  
Layer Structure ◽  
Synthesis Process ◽  
Microwave Assisted Synthesis ◽  
Electrode Gap ◽  
Sensing Material ◽  
Increasing Demand ◽  
Humidity Monitoring

(1) Background: A quest for a highly sensitive and reliable humidity monitoring system for a diverse variety of applications is quite vital. Specifically, the ever-increasing demand of humidity sensors in applications ranging from agriculture to healthcare equipment (to cater the current demand of COVID-19 ventilation systems), calls for a selection of suitable humidity sensing material. (2) Methods: In the present study, the TPPNi macromolecule has been synthesized by using a microwave-assisted synthesis process. The layer structure of the fabricated humidity sensor (Al/TPPNi/Al) consists of pair of planar 120 nm thin aluminum (Al) electrodes (deposited by thermal evaporation) and ~160 nm facile spin-coated solution-processable organic TPPNi as an active layer between the ~40 µm electrode gap. (3) Results: Electrical properties (capacitance and impedance) of sensors were found to be substantially sensitive not only on relative humidity but also on the frequency of the input bias signal. The proposed sensor exhibits multimode (capacitive and conductometric) operation with significantly higher sensitivity ~146.17 pF/%RH at 500 Hz and 48.23 kΩ/%RH at 1 kHz. (4) Conclusions: The developed Al/TPPNi/Al surface type humidity sensor’s much-improved detecting properties along with reasonable dynamic range and response time suggest that it could be effective for continuous humidity monitoring in multi environmental applications.

Relative Humidity Sensor Based on Tilted Fiber Bragg Grating With Polyvinyl Alcohol Coating

2009 ◽  
Vol 21 (7) ◽  
pp. 441-443 ◽  
Author(s):  
Yinping Miao ◽  
Bo Liu ◽  
Hao Zhang ◽  
Yuan Li ◽  
Haibin Zhou ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Polyvinyl Alcohol ◽  
Fiber Bragg Grating ◽  
Humidity Sensor ◽  
Bragg Grating ◽  
Relative Humidity Sensor

Effect of Geometric Parameters of New Semisubmersible Platform on Stability and Hydrodynamic Performance

2021 ◽  
Author(s):  
Tianying Wang ◽  
Yanjun Zhou ◽  
Honglin Tang ◽  
Shihua Zhang ◽  
Haiqing Tian
Keyword(s):  
Geometric Parameters ◽  
Hydrodynamic Performance ◽  
Geometrical Parameters ◽  
Main Body ◽  
Floating Bodies ◽  
Full Picture ◽  
New Type ◽  
Design Plan ◽  
The Stability ◽  
Shape Characteristics

Abstract The JCSM concept (short for Jackup Combined Semisubmersible Multifunction Platform) is a new type of semisubmersible platform presented by the first author, which overcomes the shortcomings of the available semisubmersible platforms, and combines the advantages of the traditional semisubmersible platform, the Jackup platform and the new FPSO concept - IQFP. Due to the complicated interaction between stability and hydrodynamic performance, it is necessary to explore the effect of geometrical parameters of the main body on the stability and hydrodynamic performance in order to obtain the optimal design plan of a JCSM platform. Firstly, the structure components and innovations of the JCSM were briefly reviewed in order to facilitate readers to understand its full picture. Then, six independent geometric parameters were selected by carefully studying the shape characteristics of the initial design plan of a JCSM study case. Furthermore, the stability heights and motion responses of various floating bodies of the JCSM case with different geometric parameters in wave were calculated using boundary element method based on potential flow theory. Lastly, effect of the shape parameters on stability and hydrodynamic performance of the JCSM was qualitatively evaluated. The research would shed lights on the shape design of the JCSM main body.

Highly sensitive BEHP-co-MEH:PPV + Poly(acrylic acid) partial sodium salt based relative humidity sensor

2017 ◽  
Vol 246 ◽  
pp. 809-818 ◽  
Author(s):  
Memoon Sajid ◽  
Hyun Bum Kim ◽  
Young Jin Yang ◽  
Jeongdai Jo ◽  
Kyung Hyun Choi
Keyword(s):  
Relative Humidity ◽  
Acrylic Acid ◽  
Sodium Salt ◽  
Humidity Sensor ◽  
Highly Sensitive ◽  
Relative Humidity Sensor ◽  
Poly Acrylic Acid

scholarly journals Evaluation of Lipases from Wild Microbial Strains as Biocatalysts in Biodiesel Production

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 53 ◽  
Author(s):  
Carlos Luna ◽  
Diego Luna ◽  
Felipa Bautista ◽  
Juan Calero ◽  
Antonio Romero ◽  
...  
Keyword(s):  
Biodiesel Production ◽  
Purification Process ◽  
Bacterial Strains ◽  
Production Methods ◽  
Mild Conditions ◽  
New Type ◽  
Microbial Strains ◽  
The Stability ◽  
Microbial Strain ◽  
Biodiesel Industry

In this study, the evaluation of the catalytic behavior of several wild bacterial strains in the 1,3-selective ethanolysis of triglycerides with ethanol to produce a new type of biodiesel (Ecodiesel) that integrates glycerol as monoacylglycerols was carried out. The Ecodiesel production not only avoids the elimination of glycerol, which is largely generated as a by-product in the biodiesel industry, but also results in an increase in the biofuel yield. The wild microbial strain samples were obtained from several lipophilic organisms. In addition to evaluate the enzymatic extracts, the minimum grade of purification of the strains, necessary to obtain similar results to those attained with commercial lipases was studied. This purification treatment included a dialysis followed by a lyophilization process. Such extracts were directly used as biocatalysts in the transesterification reaction of sunflower oil with ethanol, attaining much better results (yield close to 100%) than those obtained with strains which were not submitted to the purification process (yields lower than 10%). Furthermore, the results here obtained are similar to those obtained with commercial lipases but were achieved under mild conditions and lower reaction time (2 h). In addition, the stability of the enzymatic extracts was corroborated by subsequent reactions, showing no loss of activity. Thus, this study brings to light that enzymatic extracts obtained by a very simple purification process can be economically competitive with the conventional biodiesel production methods.

Stability of extemporaneously prepared rosuvastatin oral suspension

2017 ◽  
Vol 74 (19) ◽  
pp. 1579-1583 ◽  
Author(s):  
Abdel Naser Zaid ◽  
Rania Shtayah ◽  
Ayman Qadumi ◽  
Mashour Ghanem ◽  
Rawan Qedan ◽  
...  
Keyword(s):  
Relative Humidity ◽  
High Performance ◽  
Room Temperature ◽  
Microbial Contamination ◽  
Active Pharmaceutical Ingredient ◽  
Storage Conditions ◽  
Dissolution Profile ◽  
Stability Studies ◽  
Organoleptic Properties ◽  
The Stability

Abstract Purpose The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Methods Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. Results The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Conclusion Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature.

scholarly journals THE INFLUENCE OF THE STORAGE CONDITIONS OF RAW MATERIALS ON THE PRESERVATION OF THE PROPERTIES OF THE FUR SEMI-FINISHED PRODUCT

2021 ◽  
Vol 53 (3) ◽  
pp. 52-58
Author(s):  
Natalya P. Bodryakova
Keyword(s):  
Elevated Temperature ◽  
Relative Humidity ◽  
Raw Materials ◽  
Storage Conditions ◽  
Strength Properties ◽  
Biological Factor ◽  
Point Scale ◽  
Complex Characteristic ◽  
Characteristic Features ◽  
The Stability

This article deals with the problem of preserving the properties of a semi-finished fur product under the influence of a biological factor during the storage of raw materials. The characteristic features of the biodegradation of untreated rabbit skins during storage at elevated temperature and relative humidity are identified and described. A complex characteristic of a semi-finished fur product developed from raw materials of various degrees of microbiological spoilage is given. The author offers a point scale of assessment dynamics of the processes of destruction of fur raw materials and a point assessment of the organoleptic indicators of the semi-finished product was developed. As a result of comprehensive studies, it was found that the degree of damage to the fur raw materials being processed affects the decrease in the stability of the structure and strength properties of the finished semi-finished product.

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