Development of an auto-calibrated interfacing circuit for thick film multi-gas sensor

A simple, cheap, and integrated architecture is introduced to measure gases with a thick film gas sensor. The temperatures of the sensors are stabilized by controlling the heaters of the sensors. The heaters’ temperatures are measured by sampling the heaters resistance through the use of a voltage divider and ADCs. A microcontroller accordingly adjusts the output of DACs in order to apply the appropriate steering voltage to the heaters. The method employed to measure the gases is to sample the voltage drop over the resistances of the sensors, which are depending on the gases, by ADCs. The innovation lies in the simplicity of the design and the use of different simple methods and commercially available technologies to fabricate the circuit. Also, a single microcontroller is used to drive and control the heaters’ temperature, to compensate ambient temperature of the heaters, to measure and monitor the amount of gases detected by sensors and finally, to select the sensors. This opens the possibility to use these gas sensors for monitoring purposes at a large scale, for example in alarms and computers

Approche « Innovante » du Mythe d’Orphée : Étude de la Transition du Monde Antique au XXème Siècle par l’Eurydice de Jean Anouilh d’après la Mythanalyse de Gilbert Durand

Toute réécriture est une adaptation, une modernisation du texte, ainsi chaque époque nécessite un texte qui soit adapté aux goûts et aux attentes de ses contemporains. Jean Anouilh fait partie des dramaturges qui ont retravaillé sur les mythes antiques en essayant de leur donner une nouvelle dimension. Il introduit dans sa pièce intitulée Eurydice des nouvelles significations et, comme le titre indique, cette pièce favorise l’histoire d’une femme.Anouilh modifie quelques aspects du mythe fondateur et il ironise apparemment l’amour pur qui existe entre Orphée et Eurydice dans le mythe originel. L’approche « innovante » de ce mythe est la preuve d’un changement culturel capital, qui marque bien les changements des valeurs morales. Dans cette recherche, sera mise en évidence l’influence de la modernité qui provoque l’individualisme dans la reprise de ce mythe et en nous nous appuyant sur la mythanalyse de Gilbert Durand, nous mènerons des analyses sur les modifications imposées à ce mythe à travers l’étude des mythèmes secondaires dans la pièce d’Anouilh. Cette méthode de critique nous permet d’élaborer l’analyse de la réécriture de ce mythe au champ social. Nous étudierons les changements radicaux des valeurs morales dans la reprise de ce mythe, sous l’influence de la société du XXème siècle

Design interface circuits for thick film heater for a gas sensor resistor

In this paper an auto calibrated system of thick film resistive heater have been designed which can be adjusted to desired temperature. The circuit is consists of ADC, DAC, microcontroller, and current buffer. This circuit compensates dropt voltage across the heater which has been resulted from ambient temperature changes. Finally this circuit is able to control and adjust the heater's temperature automatically and also drives different resistive heaters for similar gas sensors

Presumed clomiphene-induced optic neuropathy: A case report

Background: Clomiphene citrate is an estrogen receptor ligand with mixed agonistic–antagonistic properties used for the treatment of female and male infertility. Various visual disturbances and several irreversible visual outcomes have been associated with clomiphene citrate. In this report, we present a patient with presumed clomiphene-induced optic neuropathy. Case: A 33-yr-old man with acute visual loss of the right eye was referred to Amiralmomenin Hospital, Rasht, Iran in November 2018. His only medication was clomiphene citrate 100 mg daily, taken for 2 wk for fertility issues. The patient presented with a sudden decrease of visual acuity in the right eye on the 14th day of starting the treatment and subsequently developed complete loss of inferior visual field within a few days. On examination, the visual acuity was 6/20 in the right and 20/20 in the left eyes, with a right relative afferent pupillary defect and decreased red color saturation. The fundus examination revealed optic disc swelling with venous dilation in the right eye and a normal left fundus with a crowded disc (disc-at-risk). The patient was evaluated for systemic disorders, all of which were normal. Findings were suggestive of non-arteritic anterior ischemic optic neuropathy most likely due to clomiphene. Conclusion: As clomiphene may increase blood viscosity, it is hypothesized that reduced flow in a posterior ciliary artery in conjunction with the disc-at-risk contributes to the anterior ischemic optic neuropathy. It is advised that patients with disc-at-risk be aware of the possible non-arteritic anterior ischemic optic neuropathy and those experiencing visual symptoms while taking clomiphene be examined promptly for evidence of optic nerve injury. Key words: Clomiphene citrate, Optic neuropathy, Visual acuity, Ischemia

Analysis of Imam Sadiq's (PBUH) Communication Approach to Zaidi's Sect Chiefs (Using PDAM Diffractive Discourse Analysis)

Imam Sadiq,(PBUH) the founder of Ja'fari School, is the main pillar of Shi'a from intellectual and ideological points of view. A large corpus of Ahlul-Bayt's traditions and instructions were disseminated by him. Imam Sadiq's (article has adopted a descriptive- analytical method and PBUH) period was a very important one since various sects emerged at that time, and Imam undertook the crucial task of preserving Shi'a by defying those deviations. Among those was the Zaidi sect which had more or less expanded in those days. Analyzing Imam's approach to that expanding sect is, therefore, of high importance. This an interdisciplinary approach with the aim of defining Imam Sadiq (PBUH) communication style when confronting the Zaidis.  A close look at Imam's conduct shows a number of treatments towards Zaidis that included attracting and repelling, defensive and offensive measures. Despite his righteousness and his dismissal of those deviated groups, he shunned any type of unethical behavior and utilized the very nature of the discourses as the promoter of Shiite. Furthermore, we learn from Imam that it was sometimes necessary do take a protective and offensive stance next to mild treatment to reject those who are not willing to submit to the truth

Analytical comparison for square, rectangular and circular diaphragms in MEMS applications

MEMS offer different fabrication process to fabricate diaphragms in various applications such as microphones, pressure sensors and micro-pumps, etc. The working principle of all these devices is based on the force applies on the one side of the diaphragm and cause the diaphragm deflects. The parameter optimization of diaphragm is the prime challenge due to achieve the best performance of the device. In this paper Displacement, Stress and Vibration analysis which affect on the operation of the diaphragm under pressures is considered. The different shapes of diaphragms (square, rectangular and circular shapes) are also play a significant role in operation in different applications. The purpose of this research is to design a framework to show which kind of diaphragm with what kind of parameters can be chosen for specific MEMS devices

Design of auto control interface circuit for thick film heater gas sensor

In this paper an automated control system of thick film resistive heater for gas sensor applications has been designed using low cost technologies. To control the desired temperature of heater, a programmable voltage with 12 bits resolution applies which can be adjusted to the appropriate temperature. The circuit consists of ADC, DAC, microcontroller, and current buffer. This circuit compensates dropt voltage across the heater which has been resulted from the ambient temperature changes. In particular, using one microcontroller for entire heater process is for the first time introduced to drive the heater, control heater temperature, and compensate ambient temperature of heater all together automatically. Fabrication of this circuit using commercially available technologies and simplicity of the circuit make it a novel and simple design in gas sensor applications. This circuit has the ability to connect to alarms and computers in order to monitoring purposes

Outcomes of Phaco-viscocanalostomy in Primary Open Angle Glaucoma versus Pseudoexfoliation Glaucoma

Purpose: Viscocanalostomy represents an alternative to standard penetrating glaucoma surgery. The aim of this study is to compare the outcomes of combined phacoemulsification and viscocanalostomy in eyes with primary open-angle glaucoma (POAG) versus eyes with pseudoexfoliation glaucoma (PEXG). Methods: In this prospective non-randomized comparative study, eyes with cataract and POAG or PEXG were enrolled. Pre- and postoperative data including best corrected visual acuity (BCVA), intraocular pressure (IOP), and the number of antiglaucoma medications administered were recorded at each visit. All patients underwent phacoviscocanalostomy. Complete success was defined as the IOP of 21 mmHg or less without the administration of medication while a qualified success reported the same IOP parameters either with or without the administration of medication. Results: Fifty-four eyes with POAG and fifty-four with PEXG underwent phacoviscocanalostomy. The mean follow-up time was 23.36 ± 8.8 months (range, 6–40 months). The mean postoperative IOP reduced significantly in both groups, although the mean IOP reduction was significantly greater in PEXG eyes (14.7 ± 8.9 vs 10.1 ± 7.7 mmHg) (P = 0.05). At the final follow-up visit, the mean postoperative IOP was 14.1 ± 2.1 and 16.6 ± 3.5 mmHg in the PEXG and POAG eyes, respectively (P = 0.001). A complete success rate of 88.9% and 75.9% was achieved in PEXG and POAG eyes, respectively (P = 0.07). The qualified success rate was 100% in the PEXG and 85.2% in POAG groups (P = 0.03). Conclusion: Phacoviscocanalostomy achieved significant IOP reduction and visual improvement in both POAG and PEXG patients. Our results indicated that in terms of IOP reduction, this procedure was more effective in treating PEXG

The Assessment of an Extended Set of Socio-Economic Determinants to Explain Anxiety and Uncertainty, Insufficient Quality and Food Intake of Afghan Refugees

OBJECTIVES: In this study, socio-economic factors associated with Afghan refugee households\u27 food insecurity, anxiety and uncertainty, insufficient quality and food intake were determined. DESIGN: Household Food Insecurity Assess Scale measurement was applied to assess food insecurity, anxiety and uncertainty, insufficient quality and insufficient food intake. Descriptive analysis and multivariable regression models were used to determine the associated factors. SETTING: The study was carried out in urban areas of Tehran province in Iran. PARTICIPANTS: To collect data, interviews were conducted among 317 Afghan households. The questionnaire was administered via face-to-face interviews to either the breadwinner of the selected households or a member who could respond on behalf of the household. RESULTS: About 11·3 % of Afghan households who resettled in Tehran province were food secure, while 11·7 % were marginally, 40·7 % moderately and 36·3 % severely food insecure. Economic and financial factors were inversely and significantly associated with food insecurity. Employment, income, distance from the central market and personal saving were inversely associated with food insecurity, while other determinants, including the length of living time in Tehran, house type and the number of male and female children, had a direct association with food insecurity. CONCLUSIONS: The associations of socio-economic factors with three categories of food insecurity differed. Elimination of occupation bans that the Iranian government imposes on refugees provides simple access to financial supports like long-term loans, and opening a bank account for refugees will benefit both Iranians and refugees

Development of auto-calibrated interfacing circuit for thick film multi-gas sensor

The gas sensors have been used for a number of applications particularly for reducing the pollution and human exposure to dangerous gasses. There are different ways of fabricating gas sensor which typically have high accuracy and high ability. One of these methods is by using thick film technology. Due to their high sensitivity and low cost of production, thick film gas sensors have been extensively employed. Screen printing is the general method of manufacturing thick film gas sensors which is a well organized technology and a low-cost way for large-scale production. The gas sensor with thick film technology consists of a sensitive layer and a heater. Each gas sensor is biased at constant temperature where the best reaction occurs at this temperature, which means they need be controlled. The effect of ambient temperature must be compensated because they will influence the heater performance negatively. The main objective of this thesis is to drive the heaters of thick film multi gas sensors by controlling the voltage and keeping the temperature of the heaters constant so that each heater will be able to compensate the effect of ambient temperature changes. Furthermore, the system can measure, monitor and display the gases detected by multi sensors in wide range. The interface circuit consists of ADC, DAC, microcontroller, current buffer, and latch buffer. The voltage divider method was used in this thesis by employing external series resistor in order to control the heater, compensate the ambient temperature, and measure the gas. Finally, a single microcontroller was employed to automatically run the entire process such as driving the heaters, controlling the heaters temperature, compensating the ambient temperature of the heaters, measuring the amount of gasses detected by the sensors and finally selecting the sensors