2,225 research outputs found
Inhibiting sulphate attack on concrete by hydrophobic green plant extract
Organic base (Amine) and inorganic base (Nitrite) have been known for protection of concrete structures but are not commercially indigenous to most developing economies due to manufacturing difficulties and are toxic to the environment. Also inhibitors are not known to stop sulphate attack in concrete. Hence, the objective of the present investigation was to study a novel, eco-friendly and hydrophobic green plant extracts inhibitor and compares its effectiveness with established calcium nitrite and ethanolamine inhibitors. Bambusa Arundinacea (Green plant extracts), calcium nitrite and ethanolamine corrosion inhibitors were selected for the present investigation. Compressive strength of 100×100×100mm concrete cubes after 7, 28 and 90 days of curing test was used. The results of the inhibitors studied showed that Bambusa Arundinacea has superior compressive strength compared to calcium nitrite and ethanolamine. Bambusa Arundinacea may be considered a better substitute for nitrite and amine- based corrosion inhibiting admixtures for durable concrete structures due its pore blocking effects
Deployment of Mobile Ad-hoc Network Ticket Based QoS Routing Protocol for Healthcare
A Mobile Adhoc Network comprises of set of portable hosts which are equipped for corresponding with one another with no aid of base stations. MANET are quick evolving topology, broad exploration is going ahead to outline directing conventions for MANETs. The Ad hoc On-Demand Distance Vector convention concerns with most limited way steering and changing the courses powerfully in work space. Quality of Service (QoS) prerequisite issues are less tended to in MANETs and the motivation behind this paper is to address QoS directing in a MANET domain and concentrate principally on ticket based QoS steering convention to figure out course fulfilling certain data transmission and delay obliges. The essential thought is to utilize tickets to keep the quantity of route searching packets to abstain from flooding and to make courses progressively to accomplish proficient Quality of Service
Nd:YAG laser welding of stainless steel 304 for photonics device packaging
Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 µm has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique
Alpinum isoflavone from Erythrina stricta Roxb.
A partir de un extracto, obtenido con n-hexano de corteza de Erythrina stricta, se aisló la alpinum isoflavona. La estructura del compuesto fue determinada por métodos espectroscópicos y comparación con datos espectroscópicos publicadosAlpinum isoflavone was isolated from the n-hexane extract of stem bark of Erythrina stricta. The structure of the compound was elucidated by extensive spectroscopic studies and comparision with published spectroscopic data
In vitro evaluation of commercially available theophylline sustained release tablets in Pakistan
The dissolution behavior of five commercially available brands of sustained release theophylline
tablets was studied in phosphate buffer solutions of pH 1.2, 4.5, 5.5, 6.0 and 7.5 at 37 °C using the
USP dissolution apparatus II (paddle method). Drug concentration in the samples was determined spectrophotometrically
at 272 nm. For predicting the release characteristics of theophylline from selected commercially
available tablets the data obtained in the dissolution studies was fitted into various mathematic
models defining kinetic parameters of drug release like zero-order rate equation, first-order rate equation,
Hixen-crowell cube root law, Higuchi equation and Korsemeyer-Peppas model. Tablets were subjected to
weight variation test, hardness, drug content and in vitro release studies. The present study revealed that
drug release increases with the increase of pH of the dissolution medium and also varies from brand to
brand. Among the five selected brands, B1 and B4 showed better pH dependency and drug release behaviour.
It has been suggested that possible reasons for difference in dissolution or drug release behaviour
are the difference in the manufacturing techniques and the quantity of hydrophobic excepients used by
different manufacturers, which retard the penetration of dissolution medium and ultimately decreases
availability of drug in the solution.Colegio de Farmacéuticos de la Provincia de Buenos Aire
In vitro evaluation of commercially available theophylline sustained release tablets in Pakistan
The dissolution behavior of five commercially available brands of sustained release theophylline
tablets was studied in phosphate buffer solutions of pH 1.2, 4.5, 5.5, 6.0 and 7.5 at 37 °C using the
USP dissolution apparatus II (paddle method). Drug concentration in the samples was determined spectrophotometrically
at 272 nm. For predicting the release characteristics of theophylline from selected commercially
available tablets the data obtained in the dissolution studies was fitted into various mathematic
models defining kinetic parameters of drug release like zero-order rate equation, first-order rate equation,
Hixen-crowell cube root law, Higuchi equation and Korsemeyer-Peppas model. Tablets were subjected to
weight variation test, hardness, drug content and in vitro release studies. The present study revealed that
drug release increases with the increase of pH of the dissolution medium and also varies from brand to
brand. Among the five selected brands, B1 and B4 showed better pH dependency and drug release behaviour.
It has been suggested that possible reasons for difference in dissolution or drug release behaviour
are the difference in the manufacturing techniques and the quantity of hydrophobic excepients used by
different manufacturers, which retard the penetration of dissolution medium and ultimately decreases
availability of drug in the solution.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Design, Development and Evaluation of Portable Washer for Lotus Rhizomes
629-633The aim of the present study was to design, develop and evaluate a low cost portable washer for Lotus Rhizomes. Different performance parameters and colour values were studied to check the performance of the developed prototype in comparison to the manual washing. The capacity and efficiency of the machine was much higher than the existing manual method of washing. The colour coordinates (L* a* b*) revealed that washing through developed washer makes lotus rhizomes more clean and bright as compared to the manual washing. Different sanitizers were also tested for shelf life enhancement of lotus rhizomes. Out of all tested sanitizers, the citric acid was found best with regard to shelf life enhancement and cleanliness of lotus rhizomes. The economic analysis reveals that the developed lotus rhizome washer can be beneficial for the people who are directly or indirectly involved in lotus rhizome trade
Vasopressin for the management of catecholamine-resistant anaphylactic shock
Severe anaesthetic anaphylaxis is relatively uncommon. Oxygen, fluids and epinephrine are considered to be the mainstay for treatment of cardiovascular collapse and current guidelines for the management of anaphylaxis list only epinephrine as a vasopressor to use in the event of a cardiovascular collapse. Recently, evidence has emerged in the support of the use of vasopressin in cardiopulmonary resuscitation, it is also recommended for the treatment of ventricular fibrillation, septic shock and post-cardiopulmonary bypass distribution shock. Currently, there is no algorithm or guideline for the management of anaphylaxis that include the use of vasopressin. We report a 24-year-old woman who developed severe anaphylactic shock at induction of anaesthesia while undergoing laparoscopic cholecystectomy. Circulation shock was refractory to epinephrine and high doses of pure alpha-agonist phenylephrine and norepinephrine. Single intravenous dose of two units of vasopressin re-established normal circulation and blood pressure
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