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Article
Low Cost Heart Rate Monitor Using Led-Led Sensor
مراقب عدد دقات القلب واطئ الكلفة باستخدام متحسس الثنائي الباعث للضوء

Author: Ahmed Mahrous Ragib احمد محروس راغب
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2009 Volume: 5 Issue: 3 Pages: 23-27
Publisher: Baghdad University جامعة بغداد

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Abstract

A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG) measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs) has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs) replaced by the pulse-based signal conversion techniques. A general purpose microcontroller has been used for the implementation of measurement protocol. The proposed approach leads to better spectral sensitivity, increased resolution, reduction in cost, dimensions and power consumption. The basic sensing configuration presented is capable of detecting the PPG signal from a finger or toe, and it is very simple to extract the heart rate and heart rate variability from such a signal.

تم تطوير متحسس قليل استهلاكه للقدرة وعالي الحساسية وقليل التكلفة لاستخدامه في الجهاز الذي يراقب عدد دقات القلب عن طريق مراقبة جريان الدم (بي بي جي). مبدأ الـ (بي بي جي) طبق ليتبع ارتخاء وانقباض الأوعية الدموية خلال الدورة القلبية. استخدم الثنائي الباعث للضوء كمشع للضوء وككاشف، ولغرض تقليل الحيز والتكلفة والقدرة المستهلكة فقد تم استبدال محول الإشارة التماثلية إلى الرقمية التقليدي تم استبداله بتقنية تحويل الإشارة بالاعتماد على النبضة. معالج دقيق متعدد الاستخدامات قد استخدم للتنفيذ والقياس. أدت الطريقة المقترحة إلى تحسس اكبر، زيادة في الدقة، تقليل في الكلفة، وكذلك الأبعاد والقدرة المستهلكة. التراكيب المقدمة قادرة على كشف إشارة الـ (بي بي جي) من الإبهام لليد والقدم وإيجاد معدل دقات القلب وتغيراته بصورة سهلة جدا.


Article
Effect of curing modes on the depth of cure of resin composite

Author: Abdul–Adheem R Al–Mallah
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 2 Pages: 195-200
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To study the effect of different curing modes of Light emitting diodes (LED) curing unit on thedepth of cure (DOC) of composite resin with light and dark shades and compare the results withconventional curing method by the use of halogen curing light. Materials and Methods: A total of 40cylindrical composite resin samples (4mm diameter and 6mm height) were prepared, 20 of light shadeand 20 of dark shade. They were subjected to four curing modes (n=5 for each group): conventionalhalogen light, and three modes related to the LED light curing unit (LCU) which were: Fast (F); Ramped(R); and Pulsed (P). The samples were irradiated to the time required by the manufacturer for each curingmode, and a digital micrometer was used to measure the depth of cure according to scraping methoddescribed in ISO 4049:2000. Data were collected and analyzed for comparison. Results: No significantdifference was found in the DOC of composite irradiated by LED curing light for all of the three curingmodes or shade. However, the LED produced significantly greater depths of cure when compared withconventional halogen curing unit for both shades. The lighter shade was cured to a significantly greaterdepth than dark one when considering halogen LCU. Conclusions: All curing modes of the LED lightcan produce similar DOC regardless of composite shade when irradiated to the time recommended by themanufacturer. However, Curing with conventional halogen curing unit yielded the least DOC values forlight or dark shades when compared with LED units. Longer irradiation times are needed to cure darkshades by the use of halogen LCUs.


Article
Synthesis and Characterization of New Polyamide Derived from Crystal Violet Dye Utilizing as Light Emitting Diode

Journal: basrah journal of science البصرة للعلوم ISSN: 18140343 Year: 2009 Volume: 27 Issue: 1A english Pages: 52-63
Publisher: Basrah University جامعة البصرة

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Abstract

New polymer Poly Crystal Violet Terephthalate (PCVT) was synthesis by condensationpolymerization of Crystal Violet dye with Terphthalic acid in acidic medium .The polymer wascharacterized by several technique such as FT-IR spectroscopy , 1H NMR spectroscopy , X-Raydiffraction (XRD) and Fluorescence technique . Curing study of new polymer was carried out byDifferential Scanning Calorimetry (DSC) under Nitrogen gas, the optimum conditions of curing wereobtained like curing temperature ,the curing energy and the activation energy of curing (ΔE).Theseanalysis indicated the correct composition of polymer .From DSC curve indicate that the reaction typeExothermic ,also the Fluorescence spectrum of polymer indicate that there are large change ofemission wavelength with high intensity as compare with dye only .So the new polymer can be use inapplications of light emitting diodes

تم تحضير نوع جديد من البوليمرات من خلال تكثيف حامض التيرفثالك مع صبغة الكريستال البنفسجية في وسطحامضي وقد تم تشخيص البوليمر الجديد بوساطة تقنيات عدة منها طيف الأشعة تحت الحمراء والرنين النووي المغناطيسيوالأشعة السينية وتقنية التفلور.درست عملية التقسية بوساطة تقنية المسح التفاضلي ألمسعري وتحت جو متحرك من النتروجين وتم تحديد الظروفالمثلى لعملية التصلب مثل درجات حرارة التقسية وطاقة التصلب وطاقة التنشيط. أثبتت الدراسة من خلال التشخيصالطيفي صحة الترآيب المقترح ومن دراسة منحنى المسح التفاضلي ألمسعري أن التفاعل من النوع الباعث للحرارة وآذلكاثبت طيف التفلور إن هناك تغير آبير في طول موجي الانبعاث وبشدة عالية جدا عما هو عليه في دراسة أطياف التفلورللصبغة وعليه يمكن مبدئيا استخدام البوليمر الجديد في تطبيقات الثنائيات الباعثة للضوء


Article
Effect of Type of Light Curing Unit on Shear Bond Strength of Resin Composite

Author: Kasim A Mohammad
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 3 Pages: S10-S17
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To compare the shear bond strength (SBS) of composite bonded to dentin cured by three light curing units (LCUs), which are quartz tungsten halogen (QTH) and two types of light emitting diode (LED) machines. Materials and Methods: Buccal dentin of 90 upper premolars was exposed, prior to restorative procedure. Samples divided into 3 groups, restoration of each group cured by Astralis 5 [Austria], Top Light, [Taiwan] and Ultradent [USA]. Each group further subdivided into three subgroups. After bonding application, each subgroup of every group restored by one of 3 composites: Point 4™, Tetric and Degufill mineral. Composite applied and cured for 40 seconds. Samples thermocycled and loaded at tooth–composite interface. Results: Analysis of variance (ANOVA) with significance p < 0.05 followed by Duncan Multiple Range Test, showed that SBS of subgroups that cured by Ultradent (400 mW/cm2) was significantly higher than Astralis 5 (405 mW/cm2) and Top Light (141 mW/cm2). The SBS of Astralis 5 was significantly higher than Top Light. No significant differences found among subgroups those cured by same LCU. Conclusions: Shear bond strength of resin composite bonded to dentin is directly proportional with the light intensity. However, better result obtained by a high intensity LEDs compared with an equivalent intensity QTH–LCUs.


Article
Fabrication of electroluminescence device for PEDOT: PSS / ploy TPD/Eu2O3 nanoparticles junction
تصنيع نبائط الأستضائية الكهربائية هجينة المفرق من PEDOT:PSS/ بولمر TPD/ جسيمات Eu2O3 النانوية

Authors: Hussein Riyadh Mohammed حسين رياض محمد --- Omer A. Ibrahim عمر عدنان ابراهيم
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2019 Volume: 17 Issue: 43 Pages: 33-40
Publisher: Baghdad University جامعة بغداد

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Abstract

The nanoparticles light emitting diode (NPs-LED) fabricated for organic and inorganic semiconductors to achieve electroluminescence (EL). The nanoparticles of Europium oxide(Eu2O3) were incorporated into the thin film layers of the organic compounds, poly(3,4,- ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT:PSS), N,N’–diphenyl-N,N’ –bis(3-methylphenyl)-1,1’-biphenyl 4,4’- diamine (poly TPD) and polymethyl methacrylate (PMMA), by the spin coating and with the help of the phase segregation method. The EL of NPs-LED, was study for the different bias voltages (20, 25, 30) V at the room temperature, from depending on the CIE 1931 color spaces and it was generated the white light at 20V, the orange light generation at 25Vand the red light at 30 V. That by benefit from transition between deep levels in energy gap for Eu2O3 nanoparticles (surface state) and magnetic dipole states for Eu+ (5D0-3 and5L6 to 7F0-6). The Current – Voltage (I-V) Behavior demonstrate that the current comparative with the voltage was good and the knee voltage was 5 V. The EL spectrum shows a broad band emission, the range from EL 485-700 nm. Finally, the range of correlated color temperature (CCT) it was between (1200 to 4000).

تم تصنيع الصمام الثنائي الباعث للجسيمات النانوية (NPs-LED) لأشباه الموصلات العضوية وغير العضوية لتحقيق الاستضائية الكهربائية (EL). حيث تم غرس الجسيمات النانوية لأكسيد اليوروبيوم (Eu2O3) في طبقات الأغشية الرقيقة للمركبات العضوية المتكونة من, poly(3,4,- ethylene dioxythiophene) N,N’–diphenyl-N,N’ –bis(3-methylphenyl)-1,1’-biphenyl 4,4’- diamine(TPD) :(PMMA) / (PDOT:PSS) بواسطة الطلاء الدوار و بمساعدة طريقة الفصل الطوري. تم دراسة الاستضائية الكهربائية للدايود الباعث للضوء، بتطبيق جهود انحياز مختلفة (20، 25، 30) فولت في درجة حرارة الغرفة، ومن أخذ مساقط الالوان على مخطط المساحات اللونية CIE 1931، لوحظ توليد الضوء الأبيض عند 20 فولت، وتوليد الضوء البرتقالي في 25 فولت و الضوء الأحمر في 30 فولت. وفسر الحصول على هذهِ الألوان من الانتقالات بين المستويات العميقة في فجوة الطاقة للجسيمات النانوية للاوكسيد اليوريبيوم (المستويات السطحية) وحالات ثنائي القطب المغناطيسيEu+ (5D0-3,5L6 - 7F0-6). كذلك يتضح سلوك التيار- الجهد (I-V) أن التيار المقابل للجهد كان جيدًا وأن جهد العتبة كان 5 فولت. من مخطط الاستضائية الكهربائية يظهر طيف انبعاث واسعاً يتراوح من (480-700) نانومتر. أخيرًا، تتراوح درجة حرارة المرتبطة باللون (CCT) بين (1200 إلى 4000).


Article
Effects of Curing Modes of Light Emitting Diode on Shear Bond Strength of Resin Composite

Authors: ALi M Rasheed --- Mohammad Gh Hamdoon --- Kasim A Mohammad
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2008 Volume: 8 Issue: 2 Pages: 168-176
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: To evaluated the SBS of three resin composites (Tetric Flow, Tetric and Heliomolar) bonded to dentin and cured by different curing modes utilizing light emitting diode (LED) light curing unit. Materialsand Method: Buccal dentin of 90 upper premolars was expose and Clearfil SE Bond applied and cured prior to restorative procedure. Samples divided into 9 groups (3 groups for each composite type),photoactivation of groups of each composite was carried out using three modes: Continuous (CO: 600 mW/cm2 for 40 s), Soft-Start (SS: 100 mW/cm2 for 10 s + 600 mW/cm2 for 30 s) and Pulse-Delay (PD:100 mW/cm2 for 3 s + 3 min wait + 600 mW/cm2 for 37 s). Samples thermocycled and loaded at toothcomposite interface at 1 mm/min cross head speed until failure. Results: Two-way ANOVA (p < 0.05) followed by Duncan multiple range test revealed that SBS of SS mode (21.5 Kg) is significantly higherthan SBS of both CO (18.1 Kg) and PD (18.7 Kg) and its also revealed that although SBS of Tetric Flow (21.2 Kg) is higher than that of Tetric (20.1 Kg) and both are significantly higher than that of Heliomolar (16.9 Kg).Conclusions: Less material’s rigidity along with slower polymerization reaction by SS mode result in higher SBS due to lesser contraction stress at the adhesive interface


Article
Evaluation of brackets shear bond strengths using two different light–emitting diode curing units

Author: Ahmad A Abdul–Mawjood
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2006 Volume: 6 Issue: 2 Pages: 171-175
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the efficiency of two types of light–emitting diode (LED) curing units in bonding orthodontics brackets. Materials and Methods: Three groups, ten teeth each, of newly extracted premolars were used in the study. In the control, the brackets were bonded using a halogen bulb light curing unit, while in the other two groups the brackets were bonded using a high and a low intensityLED curing unit, respectively. The brackets were bonded to the teeth using Transbond® light–cured orthodontic adhesive. The bonded brackets were tested for their shear bond strength using a universal compression machine. Results: The mean bond strength of brackets bonded with the high intensity LED curing unit was above the clinically accepted value and it was comparable to that of the halogenbulb light curing unit group. Meanwhile, the mean bond strength of brackets bonded with the lowintensity LED curing unit significantly differed from the other two groups and was below the clinicalacceptance level. Conclusion: The high intensity LED curing units can be used successfully in bonding orthodontic brackets. The bond strength was sufficient to consider these units as good substitutes for the halogen bulb–based units. The low intensity LED curing units are not recommended to be used inorthodontics.


Article
The Effect of Light Curing Tip Distance on Curing Depth of Resin Composite: A Comparative Study

Author: Ashraf S Qasim
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 3 Pages: S78-S83
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To determine the correlation between intensity (I) of light–emitting diode (LED) and tungsten–halogen light sources, and depth of cure of a resin composite at different distances. Materials and Methods: LED curing light (Ultra Lite 200E plus) and tungsten halogen light (Astralis 5 Vivadent) were evaluated. Intensity was measured at distances of 0, 2, 4, 6, 8, and 10mm between the light tip and detector. A blackened aluminum plate, 0.5mm thick, with a 4mm–diameter aperture was placed over the detector. The use of this aperture limited the amount of light reaching the detector to a uniform area for both curing lights and also corresponded to the area of the mould for the depth of cure studies. Both light tips were centered on this aperture to reduce any influence of varying I across the light tip. Depth of cure (DOC) of light–curing universal micro hybrid composite shade A2 was also measured. A metallic mould was used to measure the depth of cure at distances of 0, 2, 4, 6, 8, and 10mm between light tip and mould. The degree of divergence of the light of both light curing units was also determined by tracing the illuminated area at a 10mm distance for each of the curing lights. Results: For both lights, intensity decreased as distance increased. While, both I and DOC decrease with increasing distance, the relationship between these factors and distance may not be similar for both lights and may depend on the characteristics of individual lights. Conclusions: Both I and DOC decreased with increasing distances. DOC usually decreases with decreasing I, the rate of decline varies between various light brands.

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