904 research outputs found
Unified TeV Scale Picture of Baryogenesis and Dark Matter
We present a simple extension of MSSM which provides a unified picture of
cosmological baryon asymmetry and dark matter. Our model introduces a gauge
singlet field and a color triplet field which couple to the
right--handed quark fields. The out--of equilibrium decay of the Majorana
fermion mediated by the exchange of the scalar field generates adequate
baryon asymmetry for GeV and TeV. The scalar partner
of (denoted ) is naturally the lightest SUSY particle as it
has no gauge interactions and plays the role of dark matter.
annihilates into quarks efficiently in the early universe via the exchange of
the fermionic field. The model is experimentally testable in (i)
neutron--antineutron oscillations with a transition time estimated to be around
sec, (ii) discovery of colored particles at LHC with mass of
order TeV, and (iii) direct dark matter detection with a predicted cross
section in the observable range.Comment: 10 pages, one reference updated. Version to appear in Phys. Rev. Let
The Effect of Flavonoid Naringenin on Contractile Response of Thoracic Aorta Isolated from Diabetic Rats
Abstract:
Background & Aims: Considering increasing incidence of cardiovascular disorders in diabetes mellitus and some evidence on antioxidant and antidiabetic potentials of naringenin, this study was conducted to evaluate the beneficial effects of 6-week administration of naringenin on contractile reactivity of isolated thoracic aorta in diabetic rats.
Methods: Male Wistar rats were divided into control, naringenin-treated control, diabetic and glibenclamide-treated, and naringenin-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was administered (60 mg/Kg). Naringenin (10 mg/kg) was administered i.p. one week after diabetes induction in every other day intervals for 6 weeks. Serum glucose level was measured before naringenin administration and at 6th week. Finally, contractile reactivity of thoracic aortic rings to KCl and phenylephrine (PE) was cumulatively determined.
Results: Serum glucose level at week 6 showed a significant decrease in naringenin-treated diabetic group compared to diabetics (P<0.01). In addition, naringenin-treated diabetic group showed a significantly lower contraction to PE (P<0.05) as compared to diabetic group and such significant reduction was also observed for KCl (P<0.05). Meanwhile, there was also a significant difference between control and naringenin-treated control groups regarding their contractile reactivity to PE (P<0.05).
Conclusion: Subchronic administration of naringenin for 6 weeks could exert an anti-hyperglycemic effect and lowers contractile responsiveness of thoracic aorta rings to KCl and phenylephrine.
Keywords: Naringenin, Diabetes mellitus, Aorta, Contractilit
Model for Small neutrino masses at the TeV Scale
We propose a model for neutrino mass generation in wich no physics beyond a
TeV is required. We extend the standard model by adding two charged singlet
fields with lepton number two. Dirac neutrino masses are
generated at the one loop level. Small left handed majorana neutrino masses can
be generated via the seesaw mechanism with right handed neutrino masses
are of order TeV scale.Comment: 13 pages, 2 figure
Vibration pumping of mdof structures using optimised multiple dynamic absorbers
International audienceThe concept of energy pumping is an innovative dynamic phenomenon; it gives rise to new generation of dynamic absorbers. Theoretical studies and feasibility tests are necessary for better understanding of their dynamic behaviour and to be applied on real structures or machines. In this paper, numerical evidence is firstly given for the passive and broadband targeted energy transfer in the case of a linear system under shock excitation with Multiple Dynamic Absorbers or Nonlinear Energy Sink (NES). Secondly, it is shown that many NES absorb shock energy in only way and dissipate this energy locally, without "spreading" it returns to the linear system. The numerical results of optimisation in the case of NES linked to a linear beam are compared to Tuned Mass Dampers (TMD) linked to the same beam
Optical and photoelectronic properties of a new material:Optoelectronic application
With the aim of studying the optical, electrochemical, and electronic properties of a new porphyrin-based material, we have synthesized a new porphyrinic complex, namely the (4,4-bipyridine)(meso-tetratrifluoromethylphenylporphyrinato)zinc(II) 4,4-bipyridine disolvate dihydrate complex with the formula [Zn(TFMPP)(4,4-bipy)]2(4,4-bipy)2H2O (I). This species is characterized by single-crystal X-ray molecular structure. The optical study is performed by UV–visible absorption and fluorescence spectroscopy. The fluorescence intensity presents an emission in the UV–visible range, indicating that this compound can be used as an optoelectronic material. The optical energy gap is 1.95 eV, and the current–voltage characteristics and impedance spectroscopy measurements have been studied to define the electronic properties of the zinc (II) porphyrin complex. The barrier height is calculated, and the space-charge limited current mechanism is found to control the conductance. The results from the electronic study confirm that our porphyrin derivative can be used for various optoelectronic applications
Using Dates Leaves Midribs to Prepare Hierarchical Structures Incorporating Porous Carbon and Zeolite A Composites for Cesium137Cs Ion Exchange
تم في هذه الدراسة تحضير مادة مساميه سُلمية تتضمن الكربون والزيولايت نوع 4A مع كفاءة عالية لإزالة السيزيوم المشع من مخلفات المياه الملوثة اشعاعيا. استعملت الطريقة الهيدروحراريه لأنماء طبقه من زيولايت نوع 4A على سطح الكربون المسامي لتحسين عمليه نقل الكتلة وزيادة المساحة السطحية للزيولايت استخدم كرب سعف النخيل العراقي (DM) كمخلفات زراعية متوفرة محليا لتحضير كربون مسامي واطئ الكلفة باستخدام طريقة الكربنه في فرن انبوبي عند درجة حرارة 900C ولمدة ساعتين. التراكيب المسامية الُسلمية تم تحضيرها باستخدام التنشيط الميكانيكي لسطح الكربون باستعمال الموجات الفوق الصوتية بوجود عالق يحتوي على دقائق نانوية للزيولايت المطحون نوع 4A. لتحضير عالق يحتوي دقائق نانوية للزيولايت تم طحن الزيولايت التجاري باستعمال كرات زجاجيه بقطر (0.3-0.4 mm) كوسط للطحن. تعمل دقائق الزيولايت النانوية كبذور (مراكز تنوي) لزيادة تبلور جل الالوميناسليكا العشوائي على سطح الكربون المعدل. تم تشخيص الزيولايت4A المحضر و المادة المتراكبة المحضرة باستعمال المجهر الالكتروني الماسح (SEM),جهاز حيود الأشعة السينية (XRD) , جهاز قياس المساحة السطحية(BET) , و (EDX) للتحقق من الهيئة , التركيب , المساحة السطحية , والتركيب الكيميائي على التوالي.استخدم المنتج لمعالجة المخلفات السائلة الملوثة اشعاعيا والتي تحتوي على نظير السيزيوم المشعCs-137 تم جمعها من بناية مختبرات الكيمياء الإشعاعية المدمرة في موقع التويثه النووي. قيس تركيز النشاط الإشعاعي للمياه الملوثة قبل وبعد المعالجة باستعمال منظومة أطياف كاما المزودة بكاشف الجرمانيوم عالي النقاوة (HPGe) ذي كفاءة كشف نسبيه تصل الى 60%. أظهرت النتائج ان تركيز النشاط الاشعاعي للسيزيوم 137 قد انخفض بصورة ملحوظة من 4800 Bq/L الى 186 Bq/L,121 Bq/L باستخدام 0.045 gm من الزيولات 4A و DMZ على التوالي.This study synthesized zeolite 4A, and hierarchical composite structure consisting of zeolite 4A- carbon were successfully prepared. Hydrothermal method was used to grow a layer of zeolite 4A over porous carbon surfaces to enhance mass transfer and increase surface area of zeolite. The products then were used to remove radioactive cesium137Cs from liquid wastewater. Iraqi dates leaves midribs (DM) were used as locally available agricultural waste to prepare low- cost porous carbon, using carbonization method in tubular furnace at 900C for two hours. Hierarchical porous structures including zeolite are prepared by mechanically activating the carbon surface via Ultrasonicating nanoparticles suspension of ground zeolite type 4A.For preparing nanoparticles suspension, commercial zeolite has been milled using 0.3-0.4 mm diameter glass balls as grinding media. Nanoparticles of zeolite 4A acting as seeding (nucleation centers) increase the crystallization of amorphous aluminosilica gel on modification carbon surface. The products of the syntheses zeolite 4A and the hierarchal composite materials (DMZ) were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Nitrogen sorption (BET) and Energy dispersive X-ray spectrometer (EDX) to check the morphology, structure, surface area, and the chemical composition respectively. The products were used to treat radioactive wastewater contaminated with radioactive cesium 137Cs collected from destroyed building of the Radiochemistry Laboratories (RCL) in AL-Tuwaitha Nuclear Site. The activity concentration for the contamination water pre and after the treatment were measured using gamma spectroscopy system supplied with a high purity germanium detector (HPGe) with 60% relative efficiency. The results showed that the radioactivity concentration after the treatment process decreased significantly from 4800 Bq/L to 186 and Bq/L,121 Bq/L using 0.045 gm from synthesized zeolite 4A and DMZ respectively
Two wheel speed robust sliding mode control for electric vehicle drive
Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV) by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM) that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels
PERAN SANGGAR SENI SEBAGAI RUMAH PERADABAN: SEBUAH UPAYA MENJAGA WARISAN BUDAYA DI KAMPUNG MAMDA YAWAN
Pelaksanaan ihwal pengabdian masyarakat ini mengusung topik “Peran Sanggar Seni Sebagai Rumah Peradaban: Sebuah Upaya Menjaga warisan budaya di Kampung Mamda Yawan”. Tujuan dari kegiatan ini untuk melakukan sosialisasi dan penyuluhan mengenai pentingnya peran sanggar seni dalam melestarikan kebudayaan tradisional yang dimiliki oleh masyarakat pada kampung Mamda Yawan, Distrik Kemtuk Kabupaten Jayapura. Adapun yang rangkaian sosialisasi yang dilakukan meliputi, Persiapan Pelaksanaan Kegiatan, Persiapan Kelengkapan Kegiatan Penyuluhan dan Pendampingan, Pelaksanaan Penyuluhan, Pelaksanaan Pendampingan dan Pelatihan, dan Dokumentasi Akhir dan Evaluasi. Hasil pelaksanaan kegiatan memperlihatkan dari hasil kegiatan penyuluhan untuk mengembangkan sanggar seni sebagai rumah peradaban dalam rangka melestarikan kebudayaan tradisional. Namun, kendala yang masih dihadapi adalah kurangnya infrastuktur pendukung dalam pengoperasiannya, olehnya peran lisntas stakeholder, seperti pemerintah, LSM dan akademisi sangat dubutuhkan untuk bersama-sama mengawal pengembangan kebudayaan daerah, yang salah satunya melalui sanggar seni sebagai rumah peradaban
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