New Model for Passive Vibration Control of Cantilever Beams Using Two Patches of Fluidic Flexible Matrix Composite Tubes

  يعتبر الانبوب المرن المتكون من عده مواد مركبة بشكل مصفوفه متناسقة من التقنيات الناشئة والحديثة اللتي تتميز بخفه وزنها وقدرتها الفائقة في امتصاص الاهتزازات والتحكم بها. يقدم هذا البحث نموذجا جديدا لحل مشكلة الاهتزازات الناتجة عن جسم مثبت من جهة واحده ومثبته عليه الانابيب المرنة. تم اشتقاق نموذج رياضي وباستخدام المعادلات اللازمة لمعرفه مدى تاثير هذه الانابيب على الجسم. تم اشتقاق هذه المعادلات بالاعتماد على نظريات اولير وبيرنولي للمرونه. بحثت هذه الدراسة أداء النموذج الجديد للتثبيط مع تباين في حجم الأنبوب؛ وضع الترابط للانابيب على الحزمة في حالتين مختلفتين: الحالة الاولى تمت دراسة النموذج عند تغيير المسافه بينهما، وفي الحاله الثانية تم تثبيت أحدهما في اعلى النموذج والاخر اسفله. توضح النتائج التحليلية العلاقه بين الضبط الصحيح لحجم الانابيب نسبه الى نصف قطر الطبقة الداخلية، ونقاط التكامل هي المعلمات الأساسية للتحكم في الاهتزاز السلبي والتي تحقق تخفيض في مدى الاستجابه في وضع التقوس العمودي الرئيسي بشكل فعال.Flexible Matrix Composite (F2MC) tubes are emerging technologies, which can provide lightweight, compact vibration control when attached to a vibrating structure. This work presents a new model for solving a problem of vibrations in cantilever beams with attaching F2MC tubes as patches that provide passive vibration control.  Mathematical model of the compound system of patches of F2MC tubes integrated on the beam was derived. The governing equations depend on Euler-Bernoulli beam theory and Lekhnitskii’s theory of elasticity. This study examined new model’s performance for damping with variation in tube size; bonding position of the patches on the beam in two different cases:  on the beam through changing the distance between two them; one patch above and the other under the beam. Analytical results demonstrate that the proper tuning the size of tubes as a function of inner layer radius; and integration points are basic parameters for passive vibration control. They achieve reductions in response amplitude at the first vertical bending mode effectively

Antiglycation and antioxidant properties of Momordica charantia

Diabetes mellitus is a multifactorial disorder characterised by hyperglycaemia and leads to complications. These complications are caused by advanced glycation endproducts (AGEs) that form through protein glycation as a consequence of hyperglycaemia. A diversity of plants are utilised worldwide as traditional medications for the treatment of diabetes mellitus, particularly in developing nations. A considerable quantity of literature has been published on Momordica charantia (MC) as a potent folk medicine for diabetes mellitus. The aim of this study was to investigate the antiglycation and antioxidant effects of HWE and CWE of MC on protein glycation. To examine whether MC can inhibit oxidative stress in endothelial cells by studying oxidative stress-related transcription factor parameters and their expression. Model proteins such as lysozyme and BSA were glycated using sugars (glucose and methylglyoxal) as glycating agents both in the presence and absence of MC extracts. AGE formation and inhibition were monitored by a number of methods. Furthermore, different antioxidant assays were used to study the antioxidant properties of MC. The inhibitory effects of AGEs, glucose, methylglyoxal and MC extracts on proliferation of cultured BAEC were determined in this research. Western blotting was used to examine the potential modulation of the oxidative stress signalling pathways induced by AGEs. Both extracts of MC inhibited the production of AGEs in a dose-dependent fashion and the HWE exhibited the more potent inhibitory effect on AGEs production. Moreover, parameters of oxidative stress including the expression of oxidative stress-related transcription factors were assessed using real-time PCR to study the protective effects of MC. The expressional inhibition of pro-oxidaive genes and enhancement anti-oidative enzymes could be potent element of vascular complications effect of MC extracts. Thus the aqueous extracts of MC, an edible vegetable, may have therapeutic potential in the management of diabetes mellitus

Effects of Salicylic Acid on some Growth and Physiological Characteristics of Lettuce (Lactuca sativa L.) under Cadmium Stress Conditions

Lettuce (Lactuca sativa L.) is considered as the most cultivated and consumed leafy vegetable all over the world. In Erbil Governorate, most farmers used sewage water to irrigate lettuce, which caused health risks especially heavy metal pollutants including cadmium. This research was applied as a factorial experiment to investigate the effects of foliar spraying of salicylic acid (SA) (0,0.5,1, 1.5 or 2mM) followed by spraying cadmium chloride (Cd) (0, 1, 2, or 4mM) on the growth, and some physiological and biochemical characteristics of this plant. Results show that most vegetative growth characteristics responded inversely to increasing SA concentrations, whereas the response of root performance improved with using SA application. A low concentration of Cd (1mM) improved root and shoot performance, whereas increasing the concentration to 4 mM decreased these characteristics significantly compared to no Cd added plants, except for the percent of shoot dry matter. Most of photosynthetic pigments decreased significantly by foliar spraying with SA and Cd. Applications of SA increased catalase enzyme activity significantly compared to no SA treated plants. Cadmium foliar application increased peroxidase enzyme activity, ascorbic acid, proline, and percent of total carbohydrate content and decreased catalase enzyme activity and the percent of infection with watery soft rot significantly compared to no Cd treated plants. It is concluded that lettuce tolerance to cadmium stress was increased by pretreatment foliar application of SA

STUDYING THE EFFECT OF CATIONIC STARCH- ANIONIC NANOSILICA SYSTEM ON RETENTION AND DRAINAGE

Nanoparticles are widely used in the papermaking industry as retention/ drainage aids, usually in conjunction with a high mass cationic polyelectrolyte such as cationic starch. However, little convincing knowledge of their role and mechanism in the wet-end system is yet found. This work focused on the role of nanosilica on papermaking wet end system in response to some processing parameters (drainage, retention, and electrostatic force of the whole system). The observations indicated that the nanosilica performance is defined by interactions of nanosilica with the complex aqueous environment of wet end system. The interaction mechanism seems to rely on introduction of nanoparticles into a cationic starch-fines-fibers network, converting the fiber mat on the forming wire into a porous structure that is responsive to retention and drainage

Mutation in mitochondrial complex I ND6 subunit is associated with defective response to hypoxia in human glioma cells

BACKGROUND: Hypoxia-tolerant human glioma cells reduce oxygen consumption rate in response to oxygen deficit, a defense mechanism that contributes to survival under moderately hypoxic conditions. In contrast, hypoxia-sensitive cells lack this ability. As it has been previously shown that hypoxia-tolerant (M006x, M006xLo, M059K) and -sensitive (M010b) glioma cells express differences in mitochondrial function, we investigated whether mitochondrial DNA-encoded mutations are associated with differences in the initial response to oxygen deficit. RESULTS: The mitochondrial genome was sequenced and 23 mtDNA alterations were identified, one of which was an unreported mutation (T-C transition in base pair 14634) in the hypoxia-sensitive cell line, M010b, that resulted in a single amino acid change in the gene encoding the ND6 subunit of NADH:ubiquinone oxidoreductase (Complex I). The T14634C mutation did not abrogate ND6 protein expression, however, M010b cells were more resistant to rotenone, an agent used to screen for Complex I mutations, and adriamycin, an agent activated by redox cycling. The specific function of mtDNA-encoded, membrane-embedded Complex I ND subunits is not known at present. Current models suggest that the transmembrane arm of Complex I may serve as a conformationally driven proton channel. As cellular respiration is regulated, in part, by proton flux, we used homology-based modeling and computational molecular biology to predict the 3D structure of the wild type and mutated ND6 proteins. These models predict that the T14634C mutation alters the structure and orientation of the trans-membrane helices of the ND6 protein. CONCLUSION: Complex I ND subunits are mutational hot spots in tumor mtDNA. Genetic changes that alter Complex I structure and function may alter a cell's ability to respond to oxygen deficit and consolidate hypoxia rescue mechanisms, and may contribute to resistance to chemotherapeutic agents that require redox cycling for activation

Effect of He-Ne Laser on Blood Serum Testosterone and Testicular Tissue in Adult Male Rat

The current study was conducted to examine the effect of He-Ne laser therapy on the blood serum testosterone level and testicular tissue in adult male rats. Thirty five Albino Western adult male rats aged 3-4 months and weighing approximately 250-300 g were used and divided in to three groups. The  testicular tissue of rats in the first treatment was exposed to a dose of irradiation 1.02 j/cm2 (40 second) once daily for three successively days, while second treatment was exposed to a dose of irradiation 2.03 j/cm2 (80 second) once daily for three successive date, while the third group remained without any treatments (control).  The results showed that the process of irradiation adversely affected on the level of blood serum testosterone in the first and second treatment compared to the normal level in the control group. The histological examination in treatment one showed  low reduction in numbers of sertoli , leydig  and spermatid cells   at day one, while in day two  showed medium reduction in numbers of sertoli , leydig  and spermatid cells,and high reduction in numbers of sertoli , leydig  and spermatid cells  in day three of irradiation. In treatment two, the results showed   medium reduction in numbers of sertoli , leydig  and spermatid cells at day one, while in day two  showed high reduction in numbers of sertoli , leydig  and spermatid cells and very high reduction in numbers of sertoli , leydig  and spermatid cells in day three of irradiation . In conclusion the current study revealed that steers factor cause reduction in numbers of sertoli , leydig  and spermatid cells  lead to  low fertility rate within  increasing of duration and repetition of irradiation

Overview on Wireless Sensor Networks

ABSTRACT Recent advancement in wireless communications and electronics has enabled the development of low-cost sensor networks Here we describe the three major aspect of wireless sensor network.WSN Applications, Routing and clustering. In the field of a wide variety in WSN applications we specifically introduce Environmental applications, Military Applications and SHM systems in health monitoring scope. The introduction of the routing protocols with the head topics of Flooding, Gossiping, EAGR, GEAR and REAR take place in routing section

Nigella sativa and its Derivatives as Food Toxicity Protectant Agents

Exposure to food toxins generate multiple adverse health effects. Heavy metals, antibioticsresidue, mycotoxins, pesticides and some food additives are examples of the most importantfood toxins. The common mechanism of toxicity and carcinogenicity effects of food toxins is thegeneration of oxidative stress that leads to DNA damages. Moreover, based on epidemiologicevidence unhealthy eating habits and food toxicities are associated with cancers occurrence.Therefore, application of bioactive food additives as harmless or safe components in foodindustry is expensive. Nigella sativa L. is a broadly used herb-drug for various diseases all overthe world and has been used as preservative and food additive. Based on various studies N. sativahas shown various pharmacological activities including therapeutic efficacy against differenthuman diseases and antioxidant anti-inflammatory effects against environmental toxins. N.sativa decreases the adverse health effects induced by mentioned food toxins via modulating theaction of antioxidant enzymes such as glutathione peroxidase (GPx), glutathione-S-transferasecatalase and act as reactive oxygen species (ROS) scavengers in different organs. Besides, N.sativa and thymoquinone (TQ) have protective effects on food products through removal andinhibition of various toxic compounds. Therefore, in the present review we will describe allprotective effects of N. sativa and its main constituents, TQ, against food induced toxicities