An energy-efficient cuckoo search algorithm for virtual machine placement in cloud computing data centers

The Journal of Supercomputing - The advent of virtualization technology has created a huge potential application for cloud computing. In virtualization, a large hardware resource is often broken...     

Optomechanical investigating the impact of grafting polyamide-6 fibers with PMMA on its intrinsic optical properties

An optomechanical characterization was carried out to investigate the influence of grafting polyamide-6 fibers with poly (methyl methacrylate) (PMMA) on their structural relationship properties. Intrinsic optical properties of the modified sample were determined using a method based on the cold drawing process. The Mach-Zehnder interferometer attached with mechanical drawing device was used to determine the refractive indices and birefringence of the polyamide-6 samples at different draw ratios. A graphical method was used to determine the intrinsic birefringence of modified polyamide-6 with PMMA and it was found to be 0.0673 which is less than pure polyamide-6. The resulting data was used to estimate some structural parameters such as the orientation function, optical orientation angle and structural constant. The drawing effect is more significant on the modified sample than on the pure sample. It was found that the grafting process produced a material with new properties that can be used in different applications.     

A Robust Approach for Locating and Assessing Mechanical Faults in an Actual Transformer Winding Using the State Space of Its Lumped Equivalent Model

Russian Journal of Nondestructive Testing - Transfer function and state-space model are two powerful complementary tools have been used to monitoring the physical system. These two ways can be very...     

Cooling of water flowing through a night sky radiator

Experimental and theoretical studies of nocturnal cooling of water flowing through a night sky radiator unit were carried out. The system used for this study is two parallel plates night sky radiator with the top one (radiator) being a painted black aluminum plate. The radiator plate was covered by a polyethylene windscreen cover. The experimental study was conducted for a gravity flow open loop system. The parameters studied include the effect of average water mass flow rate, uncovered from the ambient versus covered supply warm water tank, and windscreen cover thickness on the performance. A new definition of the performance was expressed by an overall efficiency. A comparison between nocturnal cooling of stagnant and flowing water was also done. In the theoretical study a thorough radiation model was developed which calculates the radiation heat losses from both the cover and the radiator plate considering multiple reflections and absorptions between cover and plate. Energy balance was then applied on the cover, the radiator plate and the water. The cover and insulation were considered one lump each, while each of the radiator plate and the water were divided into discrete number of lumps. Energy storage in the radiator frame and insulation, and water elements was considered. Experimental results were used for verification of the theoretical model.     

Inflammatory pseudotumor of the orbit and suspected sarcoidosis

BACKGROUND: Orbital inflammatory lesions may be due to infection, neoplasia, systemic disease such as sarcoidosis or be idiopathic. CASE REPORT: A 13 year-old boy had uveitis and symptoms of unilateral periglobular orbital inflammation, confirmed by computed tomography. Infection and neoplasia were excluded. The serum angiotensin-converting enzyme level (ACE) was normal. Steroids were effective but three recurrences occurred with bilateralisation of the lesion. Serum ACE level increased making sarcoidosis probable. Moreover renal lesion were later found. Outcome was good with a prolonged steroid administration for ten months. CONCLUSIONS: Sarcoidosis may be revealed by an orbital inflammatory lesion. Steroids are necessary to prevent ocular functional complications.     

A study of the creep effect upon the response of a pressure sensor embedded in an ice sheet

A new numerical incremental analysis is presented for the viscoelastic bridging response of a pressure sensor embedded in an ice sheet. The analysis takes into account the effect of the time dependent creep response of both the ice sheet and pressure sensor upon the ratio between measured stress and undisturbed stress (called the registration ratio or inclusion factor). The effect of the sensor dimensions, sensor stiffness, elastic modulus of ice, creep properties of the sensor and ice, and rate of loading on the registration ratio is presented.A daily algorithm is also presented, which can be used to interpret the field data obtained using the pressure sensor by predicting the daily change in the base line (zero pressure) due to creep behaviour of the panel.