It is shown that Förster's expression for the electronic energy transfer rate can be recast in a form predicted for exciton motion that interacts strongly with molecular vibrations. Using a simple model based on the Kennard-Stepanov theory, Förster's expression for the spectral overlap is shown to be of a thermally activated form, as obtained previously by multiphonon theory. In contrast, the h...

Dynamic modulus of elasticity was determined in clearwood samples of eight tropical hardwood species using longitudinal vibrations, flexural vibration and ultrasonic transit-time methods. These samples were subsequently subjected to three point static bending test to determine static modulus of elasticity and modulus of rupture. Acoustic velocity and wood density were found to be independent pa...

In this article, application of various methods for evaluating and measuring porous food structures are reviewed. It is noted, that ultrasonic vibrations and waves, due to their physical properties and wide frequency interval, can successfully be applied when analyzing porous food structures. These methods have a lot of advantages when comparing them with other non-acoustic measurement methods....

Present manufacturing industries are facing challenges from these advanced materials viz. super alloys, ceramics, and composites, that are hard and difficult to machine, requiring high precision, surface quality which increases machining cost. To meet these challenges, non-conventional machining processes are being employed to achieve higher metal removal rate, better surface finish and greater...

In order to improve the precision and surface quality of Electrical Discharge Machining (EDM), the paper studies the application of complex programmable logic device (CPLD) used in pulse power for EDM, according to the characteristics of the device, using VHDL language input and schematic input method to design control circuit for EDM pulse power. Keyword: EDM; CPLD; VHDL language; pulse power

In this study, ultrasonic assisted machining (UAM) technique is applied in side-surface milling experiment for glass-ceramic workpiece material. The tungsten carbide cutting-tool with diamond coating is used in conjunction with two kinds of cooling/lubrication mediums such as water-soluble (WS) cutting fluid and minimum quantity lubricant (MQL). Full factorial process parameter combinations on ...

The search for electric dipole moments (EDM) of fundamental particles started approximately fifty years with Ramsey’s search for a neutron EDM. Even though the techniques have been improved and the sensitivities has reached an unprecedented small level no EDM of a fundamental particle has been observed so far. Non-the-less EDM experiments have put strict limits and constrained the parameter spa...

Electrical Discharge Machine (EDM) is especially used for the manufacturing of 3-D complex geometry and hard material parts that are extremely difficult-to-machine by conventional machining processes. In this paper authors review the research work carried out in the development of die-sinking EDM within the past decades for the improvement of machining characteristics such as Material Removal R...

In this study, vibration cutting has been applied to machining of a novel material, NiTi based shape memory alloy (SMA), using a commercial ultrasonic piezoelectric transducer to vibrate an ISO insert CCMT geometry cutting tool. The effect of vibration in turning process was characterized by investigating the surface roughness of workpiece and surface quality assessment of machined surface usin...

For the first time, response surface methodology (RSM) using a Box-Behnken Design (BBD) was employed to optimize the conditions for ultrasonic assisted extraction (UAE) of antioxidants from Chinese sumac (Rhus typhina L.) fruits. Initially, influencing factors such as liquid-solid ratio, duration of ultrasonic assisted extraction, pH range, extraction temperature and ethanol concentration were ...