Combustion and Society: A Fire-Centred History of Energy Use

Fire is a force that links everyday human activities to some of the most powerful energetic movements of the Earth. Drawing together the energy-centred social theory of Georges Bataille, the fire-centred environmental history of Stephen Pyne, and the work of a number of ‘pyrotechnology’ scholars, the paper proposes that the generalized study of combustion is a key to contextualizing human energetic practices within a broader ‘economy’ of terrestrial and cosmic energy flows. We examine the relatively recent turn towards fossil-fuelled ‘internal combustion’ in the light of a much longer human history of ‘broadcast’ burning of vegetation and of artisanal pyrotechnologies – the use of heat to transform diverse materials. A combustion-centred analysis, it is argued, brings human collective life into closer contact with the geochemical and geologic conditions of earthly existence, while also pointing to the significance of explorative, experimental and even playful dispositions towards energy and matter. © 2014, SAGE Publications. All rights reserved

Performance Investigation of Dual Wavelength Fiber Laser using different SOAs

We investigated the performance of a dual wavelength fiber laser (DWFL) using different types of semiconductor optical amplifiers (SOAs) utilizing fiber Bragg gratings (FBGs) as comb filter. The lasing performances of linear SOA (LSOA), nonlinear SOA (NLSOA) and booster optical amplifier (BOA) at different current setting were observed. LSOA produced the flattest spectrum based on its peak power difference at only 4.5 dB as compared to 66.4 dB using BOA. BOA has the worst flatness because its polarization sensitivity is the highest as compared to LSOA and NLSOA. Overall, the best lasing performance is when LSOA is used due to the lowest peak power difference with high peak power at -17.6 dBm

Air cavity-based vibrational piezoelectric energy harvesters

Introduction. Known vibrational energy harvesting methods use a source of vibration to harvest electric energy. Piezoelectric material works as a sensing element converted mechanical energy (vibration) to electrical energy (electric field). The existing piezoelectric energy harvesting (PEHs) devices have low sensitivity, low energy conversion, and low bandwidth. The novelty of the proposed work consists of the design of PEH’s structure. Air cavity was implemented in the design where it is located under the sensing membrane to improve sensitivity. Another novelty is also consisting in the design structure where the flexural membrane was located at the top of electrodes. The third novelty is a new design structure of printed circuit board (PCB). The purpose of improvised design is to increase the stress in between the edges of PEH and increase energy conversion. With the new structure of PCB, it will work as a substrate that absorbs surrounding vibration energy and transfers it to sensing element. Methods. Three techniques were successfully designed in PEH and fabricated namely PEH A, PEH B, and PEH C were characterized by two experiments: load and vibration. The load experiment measured load pressure towards the PEH, whereas the vibration experiment measured stress towards the PEH. Results. PEH C has the highest induced voltage for a weight of 5.2 kg at the frequency of 50 Hz and the highest stored voltage for a period of 4 min. The three techniques applied in PEHs were showed improvement in transducer sensitivity and energy conversion. Practical value. A piezoelectric acoustic generator was used in the experiment to compare the performance of the designed PEH with available piezoelectric transducers in the market. The new flexible membrane worked as a sensing element was worked as a cantilever beam. PVDF was used as a sensing element due to the flexibility of the polymer material, which is expected to improve sensitivity and operating bandwidth.Вступ. Відомі методи збору вібраційної енергії використовують джерело вібрації для збору електричної енергії. П’єзоелектричний матеріал працює як чутливий елемент, перетворюючи механічну енергію (вібрацію) в електричну енергію (електричне поле). Існуючі пристрої збору п’єзоелектричної енергії (ЗПЕ) мають низьку чутливість, низьке перетворення енергії і малу смугу пропускання. Новизна запропонованої роботи полягає в проектуванні конструкції ЗПЕ. У конструкції реалізована повітряна порожнина, яка розташована під чутливої мембраною для підвищення чутливості. Ще один елемент новизни полягає в конструкції, в якій вигиниста мембрана розташована у верхній частині електродів. Третя новизна - це нова конструкція друкованої плати. Мета запропонованої конструкції - збільшити механічну напругу між краями ЗПЕ і підвищити перетворення енергії. Завдяки новій конструкції друкованої плати вона буде працювати як підкладка, яка поглинає навколишню енергію вібрації і передає її на чутливий елемент. Методи. Три методи були успішно використані для проектування ЗПЕ,  і відповідно названі виготовлені ЗПЕ A, ЗПЕ Б і ЗПЕ В були описані двома експериментальними характеристиками: навантаження і вібрація. В експерименті з навантаженням вимірювався тиск навантаження на ЗПЕ, в той час як в експерименті з вібрацією вимірювалася механічна напруга на ЗПЕ. Результати. ЗПЕ В має найвищу індуковану напругу для ваги 5,2 кг при частоті 50 Гц і найвищу збережену напругу протягом 4 хвилин. Три методи, що застосовуються для ЗПЕ, показали поліпшення чутливості перетворювача і перетворення енергії. Практична цінність. В експерименті використовувався п’єзоелектричний акустичний генератор для порівняння характеристик розробленого ЗПЕ з доступними на ринку п’єзоелектричними перетворювачами. Нова гнучка мембрана працювала як чутливий елемент, що представляв собою консольну балка. В якості чутливого елемента використовувався полівініліден фторид завдяки гнучкості полімерного матеріалу, який, як очікується, поліпшить чутливість і робочу смугу пропускання

Tools and concepts of journey towards a natural capitalism with special reference to environmental impact assessment, life cycle assessment and industrial ecology.

The evolution of tool applications and approaches for industrial-environmentally related management systems in minimizing their impact on natural environment has facilitated the concept of journey to natural capitalism, notably, on physical flows and the accumulation of substances and materials due to industrial activities. These environmental management tools include risk assessment, resource accounting, costbenefit analysis, environmental impact statement, and environmental impact assessment. In addition, environmental management system (EMS) series of standards derived fromSociety of Environmental Toxicology and Chemistry (SETAC) and International Standard of Organization (ISO) Technical Committee 207 initiatives emphasizing on EMS, environmental auditing, life cycle assessment, ecolabeling, environmental performance evaluation, design for environment and climate change. Recent concept on industrial ecology (IE) was introduced and applied respectively into EMS for industrial sustainability. It is based on the integration of human dimension, industrial processes, and environmental concerns that perpetually mimics natural ecosystem processes. This paper describes how these theoretical frameworks of Environmental Impact Assessment(EIA) and Life Cycle Assessment (LCA) tools being developed and applied and subsequently used as central tenet in IE concept in meeting their objectives that indirectly could be further enhanced the journey towards natural capitalism

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

OVERVIEW OF VIDEO DATA COLLECTION FOR 3-DIMENSIONAL MOTION ANALYSIS DURING THE FINAL ROUNDS OF THOMAS & UBER CUP 2000 BADMINTON CHAMPIONSHIPS

The aim of this paper is to report on the biomechanics project during the final rounds of Thomas & Uber Cup 2000 Badminton Championships. The results of three-dimensional analysis are also reported. To capture the data of world-class badminton players in competition, six synchronized video cameras were used to record video images at 50 field/second for 3-dimensional motion analysis during the Thomas & Uber Cup 2000 Badminton Championships in Malaysia. The semi-final and final matches were recorded. Some of the data was selected, analyzed and published in this paper

Experimental of Hot Machining for Stainless Steel 316L Cutting Process

Stainless Steel 316L having excessive tensile power and resistance to temperature with excessive manganese content resulting high roughness during cutting process. The problem occurs when machining process conduct at hot conditions to soften the workpieces. To study the cutting parameters effect on surface quality and tool wear length, different temperatures were used for turning process in this study. The experiment conducted with hot machining process at temperature conditions at 200, 300 and 400 °C. The parameters of this experiment are cutting speed of 76–149 mm/min and feed rate of 0.11–0.22 mm/rev with constant value of depth of cut. The results showed the surface roughness affects the tool wear when machining at high feed rate and cutting speed compared to lower parameters conditions. The heating source temperature affects the surface roughness, area roughness parameter and tool wear in cutting process. In conclusion, the surface quality and tool wear improved at high feed rates and cutting speeds compared to lower parameters settings

Brillouin suppression through longitudinal structural variation in high nonlinearity silica holey fibers

Copyright © 2006 IEEEWe consider longitudinal variation in the fiber structure as a method of increasing the Brillouin linewidth and threshold within high nonlinearity silica holey fibers. Strategies to control the associated variation in nonlinearity and dispersion along the fiber length are described.http://www.ofcnfoec.org/materials/06AbstractsWednesday.pd

Experimental investigation of recycled machining coolant mixed with nanofluids based Al2O3

Machining coolant is used in manufacturing industry for lubrication, rusting control and cooling which are crucial in operations such as grinding and cutting process. However, the machining coolant lose efficiency in months due to the thermal degradation and contamination. To recycle the used of machining coolant while enhancing the performance, the mixture of nanofluids (N) based Al2O3 with better thermal properties to synthesize with the recycled machining coolant (RMC). This study suspended Al2O3 nanofluids in four base ratios of recycled machining coolant (i.e. 0:100, 20:80, 40:60 and 60:40) by ultrasonic homogenies. The three main parameters in cooling rate performance and rusting control are thermal conductivity, dynamic viscosity and pH indication, respectively. The thermal conductivity and dynamic viscosity are then measured at temperature range of 30 to 60°C. The highest enhancement of thermal conductivity was evaluated to be 37.9% higher than machining coolant base fluid at the temperature of 60°C in 60:40 (N:RMC). However, the enhancement of dynamic viscosity was measured to be 4.5% for 60:40 (N:RMC) at 60°C. The pH value of 60:40 (N:RMC) at ambient temperature obtained 8.18 value was nearly neutral and decreased the rusting process. Therefore, this study recommends the use of recycled machining coolants based Al2O3 as cutting fluid in the ratio of 60:40 for application in machining operations