Power SAW Research Articles

Compressive Strength Performance of Composite Sand Cement Brick with Power Saw Wood

Malaysia is experiencing an unprecedented growth of its urban centre due to its developing economy and industrialization, causing the demand of bricks production to be high. This increased the price of river sand. Further, the river sand may be depleted in the future if there is no alternative taken in reducing the usage of river sand in building materials due to the limited natural resources supply. Therefore, this research concentrates on using waste material like wood fiber waste (WFW) in order to reduce river sand in the fabrication of composite sand cement brick. This research is done in order to determine the water absorption and the compressive strength of sand cement brick with powder saw wood. Six batches of bricks were made with different composition of sawdust of 0%, 1%, 2%, 3%, 4% and 5% sawdust. All the bricks undergo 7 days of air-cured process before having the water absorption test and compression test. 3 days of water-cured process was performed on all bricks in order to investigate the results of water absorption test. For water absorption test, 0% of sawdust brick shows the lowest value while 5% of sawdust brick shows the highest value of water absorption rate. This indicated that high percentages of sawdust in composite brick will results in higher water absorption rate. This factor is due to the sawdust that is hydrophilic and porous in nature that causes the brick to containe more air space in the brick. Thus, this can be evidenced by the density data that keep decreasing with increasing percentages of sawdust. As for compressive strength test, the results presented 0%, 1%, 2%, 3%, 4% and 5% of sawdust have strength of 20.61 MPa, 25.30 MPa, 15.47 MPa, 2.03 MPa, 1.49 MPa and 1.73 MPa respectively. In summary, it can be concluded that optimum percentage of sawdust is 2% as it contains better compressive strength than other bricks although it has slightly higher water absorption rate than conventional sand cement brick. The compressive strength was influenced by the density of brick. It is shown in density results that decreasing in density will causes declining in compressive strength. As a conclusion, water absorption rate increases linearly proportional to the percentages of sawdust but inversely proportional to the compressive strength and the density of the brick.

The Impact of Safety Regulations on the Incidence of Upper-Extremity Power Saw Injuries in the United States

Over 50,000 power saw-related injuries occur annually in the United States. Numerous safety measures have been implemented to protect the users of these tools. This study was designed to determine which interventions, if any, have had a positive impact on the safety of the consumer or laborer. We queried the National Electronic Injury Surveillance System database for hand and upper-extremity injuries attributed to power saws from 1997 to 2014. Demographic information including age, sex, date of injury, device, location, body part involved, diagnosis, and disposition was recorded. We performed statistical analysis using interrupted time series analysis to evaluate the incidence of injury with respect to specific safety guidelines as well as temporal trends including patients' age. An 18% increase in power saw-related injuries was noted from 1997 (44,877) to 2005 (75,037). From 2006 to 2015 an annual decrease of 5.8% was observed. This was correlated with regulations for power saw use by the Consumer Safety Product Commission (CPSC) and Underwriters Laboratories. Mean age of injured patients increased from 48.8 to 52.9 years whereas the proportion of subjects aged less than 50 years decreased from 52.8% to 41.9%. These trends were most pronounced after the 2006 CPSC regulations. The incidence of power saw injuries increased from 1997 to 2005, with a subsequent decrease from 2006 to 2015. The guidelines for safer operation and improvements in equipment, mandated by the CPSC and Underwriters Laboratories, appeared to have been successful in precipitating a decrease in the incidence of power saw injuries to the upper extremity, particularly in the younger population. The publication of safety regulations has been noted to have an association with a decreased incidence in power saw injuries. Based on this, clinicians should take an active role in their practice as well as in their professional societies to educate and counsel patients to prevent further injury.

The Impact of Safety Regulations on the Incidence of Power Saw Injuries in the United States: Level 4 Evidence

There is no financial information to disclose. To date, no study has demonstrated the effect of safety regulations on the incidence of power saw injuries. We hypothesized that, despite the evolution of power saw technology and improved safety guidelines, there has been no decrease in the frequency or morbidity of injuries associated with these devices. The National Electronic Injury Surveillance System (NEISS) database was queried for all injuries associated with power saws from 1997-2014. The database provides both an incidence of injury seen at all participating institutions as well an estimate of historical incidence within the United States. The subset of patients sustaining injuries to an upper extremity were selected for analysis. Demographic information including age, gender, date of injury, device involved, location, body part involved, emergency room diagnosis, and the patient’s disposition were recorded. Statistical analysis included LOESS (locally weighted scatterplot smoothing), which was used for analysis of the temporal trends of total number of injuries. Student t-tests were used to compare patent age between years. A gradual annual increase of 18.0% in the incidence of power saw injuries was seen from 1997 (772 incidence and 44,877 estimate) to 2005 (1,350 incidence and 75,037 estimate), at which point the incidence of table saw injury reached a peak (R = 0.72, P < 0.001, Fig 1). From 2006 to 2015, a gradual and consistent annual decrease of 5.8% was observed with the total number of injuries decreasing from 1,370 (71,160 estimate) to 1,042 (57,992 estimate). This decrease was found to be statistically significant (R = 0.25, P = 0.014). The decline in rate of injury correlates with several landmark documents outlining safe and effective use of power saws by the Consumer Safety Product Commission (CPSC), the first of which was published in 2003. The average patient age increased slightly over the study time period from 48.8 +/-16.7 years in 1997 to 52.9 +/-16.3 years in 2014, with the proportion of subjects younger than 50 years decreasing from 52.8% to 41.9% (P for trend < 0.001). •Incidence of power saw injuries increased from 1997 to 2004.•From 2006 to 2015, the incidence of power saw injuries decreased by 5% annually.•Implementation of safer operating procedures and improvements in equipment, mandated by a landmark report by the CSPC in 2003, has been successful in precipitating a marked decrease in the overall incidence of power saw injuries to the upper extremity.•Age at time of injury is increasing, the etiology of which is likely multifactorial.

Costs of basic methods of forest landmaintenance in protective zones of high-voltage power lines in the Czech Republic

: The paper describes the basic potential methods and their costs of maintenance of forest lands in protective zones under high-voltage power lines (HVPL) 400 kV and 220 kV. In the present situation and with available information and data, it was possible to accomplish the average cost calculations for the whole area of the Czech Republic. The paper analyses the following mechanical and chemical methods of maintenance of forest lands: full-area scrub clearing with power saw (PS), selective individual scattered clearing of trees with PS, full-area scrub clearing by milling, full-area scrub clearing by the application of herbicides and arboricides, selective individual scrub clearing of individual trees by cutting followed by spray treatment with arboricides. The maintenance of forest lands in zones of HVPL (scrub clearing) by milling belongs to the economically most convenient mechanical methods, for example when removing 3,000 trees.ha&lt;sup&gt;–1&lt;/sup&gt;, the cost of this option is 20,000–23,000 CZK.ha&lt;sup&gt;–1&lt;/sup&gt;ha in a period of 3-year periodic frequency, while the most expensive method is selective individual scrub clearing of scattered individual plants with PS at costs of around 84,000 CZK.ha&lt;sup&gt;–1&lt;/sup&gt;.

Ladder Type Saw Filter and its Application to High Power Saw Devices

SAW filters with one-port SAW resonators being connected in a ladder structure, which is called ladder type SAW filter, have many features such as low insertion-loss, wide pass-band and simple filter design and so on. The design methodology, features of characteristics, and developments of higher frequency filter are described for an application in cellular phones. Furthermore, in order to apply to high power SAW devices such as the antenna duplexer of cellular phones, the material of inter-digital transducers (IDT) was improved to have high power durability. The optimum design in a ladder type SAW filter, the improvement in materials for IDT, and the optimum design of the package, all contributed the success of realizing a small SAW antenna duplexer.

LADDER TYPE SAW FILTER AND ITS APPLICATION TO HIGH POWER SAW DEVICES

SAW filters with one-port SAW resonators being connected in a ladder structure, which is called ladder type SAW filter, have many features such as low insertion-loss, wide pass-band and simple filter design and so on. The design methodology, features of characteristics, and developments of higher frequency filter are described for an application in cellular phones. Furthermore, in order to apply to high power SAW devices such as the antenna duplexer of cellular phones, the material of inter-digital transducers (IDT) was improved to have high power durability. The optimum design in a ladder type SAW filter, the improvement in materials for IDT, and the optimum design of the package, all contributed the success of realizing a small SAW antenna duplexer.

超磁歪薄膜の耐食性

The giant magnetstrictve materials (GMM) are expected in many applications such as power transducers, SAW devices, and sensor devices for under sea, a satellite orbit and outdoor. However, little discussion has been made from the view point of corrosion resistance of GMM. The anodic polarization behavior was measured in acidic, alkaline and neutral salt solutions for the samples of (Tb-Dy-Fe) thin films prepared by DC sputtering process.

A Study of Al-Alloy Electrodes for High Power SAW Filters

Durability of aluminum-alloy electrodes for high power SAW filters which are used for antenna duplexers in cellular portable telephones is experimentally investigated. Titanium added aluminum is deposited by DC magnetron sputtering. The new alloy expands the limitation on the driving power of the filters. Temperature, particularly, accelerates the degradation of the high power filters, the film resistance causes an even greater increase in temperature. Thus, optimum value for titanium of 0.4 wt.% can be achieved for high durability filters.

A Saw Stabilized Monolithic Pulse Amplitude Modulated Microtransmitter

A low power SAW stabilized monolithic microtransmitter has been developed. This new device replaces all of the RF circuitry in a low cost transmitter, such as the ones used in wireless security systems. This device makes it possible to meet FCC specifications without costly design iterations. The oscillator in the transmitter is controlled by a third generation SAW resonator which eliminates the need for impedance matching or phase shifting networks in the signal feedback path. This unique type of resonator made the monolithic transmitter design possible. The theory of operation, system architecture, and performance will all be presented in this paper.

Sputtered Al–Ti Electrodes for High Frequency and High Power SAW Devices

DC magnetron sputtering and Ti addition for Al electrodes are studied to achieve higher durability of SAW devices operating at high frequency and high power. Experiments on SAW resonators as a test medium show the following: the sputtering is better than conventional e-gun evaporation for both the reproducibility of film composition and for durability; 0.6 wt% to 0.9 wt% Ti addition to the sputtered Al films leads to durability for 3 times larger power than 0.7 wt% Cu addition to evaporated Al films, while less loss is experienced if resistivity is the same in each film.

Important aspects of chain saw noise-measurement procedure and control

The purpose of this paper is to discuss noise-measurement and reduction procedures peculiar to chain saws. Thus, outdoor and indoor measurement considerations are discussed extensively. Repeatable measurements are important for engineering development, but general industry standards are too vague to satisfy this requirement. Neither SAE proposed new engine sound-measurement procedure nor Power Saw Manufacturer Association (PSMA) standard sound-measurement procedure mentions anywhere the location of the sound source (height of the sound source from the surface), which is a very important factor in calculating the correction factor due to ground reflections. When the surface is hard, like concrete, the correction factor (total SPL, dB re free field) can be readily computed, but over dirt or grassy surfaces (PSMA standard sound-measurement procedure) rather puzzling results are often obtained, since not only is reflection incomplete, but there is a phase delay δ in the reflected wave. This paper mainly concerns an outdoor sound-measurement procedure peculiar to chain saws. Noise identification procedures are also presented and selected results of a particular case study are shown and discussed.

On the present aspect of the Power Saw (a kind of chain saw for felling and bucking), made in home and abroad

On the present aspect of the Power Saw (a kind of chain saw for felling and bucking), made in home and abroad