Spreading Length Research Articles

Comparison of Thoracic Epidural Access with Lateral Decubitus and Shoulder Rotation Positions for Repeat Thoracic Epidural Blockade

Shoulder rotation has been shown to increase the acoustic window of ultrasound for thoracic epidural access. However, this effect of shoulder rotation has not yet been confirmed in clinical practice. This study aimed to evaluate the effects of shoulder rotation on the thoracic epidural blockade in patients with acute or chronic pain in the thoracic region. Prospective crossover trial. Pain clinic of our university in the Republic of Korea. Forty patients aged 20 - 80 years with acute or chronic pain in the thoracic region who were scheduled to undergo thoracic epidural blockade more than twice. The patients underwent repeated fluoroscopy-guided thoracic epidural blockade via the paramedian approach in the lateral decubitus position either with or without shoulder rotation.The primary outcome measure was the attempt time to the confirmed spread of contrast. The number of attempts, total procedure time, vertical interpedicular distance, contrast spreading length, and complications were compared between the 2 positions. The median attempt times in the lateral decubitus and shoulder rotation positions were 138.8 and 132.5 seconds, respectively, and this difference was significant (P = 0.004). Compared with the lateral decubitus position, the shoulder rotation position was also associated with a significantly lower number of attempts (P = 0.03), shorter total procedure time (P < 0.001), and greater vertical interpedicular and contrast spreading distances (P < 0.001 and P = 0.02, respectively). The operator in this study was not blinded to the patient groups. Other researchers observed the operator's procedure and evaluated and recorded the data in an attempt to overcome this bias. However, it was difficult to completely avoid the bias. Second, epidural blockade was performed at various levels (T3-11), and the anatomical features vary among thoracic spine levels. The study findings demonstrate the clinical benefits of the shoulder rotation position versus the lateral decubitus position in terms of successful epidural access during thoracic epidural blockade using the paramedian approach.

Basic Reproduction Number of Tuberculosis Spread Model in Lamongan With DOTS Strategy

Tuberculosis (TB) will be a serious threat if not handled quickly and appropriately. The relatively long treatment in time and the high risk of death is a challenge in controlling the spread of this disease. The DOTS (Directly Observed Treatment Short-course) strategy is considered capable of controlling the spread of TB because of the high success rate, reaching 91%. The mathematical model of the spread of TB has been widely studied to determine the potential for the spread of this disease in an area. The purpose of this study is to build a model of tuberculosis spread in Lamongan to determine the rate of its spread and to predict whether it will be endemic or not. Using disease spread mathematical model type SEITR, this research has examined based on 2018 and 2019 data from the Lamongan health office then simulates the result. The research begins with the construction of the model followed by a stability analysis of the model by determining the basic reproduction number ( ), which is simulated after the parameter approach was carried out. From the simulation results, the result shows that means that TB will not endemic in Lamongan. Besides, the results of the effect of parameter ω on I(t) were obtained, which concluded that seeking and treating active TB alone would only reduce infected individuals but not reduce the length of time TB spread. Identification of the effect of parameter φ on I(t) has also been carried out which results in the conclusion that more treatment for susceptible individuals, in addition to reducing the number of infected individuals, will also reduce the length of time TB spreads in that area. This result will be a good suggestion for the government to deal faster with tuberculosis transmission.

Numerical study on dynamic behaviours of a micro-droplet impacting on a vertical wall in PEMFC

The droplet/wall interaction in the gas channel (GC) of proton exchange membrane fuel cells (PEMFCs) has significant influence on water management, which may affect the performance and durability of the cell. In this paper, a coupled level-set and volume-of-fluid (CLSVOF) method is used to simulate the dynamic behaviours of a micro-droplet impacting on a vertical wall in the GC. The effects of impact velocity (expressed by the Weber number, We), and impact angle on the spreading dynamics are evaluated. Next, the critical conditions for the transition from spreading to rebound are further discussed. For 0 < We < 80, only the spreading, retracting, and rebound are observed, and the phenomenon of air bubble entrapment is captured on different wettable walls. With an increment of We, the maximum total spreading factor l∗ tot and corresponding normalised time t∗ will increase, as well as the normalised time difference Δτ2 between the maximum spreading length and minimum height. Moreover, when increasing the impact angle, the maximum front spreading factor depending on the tangential velocity component will decrease, while the absolute value of maximum back spreading factor squeezed by the normal velocity component will increase. For the oblique downward impact, the front liquid led by the tangential velocity component plays a more important role in dominating the spreading process. The results also indicate that both the wall wettability and We can affect the transition threshold. When the static contact angle is between 90° and 150°, the effect of We on the rebound is inversely proportional to the hydrophobicity of the wall.

An integrated multi-objective optimization method to improve the performance of multilateral-well geothermal system

Operational parameters optimization is of great significance to improve overall heat extraction performance from the hydrothermal or enhanced geothermal system. Injection flowrate, injection temperature, and production pressure are several of the easily human-controlled parameters to make the best of limited geothermal resources during the planned life. The net heat power and flow impedance are two contradictory production indexes to be optimized for efficient exploitation of long-term geothermal production. In this study, an integrated approach of finite element, multiple regression, non-dominated sorting genetic algorithm, and the technique for order preference by similarity to ideal solution is proposed and applied to the multilateral-well system to realize the optimization of geothermal development. Firstly, parametric cases coupling with thermal and hydraulic models are analyzed. Then, multiple regression is employed to obtain the net heat power and flow impedance functions considering human-controlled operational parameters and reservoir physical properties. Afterward, the multi-objective optimization algorithm is used to gain the Pareto solution set of injection and production parameters. Finally, the technique for order preference by similarity to ideal solution is employed to select the optimal combination of operational parameters for geothermal extraction. It is concluded that water loss and thermal drawdown are necessarily considered in the optimization process. The proposed approach represents global optimization. Operational parameters for the optimal case are (Qin, Tin, pout) which equal (49.98 °C, 62.21 kg/s, 27.44 MPa) under the conditions of this study. From the comparison between the base case and optimal case, it is observed that horizontal spread length, 2D swept area and 3D swept volume of the low-temperature scope is reduced by 77.9 m, 10 × 104 m2, and 16 × 106 m3. Besides, the thermal breakthrough has been delayed by 1.1 years. The water loss decreases by 36.23%. The optimal case demonstrates a great improvement in production performance. Sustainable exploitation is achieved through multi-objective optimization for operational parameters. The proposed method reflects superiority, efficiency, and intelligence in geothermal development.

Morphological evolution and spreading flow of hollow oil droplet impact on a heated wall

A coupled level set and volume–of–fraction method is applied to investigate hollow oil droplet impacts on heated walls. Results show that given the increase in impact velocity, three evolutionary processes of spreading, transition, and central jet occur after the hollow oil droplet impact on a heated wall. The variation in the spreading length of hollow oil droplets is similar in different evolutionary processes, but the variation in the center height of hollow oil droplets is relatively different. The wall heat flux and the position of the maximum heat flux increase with impact velocity. In addition, the wall temperature influences the flow and heat transfer characteristics of the hollow oil droplet impingement. Considering the viscosity–temperature characteristics of the lubricating oil, the spreading length of the hollow oil droplet increases with the wall temperature, but the central height of the hollow oil droplet is unaffected by the wall surface temperature. The wall heat flux and the position of the maximum heat flux also increase with the impact velocity. Pressure and velocity distribution indicate that the bubble rupture at the central jet originates from the combined effect of inertial force and surface tension. The results of this study provide a basis for an improved understanding of the flow and heat transfer characteristics of hollow oil droplet impact on a heated wall and serve as a theoretical reference for investigating the effect of bubbles on oil–gas lubrication processes.

Experimental investigation of spreading and receding behaviors of Newtonian and viscoelastic droplet impacts on inclined dry surfaces

Drop impact on solid surfaces are widely used in oil and gas industries, surface painting, hot surfaces cooling, and agricultural products spraying. In this study, spreading and receding factor related to non-Newtonian (Boger) fluid droplets on dry inclined surfaces (such as Plexiglas and stainless steel) was laboratory tested and compared with Newtonian fluids (water, glycerol and their solution). Here, drop impacts were investigated for two impact angles (60° and 75°) at Weber numbers ranging from 245 to 545. The study aimed at evaluating the effects of impact velocity, impact angle, surface wettability, fluid viscosity, and elasticity on the dynamic behaviors of Newtonian and Boger droplets in spreading and receding stages. The results showed that with an increase in the impact velocity (growth of We), the drop was further expanded, the spreading velocity was increased, and the value and velocity of receding were incremented. By decreasing the drop impact angle, the effects of impact velocity and fluid viscosity on spreading and receding velocities were reduced at the back of the impact point. In the front zone, the drop reached maximum length of spreading and minimum length of receding over a longer period by decreasing the impact angle. On the other hand, with a decrease in the fluid viscosity, spreading velocity was increased, and maximum spreading occurred over a longer period. The surface wettability also played an important role in the receding stage for droplets with low viscosities. As fluid elasticity rose, both velocity and maximum spreading were reduced, while the value and velocity of receding were increased.

Effect of surface energy and roughness on cell adhesion and growth - facile surface modification for enhanced cell culture.

In vitro, cellular processing on polymeric surfaces is fundamental to the development of biosensors, scaffolds for tissue engineering and transplantation. However, the effect of surface energy and roughness on the cell–surface interaction remains inconclusive, indicating a lack of complete understanding of the phenomenon. Here, we study the effect of surface energy (Es) and roughness ratio (r) of a polydimethylsiloxane (PDMS) substrate on cell attachment, growth, and proliferation. We considered two different cell lines, HeLa and MDA MB 231, and rough PDMS surfaces of different surface energy in the range Es = 21–100 mJ m−2, corresponding to WCA 161°–1°, and roughness ratio in the range r = 1.05–3, corresponding to roughness 5–150 nm. We find that the cell attachment process proceeds through three different stages marked by an increase in the number of attached cells with time (stage I), flattening of cells (stage II), and elongation of cells (III) on the surface. Our study reveals that moderate surface energy (Es ≈ 70 mJ m−2) and intermediate roughness ratio (r ≈ 2) constitute the most favourable conditions for efficient cell adhesion, growth, and proliferation. A theoretical model based on the minimization of the total free energy of the cell–substrate system is presented and is used to predict the spread length of cells that compares well with the corresponding experimental data within 10%. The performance and reusability of the rough PDMS surface of moderate energy and roughness prepared via facile surface modification are compared with standard T-25 cell culture plates for cell growth and proliferation, which shows that the proposed surface is an attractive choice for efficient cell culture.

The Optimum Field Configuration for Active MASW Survey on Peat Soil

The application of the MASW method on engineering investigation required optimization of the field configuration to ensure high quality dispersion image for reasonable shear wave velocity profile estimation. The limited investigation with respect to peat soil condition has motivated the study to determine the optimum field configuration for peat soil. The challenging characteristics of peat soil including high void ratio, compressibility, water content and low shear strength further complicates the determination of optimum field configurations. The study focused on the determination of optimum field configurations for active MASW method which includes the receiver spacing, source offset, sensor frequency and sampling interval. The results obtained shows that, the optimum receiver spacing to obtain high signal to noise ratio dispersion image was 1 meter. Smaller receiver spacing causes domination of higher modes and wide bandwidth, while longer receiver spacing causes significant drop in signal to noise ratio governed by rapid energy dissipation with distance. For the source offset, the distance of half the total spread length (X1 = L/2) provides the best resolution and minimised near-field and far-field effect. While, 4.5 Hz sensor frequency and sampling interval between 100 to 250 s provides sufficient low frequencies for deeper depth investigation and denser data. Overall, the influence of receiver spacing, source offset and sensor frequency on the dispersion image resolution was significant.

Pengaruh Padat Penebaran yang Berbeda terhadap Laju Pertumbuhan Belut Sawah (Monopterus Albus) dalam Media Bioflok

The purpose of this research is to find out the solid influence of different spreads on the growth rate of rice eels in bioflok media. This study used Complete RandomIzed Design (RAL) with 3 treatments and 3 repeats, namely; solid spread 5 tails / 15 cm water level, solid spread 10/15 cm water level and solid spread 15/15 cm water level. As a result of the study, the growth value of eel weight with the spread of 5 heads 32.8gr, the spread of 10 heads of 10.56 gr and the distribution of 15 heads of 7.19. The growth value of the spread length of 5 tails is 7.73 cm, the spread of 10 tails is 6.44 cm and the distribution of 15 tails is 5.17 cm. Inference, the dense distribution of different gives a very noticeable influence on the growth of rice field eel seeds (Monopterus albus). As well as solid distribution of 5 heads / 15cm water level gives the best results to the growth of rice eels seeds (Monopterus alus) so that Bioflok does not affect water quality. The distribution of rice eel seed (Monopterus albus) should not be at too high a density because it can inhibit the growth rate of rice eels.&#x0D; Keywords: Different Distribution, Eels Rice Fields (Monopterus albus), Bioflok.

An experimental study on smoke back-layering and critical velocity in tunnel fires with canyon cross wind

This paper investigated experimentally the thermal smoke back-layering and critical velocity of the highway tunnel in alpine gorge area with canyon cross wind. A series of small-scale tests were performed using a pool fire as the fire source. The downstream tunnel portal was under the action of canyon cross wind, and the longitudinal ventilation device was set on the upstream tunnel portal. The smoke movement phenomena were studied by changing the velocities of the canyon cross wind and longitudinal ventilation, and the longitudinal position of the fire source in the tunnel. The experimental results indicated that the smoke back-layering length decreases with the increasing longitudinal ventilation velocity, and both the critical velocity and smoke back-layering length increase with the increasing canyon cross wind velocity. This is because the airflow velocity towards upstream in the tunnel increases with the canyon cross wind velocity. In contrast, the downstream smoke spread length of the fire decreases with the increasing canyon cross wind velocity, and increases with the increasing longitudinal ventilation velocity. An equation for the critical velocity was developed by taking the canyon cross wind into account.

Estimating Fuel Loads and Structural Characteristics of Shrub Communities by Using Terrestrial Laser Scanning

Forest fuel loads and structural characteristics strongly affect fire behavior, regulating the rate of spread, fireline intensity, and flame length. Accurate fuel characterization, including disaggregation of the fuel load by size classes, is therefore essential to obtain reliable predictions from fire behavior simulators and to support decision-making in fuel management and fire hazard prediction. A total of 55 sample plots of four of the main non-tree covered shrub communities in NW Spain were non-destructively sampled to estimate litter depth and shrub cover and height for species. Fuel loads were estimated from species-specific equations. Moreover, a single terrestrial laser scanning (TLS) scan was collected in each sample plot and features related to the vertical and horizontal distribution of the cloud points were calculated. Two alternative approaches for estimating size-disaggregated fuel loads and live/dead fractions from TLS data were compared: (i) a two-steps indirect estimation approach (IE) based on fitting three equations to estimate shrub height and cover and litter depth from TLS data and then use those estimates as inputs of the existing species-specific fuel load equations by size fractions based on these three variables; and (ii) a direct estimation approach (DE), consisting of fitting seven equations, one for each fuel fraction, to relate the fuel load estimates to TLS data. Overall, the direct approach produced more balanced goodness-of-fit statistics for the seven fractions considered jointly, suggesting that it performed better than the indirect approach, with equations explaining more than 80% of the observed variability for all species and fractions, except the litter loads.

Influence of photoselective shade nets on growth and yield of Asparagus

Study on “Influence of photoselective shade nets on growth and yield of Asparagus” was carried out at KRC college of Horticulture, Arabhavi, Gokak, Karnataka during 2018-19. The result revealed that, among photoselective shade nets, plant height, plant spread and internodal length were higher under red shade net. Plants grown under grey shade net recorded higher number of cut cladophylls per plant (54.89) and per square meter (406.73). Cladophylls harvested from grey shade net recorded maximum vase life (12 days) followed by red (10.28 days). Among different asparagus species, A. densiflorus ‘Sprengeri’ performed better with respect to vegetative growth and yield. Higher cumulative number of cut cladophylls per plant (61.07) and per square meter (452.50) was recorded in A. densiflorus ‘Sprengeri’ followed by A. densiflorus ‘Myers’. A. densiflorus ‘Myers’ recorded maximum vase life (10.20 days) followed by A. myriocladus (10.10 days).

2D Geo-electrical Resistivity Imaging of Clay Deposit in Agbonmwoba Village, Edo State, Nigeria

This study involves delineation of clay deposits in Agbonmwoba village area of Obaretin town, Edo state using 2D geo-electrical resistivity tomography technique to image the extent and economic quantity of the deposit, in order to appraise its commercial viability. The Wenner-Schlumberger electrode configuration was employed in five different locations within the study area, and a total of ten (10) Wenner-Schlumberger soundings were acquired in the area with a spread length of 200m along each traverse. The field data was inverted using the Earth Imager 2D inversion software program. Low resistivity geologic formations (ρ &lt; 50 Ωm) were interpreted as clay formations using knowledge of regional geology of the area as reported from previous studies. Along traverses 1, 2 and 8 sampled at old Sapele road Ekiosa clay deposits was imaged at depth of 8.9-15m at lateral spread of 30m and 70m in TR1, 8.9-17.9m in TR2 and 4m in TR8. In traverses 3 and 4 sampled along Presco road in Obaretin, clay deposits were imaged at 8.9m from the surface in TR3 and 8.9-10m in TR4 at lateral spread of 70m and 100m respectively. Traverses 5, 6 and 7 were sampled at Agbonmwoba primary school, and clay deposit was imaged at 17.9-21m in TR5 at lateral spread of 80-90m, clayey sand was imaged at 7.5m (&lt; 8.9m) and sand deposit was imaged at 24.0m (&lt; 26.8m) which underlies clay. In TR6, clay deposit was imaged at 8.9m from the surface and in TR7, clay deposits were imaged in layers at profound depths &gt;30m at lateral spreads of 20-80m and 130-160m respectively. In TR8 clay deposit was imaged at 4m from the surface. In TR9 clay deposit was imaged at 8.9-17.9m at lateral spread of 90-110m and in TR10 clay deposit was imaged at 17.9-20m at lateral spread of 40m and 100-120m respectively. This results show that clay deposits imaged along traverses 1, 2, 4, 5, 9, and 10 are located at proximal depths within the subsurface and this implies that the subsurface geology distribution along these profiles is slightly homogenous in lithology, and clay deposits along these traverses are exploitable, while clay deposits along traverses 3, 6 and 8 are found at the surface (0-8.9 m) as thin clay deposits and therefore not commercially viable for exploitation. Clay deposits imaged in traverse 7 was relatively massive in size (subsurface distribution) and was observed at profound depth of 26.8-35.7m (&gt; 30m), which makes it commercially viable for exploitation compared with other traverses. The results was correlated with borehole lithologic section drilled along TR5 in the area and both sections agreed in lithologic sequence with respect to depth. Thus, 2D resistivity imaging gives a better vertical and lateral view of subsurface layers than geo-electric sections computed from 1D models, because of its ability to give a continuous record of subsurface formations at greater depth. Keywords: Electrical resistivity tomography (ERT), Clay deposit, Wenner-Schlumberger configuration, 2D resistivity pseudosection. DOI: 10.7176/JEES/10-10-06 Publication date: October 31 st 2020

Utility of measuring anterior-posterior spread to determine distal cantilever length off a fixed implant-supported full-arch prosthesis: A review of the literature

BackgroundHistorically, anterior-posterior (AP) spread assessments were often used to determine the length that a distal cantilever could be extended off an implant-supported fixed full-arch prosthesis. Types of Studies ReviewedThe authors searched the literature for articles that used AP spread to calculate cantilever size to be constructed off implants bearing a fixed implant-supported full-arch rehabilitation. ResultsThe data indicate that the relationship between AP spread and cantilever length is not linear and many influences (such as beam theory, cantilever size differences in the mandible versus maxilla, number and distribution of placed implants, prosthetic materials, and framework design) need to be considered when computing cantilever length with respect to fixed implant-supported prostheses. Practical ImplicationsRecommendations using AP spread assessments to compute cantilever lengths have not been validated by means of prospective scientific evaluations. Therefore, AP spread evaluation is just one of many issues that need to be considered when determining distal cantilever length associated with a fixed full-arch implant-bearing prosthesis.

Hydrodynamic pattern transition of droplet train impinging onto heated titanium substrates with or without nanotube coating

The impingement of ethanol droplet train on the heated titanium substrates without or with the titanium oxide nanotube coating has been experimentally investigated in close view. The coating makes the substrate with high wettability. Four distinct but steady hydrodynamic patterns are observed on both two surfaces, namely, liquid aggregation and crown periphery instability; sub-droplet splashing and crown periphery instability; splashing and stable crown; and splashing with stable angle. However, the more wetting nanotube coated substrates push the transition between the patterns to a higher temperature. The quantitatively analysis of spreading length, diameter and height of crown and stable splashing angle further proved the transitions between the hydrodynamic patterns on the two titanium surfaces. The instability at the crown periphery may result from the low surface tension of the working fluids in first and second patterns, while the crown becomes stable on the third pattern. In the fourth pattern, a sharp shift of the splashing angle from decreasing to increasing is found at the surface temperature of 323 ∘C and 404 ∘C for the bare titanium surface and the nanotube coated surface, respectively. The shift could be attributed to the emergence of Leidenfrost effect. It is found that the Leidenfrost point at the droplet train impingement on the nanotube coated surface has been remarkably delayed.

Diffraction Limit in Theory of Light Bullets

An averaged variational procedure has been developed to study the propagation of light bullets in optical fibers using the propagation of light pulses in media with Kerr and quadratic nonlinearities as examples. Criteria for the correct choice of trial solutions are discussed. The condition under which the dispersion length is much greater than the length of diffraction spreading is called the diffraction limit. It is shown that, in this limit, the temporal and spatial dynamics of a bullet are independent of each other, while finding the dynamic parameters of a soliton is reduced to finding various solutions of the nonstationary linear Schrodinger equation for an imaginary quantum particle. The efficiency of the proposed approach is demonstrated by the example of finding solutions in the form of optical vortices in a waveguide for nonlinearities of both types.

Effect of planting methods and varieties on performance of modified TNAU cassava harvester

Cassava is one of the most important tropical tuber crops that ensure food and nutritional security in the developing countries. In India, cassava is cultivated mainly in the southern states viz., Tamil Nadu, Kerala and Andhra Pradesh. Harvesting is one of the major difficult and labour intensive operations in cassava cultivation. In India, cassava is mostly harvested manually by hand. This study was attempted to evaluate the performance of tractor operated Tamil Nadu Agricultural University (TNAU) cassava harvester with two industrial varieties (H-165 and Mulluvadi) and two commercial planting system (Mound and Ridge) using six treatments in a randomized complete block design (RCBD). Based on the field performance trial, the shank length and width of digging blade were modified and then their dimensions were optimized for better performance. Among the selected treatments, it was found that a minimum damage of 4.12% was observed for H-165 variety under manual harvesting and a maximum damage of 9.05% for Mulluvadi variety in mound planting system under mechanized harvesting was noticed. The tuber spread length was highly correlated with the per centage damage (%) of cassava tubers. Thus, the tuber spread length is an important agronomical parameter to be considered while selecting the variety for mechanization of cassava harvesting. This study also confirmed that the ridge planting system is highly suitable for operating mechanized harvester as compared to mound planting system.

GEOMETRICAL ANALYSIS OF LIGHT-EMITTING DIODE FOR ENHANCING EXTRACTION EFFICIENCY

A non-uniform current spreading in the current spreader can greatly reduce the efficiency of the light-emitting diode (LED). The effects of the electrode contact area to the spreading layer towards extraction efficiency of LED chips is analysed in analytical simulations. Length of current spreading and light extraction efficiency is analysed for variation of contact area. The contact area value is varied by changing the shape of the electrode and the value of width of contact area. The increase in contact area decreases light extraction efficiency as more light are absorbed by the bottom electrode surface. The effective current spreading length for Indium Tin Oxide (ITO) of thickness 300nm is 36.44µm. The 6 strips ‘fork’ design is the most optimum. The design has the most area for photons produced in active region to escape without reducing the area cover with current density. This enables the chip to has more extraction efficiency with more uniform current spreading.

Relationship between Eustachian Tube Dimensions and Middle Ear Cholesteatoma

Objective: To compare intact and diseased ears for Eustachian tube (ET) length and width in patients with unilateral chronic otitis media (COM), and to assess the relationship between cholesteatoma spread, stapes erosion, lateral semicircular canal (LSCC) fistula and ET width and length retrospectively. Methods: Subjects with unilateral COM (122 subjects with 244 ears) who underwent surgery for cholesteatoma were evaluated retrospectively for this study. The width of the distal orifice of the bony segment and the length of the bony segment of the ET for both the diseased and healthy ear were measured. Subjects’ healthy and diseased ears were compared for ET length and width. The diseased sides were compared to assess the relationship between ET dimensions and cholesteatoma spread, stapes erosion and LSCC fistula. Results: The mean ET length and width in healthy and diseased ears was 11.38±1.7 and 1.43±0.37 mm, and 10.99±1.6 and 1.27±0.35 mm, respectively; the difference was statistically significant (p<0.001). No significant differences were found in terms of ET length and width between the subjects with and without stapes erosion and LSCC fistula (p=0.765, p=0.573, and p=0.436, p=0.790, respectively). No significant relation was found between cholesteatoma spread and ET length and width (p=0.647). Conclusion: ET dysfunction is frequently associated with COM. Chronic otitis media with cholesteatoma is significantly related to ET length and width. Measurement of ET length and width in CT scans is a basic method that can be used in clinical practice.

Effect of Fuel Bed Width on Upslope Fire Spread: An Experimental Study

In this work, a series of experiments across a porous fuel bed of pine excelsior with two sidewalls were conducted under different slope and fuel bed width conditions. It was observed that the fire line stayed straight during fire spread after the initial line ignition for all tests. Flame length and rate of spread (ROS) increased with increasing slope angle or fuel bed width. A dimensionless correlation of ROS was developed that integrated the effects of slope and fuel bed width. For a lower slope angle (≤ 20° in this work), the reverse airflow that denoted natural convective cooling for unburnt fuel was identified from the measured flow velocity data, for which flame radiation was the dominant preheating mechanism. For a higher slope angle (30° in this work), it was identified that the forward airflow from the burning area induced convective heating ahead of the flame front, and thus the fuel preheating was controlled by both flame radiation and convective heating. The effect of convective heating was more significant under larger fuel bed widths.