Automobile Window Research Articles

Experimental Study of a Silver Layer on an Antireflection Subwavelength-Structured Surface

The optical characteristics of a silver layer deposited on an antireflection subwavelength-structured surface are investigated. The experimental results of the reflectance and the transmittance of several different thicknesses of silver layer on the subwavelength-structured surface are carried out. A subwavelength structure with the spatial period and diameter of about 230 nm and height of about 150 nm on polyethylene terphthalate film is fabricated by microreplication process. It is shown that such an element with the suitable silver layer deposited on an antireflection subwavelength-structured surface has high transmittance and low glare in the visible spectral range and high reflectance in the infrared range. Obviously, the optical film with silver layer can not only obtain the high performance of heat insulation but also give an application in automobile and house windows.

Determinants of ultrafine particle exposures in transportation environments: findings of an 8-month survey conducted in Montréal, Canada

An 8-month sampling campaign was conducted in Montréal, Canada to explore determinants of ultrafine particle (UFP) exposures in transportation environments and to develop models to predict such exposures. Between April and November 2006, UFP (0.02-1 mum) count exposure data were collected for one researcher during 80 morning and evening commutes including a 0.5-km walk, a 3-km bus ride, and a 26-km automobile ride in each direction. Ambient temperature, relative humidity, precipitation, and wind speed/direction data were collected for each transit period and the positions of bus and automobile windows were recorded. Mixing heights were also estimated. Morning UFP exposures were significantly greater than those in the evening, with the highest levels observed in the automobile and the lowest while walking. Wind speed and mixing height were highly correlated, and as a result only wind speed was considered in multivariable models owing to the accessibility of quantitative hourly monitoring data. In these models, each 10 degrees C increase in morning temperature was associated with decreases of 14,560/cm(3) (95% CI=11,111 to 18,020), 8160/cm(3) (95% CI=5060 to 11,260), and 11,310/cm(3) (95% CI=6820 to 15,810) for UFP exposures in walk, bus, and automobile environments, respectively. Likewise, each 10-km/h increase in morning wind speed corresponded to decreases of 8252/cm(3) (95% CI=5130 to 11,360), 6210/cm(3) (95% CI=3420 to 9000), and 6350/cm(3) (95% CI=2440 to 10,260) for UFP exposures in walk, bus, and automobile environments, respectively. Similar trends were observed in the evening hours. In an evaluation of model performance, moderate correlations were observed between measured and predicted UFP exposures on new bus (r=0.65) and automobile (r=0.77) routes. Further research is required to incorporate variables such as traffic density and vehicle ventilation settings into the models presented.

Forensic comparative glass analysis by laser-induced breakdown spectroscopy

Glass samples of four types commonly encountered in forensic examinations have been analyzed by laser-induced breakdown spectroscopy (LIBS) for the purpose of discriminating between samples originating from different sources. Some of the glass sets were also examined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Refractive index (RI) measurements were also made on all glass samples and the refractive index data was combined with the LIBS and with the LA-ICP-MS data to enhance discrimination. The glass types examined included float glass taken from front and side automobile windows (examined on the non-float side), automobile headlamp glass, automobile side-mirror glass and brown beverage container glass. The largest overall discrimination was obtained by employing RI data in combination with LA-ICP-MS (98.8% discrimination of 666 pairwise comparisons at 95% confidence), while LIBS in combination with RI provided a somewhat lower discrimination (87.2% discrimination of 1122 pairwise comparisons at 95% confidence). Samples of side-mirror glass were less discriminated by LIBS due to a larger variance in emission intensities, while discrimination of side-mirror glass by LA-ICP-MS remained high.

Color-neutral switchable mirrors based on magnesium-titanium thin films

In an investigation of smart-window applications of switchable mirror thin films, Pd-capped magnesium-titanium thin films were prepared by dc magnetron sputtering. Their optical properties, switching durability and crystalline structures have been investigated. We show that Pd/Mg-Ti thin films with specific thicknesses are completely color-neutral in the transparent state and their optical switching properties are suitable for building and automobile window glass applications. The ternary hydrides of Mg(1-x)Tix thin films with Pd overlayers are identified by in situ X-ray diffraction measurements during a hydrogen gas loading of 4%. Pd/Mg(1-x)Tix thin film switchable mirrors show fast hydriding and dehydriding kinetics as compared to a Pd-capped pure Mg thin film due to the catalytic role of doped metallic Ti.

Finite Element Analysis of Composite Worm Gears

Worm gears are commonly used in windshield wipers and power windows of automobiles. The goal of this work is to study several material problems, such as production bottlenecks and excessive scrap, resulting from the production of steel worm shafts. A possible solution is explored in this work by characterizing material properties of a promising candidate (glass reinforced acetal copolymer) that can replace steel in worm gears. Finite element analysis of the worm thread under static loading and constant temperature is performed in order to calculate the size of the new composite part. The results obtained in this work support the possibility of manufacturing composite worm shafts that could operate at elevated temperatures without sacrificing part performance, while reducing part weight leading to improved fuel economy, noise reduction, and manufacturing problems associated with the steel part. The finite element analysis shows that compared to a steel gear, the axial pitch of a composite worm gear must be increased by 250% in order for it to operate without failure for 10 years at a constant temperature of 23%C. This increase in the axial pitch would ramp up to 400%, if the composite worm gear is expected to operate for 10 years at a constant temperature of 100 C.

Some complementary scratch resistance characterization methods

In the characterization of mar/scratch resistance of coatings/materials with single-probe techniques, the probe usually scrapes the tested surface under a constant load or increasing load, followed by dimensional measurements of the scratch, identification of the critical force at which cracking/fracture occurs, or evaluation with optical instruments. Due to a variety of coatings/materials properties and various application requirements, the single-probe method may not provide pertinent characterization of coatings/materials in their applications in some cases. Three complementary test methods are presented in this article: i.e., a crack density measurement used for fragile thermoplastic olefin (TPO), a repeated scratching test, and a cross-scratching test used for glazing materials for automobile windows.

Sampling strategies for the analysis of glass fragments by LA-ICP-MS: Part I. Micro-homogeneity study of glass and its application to the interpretation of forensic evidence

The authors have previously reported the use of laser ablation ICP-MS as a powerful analytical tool for elemental analysis of glass. LA is a simpler, faster and less intrusive sample introduction method than the conventional solution ICP-MS. Due to the minute amount of material removed in LA (∼300 ng, 50 μm crater size), the analyst should be aware of special sampling considerations such as characterization of the glass fragments originating from the “known” source, fragment size and selection of the area and surface of ablation. The purpose of this work was to evaluate the micro-homogeneity of the elemental composition of glass samples commonly found in crime scenes like containers, architectural windows and windshields. The set of glasses under study was comprised of 56 fragments originated from glass containers, 28 fragments from automobile windshields and 20 fragments from architectural windowpanes. All fragments were selected with a size smaller than 2 mm 2 in order to simulate the typical glass fragments transferred from the crime scenarios. A Nd:YAG laser, 266 nm, flat top beam profile was used in single point mode sampling 50 μm spot size for 50 s at 10 Hz (500 shots). In this study, 29Si was used as an internal standard and the standard reference material, SRM NIST 612, was used as a single point external calibrator. In addition, SRM 621 was used as another control standard for the containers set and SRM 1831 for the automobile and architectural window sets due to their very similar matrix with the samples of interest. For each set of glasses, the mean values and standard deviation of 10 replicates ( n = 10) of a single fragment were compared with the values obtained from 10 ( n = 10) different fragments of glass within the area of interest in order to evaluate whether or not the variation within a glass was bigger than the variation due to the method. In addition, a subset of tempered glasses was evaluated to perform an elemental composition profile within different depths of the fragments. Single shot (one laser pulse per analysis) was also evaluated and its limitations for the forensic analysis of glass are also presented. The results show that float glass is homogenous even at the micro-range level allowing LA-ICP-MS as an alternative technique to perform elemental analysis of glass. However, the variation of elemental composition of headlamps and containers is larger over the source than the instrumental variation due to inherent heterogeneity and therefore specific statistical methods are recommended to compare the glass samples.

Forensic glass analysis by ICP-MS: a multi-element assessment of discriminating power via analysis of variance and pairwise comparisons

Glass fragments from 81 automobile side windows were collected and analyzed by the FBI Laboratory using ICP-AES in 1991. The FBI selected 9 elements (Al, Ba, Ca, Fe, Mg, Mn, Na, Sr and Ti) to use for discrimination among the glass samples. This multi-element discrimination showed a significant improvement in the discrimination statistics over using only refractive index (RI) measurements. Oak Ridge National Laboratory (ORNL) recently analyzed fragments from 76 of the original side window fragments using inductively coupled plasma mass spectrometry (ICP-MS). The ICP-MS analyses measured 45 elements using a hierarchical sampling scheme to estimate variances due to sampled population (VP), variance due to sample dissolution and within sample heterogeneity (VD), and variance due to replicate measurements (VM). The between-to-within ratio [B/W = VP/(VD + VM)] afforded a measure of the variance within the population to that in the analytical measurement, providing a first approximation of the discriminating power of each element. Florida International University updated the RI measurements on 72 available glass fragments. These RI measurements along with ICP-AES and ICP-MS elemental analyses were used for pairwise comparisons of all possible pairs of the 72 glasses that had a complete set of measurements. The pairwise comparisons used Tukey's HSD method to compare RI and element-by-element discrimination potential of ICP-AES and ICP-MS for analyzing glass in forensic casework.

Ultraviolet ray absorbing coatings on glass for automobiles

Ultraviolet ray (UV) absorbing coating consisting of a complex oxide of cerium and titanium was deposited on glass via the sol–gel process. Addition of TiO2 to CeO2 changed the crystallinity and coordination state of CeO2 and improved UV absorption. Formation of a double-layered coating comprised of outer CeO2–TiO2 layer and inner TiO2–SiO2 layer diminished the interference coloring and improved the adhesion of the coating to the glass substrate. The double layer coated glass shows high UV-shielding properties without visible light absorption and excellent durability against chemical and physical attacks. Therefore, it has been widely used in automobile windows.

Evaluation of high energy ion-implanted polycarbonate for eyewear applications

The combination of transparency, toughness and light weight makes polycarbonate (PC) very attractive for eyewear applications. However, PCs are easily scratched in the normal use environment because of their softness. High-energy (MeV) ion irradiation can significantly alter surface sensitive properties of polymers, including hardness and scratch/wear resistance. These improvements are also associated with changes in transparency that limit the applications of ion-irradiated PC and other transparent polymers. Specialty eyewear such as sports (including sunglasses) and protective eyewear can accept some reduction in transmission of visible light if the process can provide adequate scratch resistance. Also, applications are possible as tinted windows in automobiles. The purpose of this paper is to present the results of evaluations of high-energy (MeV) ion-irradiated PC in relation to the eyewear applications. PC lenses were irradiated with 2.5-MeV O + ions at doses in the range of 5×10 13 to 3×10 14 ions cm −2. Abrasion tests were performed using sandpapers and abrasive materials of various particle sizes that are typically used in the industry. The degree of abrasion of the lenses was measured from the change in haze or light transmission of the samples before and after abrasion. It was shown that the abrasion resistance of PC lenses could be increased by ion bombardment by approximately an order of magnitude, whereas the transmission was maintained within an acceptable limit.

Plastic car windows aim of joint venture

Polycarbonate makers General Electric and Bayer have signed a letter of intent to form a 50-50 joint venture that will accelerate the two companies' separate efforts to replace glass automobile windows with plastic. The two corporate giants see a window of opportunity in the $6 billion worldwide market for automotive glazing if they can improve the abrasion resistance of polycarbonate. Improving coatings technology is key to improving polycarbonate's scratch resistance, says Mark Whitman, direaor of plastics technology at Bayer and soon to be the new venture's vice president of technology. The partners will work on coatings technology such as GE's inorganic plasma coating and a Bayer technique to embed microscopic ceramic particles in an elastomeric siloxane coating. The two partners plan a collective investment of $40 million over the next few years in coatings technology and advanced manufacturing techniques. About 60 staffers from GE and Bayer will initially join the new venture company, ...

Surface Morphology of Silica Films Derived by the Sol-Gel Method and Its Application to a Water Repellent Glass

Silica films with various surface morphologies, such as flatness, mesoporosity, uneveness, convexity, were prepared by hydrolysis and polymerization of tetraethoxysilane, Si(OC2H5)4(TEOS) and methyltrietoxysilane, CH3Si(OC2H5)3(MTES) under acid-catalyzed conditions. The morphology of coatings could be changed by changing the molar ratio (denoted as f, f=KITES/TEOS) in TEOS-MTES mixture, as well as the conditions of drying process and heat treatment temperature. Especially, in the case of 5<f≤7.5, the surface of coatings was uneven, when films were prepared at humidities higher than 45RH%. Water repellent glasses obtained by coating hydrolyzed heptadecafluorodecyltrimethoxysilane, CF3(CF2)7CH2CH2Si(OCH3)3 on to this uneven surface showed an excellent abrasion resistance and UV-light stability for windows of automobiles and buildings.

RCS characterization of a finite ground plane with perforated apertures: simulations and measurements

The monostatic radar cross section of a finite-size perfectly conducting flat plate with perforated apertures is investigated by simulations and measurements. The geometry of a finite ground plane with triangular apertures resembles airplane and automobile windows. The method of moments surface patch formulation is used to compute the radar cross section of a solid plate, a plate with two widely spaced apertures, and a plate with two closely spaced apertures. The characteristics of the triangular patch mesh can impact the accuracy of the computed results with this formulation. The paper presents a methodology to achieve high quality meshes to ensure that the time and convenience gained by developing the general method of moments code is not lost in mesh construction and convergence tests. The results obtained using the method of moments are compared with results obtained by measurements and physical optics. It is shown that the method of moments simulations and measurements are in good agreement. The key features of the influence of the aperture separation on the RCS patterns are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Recent progress of optical thin films in the automobile industry

There are increasing demands for the application of optical thin films to transparent substrates such as glass and plastics for windows in automobiles with the view of adding fascinating optical properties to them. These properties include surface hardening of plastics, infrared reflection, ultraviolet absorption, polarization and birefringence, and hydrophobicity. Recent examples of applications of sophisticated thin-film processes of plasma treatment and physical vapor deposition are reviewed. The novelty of the functions provided by physical vapor deposition films together with their durability for practical usage are emphasized as areas in which the thin-film process has a significant impact. Characterization of the modified surface and interface is also included to demonstrate recent advances in surface chemistry. Finally, future challenges for optical modification of transparent substrates in the automobile industry are also discussed.

Power Window Control Location Stereotypes

A paper-and-pencil survey instrument and an operational test were used to assess stereotype strength for automobile power window controls. Control panel layout (square vs. linear) and mounting plane were examined along with stereotype differences between subjects with technical backgrounds and those with non-technical backgrounds. A total of 273 participants ranging in age from 16 to 50 completed the survey instrument which requested responses to questions about which control was expected to activate a specified window. Subject preference for a particular control configuration was also solicited. A square control layout mounted on the instrument panel exhibited the strongest stereotype (94% of consistent responses for a single pattern) although it was the least preferred (22%). A square configuration mounted on the door panel possessed the second strongest stereotype (67% and 28% of consistent responses for the top two response patterns) and the highest preference (47%). A linear configuration mounted on the door panel exhibited a weaker stereotype (57% and 36% of consistent responses for the top two response patterns) and was preferred by 31% of the subjects. Preference tended to follow familiarity with controls in existing vehicles rather than ease of use or isomorphic arrangement. Twenty-four of the survey participants were also tested using actual power window controls mounted in a vehicle mockup. The subject's task involved moving the left hand as quickly as possible from the steering wheel to the subject's selected control upon presentation of a pictorial or verbal cue to raise or lower a specific window. Cue presentation and measurement of reaction time and movement time were provided by a PC. The square control layout mounted on the instrument panel was superior in terms of response time, stereotype strength and response consistency.

SnS-CuxS thin film combination: a desirable solar control coating for architectural and automobile glazings

SnS-CuxS thin-film combinations deposited on glass substrates are found to offer sought-after solar control characteristics for architectural and automobile glazing applications with a choice of colours in reflection-bluish, greenish yellow, golden purple etc. The coatings were obtained by successive chemical depositions of SnS and CuxS thin films. The nontoxicity of SnS and CuxS films, their stability and the good adhesion of SnS films to glass substrates and that of CuxS films to polymer coatings are attractive features for the production of laminated or other types of solar control glazings for architectural and automobile windows which would be acceptable from legal, technical and aesthetic points of view.

The Effect of Tempered Glass on Bullet Trajectory

It was determined that tempered glass automobile windows may severely influence the trajectory of .38 Special projectiles. In replicating an actual case situation, deflections as great as 26.4 degrees were observed with jacketed hollow-point ammunition, and as high as 10.8 degrees for lead ammunition.

Plastics tape window winder

THE first major departure from conventional US automobile window mechanisms in 25 years is a tape‐drive system which relies on a new plastic tape from Du Pont in conjunction with components of Du Pont engineering plastics. Both products, it is claimed, stand up better to the frictional and tensional stresses than do the more conventional metal window‐winding mechanisms.

Management of Turbulent Shear Layers in Separated Flow

A ERODYNAMIC configurations with isolated regions of separated flow often produce unsteady flows with high levels of turbulent flow fluctuations. Some examples are: a bomb bay, an automobile window or sun roof, and a cavity flush with an aerodynamic surface. General principles are described for altering the aerodynamic configuration in order to control the free shear layer and reduce flow fluctuations. These principles were applied to an actual aerodynamic configuration. The flow fluctuations were measured in a wind tunnel and in flight. The root-mean-square velocity fluctuations beneath the shear layer were reduced to 2% of the stream velocity. Pressure fluctuations beneath the shear layer were 0.4% of the freestream dynamic pressure (of the order of the surface pressure fluctuations beneath a turbulent boundary layer on a smooth flat p la te ] ) .

Vehicle Warning Devices—Necessity versus Nuisance

Acoustical warning devices may be essential for public safety and a nuisance to nearby residents. The question arises, how much reduction in the level of the warning device can be tolerated before it loses its value as a warning signal? This paper presents the results of a short study related to possible reduction in acoustic level of a Diesel-engine horn. The important variables that were studied included (a) level and spectral content of the horn signal; (b) distance between Diesel engine and the driver of an automobile approaching a railroad crossing; (c) whether the automobile windows are open or closed; (d) the level of the masking sound the driver is experiencing. Use is made of the critical-bandwidth concept to obtain allowable Diesel-engine horn sound reductions for several automobile window configurations and three types of masking sounds.