Evaporation Source Research Articles

Experimental and analytical evaluation of an active barium vapor notch filter functioning at 355 nm.

This work presents an experimental and theoretical study of the 6s21S0→6s6p3P10 (791 nm) and 5s5d3D2→6s5f3F20 (355 nm) transitions within a low vapor pressure barium vapor in the absence of a buffer gas. To the authors' knowledge, this is the first measurement of the latter absorption feature. The study is motivated by the development of an optically controlled atomic vapor notch filter functioning at the third harmonic of the commonly used Nd:YAG laser at 355 nm. The low-pressure environment within the vapor source has enabled a deeper understanding of barium vapor collisional and velocity changing properties with a simple pump-probe spectroscopy measurement. The results demonstrate depletion of the ground state and subsequent population of the 5s5d3D2 level. Most notably, the 5s5d3D2→6s5f3F20 transition displays a non-thermal, cusped absorption curve. An analysis of this line shape in the context of existing analytical collisional kernels is presented. Additionally, a six-level kinetic model of the low-lying energy levels, incorporating spatial diffusion and collisional and radiative transitions, is introduced and compared to the measured level populations for the barium ground state and excited 5s5d3D2 state.

Isoscapes to address the regional precipitation trends in the equatorial region of Southeast Asia

This research was an attempt to understand spatiotemporal characteristics of stable isotopes in precipitation samples and their regional circulation patterns in Borneo. Two locations were selected in the Limbang River Basin (LRB). Monthly rainwater samples were collected from October 2016 to September 2017. Samples were analysed for δ2H and δ18O isotopes. Local meteoric water line (LMWL) for two locations showed common source of moisture. δ2H and δ18O composition did not show effect of temperature; but, inverse correlation with amount of rainfall was noted. The d-excess values more than 12‰ during northeast monsoon showed enhanced terrestrial recycled moisture; precipitation was inferred to be from evaporative moisture source during southwest monsoon with ∼9‰–∼15‰ d-excess. Average δ2H and δ18O values from the International Atomic Energy Association/Global Network of Isotopes in Precipitation stations of adjoining countries and LRB were considered to derive the regional meteoric water line for Southeast (SE) Asia. Comparison of LWML with global meteoric water line and available datasets from IAEA/GNIP locations showed the variation in rain events, evaporation effect, and change in source of atmospheric moisture. LRB slope value showed similar values with China, Indonesia, Myanmar, Singapore, and Thailand, indicating similar meteorological trend and moisture source. Backward air mass movement trajectory indicated that predominant air mass reaching LRB were from the Indian Ocean, Pacific Ocean, and terrestrial source. Results pointed the need of detailed and site-specific collection of rainwater samples for long period to detect climate change over water resources in SE Asia.

USE OF HYDROGEN AND OXYGEN ISOTOPES TO UNDERSTAND EVAPORATION FROM ENCLOSED WATERBODIES

Getting information on evaporation is important for water resource protection and managing regional enclosed waterbodies. Some lake water samples were collected in May and June from a representative enclosed waterbody – the Pearl Lake, Suzhou, China – and the hydrogen and oxygen isotopes determined. Most samples taken in June have higher δ18O and δD values than those in May, indicating that there are differences between the intensity of evaporation of May and June. This was further confirmed by the water samples’ d-excess values, which were below the meteoric line. However, the variations of d-excess value have been shown to be influenced by source moistures or evaporation processes, which were controlled by the local environment, e.g., whether the water was shaded or not. The residual water quantities calculated were 53 to 63% and 49 to 56% for May and June, respectively, relative to the initial water, indicating that about 5% of the water evaporated between 5 May and 5 June.

Development of lower flammability limits testing apparatus for gasoline vapor – Air mixture using an internal vaporizer at ambient conditions

Fire accidents at public fuel stations in Indonesia have urged the need to characterize the causes of these fires. In the gas station area, the formation of gasoline vapor is the main concern of this research. Therefore, this study aims to analyze lower flammability limits (LFLs) of gasoline vapor-air mixtures of the selected gasoline samples. The LFL of gasoline vapor was characterized using a 1.2 L vertical tube integrated with an internal evaporator and a high voltage electric lighter with the energy of 10 J. The tube is made of glass with a diameter of 80 mm and a height of 300 mm with an open top end. This apparatus can run two test methods of upward and downward propagation. The experiment was conducted at the ambient condition with an evaporation temperature of the sample being 150 °C for the internal evaporator. Four gasoline samples were used with varying octane numbers (RON) obtained from arbitrary public gas stations. For validation, Iso-octane (IO) reference fluid with a purity level of 99.5% was tested for the assessment of LFL. The results with the upward propagation method showed that the LFL volume-based concentration were 1.62%, 1.61%, 1.64%, 1.60% and 1.05%, and downward propagation method were 2.48%, 2.39%, 2.30%, 2.11% and 1.57% for RON_88, RON_90, RON_92, RON_95 and IO_100 samples respectively. This study shows that a downward propagation flame has a higher gas temperature with lower velocity compared to an upward flame, which suggests that lower elevation fuel vapor sources at gas stations have a higher fire potential. This research topic is in an effort to provide input on the fire hazards at gas stations that are specific for tropical conditions with traffic practices such as in Indonesia and other countries that face similar hazards and threats. This study can provide input for further transportation safety policies and research.

A near-ambient pressure flow reactor coupled with polarization-modulation infrared reflection absorption spectroscopy for operando studies of heterogeneous catalytic reactions over model catalysts.

The model catalyst approach is often used for fundamental investigations of complex heterogeneous catalysis, in which operando characterizations are critical. A flow reactor is usually adopted for gas-solid heterogeneous catalytic reactions. Herein, we report a home-designed near-ambient pressure (NAP) flow reactor coupled with polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS) and an online quadrupole mass spectrometer for operando studies of heterogeneous catalytic reactions over model catalysts. A unique gas supply system is designed and manufactured to enable a stable gas inlet to the NAP flow reactor at pressures up to ∼100mbar. An ultrahigh vacuum chamber equipped with the facilities for x-ray photoelectron spectroscopy, low-energy electron diffraction, thermal desorption spectroscopy, E-beam evaporation source, and ion sputtering gun is connected to the NAP flow reactor via a gate valve for preparations and routine characterizations of model catalysts. The functions of the system are demonstrated by in situ PM-IRAS characterization of CO adsorption on Pt(111) and operando characterizations of CO oxidation on Pt(111) under NAP conditions.

Evaporated Alkali Carbonate Effect on an Aluminum Diffusion Coated 253MA Vessel after 4000 h Discontinuous Operation—Lessons Learned

A vessel of a laboratory setup for hosting molten alkali carbonate immersion experiments was recently decommissioned after about 4000 h discontinuous operation at 800 °C. In this article, we want to describe the long-term damage of the vessel caused by evaporated alkali carbonate species in a carbon dioxide gas environment. The vessel is made of alloy 253MA and coated by an aluminum powder pack diffusion process. The degree of material loss and internal degradation did not correlate with the temperature profile across the vessel but rather with the vicinity to the gas and salt evaporation source. One millimeter of the vessel’s initial 5 mm wall thickness was completely consumed at the strongest attacked location plus another 800 µm of internal attack beneath the metal–oxide interface.

Atmospheric moisture sources of drought and wet events during 1979–2019 in the Three-River Source Region, Qinghai-Tibetan Plateau

The soil moisture observation data from the Qinghai-Tibetan Plateau permafrost and alpine wetland (PAW) monitoring network and from the National Center for Environmental Prediction (NCEP) Final Analysis (FNL) from 1989 to 2019 were adopted to drive the Lagrangian backward trajectory model to simulate the water vapour transportation paths and source regions to the three-river source region during dry and wet episodes. The results showed that the water vapour transport paths mainly came from the land and ocean in the west during the extreme drought episodes based on the standardized precipitation index (SPI), including the northern African continent, the eastern European plains, and the mid-latitudes of the Atlantic Ocean. The water vapour source regions were mainly concentrated in the Kashmir region, northeast India and southern Motuo on the Qinghai-Tibet Plateau. When the SPI indicated an extremely wet state, the transport mainly occurred to the east and south, including the Pacific Ocean and the South China Sea, where water vapour entered the mainland from East/South China, passed through the Yangtze River Basin, and finally reached the three-river source region from east or south of the Qinghai-Tibet Plateau, while the water vapour from the Indian Ocean and Arabian Sea passed through the Indian Peninsula and the Bay of Bengal and entered the three-river source region from the western and southern sides of the Qinghai-Tibet Plateau.

Enhanced performance of GeSe thin-film solar cells via bifacial charge transport materials design

Owing to non-toxic, earth abundant and stable properties, GeSe has become a promising photovoltaic absorber material in thin-film solar cells (TFSCs). Currently GeSe film is mainly prepared by rapid thermal sublimation (also called one-step method), where the evaporation source and substrate are heated together, thus it is difficult to regulate their temperatures independently, leading to the re-sublimation of GeSe film and diffusion of Cd element. In this work, a two-step method is introduced to prepare the GeSe film. Moreover, a synergic interface design is applied to enhance the performance of GeSe TFSCs. On one hand, the conductivity of CdS buffer layer is increased by post-annealing to reduce the series resistance and promote the electron transfer from GeSe to CdS, validated via linear sweep voltammetry curves. On the other hand, Cu2O is inserted as a hole transport layer for the first time. The Cu2O layer has sufficiently improved the hole extraction efficiency and suppressed the charge recombination, demonstrated by transient photovoltage spectroscopy and electrochemical impedance spectroscopy. By incorporating these bifacial modifications, the power-conversion efficiency (PCE) of the device has been improved by about four times (0.16%–0.63%), comparable to the highest PCE among all the reported GeSe TFSCs fabricated via a two-step method.

Revisiting the Effect of the Air-Water Interface of Ultrasonically Atomized Water Microdroplets on H2O2 Formation.

Studying chemical processes at the air-water interface is always challenging. A recent report claimed that H2O2 was formed spontaneously on the surface of condensed water microdroplets. However, a newer report concluded that the detected H2O2 in the previous report could originate in part from the water vapor source that involved ultrasonic atomization of liquid water. Here, this phenomenon is reinvestigated regarding the influence of ultrasonic cavitation, surface modification of droplets, and solutes in the bulk liquid on H2O2 production. When the droplet surfaces were modified by surfactants, H2O2 production did not change, whereas adding gases or inorganic compounds to the bulk solution caused significant changes in H2O2 production. These results confirm that H2O2 formation originates from cavitation in bulk solutions. It is concluded that the air-water interface of water microdroplets itself does not generate H2O2.

Processing and properties of hafnium‐doped tin‐modified lead zirconate titanate 95/5 ceramics

AbstractNiobium (Nb)‐doped lead‐tin‐zirconate‐titanate (PSZT) ceramics near the lead‐zirconate‐titanate 95/5 orthorhombic AFE‐rhombohedral FE morphotropic phase boundary (PSZT 13.5/81/5.5 ‐1.6Nb) were prepared with up to 10 mol.% of hafnium (Hf) substituted for zirconium. The ceramics were prepared by a traditional solid‐state synthesis route and sintered to near full density at 1150°C for 6 h in sealed alumina crucibles with self‐same material as the lead vapor source. All compositions were ∼98% dense with no detectable secondary phases by X‐ray diffraction. The grain size was ∼3 μm for all compositions, consisting of equiaxed grains with intergranular porosity. The compositions exhibited remnant polarization values of ∼32 μC/cm2. Depolarization by the hydrostatic pressure‐induced FE‐AFE phase transition occurred at 310 MPa for all compositions, resulting in a total depolarization output of 32.4 μC/cm2 for the PSZT ceramics. Evaluation of the R3c‐R3m and R3m‐Pm m phase transition temperatures by impedance spectroscopy showed temperatures on heating ranging from 86 to 92°C and 186 to 182°C, respectively, for increasing nominal Hf content. Thermal hysteresis of the phase transitions was also observed in the ceramics, with the transition temperature on cooling being 1–4°C lower. The study demonstrated that the PSZT ceramics are relatively insensitive to variations in Hf content in the range of 0 to 10 mol.%.

Asian Summer Monsoon Changes Inferred From a Stalagmite δ18O Record in Central China During the Last Glacial Period

The reconstruction of Asian summer monsoon (ASM) changes during the last glacial period is of great significance for better understanding monsoon dynamics. The phase relationship between the Indian summer monsoon (ISM) and East Asian summer monsoon (EASM) subsystems on different timescales is still unclear. The comparative analysis of speleothem records in the ISM region, EASM region, and central China helps to clarify the relationship between the ISM and EASM. Based on the well-dated isotope records of stalagmite DDH-B15 from the Didonghe (DDH) Cave in Hanzhong, Shaanxi, we reconstructed ASM changes during the past 34–13 thousand years before the present (kyr BP). The small average error (61 years) of 18 uranium-series ages enables a precise comparison of the stalagmite δ18O record with other well-dated records from the orbital to the millennial timescales. The δ18O signal of the DDH-B15 stalagmite is controlled by changes of the low latitude northern hemisphere summer insolation (NHSI) on the orbital timescale. It records cold Heinrich Stadial (HS) and Dansgaard–Oeschger (DO) cycles which are originated from the northern high latitude on the millennial time scale. The δ18O changes of stalagmites from the three regions are similar on the millennial and centennial timescales. But on the orbital-suborbital timescale, stalagmite δ18O changes during the last glacial cycle have different characteristics. The stalagmite δ18O values in eastern China became gradually negative, and the stalagmite δ18O values in the Indian monsoon domain showed a increasing trend, but the stalagmite δ18O values in Central China adopted an intermediate state between the EASM and ISM. Then we argued that the δ18O value of stalagmites in Central China is a mixed signal of the ISM and EASM, which indicates a change of the water vapor source as an important influence on the Chinese stalagmite δ18O record.

System development and simulation investigation on a novel compression/ejection transcritical CO2 heat pump system for simultaneous cooling and heating

The problems that the expansion work cannot be recovered and the heat source of the evaporator is insufficient have been found in the previous experimental research, and thus this paper proposes a novel compression/ejection transcritical CO2 heat pump system for simultaneous cooling and heating. An ejector and a water source evaporator are added to the novel system, which realizes the improvement of the compressor inlet grade and the utilization of multiple heat sources. The feasibility of the novel system is verified at first, by numerically analyzing the system operating characteristics variation tendency. The simulation results show that COPtotal of the novel system can reach 11.7 in the compressor frequency of 30 Hz and the discharge pressure of 8000 kPa. In addition, the novel system is compared with the basic transcritical CO2 heat pump system and the transcritical CO2 ejector heat pump system in the exergy, energy and economic aspects. The dual-evaporator design helps the novel system achieve the highest total COP. The simulation results show that the novel system owns 12% higher exergy efficiency over the ejector system, and yields the shortest payback period of 1.10 years among the three considered systems.

Characteristics and Source Apportionment of Vehicular VOCs Emissions in a Tunnel Study

To explore the emission characteristics of volatile organic compounds (VOCs) from vehicular exhaust sources and evaporative sources with ethanol gasoline (E10) as the main fuel, VOCs sampling campaigns were carried out in the north third ring tunnel of Zhengzhou city for two consecutive weeks in December 2019. In addition, the characteristics of traffic flow and environmental information were also monitored in the tunnel. Firstly, 106 VOCs were quantified using gas chromatography/mass spectrometry (GC/MS), and then source apportionment of VOCs in the tunnel was carried out using a positive matrix factorization (PMF5.0)-chemical mass balance (CMB8.2) composite model. Finally, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) of vehicle exhaust sources and evaporative sources were analyzed using the maximum incremental reactivity (MIR) and fractional aerosol coefficient (FAC). The results showed that ρ(VOCs) in the tunnel was (2794.5±147.4) μg·m-3 during the experiment, among which halogenated hydrocarbons[(32.4±2.0)%] accounted for the highest proportion, followed by aromatic hydrocarbons[(27.5±0.6)%] and alkanes[(23.3±0.8)%]. Source apportionment of vehicular VOCs showed that exhaust emissions (62.5%)>evaporative emissions (37.5%), whereas the contribution of OFP was that exhaust emissions (71.9%)>evaporative emissions (28.1%), and the contribution of SOAFP was that exhaust emissions (75.8%)>evaporative emissions (24.2%). The dominant components of OFP in evaporative sources were m,p-diethylbenzene, isoprene, and trans-2-pentene, whereas m,p-diethylbenzene, m,p-xylene, and 1,2,3-trimethylbenzene were the dominant components of SOAFP. The major components of OFP in exhaust sources were m,p-xylene, 1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene, whereas m,p-xylene, m,p-diethylbenzene, and 1,3,5-trimethylbenzene were the dominant components of SOAFP. In regions where ethanol gasoline is used, special attention should be paid not only to the exhaust emissions control but also to strengthening the emissions reduction of VOCs from vehicle evaporative sources, especially the high active components such as aromatic hydrocarbons and alkenes.

Collimated versatile atomic beam source with alkali dispensers

Alkali metal dispensers have become an indispensable tool in the production of atomic vapors for magnetometry, alkali vapor cell clocks, and laser cooling experiments. A primary advantage of these dispensers is that they contain alkali metal in an inert form that can be exposed to air without hazard. However, their high temperature of operation (>600 °C) is undesirable for many applications, as it shifts the atomic speed distribution to higher values and presents a radiative heat source that can raise the temperature of its surroundings. For this reason, dispensers are typically not used in line-of-sight applications, such as atomic beam generation. In this work, we present an integrated rubidium dispenser collimating device with a thickness of only 2 mm that produces a beam of atoms traveling primarily in the forward direction. We find that the collimator plate serves to both shield the dispenser's radiation and moderate the velocity of the atomic beam so that the measured longitudinal speed distribution is comparable to that of an ordinary alkali oven at only a slightly elevated temperature of 200 °C. To confirm our theory, we also constructed another compact apparatus consisting of a dispenser and a silicon collimator and the measurements support our conclusion. Our integrated dispenser collimator will particularly be useful in integrated photonics and cavity QED on-chip, where a localized, directed source of Rb vapor in small quantities is needed.

Monsoon Fringe Area Moisture Transportation Revealed by Water Stable Isotopes: A Lanzhou River Valley Case Study

Because of global warming, the water cycle has intensified and precipitation has changed, with monsoons evolving to become more complex, particularly in monsoon fringe areas. Therefore, it is important to use stable isotopes to trace moisture sources in monsoon fringe areas, such as semiarid areas. In this study, in situ measurements of water vapor isotopes were obtained in the monsoon fringe areas of Lanzhou (36.1° N, 103.7° E), between May and November 2019 with the aim of analyzing the stable isotope composition and atmospheric water vapor variation to improve our understanding of moisture transport. The following results were obtained: stable isotopic variation of atmospheric water vapor shows an alternation between west and southwest moisture with wind directions and sources of water vapor, with δ18O and δ2H varying from high to low. In the Lanzhou valley, water vapor isotopes show a distinct daily cycle of δ17O, δ18O, and δ2H and are consistent with temperature changes. Water vapor isotopes, particularly d-excess, are correlated with temperature and absolute humidity. With regard to the local atmospheric water vapor line (LAVL), we show that the slope and intercept of the LAVL are affected by sub-cloud secondary evaporation and topography.

Comparison of VOCs Pollution Characteristics Between an Urban Site and a Background Site in Summer in Zibo

To study the differences in volatile organic compound (VOCs) pollution characteristics between an urban site and a background site in summer, ambient VOCs were monitored using an online gas chromatograph (GC) at an urban site and a background site (Mt. Lu) in Zibo in July 2020. The VOCs pollution characteristics and chemical reactivity were analyzed, and the sources of VOCs were identified using the positive matrix factorization model(PMF). The results showed that ρ(TVOC) and ρ(NOx) were higher at the urban site, but ρ(O3) was higher at the background site. Diurnal average characteristics of ρ(TVOC) and ρ(NOx) were high at night and low during the day at the urban site, and there were no obvious variation characteristics at the background site. The diurnal average characteristics of ρ(O3) were consistent at the urban and background sites, showing low level at night and high level during the day; however, the peak in the background site was later than that at the urban site. The average ρ(TVOC) at the urban site and background site were (44.9±27.5) μg·m-3 and (17.3±9.1) μg·m-3, respectively, and the mass fraction of each component was ordered as alkanes>aromatics>alkenes>alkynes in both sites. The average ozone formation potentials(OFP)were (115.5±63.1) μg·m-3 and (38.0±20.2) μg·m-3, and the contribution of each component was ordered as alkenes>aromatics>alkanes>alkynes. The respective average values of·OH radical loss rate(L·OH) were (3.9±2.3) s-1 and (1.0±0.6) s-1, with the highest contribution of alkenes and the lowest contribution of alkynes in both sites. The average values of secondary organic aerosol formation potential(SOAp) were (0.5±0.3) μg·m-3 and (0.2±0.06) μg·m-3, respectively, with aromatic being the most abundant group. According to the source appointment by the PMF model, the main source of VOCs in the urban site was traffic sources (52.4%), followed by petroleum evaporation (19.2%), solvent evaporation (17.3%), and oil and biological sources (11.1%). The source of VOCs in the background site mainly came from traffic sources (40.2%), followed by solvent evaporation (31.3%), combustion sources (19.3%), and biological sources (9.2%). Zibo City should strengthen the management and control of motor vehicle emissions, petroleum evaporation, and the use of industrial solvents.

Effects of nanomaterials on Cs3Sb photocathode emission performance

A new approach to preparing the cesium antimonide photocathode has been developed. A tungsten sponge diffusion barrier layer, instead of the conventional nickel pipe, was used as the evaporation source so that a slow and uniform evaporation of the photoemissive materials, whose direction and amount could be well controlled, was realized. Then, the cathode substrate surface was modified with a nanoparticle layer, resulting in better photoemissive material adsorption and higher light absorbance. A new technique of treating the tungsten sponge, which worked as the barrier layer to the diffusion of the photoemissive materials, was studied. The tungsten–copper alloy was subjected to direct high-frequency heating in a vacuum chamber so that the copper in the alloy evaporated rapidly, resulting in smooth and shiny tungsten sponge. In comparison with the conventional method for fabricating the tungsten sponge, in which the copper in the tungsten–copper alloy was removed chemically, the new method removed the copper more completely, took less time, and caused less pollution. By means of direct-current magnetic sputtering, a layer of osmium nanoparticles of 50 nm diameter was deposited on the photocathode substrate surface. Then, a diode tube for the photocathode emission test equipped with a small titanium ion pump, whose pressure was as low as 5 × 10−8 Pa, was developed. A comparative emission performance test was carried out on the photocathode with the substrate surface covered with an osmium film vs that covered with osmium nanoparticles. The highest quantum efficiencies of the stable photoemission from the two photocathodes were 1.80 × 10−3 and 5.13 × 10−3, respectively. Moreover, the light absorptivity of the osmium nanoparticle-coated photocathode was 2.16 times that of the osmium film-coated photocathode, and the quantum efficiency of the former was 2.85 times that of the latter. Therefore, the improvement in the quantum efficiency of the osmium nanoparticle-coated photocathode is mainly attributed to the increase in the light absorptivity.

Response of spray number density and evaporation rate to velocity oscillations

A theoretical investigation of the effect of gas velocity oscillations on droplet number density and evaporation rate is presented. Oscillations in gas velocity cause a number density wave, i.e. an inhomogeneous, unsteady variation of droplet concentration. The number density wave, as it propagates downstream at the mean flow speed, causes modulation of the local evaporation rate, creating a vapour wave with corresponding oscillations in equivalence ratio. The present work devises an analytical formulation of these processes. Firstly, the response of a population of droplets to oscillations in the gas velocity is modelled in terms of a number density wave. Secondly, the formulation is extended to incorporate droplet evaporation, such that an analytical expression for the evaporation rate modulation is obtained. Subsequently, the droplet 1D convection-diffusion transport equation with the calculated evaporation source term is solved using an appropriate Green’s function to determine the resulting equivalence ratio perturbations. The dynamic response of equivalence ratio fluctuations to velocity oscillations is finally characterized in terms of a frequency-dependent transfer function. The aforementioned analytical approach relies on a number of simplifying approximations, nevertheless it was validated with good agreement against 1D Euler-Lagrange CFD simulations.

Identifying water vapor sources of precipitation in forest and grassland in the north slope of the Tianshan Mountains, Central Asia

Identifying water vapor sources of precipitation in forest and grassland in the north slope of the Tianshan Mountains, Central Asia

Spatially selective nanoplasmonic response in Ag embedded GLAD TiO2 nanocomposite thin films

The nanoplasmonic behaviour of Ag decorated TiO2 film structure was spatially varied across the sample surface by utilizing the tailored optical response of the underlying dielectric TiO2 thin film prepared using a novel collimated glancing angle deposition technique (collimated-GLAD). A blue shift in maximum attenuation coefficient region and minimum film transmittance region of the Ag/collimated-GLAD TiO2 nanocomposite coating with increase in height from the evaporation source was detected. The presence of minimum transmittance region was found to have occurred due to localized surface plasmon resonance (LSPR) phenomenon with additional contribution from thin film interference. The measured transmittance spectra showed spatial selectivity in LSPR wavelength of ∼22 nm with increase in height from the evaporation source. The variation of surrounding medium's (i.e. the TiO2 layer) refractive index (with height from the evaporation source) of the Ag nanostructures was the key factor responsible for the spatially varying nanoplasmonic response of Ag/collimated-GLAD TiO2 film across the sample surface. The Surface enhanced Raman scattering (SERS) characterization of the Ag/collimated-GLAD TiO2 film revealed photocatalysis driven dimerization conversion of p-aminothiophenol (p-ATP) molecules to p,p’-dimercaptoazobisbenzene (DMAB) due to the localized surface plasmons of the film structure along with the substantial enhancement in the Raman peak intensities compared to the blank substrate.