Full Air Research Articles

Evaluation of Indoor Air Quality Screening Strategies: A Step-Wise Approach for IAQ Screening.

Conducting a full indoor air quality (IAQ) assessment in air-conditioned offices requires large-scale material and manpower resources. However, an IAQ index can be adopted as a handy screening tool to identify any premises (with poor IAQ) that need more comprehensive IAQ assessments to prioritize IAQ improvements. This study proposes a step-wise IAQ screening protocol to facilitate its cost-effective management among building owners and managers. The effectiveness of three IAQ indices, namely θ1 (with one parameter: CO2), θ2 (with two parameters: CO2 and respirable suspended particulates, RSP) and θ3 (with three parameters: CO2, RSP, and total volatile organic compounds, TVOC) are evaluated. Compared in a pairwise manner with respect to the minimum satisfaction levels as stated in the IAQ Certification Scheme by the Hong Kong Environmental Protection Department, the results show that a screening test with more surrogate IAQ parameters is good at identifying both lower and higher risk groups for unsatisfactory IAQ, and thus offers higher resolution. Through the sensitivity and specificity for identifying IAQ problems, the effectiveness of alternative IAQ screening methods with different monitoring parameters is also reported.

Prevention and Management of Pupil Block After Descemet Membrane Endothelial Keratoplasty.

To assess frequency, associations, and outcomes of full air fill after Descemet membrane endothelial keratoplasty (DMEK). This retrospective study reviewed 368 consecutive DMEK cases performed to treat Fuchs dystrophy, bullous keratopathy, or failed keratoplasty. Primary outcomes were air bubble status, intraocular pressure, and incidence of pupil block and air reinjection. Using an air management algorithm, slit-lamp assessment 1 hour after DMEK identified complete air fill in 80/368 eyes (22%). This spontaneously resolved in 45 eyes. Air was removed from 35 eyes (9%). Eyes that required air removal were more likely to have occluded iridotomy than did eyes in which the full air fill spontaneously resolved (23% vs. 6.6%, respectively), P = 0.05. Although full air fill was more likely after DMEK combined with cataract surgery (P = 0.001), air removal was more likely after DMEK-only procedures (P = 0.01). Eyes that underwent air removal tended to have lower rebubble rates, although this did not reach statistical significance (P = 0.06). No cases of pupillary block glaucoma occurred, and full air fill did not significantly affect 6-month postoperative vision or endothelial cell density. A careful air management strategy successfully prevented pupil block in eyes that developed full air fill. DMEK-only procedures were more likely to require air removal than those combined with cataract surgery, which suggests that decreased zonular flexibility may prevent the air bubble from taking a more spherical shape and more easily allow occlusion of iridotomy.

Results of Testing of the GTÉ-110 Gas-Turbine Low-Emission Combustor in Full Operating Conditions

The results of testing the GTE-110 gas-turbine low-emission combustor (LEC) at an operating pressure of 1500 kPa are presented. It is shown that the developed technical solution provides pulsation-free changeover to low-emission operation of the LEC. The measurements confirm low NOx emissions and high combustion efficiency in the 50 – 100% load range. The stages of LEC development, the justification of the technical solution, and the results of testing the pilot LEC at an inlet air pressure of 350 kPa were detailed earlier in [1]. Comparing and analyzing the results of tests at reduced and full air pressures reveal that the combustor wall temperatures, gas temperature profiles, and combustion efficiencies are identical. Moreover, the results confirm the adequate simulation of acoustic boundary conditions at test facilities providing reduced and full operating conditions.

Saltwater experiments with air curtains for smoke control in the event of fire

Smoke flow inside buildings is a major cause of death in the event of fire. Presently, fire or smoke doors are used, together with smoke control systems, to avoid smoke flowing beyond the boundaries of the fire compartment. In this research, it is proposed the use of downward air curtains to stop smoke flow, which will not impair visibility in escape routes. The methodology followed in this research includes: (i) the development of an analytical model that relates the relevant characteristic quantities of a plane jet with the characteristics of the environment in which the fire develops, (ii) small scale experiments with saltwater modelling to assess the convective parameters that control the smoke tightness of the curtain, (iii) CFD simulations to assess the performance of a full scale air curtain near a fire source and (iv) fire experiments with a full-scale test specimen. In this paper both the analytical model and the saltwater experiments are presented. Test results confirm that vertical downward air curtains are able to avoid smoke flow through openings and show a good agreement with the theoretical model for predicting the minimum exhaust rate from the fire compartment. It has been shown that the exhaust flow rate depends on the air curtain flow rate and on the fluid heat expansion due to fire. Test results also make it possible to assess the minimum nozzle velocity to avoid smoke leakage.

Current generation by deep-water breaking waves

We examine the partitioning of the energy transferred to the water column by deep-water wave breaking; in this case between the turbulent and mean flow. It is found that more than 95 % of the energy lost by the wave field is dissipated in the first four wave periods after the breaking event. The remaining energy is in the coherent vortex generated by breaking. A scaling argument shows that the ratio between the energy in this breaking generated mean current and the total energy lost from the wave field to the water column due to breaking scales as $(hk)^{1/2}$, where $hk$ is the local slope at breaking. This model is examined using direct numerical simulations of breaking waves solving the full two-phase air–water Navier–Stokes equations, as well as the limited available laboratory data, and good agreement is found for strong breaking waves.

Sensitivity study of (10,100) GeV gamma-ray bursts with double shower front events from ARGO-YBJ**Supported by National Natural Science Foundation of China (11475141) and Fundamental Research Funds for Central Universities (2682014CX091)

ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory (4300 m a.s.l., Tibet, China), is a full coverage air shower array, with an energy threshold of ∼300 GeV for gamma-ray astronomy. Most of the recorded events are single front showers, satisfying the trigger requirement of at least 20 particles detected in a given time window. However, in ∼11.5% of the events, two randomly arriving showers may be recorded in the same time window, and the second one, generally smaller, does not need to satisfy the trigger condition. These events are called double shower front events. By using these small showers, well under the trigger threshold, the detector primary energy threshold can be lowered to a few tens of GeV. In this paper, the angular resolution that can be achieved with these events is evaluated by a full Monte Carlo simulation. The ARGO-YBJ sensitivity in detecting gamma-ray bursts (GRBs) by using double shower front events is also studied for various cutoff energies, time durations, and zenith angles of GRBs in ARGO’s field of view.

Reconstruction of full glacial environments and summer temperatures from Lago della Costa, a refugial site in Northern Italy

Vegetation and climate during the last ice age and the Last Glacial Maximum (LGM, ∼23,000–19,000 cal BP) were considerably different than during the current interglacial (Holocene). Cold climatic conditions and growing ice-sheets during the last glaciation radically reduced forest extent in Europe to a restricted number of so-called “refugia”, mostly located in the southern part of the continent. On the basis of paleobotanical analyses the Euganian Hills (Colli Euganei) in northeastern Italy have previously been proposed as one of the northernmost refugia of temperate trees (e.g. deciduous Quercus, Tilia, Ulmus, Fraxinus excelsior, Acer, Abies alba, Fagus sylvatica, Carpinus and Castanea) in Europe. In this study we provide the first quantitative, vegetation independent summer air temperature reconstruction for Northern Italy spanning the time ∼31,000–17,000 cal yr BP, which covers the coldest periods of the last glacial, including the LGM and Heinrich stadials 1 to 3. Chironomids preserved in a lake sediment core from Lago della Costa (7m a.s.l.), a small lake at the south-eastern edge of the Euganean Hills, allowed quantitative reconstruction of Full and Late Glacial summer air temperatures using a combined Swiss-Norwegian temperature inference model based on chironomid assemblages from 274 lakes. Chironomid and pollen evidence from Lago della Costa derives from finely stratified autochthonous organic gyttja sediments, which excludes major sediment mixing or reworking. After reconstructing paleo-temperatures, we address the question whether climate conditions were warm enough to permit the local survival of temperate tree species during the LGM and whether local expansions and pollen-inferred contractions of temperate tree taxa coincided with chironomid-inferred climatic changes. Our results suggest that chironomids at Lago della Costa have responded to major climatic fluctuations such as temperature decreases during the LGM and Heinrich stadials. The vegetation of the Euganean Hills shows responses to these climatic oscillations although the effects of temperature changes were probably also strongly influenced by changes in humidity. Reconstructed July air temperatures at Lago della Costa never fell below 10–13 °C (error range of reconstruction ∼ ±1.5–1.6 °C), which is considerably above the limit considered necessary for forest growth (8–10 °C). Instead rather mild climatic conditions prevailed ∼31,000–17,000 cal yr BP with average summer temperatures between ∼12 and 16 °C, which most likely allowed survival of temperate tree taxa in the warmest (and moistest) microhabitats of the Euganean Hills during the LGM. Only assuming local survival is it possible to explain the repeated expansions and collapses of temperate trees at Lago della Costa which faithfully accompanied the climatic oscillations.

Experimental Investigation of the Efficiency of Heat Pump Drying System with Full Air Recirculation

AbstractThe paper presents results of an experimental investigation of convective drying of apples “var. Idared,” potatoes “var. Désirée” and bananas “var. Grand Nein,” in full recirculation laboratory‐scale dryer. The experiments were conducted with cube‐shaped apple samples (side length 10 and 13 mm), potato chips (slice thickness 2 and 3 mm) and banana cylinders (slice thickness 6 and 7 mm), without pre‐treatment. The drying experiment was conducted at fully controlled air temperature (35–45–55°C), relative humidity (10–20–30%) and air velocity (1–1.5–2 m/s). Results are discussed through their comparison with other heat pump drying system scenarios in order to find the most efficient one. The efficiency of the heat pump drying (HPD) system was analyzed using the several indicators: specific moisture extraction rate (SMER), specific energy consumption (SEC), heat pump dryer efficiency (HPDE) and moisture extraction rate (MER). The average values of the full air recirculation HPD system efficiency indicators were obtained in range: SMERHP = 0.030–1.317 kg/kWh, SMERHPD = 0.047–0.651 kg/kWh, SEC = 0.211–9.358 MJ/kg, HPDE = 0.426–20.7 MJ/kg and MER = 1.362–17.194 kWh/kg. The results were evaluated in order to provide better information about the benefits of full air recirculation usage in HPD systems in regards to the other similar dryer configurations.Practical ApplicationsThis study uses full air recirculation to provide better control of the main drying parameters and to minimize impact of the surroundings. The novelty of this study lies in the fact that RH of the drying air was precisely controlled during all experiments. The evaluation of the relevance of full air recirculation HPD system is rare in literature and therefore the present study is directed toward quantification of influence of HPD system configuration on drying process efficiency. Dependence of several energy efficiency indicators of HPD system performance: SMER, SEC, HPDE and MER on HPD system air recirculation rate were investigated. The results were evaluated in order to provide better information about the benefits of full air recirculation usage in HPD systems in regards to the other similar dryer configurations.

Optimization of Cultured Human Corneal Endothelial Cell Sheet Transplantation and Post-Operative Sheet Evaluation in a Rabbit Model

ABSTRACTPurpose: To optimize cultured human corneal endothelial cell (cHCEC) sheet transplantation technique for maintenance of cHCEC viability.Materials and Methods: cHCEC sheets cultured on a collagen scaffold were covered with or without Viscoat® and exposed to humidified air in the incubator. cHCEC sheets with or without Viscoat® were transplanted into cadaveric porcine eyes by the DSAEK technique with full air tamponade and incubated for various time periods. Then cell viability was determined by using the live/dead assay kit. cHCEC sheets with Viscoat® were transplanted into rabbit eyes and the sheets were histologically evaluated before and 14 days after transplantation.Results: A collagen scaffold and Viscoat® were effective for protecting cHCEC from damage due to air exposure in vitro. All cells died after 18 hours of air exposure in porcine eyes in Viscoat® untreated control. In contrast, Viscoat® treatment sustained full cell viability following 2 hours and could maintain approximately 80% viability after 18 hours. In a rabbit model, transplanted cHCEC sheet with Viscoat® maintained cell density at 2803 ± 229 mm2 (18% cell loss) and expression of N-cadherin, zonula occludens-1, and actin-filament localized to cell boundary as similar as donor HCEC.Conclusion: Viscoat® can contribute to cHCEC protection from damage caused by exposure to air.

Immediate Postoperative Intraocular Pressure Changes After Anterior Chamber Air Fill in Descemet Membrane Endothelial Keratoplasty.

To monitor the intraocular pressure (IOP) changes immediately after anterior chamber air tamponade in Descemet membrane endothelial keratoplasty (DMEK). Twenty-four patients undergoing DMEK and 16 patients undergoing rebubbling after DMEK were enrolled (n = 40). All DMEK patients had inferior iridectomy and nearly full intracameral air tamponade with an aimed IOP of 25 mm Hg at the end of surgery. The IOP was measured at 1, 2, 3, 5, 12, 24 hours and 1 week postoperatively. After anterior chamber air fill in DMEK, the IOP increased from preoperative baseline, 12.1 ± 2.9 mm Hg, to 26.3 ± 4.7 mm Hg, P < 0.001. Mean IOP was significantly elevated in the first 2 hours, 19.4 ± 10.5 mm Hg and 17.0 ± 7.4 mm Hg, P = 0.007 and 0.006, respectively. Then, it lowered to the baseline level, 14.0 ± 4.7 mm Hg, P > 0.05, and remained stable during follow-ups. An asymptomatic IOP elevation above 30 mm Hg was detected in 3 patients (12.5%) within the first 2 hours. None had preexisting glaucoma. Most episodes could be controlled by antiglaucoma medications and upright positioning. The pattern of IOP changes after rebubbling was similar to that after DMEK but the IOP dropped sharply to the baseline level after 1 hour and had no incidence of IOP elevations beyond 30 mm Hg. Adequate inferior iridectomy greatly alleviates the risk and severity of acute IOP rises after nearly full anterior chamber air tamponade in DMEK. Standard IOP adjustment at the end of DMEK surgery with postoperative IOP monitoring especially in the first 2 postoperative hours is advisable when there is no postoperative default air release.

立軸斜流ポンプ羽根車に働く軸スラストの挙動

Axial thrust forces acting on an impeller of a diffuser type mixed flow pump have been studied. The behavior of the axial thrust generated by the vortex occurrence in a pump intake sump was investigated. The thrust of distinct discontinuities such as hysteresis phenomenon from a pump hydraulic performance was measured. In pump partial load operation the axial thrust increases discontinuously because of the reverse flow at impeller inlet. Synchronous and non-synchronous components of axial thrust increase during the onset of reverse flow zones. A prediction method for static axial thrust was derived based on Oshima's theory accounting for the pump suction bell-mouth pressure reduction due to vortex. Qualitative comparison with the measured experimental results for static axial thrust showed reasonable agreement around pump best efficiency flow rate. The pump intake sump test apparatus，in which both an air-entrained surface vortex and a submerged vortex will occur，was employed and the axial thrust was measured. The level of axial thrust is dependent on the pump intake sump water level. The dynamic axial thrust begins to increase due to the occurrence of a full air core vortex to intake. When submerged as well as full air core continuous vortices occur，the axial thrust and the fluctuation of total pump head become abruptly large. The fluctuation of axial thrust becomes the highest when the impeller sucks the air-drawing large vortex imposing a pressure fluctuation which generates not only a rotational speed but also nZ vane passing and low frequency components.

Analysis of accumulated lubricant for air–helium gas mixture in HDDs

For higher areal density, full helium as well as air---helium gas mixtures are currently being investigated as candidates for use in advanced drives. Moreover, the head mechanical spacing and the amount of accumulated lubricant on the bottom surface of the slider should be reduced for higher areal density. To analyze the characteristics of accumulated lubricant under these conditions, gas property equations for binary gas mixtures as functions of helium fraction ratio and temperature were derived. Accumulated lubricant equations were derived by considering the attractive forces, such as the dispersive and polar effects. An increase in the helium fraction ratio reduces the small shear stress on the bottom surface of the slider, which leads to a decrease in lubricant transfer capability. As a result, the amount of total lubricant transfer and accumulation are increased markedly. Also, with a decrease in lubricant thickness, the amount of accumulated lubricant increases greatly with a high helium fraction ratio. In conclusion, the HDI problems induced by lubricant transfer should be considered in full helium-filled or air---helium gas mixture drives.

Investigation on air flow patterns of evaporative cooling and dehumidification process for a hybrid refrigeration system

In this paper, two different air flow patterns (close-pattern and open-pattern) are studied to achieve the optimum configurations of a hybrid refrigeration system, in which the refrigerant is subcooled by evaporative cooling of dry air dehumidified by the liquid desiccant. With different ambient air ratios (Ramb), full return air (Ramb = 0) is used in the close-pattern; full ambient air (Ramb = 1) and mix air (0 < Ramb < 1) are chosen in the open-pattern respectively. Comparisons of the close-pattern and open-pattern are made under typical climate condition and extremely humid climate condition. Both of the close-pattern and open-pattern (Ramb = 1) show much higher COP than the traditional refrigeration system, with the maximum COP improvement 12.3% and 9.8%, respectively. Under typical climate condition, the open-pattern (Ramb = 0.3) is suggested, the regenerator size has little influence on the system performance and the optimum mass flow ratio of ambient air to solution (ṁamb/ṁs) is between 0.5 and 2 in the regenerator; under extremely humid climate condition, the close-pattern is proposed, the optimum ṁamb/ṁs is 0.4 and larger regenerator size is suggested. In addition, the latent and sensible heat capacities in the indirect evaporative cooler are illustrated. These findings will be beneficial for the system design and optimization.

Effect of injection pressure on the performance and emission characteristics of CI engine using canola emulsion fuel

ABSTRACTBiodiesel is a promising renewable alternative fuel for diesel. The need of biodiesel fuels for the diesel engines is to restrict the dependency on the fossil fuels in context to the world energy oil crisis. The objective of this article is to investigate the performance and emission characteristics of a CI engine with diesel and blends of canola biodiesel Emulsion at 200, 220 and 240 bar. The fuel injection system in a diesel engine is to achieve a high degree of atomisation for better penetration of fuel in order to utilise the full air charge and to promote the evaporation in a very short time and to achieve higher combustion efficiency. Emulsified fuels showed an improvement in brake thermal efficiency of 28.8% at 240 bar accompanied by the drastic reduction in NOx at 200 bar.

Visible light TiO2 photocatalysts assessment for air decontamination

Different visible light responses of commercial TiO2 photocatalysts are assessed for their application in air decontamination. To do that the modified TiO2 catalysts were immobilized on borosilicate glass plates according to a dip coating method. Then, the photocatalytic performance of these plates was evaluated in a continuous gas flat plate photoreactor irradiated with visible light lamps using two representative air pollutants: nitrogen oxide and acetaldehyde. Working under visible light, the modified TiO2 catalysts were compared by means of efficiency parameters: the true quantum efficiency, which relates the moles of degraded pollutant with the moles of the absorbed photons, and the apparent photonic efficiency, which relates the moles of degraded pollutant with the moles of incident photons. Also, the photocatalytic pollutants degradation by immobilized modified TiO2 could be related with their optical properties, finding a clear correlation between them. These results are useful to decide which TiO2 will be more efficient for a full scale air decontamination process under visible light illumination.

Comparative study of the methane production based on the chemical compositions of Mangifera Indica and Manihot Utilissima leaves.

Leaves of Mangifera Indica (MI, mango leaves) and Manihot Utilissima (MU, cassava leaves) are available in tropical regions and are the most accessible vegetal wastes of Kinshasa, capital of Democratic Republic of Congo. These wastes are not suitably managed and are not rationally valorized. They are abandoned in full air, on the soil and in the rivers. They thus pollute environment. By contrast, they can be recuperated and treated in order to produce methane (energy source), organic fertilizer and clean up the environment simultaneously. The main objective of this study was to investigate methane production from MI and MU leaves by BMP tests at 30°C. The yields achieved from the anaerobic digestion of up to 61.3 g raw matter in 1 l medium were 0.001 l/g and 0.100 l CH4/g volatile solids of MI and MU leaves, respectively. The yield of MU leaves was in the range mentioned in the literature for other leaves because of a poor presence of bioactive substrates, and low C/N ratio. This methane yield corresponded to 7% of calorific power of wood. By contrast, the methane yield from MI leaves was almost nil suggesting some metabolism inhibition because of their rich composition in carbon and bioactive substrates. Whereas classical acidogenesis and acetogenesis were recorded.Therefore, methane production from the sole MI leaves seems unfavorable by comparison to MU leaves at the ambient temperature in tropical regions. Their solid and liquid residues obtained after anaerobic digestion would be efficient fertilizers. However, the methane productivity of both leaves could be improved by anaerobic co-digestion.

The Use of Full Range Leadership and Air Force Smart Operations for the 21st Century to Improve a Nutritional Medicine Food Service Operation

Describe the ‘6S’ principles used to improve a food service operation.

A new highly sensitive method to assess respiration rates and kinetics of natural planktonic communities by use of the switchable trace oxygen sensor and reduced oxygen concentrations.

Oxygen respiration rates in pelagic environments are often difficult to quantify as the resolutions of our methods for O2 concentration determination are marginal for observing significant decreases during bottle incubations of less than 24 hours. Here we present the assessment of a new highly sensitive method, that combine Switchable Trace Oxygen (STOX) sensors and all-glass bottle incubations, where the O2 concentration was artificially lowered. The detection limit of respiration rate by this method is inversely proportional to the O2 concentration, down to <2 nmol L−1 h−1 for water with an initial O2 concentration of 500 nmol L−1. The method was tested in Danish coastal waters and in oceanic hypoxic waters. It proved to give precise measurements also with low oxygen consumption rates (∼7 nmol L−1 h−1), and to significantly decrease the time required for incubations (≤14 hours) compared to traditional methods. This method provides continuous real time measurements, allowing for a number of diverse possibilities, such as modeling the rate of oxygen decrease to obtain kinetic parameters. Our data revealed apparent half-saturation concentrations (Km values) one order of magnitude lower than previously reported for marine bacteria, varying between 66 and 234 nmol L−1 O2. Km values vary between different microbial planktonic communities, but our data show that it is possible to measure reliable respiration rates at concentrations ∼0.5–1 µmol L−1 O2 that are comparable to the ones measured at full air saturation.

Doubling Down

The us Air Force’s and Navy’s semi-autonomous radar- and infrared-guided air-to-air missiles performed miserably in air combat over Vietnam. Despite accusations that the military’s overreliance on complex technology was to blame, the two services continued to invest in ever-more advanced fighter aircraft and high-tech missiles after the war. In 1977 at the behest of Congress, the Air Force and Navy spent almost a full year evaluating air combat tactics and new infrared-guided air-to-air missiles. According to the services’ interpretation of the results from the aimval and aceval tests, future air combat demanded both improved infrared-guided missiles and revolutionary radar-guided missiles. The apparent paradox—testing infrared missiles to justify a more expensive radar-guided missile—was seized on by the military “Reformers” as emblematic of the us military’s unhealthy fascination with exorbitantly priced high-technology. This paper discusses the pivotal aimval-aceval tests, including their laborious design process and execution, and their subsequent role animating the early-1980s public debate over military technology. This understanding is crucial when evaluating the relative significance of organizational inertia in the Air Force’s air-to-air procurement decisions following Vietnam. Additionally, the aimval-aceval tests offer evidence of three pathologies that distinguish military tests from their typical civilian exemplars: military tests cannot be conducted independent of the service(s); the tests are generally inflexible and unreplicable; and their data are usually shrouded by classification concerns. These pathologies make it difficult to reconcile divergent interpretations and resolve controversies that emerge from military testing activities.

The influence of ENSO on the equatorial Atlantic precipitation through the Walker circulation in a CGCM

The link between El Nino/Southern Oscillation (ENSO) and the equatorial Atlantic precipitation during boreal spring (March–April–May) is explored using a coupled general circulation model (CGCM). Interannual variability of the equatorial Atlantic sea surface temperature (SST) in the CGCM is excluded by nudging the modeled SST toward the climatological monthly mean of observed SST in the equatorial Atlantic, but full air–sea coupling is allowed elsewhere. It is found that the equatorial Atlantic precipitation is reduced (increased) during El Nino (La Nina) in the case where the interannual variability of the equatorial Atlantic SST is disabled. The precipitation anomalies in the equatorial Atlantic during ENSO are not strongly associated with the meridional migration of the Atlantic inter-tropical convergence zone. We find the reduced precipitation in the equatorial Atlantic during El Nino is associated with an enhanced Atlantic Walker circulation characterized by strengthened low-level easterlies and anomalous dry, downward winds over the equatorial Atlantic, while the Pacific Walker circulation is weakened. The upper-level anomalous westerlies over the equatorial Atlantic are consistent with a Matsuno–Gill-type response to heating in the eastern equatorial Pacific. Our results of the CGCM experiments suggest that changes to the Walker circulation induced by ENSO contribute significantly to changes in precipitation over the equatorial Atlantic.