Deposition Of Carbon Particles Research Articles

Study on carbon particle deposition distribution of turbocharger turbine blade based on the gas-solid two-phase flow theory

The formation mechanism of non-uniform carbon deposition on the turbine blade under the gas-solid two-phase flow is analyzed, and the finite element model of turbine blade deposition is established. The carbon formation on turbine blade surfaces of turbochargers at different rotational speeds is investigated. The particle deposition test bench is designed and built. The distribution of turbine blade particle deposition is verified by the experiment of turbine blade particle deposition. The results show that the particles are mainly deposited on the pressure surface of the turbine blade, and the position of the carbon deposition varies with the change of the rotational speed.

Postmortem Lung Biopsy in a Sample of COVID-19 Patients in Iraq

Background: The entire world was affected by the outbreak of novel coronavirus 2 (SARS-CoV-2), which influenced daily life worldwide and affected the medical, social, and economic prospects of all nations. This virus occurs clinically in four variants: asymptomatic; mild upper respiratory tract infection (URTI); anosmia and/ or ageusia as the only symptoms; and severe systemic disease, such as bilateral interstitial pneumonia. Approximately 20% of the population develops the severe course associated with cytokine release syndrome (CRS). Those who develop lung injury and dyspnea have higher mortality. An autopsy can reveal the pathogenesis and determine the cause of death. Objectives: To understand the pathophysiological changes in lung tissue in COVID-19-affected individuals. Patients and Methods: This is a case series of post-mortem lung histopathology examinations of deceased COVID-19-positive patients. Samples were collected from postmortem models acquired from six diseased individuals who tested positive for SARS-CoV-2 by reverse transcriptase polymerase chain (PCR) reaction and subsequently passed away in the tertiary hospital between July and September 2020 because of COVID-19. Their slides and paraffin-embedded blocks of lung biopsies, as well as their reports, were collected and sent to two pathologists for further evaluation of COVID-19-related changes in the lungs. Results: Only two of the six patients confirmed features of diffuse alveolar injury with hyaline layer and fibrin thrombi in pulmonary arteries, small vessel congestion, and pulmonary infarction. Two patients demonstrated diffuse alveolar fibrosis (organizing pneumonia), severe inflammation, and foci of squamous metaplasia, in addition to the deposition of carbon particles. One case had diffuse pulmonary fibrosis with pulmonary artery thrombosis without an inflammatory background. In another case, there were atypical large cells, ischemic necrosis, and severe inflammation with macrophages and pneumocyte hyperplasia inside the alveoli. Conclusion: the thromboembolic events suggest a role for COVID-19-induced coagulopathy. Molecular mechanisms and clinical features of COVID -19 should be studied. Atypical alterations need to be investigated to confirm their relation to COVID-19 infection.

Effect of deposition of carbon deposits on charge flow in EGR valve in CI engine

The exhaust gas recirculation (EGR) valve regulates the exhaust gas flow between the engine exhaust manifold and the inlet one. This allows the inlet air to warm up, improving fuel evaporation and reducing the combustion temperature of the charge. Such a valve reduces the number of harmful substances in the exhaust gas. The valve sticks when too much sediment builds on the walls of the exhaust system, especially during driving in urban conditions or when leaks in the vacuum or exhaust pipes occur. A faulty valve causes the engine to run unevenly at idle speed and under light loads. The defective EGR valve weakens the inlet manifold capacity, increases combustion, clogging of the particulate filter, damage to the lambda probe. A blocked EGR valve may lead to engine immobilization as a result of the operation of its computerized control system. A model of the EGR valve of a selected diesel engine was developed to determine the velocity distribution of the load flowing in it for different values of the degree of valve opening and the volume of deposits on the valve walls. The volume of accumulated carbon deposits on the walls of the EGR valve was measured using a real engine. Based on the recorded mileage of the vehicle, the assumed average speed of the car, and the driving style of the driver, the intensity of deposition of carbon particles on the walls was estimated.

Biochemical and cytological analyses of pleural effusion in patients with lung anthracosis and antracofibrosis

BackgroundAnthracosis and anthracofibrosis are attributed to the deposition of carbon particles along with fibrosis, adhesion, narrowing, and collapse. There has been no study on the characteristics of the pleural fluid in anthracosis. The present study analyzed the biochemical characteristics of pleural effusion in patients with pulmonary anthracosis. Patients and methodsThe study is a cross-sectional study which included patients who were referred to the Afzalipour Hospital in Kerman, eastern Iran. Between April 2018 and October 2019, patients who had undergone bronchoscopy and were diagnosed with anthracosis and pleural effusion were selected through the census method. The characteristics of the pleural fluid were analyzed for protein, albumin, LDH, PH, Triglyceride, cholesterol, glucose, and cytology. Concomitant blood samples were examined for LDH, albumin, total protein, and glucose. After it was specified whether the pleural effusion was transudative or exudative, patients with lymphocyte-dominant exudative pleural fluid became candidates for thoracoscopy. Result106 patients (6.21 %) of 1705 patients had anthracosis and anthracofibrosis; 37 of these patients (34.9 %) had coexisting pleural effusion. 31 patients gave written informed consent for thoracentesis. The mean age of the patients was 76.48 ± 8.81. In addition, 67.74 % of the patients were female. Pleural effusion was transudative in 29 (93.54 %). Except for one case, all patients had diffuse anthracofibrosis and 67.74 % of the patients had a history of baking bread. ConclusionAccording to the findings of this study, most cases had transudative lymphocyte-dominant pleural fluid with mostly diffuse anthracofibrosis. In addition, this condition is more prevalent in women, with a prevalence of approximately twice that of men.

Surface alloying of D2 steel using EDM with WC/Co P/M electrodes made of Nano and Micron sized particles

The present study is an experimental work carried for surface alloying/modification of D2 alloy steel using WC/Co powder metallurgy (P/M) electrode made of nano, micron and mixture of nano and micron sized particles. Both, machine tool and electrode parameters were selected for study and experiments were planned as per Taguchi’s L18 mixed orthogonal array. Optimal combination of parameters was obtained using Taguchi’s method and analysis of variance (ANOVA) was performed to evaluate influence of parameters on surface roughness (SR) and micro-hardness (MH). The parameters Peak current (IP), pulse on time (TON) and particle size (PS) were found to be most influential on both SR and MH. In EDM, surface modification is performed by deliberate transfer of tool elements onto the work surface. In the present investigation, EDS analysis reveals the migration of tungsten (W) and cobalt (Co) electrode particles, deposition of carbon particles and diffusion of oxygen particles onto the work surface. High reactive surface area of nano particles made greater surface alloying than other tool electrodes and has shown its influence positively on both SR and MH. Low thermal conductivity of nano particle electrodes (NP) makes improved surface alloying than other tool electrodes. Because of the particle size is reduced to nano level its dimension is smaller than the spark gap dimension hence, reduced arcing and improved process stability was obtained, which eventually improved the surface roughness of the component. At optimum MH, higher values of TON and IP gives the sufficient time and temperature for formation of following carbides and oxides viz., Fe3C, Cr23C6 , Cr2Fe14C, Fe2W2C, W3O and Cr3O were responsible for increased hardness of the work surface. The range of roughness values obtained in the present investigation is 1.65-5.82 μm. The highest hardness of 981 HV was obtained without much sacrificing the surface finish.

Protective effects of a novel facial cream against environmental pollution: in vivo and in vitro assessment.

BackgroundThe effects of pollution on health have received increasing attention in recent years. Extrinsic skin aging occurs via multiple processes, and pollution is now recognized as a major component, causing increased pigmentation and wrinkles via oxidative mechanisms. We tested the antipollution efficacy of a cosmetic facial cream (FC) by assessing its effects on carbon particle adhesion to skin and on oxidative and inflammatory pathways in the skin.MethodsIn an in vivo study, FC was applied once to the forearms of healthy subjects. Carbon E153 powder was applied, and the skin was washed under standardized conditions. Images were taken using a dermoscope to determine the area of particle adherence. Each participant served as their own control, with the contralateral forearm being untreated with the FC but otherwise following the same protocol. In a 5-day ex vivo study, skin explants were treated with the FC daily and exposed to vaporized pollutants on day 2 and day 4 via a closed system. Explants were sampled at baseline and day 5 and culture media on day 5. The parameters evaluated were cellular viability on microscopy, Nrf2 immunostaining, malondialdehyde (MDA) levels in culture, melanin levels, and gene expression profile (TYR, IL6, and CYP1A1).ResultsIn the in vivo adhesion study, after standardized washing, carbon particle deposition on skin treated with the FC was significantly lower than that on untreated skin. In the ex vivo study, samples treated with the FC had reduced Nrf2 staining and MDA levels vs polluted controls. Melanin did not change significantly. The FC modulated pollution-induced increases in CYP1A1, IL-6, and TYR.ConclusionThis FC reduces particle adhesion to skin after a single application and protects against pollution-induced oxidative and inflammatory pathways in the skin.

Latest advances in degumming feedstock oils for large‐scale biodiesel production

The removal of gummy or mucilaginous substances from vegetable oils, commonly known as degumming, is required for the use of crude vegetable oils as the feedstock for biodiesel production. These gums reduce the rate of transesterification reactions by deactivation of the catalyst and they hinder the separation of the glycerol phase from the biodiesel. They also cause the deposition of carbon particles within engine machinery and affect performance. To take care of these issues, gums should be separated from the oils to make the oils suitable for use as fuel. Chemical treatment, membrane separation, and biological separation processes have been reported in the literature for this purpose. In the chemical treatment process aqueous solutions of chemicals like acids, bases, ethylenediaminetetraacetic acid (EDTA), and water are used for separating gums. The membrane separation process is based on size exclusion, and polymeric, ceramic, and inorganic membranes are used to separate gums from oil. In biological degumming, phospholipase groups of enzymes are used. These enzymes hydrolyze gums into fatty acids and lipophilic substances. Enzyme degumming also enhances oil‐phase yield. This paper reviews the chemical nature of gums and presents a comprehensive critical summary of different degumming technologies, their specific features, effecting parameters, advantages and disadvantages, and industrial uses. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Computational Fluid Dynamics and Particle Image Velocimetry Characterization of a Solar Cyclone Reactor

Solar thermal cracking of methane produces two valuable products, hydrogen gas and solid carbon, both of which can be used as a fuel and as a commodity. During the course of this two-phase phenomenon, carbon particles tend to deposit on the solar reactor window, wall, and exit. When they accumulate at the reactor exit, the agglomeration of these particles completely blocks the exit. This problem has been the major issue preventing solar cracking reactors from running continuously. To address this problem, a cyclone solar reactor was designed to enhance the residence time and allow carbon particles to rotate in the reactor instead of moving towards the exit inlarge particle groups together. A prototype reactor was manufactured to test the concept, to better understand and explain the flow dynamics inside the solar cyclone reactor and to analyze the flow via particle image velocimetry (PIV). Advanced measurement and computational techniques were applied to build the prototype reactor. Computational fluid dynamics (CFD) analysis employing discrete phase model (DPM) was used to predict the particle transport phenomenadel (DPM), whereas PIV was applied for the experimental part of the work. To understand the flow evolution along the vortex line, several images in the axial direction along the vortex line were captured. The results showed that when the main flow was increased by 25%, the axial velocity components became larger. It was also observed that the vertical vortices along the vortex line showed stronger interaction with outward fluid in the core region. This implied that the horizontal twisting motion dominated the region due to the main flow, which could trap the particles in the reactor for a longer time. Furthermore, when the main flow was increased by 50%, the flow displayed a cyclone-dominated structure. During the velocity evolution along the vortex line, more vortices emerged between the wall region and core region, implying that the energy was transferred from order to disorder. In summary, by appropriate selection of parameters, the concept of an aero-shielded solar cyclone reactor can be an attractive option to overcome the problem of carbon particle deposition at the reactor walls and exit.

Numerical investigation of particle deposition inside aero-shielded solar cyclone reactor: A promising solution for reactor clogging

Solar cracking of methane is considered to be an attractive option due to its CO2 free hydrogen production process. Carbon particle deposition on the reactor window, walls and exit is a major obstacle to achieve continuous operation of methane cracking solar reactors. As a solution to this problem a novel “aero-shielded solar cyclone reactor” was created. In this present study the prediction of particle deposition at various locations for the aero-shielded reactor is numerically investigated by a Lagrangian particle dispersion model. A detailed three dimensional computational fluid dynamic (CFD) analysis for carbon deposition at the reactor window, walls and exit is presented using a Discrete Phase Model (DPM). The flow field is based on a RNG k–ε model and species transport with methane as the main flow and argon/ hydrogen as window and wall screening fluid. Flow behavior and particle deposition have been observed with the variation of main flow rates from 10–20L/min and with carbon particle mass flow rate of 7×10−6 and 1.75×10−5kg/s. In this study the window and wall screening flow rates have been considered to be 1L/min and 10L/min by employing either argon or hydrogen. Also, to study the effect of particle size simulations have also been carried out (i) with a variation of particle diameter with a size distribution of 0.5–234μm and (ii) by taking 40μm mono sized particles which is the mean value for the considered size distribution. Results show that by appropriately selecting the above parameters, the concept of the aero-shielded reactor can be an attractive option to resolve the problem of carbon deposition at the window, walls and exit of the reactor.

Smart solar reactor for co-production of hydrogen and industrial grade carbon under any weather conditions

Abstract The impending shortage of fossil fuels and environmental consequences of fossil fuel consumption are two of the most imperative problems in the world. This presentation is about a novel design of a solar reactor cavity system composed of a camera-like aperture and moving-wall system to house a unique thermo-fluid-chemical process known as ‘solar cracking’. Differing from typical solar powered Rankine cycles, solar cracking uses concentrated solar energy as a heat source for direct decomposition of natural gas into gaseous H2 and particulate carbon. This process offers a CO2 emission free hydrogen production method, as the carbon is collected in a high-grade and/or nanotube form. However, solar cracking reactors have two implicit major problems: The intrinsic losses in energy conversion efficiency as a result of the high internal temperatures and corresponding re-radiation losses as well as the inherently transient nature of the solar energy. Literature on solar reactors reveals a distinct focus on optimal reactor design for steady state efficiency, but little regarding transient inefficiencies. This presentation provides an advanced perception to solar cracking reactors by presenting you the latest results of our research at Sustainable Energy Research Lab on the design of a ‘smart solar reactor’ that is sensitive to variations in solar flux, and can adjust itself accordingly to maintain quasi-equilibrium internal conditions. A unique system design is presented featuring a solar-flux intensity sensitive aperture that can enlarge the aperture diameter when the flux is low and reduce the diameter when the flux is high. Carbon particle deposition on the reactor window, walls, and at the exit. Carbon deposition. particularly at the exit, causes reactor clogging. There have been many innovative reactor designs aimed to achieve increased conversion efficiencies through novel flows developed at ETH-Zurich, CNRS-France, WIS-Israel, Colorado-USA, Florida-USA, and DLR-Germany. From vortex-flow to tornado, and from fluidized bed to rotating cavity, the designs of these reactors have moved toward the goal of seeking enhanced flow conditions that result in improved overall efficiencies, but have not solved the carbon deposition problem. Our latest research results at Sustainable Energy Research Lab shows that our ‘aero-shielded cyclone solar reactor’ concept provides a laminar flow shield covering the walls as a thin layer flow with a velocity that is strong enough to sweep carbon particles away. This presentation will show you the results of our research on this concept with a 3D animation of the reactor.

Pulmonary anthracosis in Dhaka Zoo collections – a public health forecasting for city dwellers

Anthracosis is a lung disease associated with inhalation of coal dust and carbon particles. We tested for anthracosis symptoms in 36 captive animals in the Dhaka Zoo. Necropsy revealed 27 out of 36 animals to be affected by pulmonary anthracosis. The changes included minute black spots to blackish discoloration and congestion in the lungs. In some cases, the lungs showed yellow-white caseous nodules of variable size. Lung tissue samples were stored in 10% neutral buffered formalin. Fixed tissues were processed and stained as per standard procedure. Histopathological examination revealed deposition of carbon particles of varying sizes, shapes and amounts in the lung parenchyma, in the alveolar septa and in and around granuloma. Reptiles, newly arrived animals and animals less than one year of age were found free from anthracosis. This report confirms the occurrence of anthracosis in captive animals at Dhaka zoo indicating severe air pollution in and around the zoo.

Lagrangian characterization of multi-phase turbulent flow in a solar reactor for particle deposition prediction

Solar cracking of methane is a promising technology for emission free hydrogen production. One of the major problems affecting methane cracking solar reactors' performance is the carbon particle deposition on the window, walls, and at the exit. In present study, a Lagrangian particle dispersion model has been implemented for predicting the particle deposition on the window of a seeded solar thermal reactor. A three-dimensional Computational Fluid Dynamics (CFD) analysis using Discrete Phase Model (DPM) has been done for qualitative validation of the experimental observations. In order to evaluate the turbulent quantities in the solar reactor; RNG k– ɛ model has been applied. Species transport has been solved by taking the gas for window screening as different from that used in the main flow. In addition, this paper presents a thorough parametric study predicting the particle deposition on reactor window for various flow configurations and flow conditions, which can be summarized as; (1) when the inlet flow angle is smaller, higher tangential velocities or swirl strength is obtained, (2) higher tangential velocities help in maintaining a stronger swirl, which keeps the screening flow close to the reactor window, (3) by increasing the main flow and the screening flow rates, the particle deposition on window is reduced, (4) when a lower density fluid is used as window screening gas, the particle deposition is reduced because the Taylor instabilities are avoided. The CFD work and the findings presented in this paper would be used as a guide in designing a solar reactor or improving the configuration of existing reactor.

Involvement of alveolar macrophages in the formation of 8-oxodeoxyguanosine associated with exogenous particles in human lungs

Lung specimens were collected from 161 non-smoking male patients with carcinoma to determine the deposition of carbon particles and oxidative damage in lung tissues. Morphologically, carbon particles deposited in human lungs with carcinoma were similar to those of diesel exhaust like particles, and mass of particles showed a significant increase with the increasing age of the patients. An increasing age of patient with carcinomas was also associated with 8-oxodeoxy-guanosine (8-oxo-dG) formation, which was analyzed using the HPLC-electrochemical detector method. In addition, it was found that 8-oxo-dG increased in cancerous tissues rather than in non-cancerous ones. To determine whether particles in lung tissues were associated with 8-oxo-dG formation, carbon particles deposited in lung tissues were partially purified by cycling of alkali fusion with 1M KOH; mutagenic chemicals in particles were extracted and excluded by removal with an equal volume of benzene/methanol and dichloromethane. It was also found that 8-oxo-dG was formed by non-mutagenic particles, and enhanced in the in vivo test using mouse rather than in the in vitro using RAW 254.7 tissue cultured cells. The 8-oxo-dG formation in vivo was due to the fact that hydroxyl radicals might be involved with phagocytosis of non-mutagenic particles in inflammatory cells, and the mutation was induced by hydroxylation of guanine residue on DNA. These results were also demonstrated by the occurrence of alveolar macrophages and neutrophils after intratracheal instillation of particles. These observations suggest that small particles from lung cancer patients further promote oxidative damage when used to treat the mouse lung. Especially, particles from which organic chemicals were removed were highly reactive to oxidative damage and formed 8-oxo-dG.

Kinetics of deposition of carbon particles on plastic spheres

The kinetics of particle deposition onto the surface of spherical collector particles suspended in a stirred batch vessel was investigated. The study considered monodisperse particle and monodisperse spherical collector particles. The Langmuir model for the deposition process was presented with model parametric study as well as model limiting cases of Smoluchowski analysis and equilibrium state. A method for obtaining the model parameters from model limiting cases was demonstrated. The model was experimentally tested by studying the deposition of small carbon particles onto plastic spheres. This is useful in the de-inking process of waste paper using plastic spheres. The obtained deposition curves are fitted to the model. The estimated parameters from model limiting cases are in agreement with those, obtained from the full deposition curves fitted to Langmuir kinetics. The maximum number of carbon particles that can deposit on plastic particles is estimated theoretically from geometrical analysis. The estimated value is very close to that determined from the model.

Deposition studies of carbon particles on stainless steel surfaces from hydrocarbon media

Abstract The adsorption isotherms for carbon particles of about 200 nm size, in the presence of various combinations of a terminally functionalised (amine) polyisobutylene polymer and alkylpropoxylate/alkylbutoxylate surfactant molecules, on 7 μm diameter stainless steel beads from isooctane solutions have been obtained. The deposition of carbon particles on stainless steel plates was achieved using a flow-cell and analysed using scanning electron microscopy. The flow-cell was also used to study the “cleaning” properties of various polymer/surfactant solutions, in their ability to remove deposited particles. It was found that the polymer molecules were much more effective dispersants and stabilisers for the carbon particles, but the surfactant molecules were much better at effecting anti-deposition and subsequent removal of deposited carbon particles, and provide carried adsorbed polymer chains.

Effect of physicochemical and hydrodynamic conditions on kinetics of carbon particles deposition on plastic particles

Deposition of carbon particles on plastic spheres was experimentally investigated. The effects of CaCl 2 concentration, soap concentration and the mixing speed on the deposition rate and the equilibrium particle concentration were studied. The effect of the above parameters on the Langmuir model constants was also determined. In the absence of CaCl 2, almost no deposition takes place. However, when CaCl 2 was added, the deposition becomes very fast. A large equilibrium constant was obtained when the concentration of CaCl 2 equals the stoichiometric amount necessary to react with the sodium stearate soap. On the other hand, when the concentration of CaCl 2 was above the stoichiometric amount, both coagulation of carbon particles and deposition took place simultaneously. When the soap concentration was above the stoichiometric amount the deposition rate is slow. Further increase in the soap concentration has similar effect on the deposition rate. The effect of mixing speed on the deposition rate was examined. Mixing speeds of 100, 300 and 500 rpm were used. Results showed that the deposition rate increases as the mixing speed increases until a certain point is reached where it starts to decrease.

Paleoenvironmental studies of black carbon deposition in the High Arctic: a case study from Northern Ellesmere Island

The application of palcolimnological techniques to studies of anthropogenic black carbon particles in Lower Dumbell Lake, Northern Ellesmere Island, Northwest Territories, Canada, reveals a stratigraphic record of particle deposition over time. Comparison of the anthropogenic black carbon record with the paleoecological record of diatom assemblages in this lake indicates that the diatom flora developed within the period of anthropogenic black carbon particle deposition. This result supports an inference of very recent environmental change.

Pathways of cellular efflux and particulate clearance after carbon instillation to the lung.

The pulmonary response to the deposition of carbon particles was investigated to determine the routes of cellular efflux and the mechanisms of particulate clearance. At intervals to 6 months after the intratracheal instillation of 4 mg carbon, the lungs of mice were fixed in situ by perfusion without lavage. Within a few hours, migration of granulocytes into the bronchioles was observed; large numbers of PMNs were not seen in alveoli until 24 h. Associated with the PMN efflux there was transient oedema with no evidence of pulmonary cell necrosis. The number of free macrophages increased in response to the carbon and mononuclear cell migration into alveoli and bronchioles was also observed. The bronchiolar component of the cellular efflux indicates that PMNs and macrophages recovered from the lung by lavage are not entirely of alveolar origin. Whereas most particles, either free or in phagocytic cells, were cleared by the bronchial tree, some transepithelial passage of free particles to the interstitium was observed. Some carbon was found in hilar lymph nodes but overall lymphatic clearance was low.

Response in distant lymph nodes of mice to infection in the hind footpad with Mycobacterium marinum.

In an attempt to demonstrate the importance of the popliteal lymph node in limiting the progress of infection with Mycobacterium marinum in the hind footpads of C57BL mice, such infections were studied in mice subjected to popliteal or popliteal and inguinal adenectomies. In the absence of the popliteal node, the footpad infection was only slightly enhanced compared with infections of sham-operated control mice; the inguinal node was found to be greatly enlarged and appeared to have substituted for the absent popliteal node. In the absence of both popliteal and inguinal nodes, the disease process in the footpads was again only slightly enhanced, and the axillary node appeared to have enlarged greatly and to have functionally replaced the missing, more proximate nodes. In additional experiments, mice subjected to adenectomy only on one side and injected in that hind footpad with phytohemagglutinin or India ink demonstrated hypertrophy or deposition of carbon particles in the more distant node only on the side of the injection. Thus, there appear to be rather direct functional connections among popliteal, inguinal, and axillary nodes that do not depend on blood circulation.

Lymphatics of the Human Pulmonary Alveoli: Preliminary Report

The subpleural lymphatics of a normal human lung were injected with a dilute, green-colored latex solution after the lung had been made edematous by normal saline infusions. The tracheobronchial tree was then filled with a white latex, following which the preparation was submerged in concentrated HCl to achieve corrosion of the tissues. Microscopic dissection of the model revealed that there were lymphatic capillary networks not only on the subpleural alveoli but also on alveoli within the lobules. During the microdissection a cluster of intralobular alveoli was found in which the capillary vessels in addition to being injected with latex were also outlined by deposition of carbon particles alongside their walls. This gave credence to the belief that the capillaries were, indeed, lymphatic in nature. The difference between the lymphatic and blood capillary networks have been described.