Spiral classifier - Our report on the Spiral Classifier Market provides a comprehensive overview of the current market trends and dynamics. It offers an in-depth analysis of the leading players in the market, along ...

 
Spiral classifier is composed of motor, reducer, cylindrical gear and bevel gear. 2. Spiral (left and right) It is composed of the hollow shaft, bracket, spiral blade, lining iron, etc. The hollow shaft is welded by seamless steel pipe, journal and flange. Wear-resistant life is the key in use, so the lining iron is made of wear-resistant ... . 3 d hentai porn

Mokup of classifier, 2 principles, 1600 mm screw diameter. Still in use in several silica sand plant: wash drain and dedusting. spiral classifier 1600 | 3D CAD Model Library | GrabCADProduct Features. 1.This classifier adopts sealing immersed bearing. 2. Independent hoisting equipment with strong reshipment power. 3. Wearable liner of bolt installed to prolong the service life. 4. Cell body in long and narrow shape can reach a good mixing effect and prolong the suspension time of materials.Nov 28, 2022 · High Weir Spiral Classifier, one of the segments analyzed in the report, is projected to record 2.3% CAGR and reach US$827.7 Million by the end of the analysis period. Taking into account the ... Nesans Spiral Classifier consists of an open trough with a chute provided for the input feed material. Before being fed into the spiral classifier, the dust from the screen is mixed with water and it is carried to the input chute through a slurry pump. The inlet flow is evenly distributed across the surface area of the spirals. The ball mill is for grinding 0-20mm to small powder. It works together with the spiral classifier, so the overflow slurry from the classifier is about 80% 200mesh powder. The oversize particle from the classifier will go back to the ball mill grinding again, to form a closed-loop.Spiral classifier. Spiral classifier is one of the classifying equipment in mineral processing. It is suitable for classifying materials in the mineral processing plant as well as the desliming and dehydrating in the mineral washing operating process and widely applied to separate the particles into a number of products graded according to size in the complete closed loop together with ball ... Spiral washer is a type of sand washing machine, while spiral classifier is a mineral processing equipment. There are many similarities between spiral washers and spiral classifiers in appearance, many users can not distinguish them. In this article, will introduce 6 differences between spiral washers and spiral classifiers. 1. Different ...The concept of spiral classifiers cathodic protection presented in this paper may become an alternative to the anti-corrosion protection methods of machinery and equipment used now at the KGHM ...Sep 5, 2023 · Chapter 1: Submerged Spiral Classifier Market Product Definition, Product Types, Volume, and Revenue Analysis of Each Type in North America, Europe, Asia-Pacific, Latin America, Middle East, and ... Spiral classifier is used to treat alluvial placer, especially for those with high dissociation degree and flat shape of mineral monomer. Spiral classifier and ball mill generally cooperate, mostly used for mineral processing. The classifier has the characteristics of simple structure, reliable operation, convenient operation, high efficiency ... Aug 23, 2019 · The ball mill is for grinding 0-20mm to small powder. It works together with the spiral classifier, so the overflow slurry from the classifier is about 80% 200mesh powder. The oversize particle from the classifier will go back to the ball mill grinding again, to form a closed-loop. The rake classifier such as the Dorr classifier consists of a rectangular tank with a sloping/inclined bottom. The tank is provided with movable rakes (reciprocating rakes). The feed in the form of a suspension (slurry) is introduced continuously near the middle of the tank. The lower end of the tank has a weir overflow (discharge weir) from ...Published Jun 28, 2023. + Follow. The market research conducted by Global High Weir Spiral Classifier Market offers an in-depth analysis of the global market, with a focus on future projections ...The Global Spiral Classifier Market can be segmented based on various factors to gain a comprehensive understanding of its dynamics and opportunities. The segmentation allows for a more targeted ...The Global Spiral Classifier Market can be segmented based on various factors to gain a comprehensive understanding of its dynamics and opportunities. The segmentation allows for a more targeted ...Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ...Spiral classifier is used for material classification with spirals used to stir and convey materials according to the difference in material settling velocities. It is a kind of gravitational and hydraulic classifiers. The specification of spiral classifiers is represented by the number and diameter of spirals.The spiral classifier is widely applied for the following fields: combine with ball grinder into closed circulation for ore-sand separation in the ore separation plant; classify ore sand and fine sludge in gravity ore separation plant; classify the grain of ore pulp at the metal ore separation process; and remove sludge/water at the ore separation process.Sep 8, 2023 · Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ... A Spiral Classifier is a machine that is primarily used to classify the slimes (fines) from a coarser, sandy sized material. It has an inclined trough with one or two spirals revolving slowly and free from touching the sides or bottom of the tank.Triveni Spiral Classifiers utilize an increased for maximum torque and quiet, trouble free. lead or helix angle to form the continuous high pitch performance. Spiral for greater raking capacity. The upper main bearing is over sized for normal. Classifier service. Also this bearing and gear pivot is on. Walker mining produce Submerged and hig weir double spiral classifier,Submerged and High-weir double spirals classifier. Product Introduction Spiral classifier is a common beneficiation equipment. It’s widely used in concentrators and ball mills to form a closed-circuit cycle and separate ore sand, or in gravity concentrators to classify ore ...A Spiral Classifier is a machine that is primarily used to classify the slimes (fines) from a coarser, sandy sized material. It has an inclined trough with one or two spirals revolving slowly and free from touching the sides or bottom of the tank.Oct 22, 2019 · Misconception 4: Fine Material Screws are recommended for cutting at a coarse sand size. Fine Material Screw Washers generally are not recommended for removing fine solids larger than 150 micron or 100 mesh. When a separation ranging from 150 to 800 micron (or 100 to 20 mesh) is required, other types of classifiers, like Hydrosizers™ (or ... Now, the common classifiers in mineral processing plant are mainly mechanical classifier and hydrocyclone. Among them,mechanical classifier can be divided into spiral classifier, rake classifier,tank classifier and other types. With the development of classification operation, rake classifier is already replaced by spiral classifier, tank ...Product Features. 1.This classifier adopts sealing immersed bearing. 2. Independent hoisting equipment with strong reshipment power. 3. Wearable liner of bolt installed to prolong the service life. 4. Cell body in long and narrow shape can reach a good mixing effect and prolong the suspension time of materials. The concept of spiral classifiers cathodic protection presented in this paper may become an alternative to the anti-corrosion protection methods of machinery and equipment used now at the KGHM ...Misconception 4: Fine Material Screws are recommended for cutting at a coarse sand size. Fine Material Screw Washers generally are not recommended for removing fine solids larger than 150 micron or 100 mesh. When a separation ranging from 150 to 800 micron (or 100 to 20 mesh) is required, other types of classifiers, like Hydrosizers™ (or ...SPIRAL CLASSIFIER / SCREW CLASSIFIER. DOVE Spiral Classifier, also referred to as Screw Classifier, or Spiral Mineral Separator, is highly efficient classifier designed for closed circuit wet classification and separation of the Slimes (Fines) from a sandy sized (Coarse) material. It is well suited for classification, where a two product size ...Nesans Spiral Classifier consists of an open trough with a chute provided for the input feed material. Before being fed into the spiral classifier, the dust from the screen is mixed with water and it is carried to the input chute through a slurry pump. The inlet flow is evenly distributed across the surface area of the spirals.The preferential classification benefit of cyclones is further illustrated in Table 2 which compares the metallurgical results of cyclones versus spiral classifiers in a copper grinding circuit. The cyclone produced an overflow product containing more copper in the finer size ranges where it will be subject to higher recovery in flotation. Nesans Spiral Classifier consists of an open trough with a chute provided for the input feed material. Before being fed into the spiral classifier, the dust from the screen is mixed with water and it is carried to the input chute through a slurry pump. The inlet flow is evenly distributed across the surface area of the spirals. Dec 1, 2020 · This is an example of vanilla Tensorflow playground with no added features and no modifications. The run for Spiral was between 187 to ~300 Epoch, depending. I used Lasso Regularization L1 so I could eliminate coefficients. I decreased the batch size by 1 to keep the output from over fitting. Aug 6, 2015 · The spiral classifier such as the Akins classifier consists of a semi-cylindrical trough (a trough that is semicircular in cross-section) inclined to the horizontal. The trough is provided with a slow-rotating spiral conveyor and a liquid overflow at the lower end. Lab Spiral Classifier. This Lab Spiral classifiers suitable for dewatering, medium drainage and desliming and wet and dry classifying for ore, Non-metallic materials, etc. Spiral classifier is a type of classifying equipment which realizes mechanical classification under the principle that materials settle in the liquid at different speeds due ... Now, the common classifiers in mineral processing plant are mainly mechanical classifier and hydrocyclone. Among them,mechanical classifier can be divided into spiral classifier, rake classifier,tank classifier and other types. With the development of classification operation, rake classifier is already replaced by spiral classifier, tank ...It is evident that no linear classifier will be able to do a good job classifying spiral data where the boundary between two classes is a curve. A simple two layer network with RELU activation on the hidden layer automatically learns the decision boundaries and achieves a 99% classification accuracy on such a data set.Apr 13, 2023 · Spiral classifier is used for material classification with spirals used to stir and convey materials according to the difference in material settling velocities. It is a kind of gravitational and hydraulic classifiers. The specification of spiral classifiers is represented by the number and diameter of spirals. Classifier. The Spiral Classifier used for the study was manufactured by Nick and Paul. 2.2 Designing of Test Works Prior to test work design, visit to the oxide plant at Ghana Manganese Company (GMC) were made with the aim of getting acclimatize with the current operations at the plant. The Spiral classifier was operated in batch mode. May 26, 2016 · Spiral Classifier. In mineral processing, the Akins AKA spiral or screw Classifier has been successfully used for so many years that most mill operators are familiar with its principle and operation. This classifier embodies the simplest design, smallest number of wearing parts, and an absence of surge in the overflow. Apr 28, 2007 · spiral classifier consists of a sloping elongated . round-bottom tank and a sand-raking spiral [46]. The raw materials are fed to the central . section of the pool and flow to the weir while . 13.5.3.4 Spiral Concentrator. The spiral concentrator is a modern high-capacity and low-cost device. It is developed for concentration of low-grade ores and industrial minerals in slurry form. It works on a combination of solid particle density and its hydrodynamic dragging properties.To understand how these two classifiers make use of this settling action, a description of them is required. First, to have the classification happen, the slurry must be able to flow. This means the classifiers must be inclined. The working portion of these two classifiers are the RAKES or SPIRAL/screw which are placed into the flow of ore. To ...These spiral classifier price types include vibrating shaker tables and alluvial washing machines, and they can be used alongside more precise separation tools. Choose from shaft tables and hydraulic tables that are equipped with hydraulics for conducting compression tests and come with distinct power capacities.Aug 24, 2023 · Compared with these two classifiers, the hydrocyclone has a better classification effect when processing finer-grained materials (the separation particle size range is generally 0.3-0.01mm). 2. Floor area. Obviously, the footprint of the hydrocyclone is significantly smaller than that of the spiral classifier. Mokup of classifier, 2 principles, 1600 mm screw diameter. Still in use in several silica sand plant: wash drain and dedusting.Spiral classifier is used to treat alluvial placer, especially for those with high dissociation degree and flat shape of mineral monomer. Spiral classifier and ball mill generally cooperate, mostly used for mineral processing. The classifier has the characteristics of simple structure, reliable operation, convenient operation, high efficiency ... 13.5.3.4 Spiral Concentrator. The spiral concentrator is a modern high-capacity and low-cost device. It is developed for concentration of low-grade ores and industrial minerals in slurry form. It works on a combination of solid particle density and its hydrodynamic dragging properties. Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ...Aug 6, 2015 · The spiral classifier such as the Akins classifier consists of a semi-cylindrical trough (a trough that is semicircular in cross-section) inclined to the horizontal. The trough is provided with a slow-rotating spiral conveyor and a liquid overflow at the lower end. Spiral classifiers suitable for dewatering, de-medium, desliming and wet and dry classifying in mine.This machine is mainly used in the production flow of me... Spiral Classifiers are available in sizes up to 120″ diameter, three tank styles, single, double and triple pitch spirals, three degrees of spiral submergence —flexibility to provide a unit built for your job. Write for detailed recommendation on the correct size and type of Spiral Classifier to do your job economically and profitably.Lab Spiral Classifier. This Lab Spiral classifiers suitable for dewatering, medium drainage and desliming and wet and dry classifying for ore, Non-metallic materials, etc. Spiral classifier is a type of classifying equipment which realizes mechanical classification under the principle that materials settle in the liquid at different speeds due ...Spiral classifier is one of beneficiation equipment, based on user requirements, it can be divided into single and double spiral classifier. Depend on specific gravity of solid particles, so different sedimentation velocity in a liquid principle, spiral classifier is a mechanical grading equipment. The spiral classifier such as the Akins classifier consists of a semi-cylindrical trough (a trough that is semicircular in cross-section) inclined to the horizontal. The trough is provided with a slow-rotating spiral conveyor and a liquid overflow at the lower end.High Weir Spiral Classifier, one of the segments analyzed in the report, is projected to record 2.3% CAGR and reach US$827.7 Million by the end of the analysis period. Taking into account the ...Spiral Classifier Wet classification is the art of solid-liquid separators i.e spiral separator, separating the solid particles in a mixture of solids and liquids into fractions according to particle size or density by methods other than screening. Nov 28, 2022 · High Weir Spiral Classifier, one of the segments analyzed in the report, is projected to record 2.3% CAGR and reach US$827.7 Million by the end of the analysis period. Taking into account the ... China Spiral Classifier manufacturers - Select 2023 high quality Spiral Classifier products in best price from certified Chinese Mining Equipment, Mining Machine suppliers, wholesalers and factory on Made-in-China.comOur report on the Spiral Classifier Market provides a comprehensive overview of the current market trends and dynamics. It offers an in-depth analysis of the leading players in the market, along ...Shaker Tables. MBMM produces high-performance shaker tables for gravity separation based on different material densities. They are designed for maximum performance by combining the best of many proven designs, refined after many hundreds of hours of R&D. The most notable feature is from an old 1909 Deister patent: a ramp and plateau system ...Spiral classifier. Spiral classifier is one of the classifying equipment in mineral processing. It is suitable for classifying materials in the mineral processing plant as well as the desliming and dehydrating in the mineral washing operating process and widely applied to separate the particles into a number of products graded according to size in the complete closed loop together with ball ... 13.5.3.4 Spiral Concentrator. The spiral concentrator is a modern high-capacity and low-cost device. It is developed for concentration of low-grade ores and industrial minerals in slurry form. It works on a combination of solid particle density and its hydrodynamic dragging properties.The spiral classifier such as the Akins classifier consists of a semi-cylindrical trough (a trough that is semicircular in cross-section) inclined to the horizontal. The trough is provided with a slow-rotating spiral conveyor and a liquid overflow at the lower end.May 15, 2016 · Spiral classifiers. A typical spiral classifier is shown in Fig. 1. The geometry of a spiral is characterized by the length or number of turns, the diameter, the pitch and the shape of the trough ( Burt, 1984). The spiral feed is a mixture of water and ground particles that is gravity fed at the top of the spiral. Apr 28, 2007 · spiral classifier consists of a sloping elongated . round-bottom tank and a sand-raking spiral [46]. The raw materials are fed to the central . section of the pool and flow to the weir while . Walker mining produce Submerged and hig weir double spiral classifier,Submerged and High-weir double spirals classifier. Product Introduction Spiral classifier is a common beneficiation equipment. It’s widely used in concentrators and ball mills to form a closed-circuit cycle and separate ore sand, or in gravity concentrators to classify ore ... A Spiral Classifier is a machine that is primarily used to classify the slimes (fines) from a coarser, sandy sized material. It has an inclined trough with one or two spirals revolving slowly and free from touching the sides or bottom of the tank. The motion of the spiral creates Pool Hindered Settling in the bottom pool area, where the ... May 15, 2016 · Spiral classifiers. A typical spiral classifier is shown in Fig. 1. The geometry of a spiral is characterized by the length or number of turns, the diameter, the pitch and the shape of the trough (Burt, 1984). The spiral feed is a mixture of water and ground particles that is gravity fed at the top of the spiral. Aug 24, 2023 · Compared with these two classifiers, the hydrocyclone has a better classification effect when processing finer-grained materials (the separation particle size range is generally 0.3-0.01mm). 2. Floor area. Obviously, the footprint of the hydrocyclone is significantly smaller than that of the spiral classifier. Spiral Classifier Wet classification is the art of solid-liquid separators i.e spiral separator, separating the solid particles in a mixture of solids and liquids into fractions according to particle size or density by methods other than screening. The spiral speed and feed tonnage correlated negatively to the Mn grade with washing time correlating positively. Operating the spiral classifier at a feed rate, spiral speed and washing time of 6 t, 25 rev/min, and 30 min, respectively, yielded Mn grade of 53%.The spiral classifier such as the Akins classifier consists of a semi-cylindrical trough (a trough that is semicircular in cross-section) inclined to the horizontal. The trough is provided with a slow-rotating spiral conveyor and a liquid overflow at the lower end.These spiral classifier price types include vibrating shaker tables and alluvial washing machines, and they can be used alongside more precise separation tools. Choose from shaft tables and hydraulic tables that are equipped with hydraulics for conducting compression tests and come with distinct power capacities.The result of that the 900mm spiral classifier has the best beneficiation effect in the cases of the same grade concentrate ore. The scavenging effect of 900mm pitch spiral separator machine has the output of 3.42t/h, the productivity of 32.18%, the grade of concentrate mineral 17.46%, recovery rate 17.16%, and comprehensive efficiency of 27.74%.Spiral classifier is one of beneficiation equipment, based on user requirements, it can be divided into single and double spiral classifier. Depend on specific gravity of solid particles, so different sedimentation velocity in a liquid principle, spiral classifier is a mechanical grading equipment. Sep 7, 2023 · Chapter 1: High Weir Spiral Classifier Market Product Definition, Product Types, Volume, and Revenue Analysis of Each Type in North America, Europe, Asia-Pacific, Latin America, Middle East, and ... The design of a McLanahan Fine Material Screw Washer provides significant advantages over other sand screws you could consider that include: Larger pool settling areas behind the feed box/baffle plate that provide higher retention of +75 micron (200 mesh) product sized solids. A machine design that has a 2.5" (65mm) gap between the screw shaft ...Sep 8, 2023 · Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ... Spiral classifier. Spiral classifier is one of the classifying equipment in mineral processing. It is suitable for classifying materials in the mineral processing plant as well as the desliming and dehydrating in the mineral washing operating process and widely applied to separate the particles into a number of products graded according to size in the complete closed loop together with ball ...These spiral classifier price types include vibrating shaker tables and alluvial washing machines, and they can be used alongside more precise separation tools. Choose from shaft tables and hydraulic tables that are equipped with hydraulics for conducting compression tests and come with distinct power capacities.Sep 3, 2021 · The spiral classifier agitates the pulp by spiral low-speed rotation, by which the fine particles float to the overflow, and the coarse particles sink to the bottom of the tank and are discharged ...

EIMCO-K.C.P. Spiral Classifiers are mechanically the devices are powerfully built, and functionally they are versatile and flexible. Today’s worldwide acceptance of EIMCO-K.C.P. Classifiers for washing and dewatering pulps, and in closed-circuit grinding is the result of many years of experience in solving wet classification problems.. Databricks certified associate developer for apache spark 3.0 python

spiral classifier

Spiral classifier is used to treat alluvial placer, especially for those with high dissociation degree and flat shape of mineral monomer. Spiral classifier and ball mill generally cooperate, mostly used for mineral processing. The classifier has the characteristics of simple structure, reliable operation, convenient operation, high efficiency ... Spiral Screw Classifier for Sand Washing. new. Manufacturer: Gandong; Descriptions The classifier which form closed-circuit work with grinding mill in the factory need the machine which can lift grit, so this kind of classifier called mechanical classifier, actually the classifying...Sep 29, 2017 · It is evident that no linear classifier will be able to do a good job classifying spiral data where the boundary between two classes is a curve. A simple two layer network with RELU activation on the hidden layer automatically learns the decision boundaries and achieves a 99% classification accuracy on such a data set. Oct 20, 2017 · Mokup of classifier, 2 principles, 1600 mm screw diameter. Still in use in several silica sand plant: wash drain and dedusting. May 26, 2016 · Spiral Classifier. In mineral processing, the Akins AKA spiral or screw Classifier has been successfully used for so many years that most mill operators are familiar with its principle and operation. This classifier embodies the simplest design, smallest number of wearing parts, and an absence of surge in the overflow. Jan 1, 2016 · The classifier designs differ mainly in the mode of removing the underflow and the overflow slurries. Immersed spiral or rakes are generally used for underflow slurries and an open launder carries the overflow. Figure 13.1 is a sketch of a spiral classifier where the spiral conveyor is installed within the bowl. The spiral operates along the ... Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ... Misconception 4: Fine Material Screws are recommended for cutting at a coarse sand size. Fine Material Screw Washers generally are not recommended for removing fine solids larger than 150 micron or 100 mesh. When a separation ranging from 150 to 800 micron (or 100 to 20 mesh) is required, other types of classifiers, like Hydrosizers™ (or ...May 15, 2016 · Spiral classifiers. A typical spiral classifier is shown in Fig. 1. The geometry of a spiral is characterized by the length or number of turns, the diameter, the pitch and the shape of the trough (Burt, 1984). The spiral feed is a mixture of water and ground particles that is gravity fed at the top of the spiral. Lab Spiral Classifier. This Lab Spiral classifiers suitable for dewatering, medium drainage and desliming and wet and dry classifying for ore, Non-metallic materials, etc. Spiral classifier is a type of classifying equipment which realizes mechanical classification under the principle that materials settle in the liquid at different speeds due ...XBM Mining is a leading global supplier of equipment and tools, service and technical solutions for the mining industry,especially specialized in ore benefic...Sep 3, 2021 · The spiral classifier agitates the pulp by spiral low-speed rotation, by which the fine particles float to the overflow, and the coarse particles sink to the bottom of the tank and are discharged ... Sep 29, 2017 · It is evident that no linear classifier will be able to do a good job classifying spiral data where the boundary between two classes is a curve. A simple two layer network with RELU activation on the hidden layer automatically learns the decision boundaries and achieves a 99% classification accuracy on such a data set. Submerged Spiral Classifier Market Enigma on a Global Stage | Phenomenal Growth Outlook to 2030 Sep 8, 2023 ...Aug 6, 2015 · The rake classifier such as the Dorr classifier consists of a rectangular tank with a sloping/inclined bottom. The tank is provided with movable rakes (reciprocating rakes). The feed in the form of a suspension (slurry) is introduced continuously near the middle of the tank. The lower end of the tank has a weir overflow (discharge weir) from ... Walker mining produce Submerged and hig weir double spiral classifier,Submerged and High-weir double spirals classifier. Product Introduction Spiral classifier is a common beneficiation equipment. It’s widely used in concentrators and ball mills to form a closed-circuit cycle and separate ore sand, or in gravity concentrators to classify ore ... 10.3.2 Bahan. Bahan yang digunakan dalam percobaan Spiral Classifier yaitu : 1. Mineral Kasiterit (SnO2) dengan ukuran – 40 + 70 # yakni sebanya 1 kg. 2. Zeolit yakni hasil kominusi dengan ukuran – 8 + 12 #, sebanyak 3 kg. Sumber : Data Hasil Praktikum PBG, 2017. Foto 10.11 Zeolit.In this video, Jason describes the many benefits and uses of our Spiral Classifier, also called a Screw Conveyor, De-watering Screw, and Auger Conveyor. The ...Aug 6, 2015 · To understand how these two classifiers make use of this settling action, a description of them is required. First, to have the classification happen, the slurry must be able to flow. This means the classifiers must be inclined. The working portion of these two classifiers are the RAKES or SPIRAL/screw which are placed into the flow of ore. To ... A Spiral Classifier is a machine that is primarily used to classify the slimes (fines) from a coarser, sandy sized material. It has an inclined trough with one or two spirals revolving slowly and free from touching the sides or bottom of the tank.Shaker Tables. MBMM produces high-performance shaker tables for gravity separation based on different material densities. They are designed for maximum performance by combining the best of many proven designs, refined after many hundreds of hours of R&D. The most notable feature is from an old 1909 Deister patent: a ramp and plateau system ... .

Popular Topics