API 671 5.pdf
•
0 likes•214 views
Pemerintah mendorong masyarakat untuk tetap beraktivitas namun harus mematuhi protokol kesehatan untuk mencegah penyebaran Covid-19. Vaksinasi masih terus dilakukan untuk mencapai kekebalan komunitas. Masyarakat disarankan untuk tetap waspada meski pandemi mulai terkendali.
Report
Share
Report
Share
Download to read offline
Recommended
U.S. Bellows 101: The Basics of Expansion Joints
This document is a presentation from US Bellows about expansion joint basics. It contains information about US Bellows' facilities and certifications. It also provides details on bellows movement and motion, types of expansion joints, bellows fabrication, testing procedures, and applications for expansion joints. The presentation aims to educate attendees on fundamental expansion joint topics.
Weld defects 1
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise has also been shown to increase gray matter volume in the brain and reduce risks for conditions like Alzheimer's and dementia.
Radiographic interpretation
This document provides definitions for various defects that may appear on radiographic images of welds, including:
- Excessive root penetration appears as a light irregular band within the weld image.
- Root concavity appears as dark areas along the weld center varying in density by imperfection depth.
- Incomplete filled groove appears as a dark area at the weld center with diffuse edges.
- Cracks appear as dark, fine lines that are usually diffuse or discontinuous.
Presentation on wpqr wps asme_ix
This document provides a summary of Module 7, which covers Weld Procedure Qualification according to ASME Section IX. It discusses the 5 step process for qualifying a welding procedure and the variables that must be addressed in the Procedure Qualification Record (PQR). These include joint design, base metal, filler metal, position, preheat, post-weld heat treatment, gas, and electrical characteristics. An example procedure qualification is provided for a manual GTAW and GMAW weld on 0.75-inch thick A36 steel in the flat position, with no preheat or PWHT, using ER80S-D2 wire for GTAW and ER70S-6 wire for GMAW
Asme sec ix
This document outlines requirements for welding procedure and procedure qualification records according to ASME Section IX. It discusses test positions, mechanical tests like tension tests and bend tests, and requirements for welding procedure specifications and procedure qualification records including essential variables that must be documented.
ASNT Radiographic Film Interpretation (RTFI) Notes-Dr. Samir Saad
The document discusses the history and impact of climate change over the past century. It notes that global temperatures and sea levels have risen significantly, with extreme weather events like hurricanes also increasing. The causes are attributed to human activities like burning fossil fuels that release greenhouse gases and trap heat in the lower atmosphere. Major impacts are expected to continue and worsen if emissions are not reduced substantially in the coming decades.
Rt Acceptance
The document provides acceptance criteria for various types of defects found during radiographic testing of welds based on different codes and standards including API 1104, SP-1174, B31.3, and ASME Section IX. It lists the maximum allowable size, length, and aggregate length of defects such as cracks, incomplete penetration, incomplete fusion, burn through, slag inclusions, porosity, and undercutting.
WPS -PQR - Welder Qualifications .pdf
This document discusses the requirements and process for welding procedure and performance qualifications according to the ASME Boiler and Pressure Vessel Code. It explains that qualifications are required to prove the quality of welds and performance of welders. The process involves writing a welding procedure specification, making a test coupon according to the specification, conducting mechanical tests on the coupon, and documenting the results in a procedure qualification record. It provides details on various variables that need to be considered for different welding processes and their classification as essential, supplementary essential, or nonessential for qualifications.
Recommended
U.S. Bellows 101: The Basics of Expansion Joints
This document is a presentation from US Bellows about expansion joint basics. It contains information about US Bellows' facilities and certifications. It also provides details on bellows movement and motion, types of expansion joints, bellows fabrication, testing procedures, and applications for expansion joints. The presentation aims to educate attendees on fundamental expansion joint topics.
Weld defects 1
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise has also been shown to increase gray matter volume in the brain and reduce risks for conditions like Alzheimer's and dementia.
Radiographic interpretation
This document provides definitions for various defects that may appear on radiographic images of welds, including:
- Excessive root penetration appears as a light irregular band within the weld image.
- Root concavity appears as dark areas along the weld center varying in density by imperfection depth.
- Incomplete filled groove appears as a dark area at the weld center with diffuse edges.
- Cracks appear as dark, fine lines that are usually diffuse or discontinuous.
Presentation on wpqr wps asme_ix
This document provides a summary of Module 7, which covers Weld Procedure Qualification according to ASME Section IX. It discusses the 5 step process for qualifying a welding procedure and the variables that must be addressed in the Procedure Qualification Record (PQR). These include joint design, base metal, filler metal, position, preheat, post-weld heat treatment, gas, and electrical characteristics. An example procedure qualification is provided for a manual GTAW and GMAW weld on 0.75-inch thick A36 steel in the flat position, with no preheat or PWHT, using ER80S-D2 wire for GTAW and ER70S-6 wire for GMAW
Asme sec ix
This document outlines requirements for welding procedure and procedure qualification records according to ASME Section IX. It discusses test positions, mechanical tests like tension tests and bend tests, and requirements for welding procedure specifications and procedure qualification records including essential variables that must be documented.
ASNT Radiographic Film Interpretation (RTFI) Notes-Dr. Samir Saad
The document discusses the history and impact of climate change over the past century. It notes that global temperatures and sea levels have risen significantly, with extreme weather events like hurricanes also increasing. The causes are attributed to human activities like burning fossil fuels that release greenhouse gases and trap heat in the lower atmosphere. Major impacts are expected to continue and worsen if emissions are not reduced substantially in the coming decades.
Rt Acceptance
The document provides acceptance criteria for various types of defects found during radiographic testing of welds based on different codes and standards including API 1104, SP-1174, B31.3, and ASME Section IX. It lists the maximum allowable size, length, and aggregate length of defects such as cracks, incomplete penetration, incomplete fusion, burn through, slag inclusions, porosity, and undercutting.
WPS -PQR - Welder Qualifications .pdf
This document discusses the requirements and process for welding procedure and performance qualifications according to the ASME Boiler and Pressure Vessel Code. It explains that qualifications are required to prove the quality of welds and performance of welders. The process involves writing a welding procedure specification, making a test coupon according to the specification, conducting mechanical tests on the coupon, and documenting the results in a procedure qualification record. It provides details on various variables that need to be considered for different welding processes and their classification as essential, supplementary essential, or nonessential for qualifications.
Welding defects
The document discusses the results of a study on the impact of COVID-19 lockdowns on air pollution. Researchers analyzed data from dozens of countries and found that lockdowns led to an average decline of nearly 30% in nitrogen dioxide levels over cities. However, they also observed that this improvement was temporary and air pollution rebounded once lockdown restrictions began lifting. Overall, the study highlights how human activities are a major driver of air pollution but also that systemic changes are needed for long-term air quality improvements.
Rolling,Rolling mills,Rolling processes &Rolling Applications by polayya chin...
The document discusses rolling as a metal forming process. It describes rolling as a process where metal is passed between circular cylinders to change its shape through plastic deformation. Both hot and cold rolling processes are used, with hot rolling used for more drastic shape changes. Different types of rolling mills are covered, including two-high, three-high, four-high, cluster, and planetary mills. The advantages and disadvantages of rolling and its applications in producing items like tubes, rods, gears, and construction materials are also summarized.
Asme sec viii div 1 s
The document summarizes ASME Section VIII Division 1 code requirements for material identification, repair of material defects, Charpy impact testing of production test coupons, weld joint categories, radiographic and ultrasonic examination, welding requirements, and acceptance standards for non-destructive examination. Key points include requirements for original material markings, testing procedures that vary based on joint category and position, examination types based on joint size and material thickness, welder identification, pre-welding surface preparation, and imperfection acceptance criteria.
radiographer-s-weld-interpretation-reference
The document provides descriptions of common welding defects along with their corresponding radiographic images. It describes 14 different types of defects including misalignments, lack of penetration, inclusions, cracks, and more. Each defect entry explains what it is, such as offset or mismatch being a misalignment of pieces to be welded, and describes its radiographic image appearance, such as an abrupt change in film density across the weld image width. In total, it covers 14 common welding defects and their radiographic signatures for non-destructive testing interpretation.
Gmaw transfer modes
Explained Molten metal transfers in GMAW process ( MIG / MAG)
and equipments used in GMAW process and set up images are arranged in this welding process
Welding process
Welding Processes
Two Categories of Welding Processes
Arc Welding
Resistance Welding
Oxy-fuel Gas Welding
Other Fusion Welding Processes
Solid State Welding
Shielded Metal Arc Welding
Gas Metal Arc Welding
Flux‑Cored Arc Welding
Electro gas Welding
Submerged Arc Welding
Gas Tungsten Arc Welding (GTAW) or TIG
Resistant Welding
Brazing and Soldering
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
WHAT IS ASME? WHO IS ASME? WHAT ASME SECTION IX MEANS? WHAT ARE WELDING DOCUM...
PDF file for ASME SECTION IX and what is ASME. It will also give you information about WPS, PQR and WPQ. here you will get all that you want to know about WELDING DOCUMENTS.
pipeline components
Komponen sistem perpipaan terdiri atas berbagai jenis seperti siku, belokan, kopling, tutup, tee, reducer, dan lainnya yang terbuat dari berbagai material seperti besi tuang, besi tempa, baja tuang, baja tempa, dan non-besi. Komponen utama lainnya adalah katup seperti katup bola, katup sayap, katup penghalang aliran balik, katup membran, katup gerbang, katup bola
Welding processes
This document discusses various welding processes. It separates welding into two categories: fusion welding processes that melt the base metals like arc welding, and solid state welding processes that join metals without melting, like friction welding. The document focuses on describing several common arc welding processes including: shielded metal arc welding, gas metal arc welding, flux-cored arc welding, gas tungsten arc welding, plasma arc welding, and submerged arc welding. It also covers resistance spot welding, a type of resistance welding used to join sheet metals.
Asme viii Div. 1 presentation rev.0
This document provides an overview and introduction to ASME Section VIII Division 1, which establishes rules for the construction of pressure vessels. It discusses the historical context that led to the development of pressure vessel codes, an overview of ASME's codes and standards, key definitions, and the design requirements and considerations specified in Section VIII Division 1. The document covers topics such as material selection, corrosion allowances, minimum thickness requirements, design pressure, and loadings that must be considered in pressure vessel design.
Electrode selection
This document provides a summary of welding procedure specifications (WPS). It lists 69 WPS entries that include the process, filler metal, base metal, thickness range, diameter range, and post weld heat treatment requirements. The WPS cover a variety of welding processes including shielded metal arc welding, gas tungsten arc welding, flux cored arc welding, and submerged arc welding. The WPS specify the materials, thicknesses, diameters, and heat treatments for welding different material grades.
Wis5 welding defects 02
The document discusses various welding defects that can be visually detected, including cracks, lack of solid metal, lack of fusion, lack of smoothly blended surfaces, and miscellaneous defects. It provides details on different types of each defect, their causes, and methods for prevention. It also discusses welding repairs, noting that repairs require authorization and testing to ensure defects have been fully removed before performing the repair weld.
Qc piping guide
The document provides information for a piping inspector, including:
1. The duties of a piping inspector are to ensure piping activities such as material receiving, fabrication, erection, testing, and re-instatement comply with Saudi Aramco specifications and procedures.
2. Inspection is to be carried out according to Schedule Q, Saudi Aramco standards and specifications, and approved procedures and ITPs.
3. Piping construction drawings include plans, arrangements, supports, details, hook-ups, schedules, P&IDs, and isometrics.
Welding lectures 14 16
This document discusses various weld defects including geometric defects like misalignment and metallurgical defects like cracks, porosity, and embrittlement reactions. It explains the causes and remedies for different types of defects such as angular distortion, longitudinal distortion, incomplete fusion, cracks, and porosity. The document also covers residual stresses during welding, gas dissolution and solid solution hardening, hydrogen effects including hydrogen embrittlement and cracking, and common weld testing methods like tension tests, bend tests, hardness tests, and non-destructive tests including visual inspection, liquid penetrant, magnetic particle, x-ray and ultrasonic testing.
Pipe Support Field Inspection, Installation & Maintenance
The document is about a webinar on pipe support field inspection, installation, and maintenance presented by Jerry Godinaer. It provides information on inspecting, installing, and maintaining different types of pipe supports including variable and constant spring hangers, restraint devices, pipe shoes, slide plates, and hardware components. It discusses guidelines for on-site surveys, what to inspect for existing supports, and criteria for adjusting or replacing supports if needed.
178383099-Gating-System-Design (1).ppt
The document discusses key aspects of gating system design including pouring time, choke area, sprue design, pouring basin, sprue base well, gating ratios, ingate design, and slag trap systems. It provides equations and guidelines for calculating pouring time, choke area, sprue taper, and gating ratios. It also describes non-pressurized and pressurized gating systems and discusses Bernoulli's theorem and the law of mass continuity as they relate to fluid flow in gating design.
Welding defects
This document provides a classification and overview of common welding defects. It divides defects into three main categories: planar defects, linear volumetric defects, and non-planar defects. Examples of each type of defect are given. The document also describes specific defect types such as cracks, inclusions, lack of fusion, porosity, overlap, undercut and provides potential causes of each.
Sand casting of metals - Gating system for sand casting mould
Topics covered: Sand Casting of Metals
Design and manufacture of gating system
Pouring basin
Sprue
Runners
In-gates
Riser
ASME SEC IX PPT.pdf
The document summarizes the key aspects of ASME Section IX (Ed. 2019), which contains requirements for welding procedure and performance qualifications. It discusses the history and timeline of ASME standards development. It also provides an overview of the various articles within ASME Section IX, including Article I on general welding requirements, Article II on welding procedure qualification, Article III on welding performance qualification, and Article IV on welding data. Key terms like essential variables, P-numbers, F-numbers, and A-numbers used for material grouping are also defined in the document.
More Related Content
What's hot
Welding defects
The document discusses the results of a study on the impact of COVID-19 lockdowns on air pollution. Researchers analyzed data from dozens of countries and found that lockdowns led to an average decline of nearly 30% in nitrogen dioxide levels over cities. However, they also observed that this improvement was temporary and air pollution rebounded once lockdown restrictions began lifting. Overall, the study highlights how human activities are a major driver of air pollution but also that systemic changes are needed for long-term air quality improvements.
Rolling,Rolling mills,Rolling processes &Rolling Applications by polayya chin...
The document discusses rolling as a metal forming process. It describes rolling as a process where metal is passed between circular cylinders to change its shape through plastic deformation. Both hot and cold rolling processes are used, with hot rolling used for more drastic shape changes. Different types of rolling mills are covered, including two-high, three-high, four-high, cluster, and planetary mills. The advantages and disadvantages of rolling and its applications in producing items like tubes, rods, gears, and construction materials are also summarized.
Asme sec viii div 1 s
The document summarizes ASME Section VIII Division 1 code requirements for material identification, repair of material defects, Charpy impact testing of production test coupons, weld joint categories, radiographic and ultrasonic examination, welding requirements, and acceptance standards for non-destructive examination. Key points include requirements for original material markings, testing procedures that vary based on joint category and position, examination types based on joint size and material thickness, welder identification, pre-welding surface preparation, and imperfection acceptance criteria.
radiographer-s-weld-interpretation-reference
The document provides descriptions of common welding defects along with their corresponding radiographic images. It describes 14 different types of defects including misalignments, lack of penetration, inclusions, cracks, and more. Each defect entry explains what it is, such as offset or mismatch being a misalignment of pieces to be welded, and describes its radiographic image appearance, such as an abrupt change in film density across the weld image width. In total, it covers 14 common welding defects and their radiographic signatures for non-destructive testing interpretation.
Gmaw transfer modes
Explained Molten metal transfers in GMAW process ( MIG / MAG)
and equipments used in GMAW process and set up images are arranged in this welding process
Welding process
Welding Processes
Two Categories of Welding Processes
Arc Welding
Resistance Welding
Oxy-fuel Gas Welding
Other Fusion Welding Processes
Solid State Welding
Shielded Metal Arc Welding
Gas Metal Arc Welding
Flux‑Cored Arc Welding
Electro gas Welding
Submerged Arc Welding
Gas Tungsten Arc Welding (GTAW) or TIG
Resistant Welding
Brazing and Soldering
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
WHAT IS ASME? WHO IS ASME? WHAT ASME SECTION IX MEANS? WHAT ARE WELDING DOCUM...
PDF file for ASME SECTION IX and what is ASME. It will also give you information about WPS, PQR and WPQ. here you will get all that you want to know about WELDING DOCUMENTS.
pipeline components
Komponen sistem perpipaan terdiri atas berbagai jenis seperti siku, belokan, kopling, tutup, tee, reducer, dan lainnya yang terbuat dari berbagai material seperti besi tuang, besi tempa, baja tuang, baja tempa, dan non-besi. Komponen utama lainnya adalah katup seperti katup bola, katup sayap, katup penghalang aliran balik, katup membran, katup gerbang, katup bola
Welding processes
This document discusses various welding processes. It separates welding into two categories: fusion welding processes that melt the base metals like arc welding, and solid state welding processes that join metals without melting, like friction welding. The document focuses on describing several common arc welding processes including: shielded metal arc welding, gas metal arc welding, flux-cored arc welding, gas tungsten arc welding, plasma arc welding, and submerged arc welding. It also covers resistance spot welding, a type of resistance welding used to join sheet metals.
Asme viii Div. 1 presentation rev.0
This document provides an overview and introduction to ASME Section VIII Division 1, which establishes rules for the construction of pressure vessels. It discusses the historical context that led to the development of pressure vessel codes, an overview of ASME's codes and standards, key definitions, and the design requirements and considerations specified in Section VIII Division 1. The document covers topics such as material selection, corrosion allowances, minimum thickness requirements, design pressure, and loadings that must be considered in pressure vessel design.
Electrode selection
This document provides a summary of welding procedure specifications (WPS). It lists 69 WPS entries that include the process, filler metal, base metal, thickness range, diameter range, and post weld heat treatment requirements. The WPS cover a variety of welding processes including shielded metal arc welding, gas tungsten arc welding, flux cored arc welding, and submerged arc welding. The WPS specify the materials, thicknesses, diameters, and heat treatments for welding different material grades.
Wis5 welding defects 02
The document discusses various welding defects that can be visually detected, including cracks, lack of solid metal, lack of fusion, lack of smoothly blended surfaces, and miscellaneous defects. It provides details on different types of each defect, their causes, and methods for prevention. It also discusses welding repairs, noting that repairs require authorization and testing to ensure defects have been fully removed before performing the repair weld.
Qc piping guide
The document provides information for a piping inspector, including:
1. The duties of a piping inspector are to ensure piping activities such as material receiving, fabrication, erection, testing, and re-instatement comply with Saudi Aramco specifications and procedures.
2. Inspection is to be carried out according to Schedule Q, Saudi Aramco standards and specifications, and approved procedures and ITPs.
3. Piping construction drawings include plans, arrangements, supports, details, hook-ups, schedules, P&IDs, and isometrics.
Welding lectures 14 16
This document discusses various weld defects including geometric defects like misalignment and metallurgical defects like cracks, porosity, and embrittlement reactions. It explains the causes and remedies for different types of defects such as angular distortion, longitudinal distortion, incomplete fusion, cracks, and porosity. The document also covers residual stresses during welding, gas dissolution and solid solution hardening, hydrogen effects including hydrogen embrittlement and cracking, and common weld testing methods like tension tests, bend tests, hardness tests, and non-destructive tests including visual inspection, liquid penetrant, magnetic particle, x-ray and ultrasonic testing.
Pipe Support Field Inspection, Installation & Maintenance
The document is about a webinar on pipe support field inspection, installation, and maintenance presented by Jerry Godinaer. It provides information on inspecting, installing, and maintaining different types of pipe supports including variable and constant spring hangers, restraint devices, pipe shoes, slide plates, and hardware components. It discusses guidelines for on-site surveys, what to inspect for existing supports, and criteria for adjusting or replacing supports if needed.
178383099-Gating-System-Design (1).ppt
The document discusses key aspects of gating system design including pouring time, choke area, sprue design, pouring basin, sprue base well, gating ratios, ingate design, and slag trap systems. It provides equations and guidelines for calculating pouring time, choke area, sprue taper, and gating ratios. It also describes non-pressurized and pressurized gating systems and discusses Bernoulli's theorem and the law of mass continuity as they relate to fluid flow in gating design.
Welding defects
This document provides a classification and overview of common welding defects. It divides defects into three main categories: planar defects, linear volumetric defects, and non-planar defects. Examples of each type of defect are given. The document also describes specific defect types such as cracks, inclusions, lack of fusion, porosity, overlap, undercut and provides potential causes of each.
Sand casting of metals - Gating system for sand casting mould
Topics covered: Sand Casting of Metals
Design and manufacture of gating system
Pouring basin
Sprue
Runners
In-gates
Riser
ASME SEC IX PPT.pdf
The document summarizes the key aspects of ASME Section IX (Ed. 2019), which contains requirements for welding procedure and performance qualifications. It discusses the history and timeline of ASME standards development. It also provides an overview of the various articles within ASME Section IX, including Article I on general welding requirements, Article II on welding procedure qualification, Article III on welding performance qualification, and Article IV on welding data. Key terms like essential variables, P-numbers, F-numbers, and A-numbers used for material grouping are also defined in the document.
What's hot (20)
Rolling,Rolling mills,Rolling processes &Rolling Applications by polayya chin...
Rolling,Rolling mills,Rolling processes &Rolling Applications by polayya chin...
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
Welded Joint Category as per ASME VIII Div.1--Dr.Samir Saad
WHAT IS ASME? WHO IS ASME? WHAT ASME SECTION IX MEANS? WHAT ARE WELDING DOCUM...
WHAT IS ASME? WHO IS ASME? WHAT ASME SECTION IX MEANS? WHAT ARE WELDING DOCUM...
Pipe Support Field Inspection, Installation & Maintenance
Pipe Support Field Inspection, Installation & Maintenance
Sand casting of metals - Gating system for sand casting mould
Sand casting of metals - Gating system for sand casting mould
Recently uploaded
ANALISIS PENGARUH INDUSTRI BATU BARA TERHADAP PENCEMARAN UDARA.pdf
Industri batu bara telah menjadi salah satu penyumbang utama pencemaran udara global. Proses ekstraksi batu bara, baik melalui penambangan terbuka maupun penambangan bawah tanah, menghasilkan debu dan gas beracun yang dilepaskan ke atmosfer. Gas-gas tersebut termasuk sulfur dioksida (SO2), nitrogen oksida (NOx), dan partikel-partikel halus (PM2.5) yang berbahaya bagi kesehatan manusia dan lingkungan. Selain itu, pembakaran batu bara di pembangkit listrik dan industri menyebabkan emisi karbon dioksida (CO2), yang merupakan penyebab utama perubahan iklim global dan pemanasan global.
Pencemaran udara yang disebabkan oleh industri batu bara juga memiliki dampak lokal yang signifikan. Di sekitar area penambangan, debu batu bara yang dihasilkan dapat mengganggu kesehatan masyarakat dan ekosistem lokal. Paparan terus-menerus terhadap debu batu bara dapat menyebabkan masalah pernapasan seperti asma dan bronkitis, serta berkontribusi pada penyakit paru-paru yang lebih serius. Selain itu, hujan asam yang disebabkan oleh emisi sulfur dioksida dapat merusak tanaman, air tanah, dan ekosistem sungai, mengancam keberlanjutan lingkungan di sekitar lokasi industri batu bara.
Recently uploaded (8)
PROGRAM PERCEPATAN PENINGKATAN TATA GUNA AIR IRIGASI 2024.pdf
PROGRAM PERCEPATAN PENINGKATAN TATA GUNA AIR IRIGASI 2024.pdf
1 - Metode Pelaksanaan Pondasi Tiang Pancang-1.pptx
1 - Metode Pelaksanaan Pondasi Tiang Pancang-1.pptx
ANALISIS PENGARUH INDUSTRI BATU BARA TERHADAP PENCEMARAN UDARA.pdf
ANALISIS PENGARUH INDUSTRI BATU BARA TERHADAP PENCEMARAN UDARA.pdf
111078825-Nilai-Maksimum-Dan-Minimum-Turunan-Fungsi.pptx
111078825-Nilai-Maksimum-Dan-Minimum-Turunan-Fungsi.pptx
DAMPAK POLUSI UDARA TERHADAP KESEHATAN MASYARAKAT.pdf
DAMPAK POLUSI UDARA TERHADAP KESEHATAN MASYARAKAT.pdf