Avoiding Component Failure in Industrial Refrigeration Systems

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Avoiding Component Failure in Industrial Refrigeration Systems"

Transcription

1 Avoiding Componen Failure in Indusrial Refrigeraion Sysems By Tim Kroeger, segmen markeing manager indusrial refrigeraion, Asia Pacific & India The aricle caegorises and gives examples of ypical componen failures in indusrial refrigeraion sysems. I liss he roo causes and describes how o avoid hem. Focus is on liquid hammer, safe ho gas defros and general refrigeraion piping. Opimum resuls by correc selecion, inegraion and operaion indusrialrefrigeraion.danfoss.com

2 1. Liquid hammer 1.1 Definiion Liquid hammer is a erm used o describe a pressure spike caused when a fluid in moion is forced o sop or change direcion suddenly (momenum change) 1. Liquid hammer can occur when a valve closes suddenly a he end of a pipeline sysem, and a pressure wave propagaes in he pipe. Liquid Hammer can also occur when liquid is suddenly acceleraed and hen forced o change momenum. Liquid hammer is also called hydraulic shock. Examples of liquid hammer include he following: Sudden deceleraion. High impac forces can occur when a valve is closed quickly. Sudden acceleraion. Mos commonly encounered during ho gas defros iniiaion and erminaion. Also referred o as Vapour Propelled Liquid Slug (VPLS). CIS (Condensaion-Induced Hydraulic Shock). Sudden condensaion of vapour bubbles in highly sub-cooled (>20K) liquid. No covered in his aricle. 1.2 Sudden deceleraion An esimaion of he pressure spike occurring during he sudden deceleraion of a liquid in moion can be aemped by visualising a moving column or slug of liquid in a pipe ahead of a valve or an armaure, see figure 1. V The force generaed by he deceleraion can be calculaed as wih: p pressure [Pa] A cross secion [m 2 ] m mass [kg] a acceleraion [m/s 2 ] Δv velociy change [m/s] ime of deceleraion [s] or: wih: F = p x A = m x a = F = p x A = m x a = p = L x ρ x Δv m x Δv L x A x ρ x Δv L lengh of pipe [m] ρ cross secion [kg/m 3 ] A Example A solenoid valve is insalled in a 20 mere sraigh run in a slighly undersized liquid line (velociy 3 ms -1 ). Refrigeran is ammonia (densiy 600 kg/m 3 ). The closing ime of he solenoid valve is esimaed a 20 ms. Esimaion of pressure surge V L x ρ x v 20 m x 600 kgm p = = -3 x 3 ms s Figure 1: Moving liquid in pipe When his slug of liquid is suddenly sopped, a force builds up agains he cross secion of he valve or armaure which equals he force resuling from he rae of change of momenum. m kgm -3 ms -1 kgm m p = 1,800,000 = 1.8 x 10 6 s s 2 m 2 = 1.8 x 10 5 Pa =18 bar This is an over pressure, i.e. above he already exising liquid pressure of he sysem (mos commonly he condensing pressure). This could easily resul in exceeding he maximum safe operaing pressure of componenry. Hydraulic shock caused by deceleraion can be observed by banging or knocking of he valve and over ime can lead o sress fracures. 1 ) Wikipedia, definiion of fluid hammer.

3 Recommendaions If he solenoid valve is insalled in a HP liquid line (e.g. feed line ino a LP vessel) and is no pilo operaed, he closing ime will be raher shor, due o he high pressure differenial across he valve. In order o minimise he inernal volume of liquid line valve saions, he use of compac valve saions designed for high pressure applicaions such as he Danfoss ICF should be considered (see figure 5). Therefore, one should consider a proporional liquid level conrol wih a moorised valve, see figure 2. M Figure 5: Danfoss ICF Valves Saion Figure 2: Moorised valve for liquid level conrol Excessive pipe runs beween solenoid valve and meering device (hand regulaing valve) should be avoided for overfeed evaporaors. When he solenoid valve is acivaed, he sudden inrush of liquid can cause hammering a he hand regulaing valve, see figure Sudden acceleraion Acceleraed liquid ofen occurs when high pressure vapour mees low o medium pressure liquid. When he acceleraed liquid mees an obsrucion, which in urn resuls in a change of momenum, pressure spikes much higher han hose caused by deceleraed liquid occur. This is called Vapour Propelled Liquid Slugging (VPLS). VPLS can be classified ino wo forms of liquid slugs: saic and dynamic 2. A saic slug is liquid rapped in a porion of he piping, compleely filling i. A dynamic slug is a fron of liquid, propelled by vapour. In a 6 pipe, as lile as 1 ½ of liquid can lead o a dynamic slug, see figure 6. Figure 3: Avoid excessive pipe runs I should also be ensured ha all liquid line valve saions are sized correcly by aking ino consideraion he overfeed raio. An oversized liquid feed valve can lead o excessive liquid velociy. During commissioning, care mus be aken ha all regulaing valves are adjused correcly. A wide open regulaing valve can also cause excessive velociy, see figure 4. Saic Dynamic Figure 6: Saic and dynamic liquid slugging Figure 4: Effec of oversized liquid feed valves 2 ) Shelon and Jacobi e alera, 1997

4 2. Ho gas defros and VPLS The roo cause of VPLS is ofen an incorrecly designed and operaed ho gas defros sysem. For example, if he ho gas defros pressure is conrolled by a muli-purpose valve in he we reurn line, and he ho gas is herefore injeced ino he boom of he evaporaor coil, here will be a high risk of acceleraed liquid. Also, if a single sep solenoid valve is used in he we reurn line, here will be a sudden pressure equalisaion afer defros erminaion. This can also lead o acceleraed liquid. As he velociies are much higher han in he previous example for deceleraed liquid, pressure spikes of up o 250 bar can occur, see figure 7. In he correcly designed ho gas defros sysem, he ho gas is inroduced ino he evaporaor during defros from he op, hus eliminaing he risk of acceleraed liquid a defros iniiaion. The defros pressure is conrolled by a separae pressure conrol valve, enabling a purpose designed wosep solenoid valve wih minimal pressure drop (usually ho gas powered) o be used in he we reurn line. These valves are available on he marke oday (e.g. Danfoss ICLX). See figure 8. NC NO Figure 7: Commonly designed ho gas defros sysem (no recommended) Figure 8: Moving liquid in pipe Operaion Liquid We reurn Ho gas Fan Timer [s] Commen Cooling Open Open Closed On N/A Conrolled by hermosa Defros sar Closed Open Closed On Closed Closing Closed Off Closed Closed Closed Off Pump down ime depending on evporaor size Closing ime for ho gas powered sucion valve - ICLX Allowing remaining liquid o sele a boom of evaporaor Defros Closed Closed Open Off Depends on applicaion Closed Closed Closed Off Drip ime Defros sop Closed Open Closed Off Sucion valve opens slowly. Saic cooling o freeze droples Open Open Closed Off Saic cooling o freeze droples Cooling Open Open Closed On N/A Conrolled by hermosa Table 1: Safe and efficien ho gas defros sequence

5 3. Piping design and layou ASME 3 code for pressure piping sipulaes ha consideraion mus be given o he expansion of liquid refrigeran rapped in or beween closed valves and a means mus be provided o preven over pressure. Examples of such occurrences are shown in figure 9, e.g. liquid rapped beween wo shu-off valves, beween a nonreurn valve and a solenoid valve or even beween a nonreurn valve and a back pressure dependen regulaor. In all hese cases, suiable measure o preven over pressure (such as relief valves) mus be used. Figure 9: Examples of rapped liquid 4. Summary In conclusion, i mus be said ha when inroducing auomaic conrols for sysems previously conrolled by manual means, i is imperaive o selec he correc componens for he purpose a hand, inegrae hese componens in a safe way ino properly designed indusrial refrigeraion sysems and operae hem in an efficien safe way o obain opimum resuls.

6 We engineer echnologies ha enable he world of omorrow o do more wih less 80+ years The indusry s wides experise a your disposal. We ve been looking ahead since 1933 To read more abou indusrial refrigeraion, please visi ir.danfoss.com For quesions, please conac your local Danfoss indusrial refrigeraion specialis. Danfoss can accep no responsibiliy for possible errors in caalogues, brochures and oher prined maerial. Danfoss reserves he righ o aler is producs wihou noice. This also applies o producs already on order provided ha such aleraions can be made wihou subsequenial changes being necessary in specificaions already agreed. All rademarks in his maerial are propery of he respecive companies. Danfoss and he Danfoss logoype are rademarks of Danfoss A/S. All righs reserved. DKRCI.EE.000.F H10622 Danfoss DCS (jk)

Name Class Date. Step 2: Rearrange the acceleration equation to solve for final speed. a v final v initial v. final v initial v.

Name Class Date. Step 2: Rearrange the acceleration equation to solve for final speed. a v final v initial v. final v initial v. Skills Workshee Mah Skills Acceleraion Afer you sudy each sample problem and soluion, work ou he pracice problems on a separae shee of paper. Wrie your answers in he spaces provided. In 1970, Don Big Daddy

More information

KINEMATICS IN ONE DIMENSION

KINEMATICS IN ONE DIMENSION chaper KINEMATICS IN ONE DIMENSION Secion 2.1 Displacemen Secion 2.2 Speed and Velociy 1. A paricle ravels along a curved pah beween wo poins P and Q as shown. The displacemen of he paricle does no depend

More information

Instruction Manual. Rugged PCB type. 1 Terminal Block. 2 Function. 3 Series Operation and Parallel Operation. 4 Assembling and Installation Method

Instruction Manual. Rugged PCB type. 1 Terminal Block. 2 Function. 3 Series Operation and Parallel Operation. 4 Assembling and Installation Method Rugged PCB ype Insrucion Manual 1 Terminal Block Funcion.1...4.5.6.7 Inpu volage range Inrush curren limiing Overcurren proecion Overvolage proecion Oupu volage adjusmen range Isolaion Remoe ON/OFF E9

More information

Morningstar Investor Return

Morningstar Investor Return Morningsar Invesor Reurn Morningsar Mehodology Paper March 3, 2009 2009 Morningsar, Inc. All righs reserved. The informaion in his documen is he propery of Morningsar, Inc. Reproducion or ranscripion by

More information

What the Puck? an exploration of Two-Dimensional collisions

What the Puck? an exploration of Two-Dimensional collisions Wha he Puck? an exploraion of Two-Dimensional collisions 1) Have you ever played 8-Ball pool and los he game because you scrached while aemping o sink he 8-Ball in a corner pocke? Skech he sho below: Each

More information

Flow Switch LABO-VHZ-S

Flow Switch LABO-VHZ-S Flow Swich S Volumeric flow swiching Almos no effec from differing viscosiies Versaile, configurable swiching oupu in push-pull design Robus consrucion Compac design Characerisics he VHZ gearwheel flow

More information

INSTRUCTIONS FOR USE. This file can only be used to produce a handout master:

INSTRUCTIONS FOR USE. This file can only be used to produce a handout master: INSTRUCTIONS OR USE This file can only be used o produce a handou maser: Use Prin from he ile menu o make a prinou of he es. You may no modify he conens of his file. IMPORTNT NOTICE: You may prin his es

More information

Zelio Control Measurement Relays RM4L Liquid Level Relays

Zelio Control Measurement Relays RM4L Liquid Level Relays Zelio Conrol Measuremen elays FNCTIONS These devices monior he levels of conducive liquids. They conrol he acuaion of pumps or valves o regulae levels; hey are also suiable for proecing submersible pumps

More information

US 9,615,553 B2 Apr. 11,2017

US 9,615,553 B2 Apr. 11,2017 111111111111111111111111111111111111111111111111111111111111111111111111111 US009615553B2 (12) Unied Saes Paen Coniglio e al. (10) Paen No.: (45) Dae of Paen: US 9,615,553 B2 Apr. 11,2017 (54) ARTIFICIAL

More information

ScienceDirect. Cycling Power Optimization System Using Link Models of Lower Limbs with Cleat-Shaped Biaxial Load Cells

ScienceDirect. Cycling Power Optimization System Using Link Models of Lower Limbs with Cleat-Shaped Biaxial Load Cells Available online a www.sciencedirec.com ScienceDirec Procedia Engineering 72 ( 20 ) 8 7 The 20 conference of he Inernaional Spors Engineering Associaion Cycling Power Opimizaion Sysem Using ink Models

More information

Time & Distance SAKSHI If an object travels the same distance (D) with two different speeds S 1 taking different times t 1

Time & Distance SAKSHI If an object travels the same distance (D) with two different speeds S 1 taking different times t 1 www.sakshieducaion.com Time & isance The raio beween disance () ravelled by an objec and he ime () aken by ha o ravel he disance is called he speed (S) of he objec. S = = S = Generally if he disance ()

More information

Clemco Industries Corp. ISO 9001 Certified

Clemco Industries Corp. ISO 9001 Certified Clemco Indusries Corp. ISO 9001 Cerified 6 cuf Classic Blas Machines Exclusively from... SIMPLE, RUGGED, RELIABLE More han 75 years of reliable field service have made Clemco blas machines he preferred

More information

An Alternative Mathematical Model for Oxygen Transfer Evaluation in Clean Water

An Alternative Mathematical Model for Oxygen Transfer Evaluation in Clean Water An Alernaive Mahemaical Model for Oxygen Transfer Evaluaion in Clean Waer Yanjun (John) He 1, PE, BCEE 1 Kruger Inc., 41 Weson Parkway, Cary, NC 27513 Email: john.he@veolia.com ABSTRACT Energy consumpion

More information

A Probabilistic Approach to Worst Case Scenarios

A Probabilistic Approach to Worst Case Scenarios A Probabilisic Approach o Wors Case Scenarios A Probabilisic Approach o Wors Case Scenarios By Giovanni Barone-Adesi Universiy of Albera, Canada and Ciy Universiy Business School, London Frederick Bourgoin

More information

SWIMMING POOL HEAT PUMP UNITS. Installation & Instruction Manual DURA - series

SWIMMING POOL HEAT PUMP UNITS. Installation & Instruction Manual DURA - series SWIMMIG POO HEAT PUMP UITS Insallaion & Insrucion Manual DUA - series ev. 1.12 29.07.2014 Conens SWIMMIG POO HEAT PUMP UITS... 1! Conens... 2! 1. Preface... 3! 2. Specificaions... 4! 2.1 Technical daa

More information

LSU RISK ASSESSMENT FORM Please read How to Complete a Risk Assessment before completion

LSU RISK ASSESSMENT FORM Please read How to Complete a Risk Assessment before completion Please read How o Complee a Risk Assessmen before compleion EVENT OR ACTIVITY BEING RISK ASSESSED (add name of even where relevan) NAME OF DEPARTMENT Squad Training Neball DATE OF COMPLETION OF RISK ASSESSMENT

More information

INSTALLATION AND OPERATION MANUAL

INSTALLATION AND OPERATION MANUAL IMPORTANT SAFETY INSTRUCTIONS SAVE THESE INSTRUCTIONS PLEASE READ THE ENTIRE CONTENTS OF THIS MANUAL PRIOR TO INSTALLATION AND OPERATION. BY PROCEEDING WITH LIFT INSTALLATION AND OPERATION YOU AGREE THAT

More information

What is a Practical (ASTM C 618) SAI--Strength Activity Index for Fly Ashes that can be used to Proportion Concretes Containing Fly Ash?

What is a Practical (ASTM C 618) SAI--Strength Activity Index for Fly Ashes that can be used to Proportion Concretes Containing Fly Ash? 2017 World of Coal Ash (WOCA) Conference in Lexingon, KY - May 9-11, 2017 hp://www.flyash.info/ Wha is a Pracical (ASTM C 618) SAI--Srengh Aciviy Index for Fly Ashes ha can be used o Proporion Concrees

More information

EXAMINING THE FEASIBILITY OF PAIRED CLOSELY-SPACED PARALLEL APPROACHES

EXAMINING THE FEASIBILITY OF PAIRED CLOSELY-SPACED PARALLEL APPROACHES EXAMINING THE FEASIBILITY OF PAIRED CLOSELY-SPACED PARALLEL APPROACHES Seven J. Landry and Amy R. Priche Georgia Insiue of Technology Alana GA 30332-0205 ABSTRACT Paired closely-spaced parallel approaches

More information

Ministry of Agriculture and Rural Development Animal and Plant Health Regulatory Directorate

Ministry of Agriculture and Rural Development Animal and Plant Health Regulatory Directorate Minisry of Agriculure and Rural Developmen Animal and Plan Healh Regulaory Direcorae Checklis for saus of slaugherhouses for cale, sheep and goas (General informaion) i Addis Ababa Ehiopia 1 1. Background

More information

Solenoid valve type EVR for Hydrocarbons

Solenoid valve type EVR for Hydrocarbons MAKING MODERN LIVING POSSIBLE Technical brochure Solenoid valve type EVR for Hydrocarbons EVR for Hydrocarbons is a direct or servo operated solenoid valve especially designed for liquid, suction, and

More information

SIMULATION OF WAVE EFFECT ON SHIP HYDRODYNAMICS BY RANSE

SIMULATION OF WAVE EFFECT ON SHIP HYDRODYNAMICS BY RANSE 1 h Inernaional Conference on Sabiliy of Ships and Ocean Vehicles 591 SIMULATION OF WAVE EFFECT ON SHIP HYDRODYNAMICS BY RANSE Qiuxin Gao, Universiy of Srahclyde, UK, Gao.q.x@srah.ac.uk Dracos Vassalos,

More information

INVERTER HEATPUMP FOR SWIMMING POOLS

INVERTER HEATPUMP FOR SWIMMING POOLS IVE HEATPUMP FO SWIMMIG POOS Insallaion & Insrucion Manual hea pumps 0-0071-1611 Table of conens 1. Preface 3. Specificaions.1 Performance Daa. Dimensions 6 3. Insallaion and Connecion 3.1 Hea Pump ocaion

More information

29 B ROUTE Bus Times Summer NOTES a = Time at Vicarage Way. * = On Schooldays bus operates up to 5 minutes later.

29 B ROUTE Bus Times Summer NOTES a = Time at Vicarage Way. * = On Schooldays bus operates up to 5 minutes later. Brighon Lewes Ringmer / Touris Aracions Lewes for Hisoric own wih Casle; Isfield for Lavender Line Railway; for Spa Valley Railway, Paniles CiySAVER ickes are only valid beween Brighon and Falmer. nework

More information

CHARACTERIZATION AND MODELING OF A PROPORTIONAL VALVE FOR CONTROL SYNTHESIS

CHARACTERIZATION AND MODELING OF A PROPORTIONAL VALVE FOR CONTROL SYNTHESIS CHARACTERIZATION AND MODELING OF A PROPORTIONAL VALVE FOR CONTROL SYNTHESIS Osama. OLABY, Xavier. BRN, Sylvie. SESMAT, Tanneguy. REDARCE and Eric. BIDEAX Laboraoire d Auomaique Indusrielle - hp://www-lai.insa-lyon.fr

More information

I t ' 4 ti. t ti. IQ:::: mass x heat of fusion (or heat of vaporization) I HEAT AND ITS MEASUREMENT. t t. t f I I I. Name

I t ' 4 ti. t ti. IQ:::: mass x heat of fusion (or heat of vaporization) I HEAT AND ITS MEASUREMENT. t t. t f I I I. Name HEAT AND TS MEASUREMENT Name a (or energy) can be measured in unis of calories or joules. When here is a,,,,,,nperaure change (AT), hea (Q) can be calculaed using his formula: During a phase change, we

More information

KEY CONCEPTS AND PROCESS SKILLS. 1. An allele is one of the two or more forms of a gene present in a population. MATERIALS AND ADVANCE PREPARATION

KEY CONCEPTS AND PROCESS SKILLS. 1. An allele is one of the two or more forms of a gene present in a population. MATERIALS AND ADVANCE PREPARATION Gene Squares 61 40- o 2 3 50-minue sessions ACIVIY OVERVIEW P R O B L E M S O LV I N G SUMMARY Sudens use Punne squares o predic he approximae frequencies of rais among he offspring of specific crier crosses.

More information

RECOMMENDATION FOR INTERCHANGEABLE STUD BOLTS AND TAP END STUDS FOR API SPEC 6A FLANGES

RECOMMENDATION FOR INTERCHANGEABLE STUD BOLTS AND TAP END STUDS FOR API SPEC 6A FLANGES Issue Dae: June 6 15 Revision B June 2010 RECOMMENDAION FOR INERCHANGEABE UD BO AND A END UD FOR AI EC 6A FANGE ECHNICA REOR R501 Revision B AWHEM publicaions may be use by anyone esiring o o so. Every

More information

OPTIMAL ENERGY SOURCE FOR AN ENVIRONMENTALLY-FRIENDLY GO-KART

OPTIMAL ENERGY SOURCE FOR AN ENVIRONMENTALLY-FRIENDLY GO-KART Journal of Ecological Engineering Volume 17, Issue 5, Nov. 016, pages 90 95 DOI: 10.1911/998993/65454 Research Aricle OPTIMAL ENERGY SOURCE FOR AN ENVIRONMENTALLY-FRIENDLY GO-KART Pior Zbigniew Filip 1,

More information

Performance Attribution for Equity Portfolios

Performance Attribution for Equity Portfolios PERFORMACE ATTRIBUTIO FOR EQUITY PORTFOLIOS Performance Aribuion for Equiy Porfolios Yang Lu and David Kane Inroducion Many porfolio managers measure performance wih reference o a benchmark. The difference

More information

FORECASTING TECHNIQUES ADE 2013 Prof Antoni Espasa TOPIC 1 PART 2 TRENDS AND ACCUMULATION OF KNOWLEDGE. SEASONALITY HANDOUT

FORECASTING TECHNIQUES ADE 2013 Prof Antoni Espasa TOPIC 1 PART 2 TRENDS AND ACCUMULATION OF KNOWLEDGE. SEASONALITY HANDOUT FORECASTING TECHNIQUES ADE 2013 Prof Anoni Espasa TOPIC 1 PART 2 TRENDS AND ACCUMULATION OF KNOWLEDGE. SEASONALITY HANDOUT February 2013 MAIN FACTORS CAUSING TRENDS Increases in populaion. Seady inflaion.

More information

2nd Regional Conference On Enhancing Transport Technology For Regional Competitiveness

2nd Regional Conference On Enhancing Transport Technology For Regional Competitiveness nd Regional Conference On Enhancing Transpor Technology For Regional Compeiiveness SESSION C TBLE OF CONTENTS PREFCE... 4 ORGNISING COITTEE... 5 KEYNOTE DDRESS... 6 Session : UTOOTIE... 7 Session B : ERONUTICS...

More information

R410A Rotary Compressor Bearing Design Considerations

R410A Rotary Compressor Bearing Design Considerations Prde Universiy Prde e-pbs Inernaional Compressor Engineering Conference School of Mechanical Engineering 1998 R41A Roary Compressor Bearing Design Consideraions J. R. Lenz Tecmseh Prodcs Company Follow

More information

Economics 487. Homework #4 Solution Key Portfolio Calculations and the Markowitz Algorithm

Economics 487. Homework #4 Solution Key Portfolio Calculations and the Markowitz Algorithm Economics 87 Homework # Soluion Key Porfolio Calculaions and he Markowiz Algorihm A. Excel Exercises: (10 poins) 1. Download he Excel file hw.xls from he class websie. This file conains monhly closing

More information

CONTROL VALVES IN TURBO-COMPRESSOR ANTI-SURGE SYSTEMS

CONTROL VALVES IN TURBO-COMPRESSOR ANTI-SURGE SYSTEMS CONTROL VALVES IN TURBO-COMPRESSOR ANTI-SURGE SYSTEMS keninrol CONTROL VALVES IN TURBO-COMPRESSOR ANTI-SURGE SYSTEMS CONTROL VALVES IN TURBO-COMPRESSOR ANTI-SURGE SYSTEMS 0 KOSO KENT INTROL SUPPLIES A

More information

Proceedings of the ASME 28th International Conference on Ocean, Offshore and Arctic Engineering OMAE2009 May 31 - June 5, 2009, Honolulu, Hawaii

Proceedings of the ASME 28th International Conference on Ocean, Offshore and Arctic Engineering OMAE2009 May 31 - June 5, 2009, Honolulu, Hawaii Proceedings of he ASME 28h Inernaional Conference on Ocean, Offshore and Arcic Engineering OMAE29 May 31 - June 5, 29, Honolulu, Hawaii OMAE29-79385 ANALYSIS OF THE TUNNEL IMMERSION FOR THE BUSAN-GEOJE

More information

Sources of Over-Performance in Equity Markets: Mean Reversion, Common Trends and Herding

Sources of Over-Performance in Equity Markets: Mean Reversion, Common Trends and Herding The Universiy of Reading THE BUSINESS SCHOOL FOR FINANCIAL MARKETS Sources of Over-Performance in Equiy Markes: Mean Reversion, Common Trends and Herding ISMA Cenre Discussion Papers in Finance 2003-08

More information

The t-test. What We Will Cover in This Section. A Research Situation

The t-test. What We Will Cover in This Section. A Research Situation The -es 1//008 P331 -ess 1 Wha We Will Cover in This Secion Inroducion One-sample -es. Power and effec size. Independen samples -es. Dependen samples -es. Key learning poins. 1//008 P331 -ess A Research

More information

Machine Learning for Stock Selection

Machine Learning for Stock Selection Machine Learning for Sock Selecion Rober J. Yan Compuer Science Dep., The Uniersiy of Wesern Onario jyan@csd.uwo.ca Charles X. Ling Compuer Science Dep., The Uniersiy of Wesern Onario cling@csd.uwo.ca

More information

Sensors and Actuators A: Physical

Sensors and Actuators A: Physical Sensors and Acuaors A 144 (2008) 354 360 Conens liss available a ScienceDirec Sensors and Acuaors A: Physical journal homepage: www.elsevier.com/locae/sna A micro-robo fish wih embedded SMA wire acuaed

More information

Stock Return Expectations in the Credit Market

Stock Return Expectations in the Credit Market Sock Reurn Expecaions in he Credi Marke Hans Bysröm * Sepember 016 In his paper we compue long-erm sock reurn expecaions (across he business cycle) for individual firms using informaion backed ou from

More information

EFFECTS OF WIND SPEED ON WIND TURBINE AVAILABILITY

EFFECTS OF WIND SPEED ON WIND TURBINE AVAILABILITY EFFECTS OF WIND SPEED ON WIND TURBINE AVAILABILITY S. Faulsich 1, P. Lyding 1, P. J. Tavner 2 1 Fraunhofer Insiue for Wind Energy and Energy Sysem Technology (IWES) 2 Energy Group, School of Engineering,

More information

Market timing and statistical arbitrage: Which market timing opportunities arise from equity price busts coinciding with recessions?

Market timing and statistical arbitrage: Which market timing opportunities arise from equity price busts coinciding with recessions? Journal of Applied Finance & Banking, vol.1, no.1, 2011, 53-81 ISSN: 1792-6580 (prin version), 1792-6599 (online) Inernaional Scienific Press, 2011 Marke iming and saisical arbirage: Which marke iming

More information

MODEL SELECTION FOR VALUE-AT-RISK: UNIVARIATE AND MULTIVARIATE APPROACHES SANG JIN LEE

MODEL SELECTION FOR VALUE-AT-RISK: UNIVARIATE AND MULTIVARIATE APPROACHES SANG JIN LEE MODEL SELECTION FOR VALUE-AT-RISK: UNIVARIATE AND MULTIVARIATE APPROACHES By SANG JIN LEE Bachelor of Science in Mahemaics Yonsei Universiy Seoul, Republic of Korea 999 Maser of Business Adminisraion Yonsei

More information

Dual Boost High Performances Power Factor Correction (PFC)

Dual Boost High Performances Power Factor Correction (PFC) Dual Boos High Performances Power Facor Correcion (PFC) C. Aaianese, Senior Member, IEEE - V. Nardi, Member, IEEE - F. Parillo - G. Tomasso, Member, IEEE Deparmen of Auomaion, Elecromagneism, Compuer Science

More information

Cal. 7T85 INSTRUCTIONS (P. 3) BEDIENUNGSANLEITUNG (S. 27) INSTRUCTIONS (P. 51) ISTRUZIONI (P. 75) INSTRUCCIONES (P. 99) INSTRUÇÕES (P.

Cal. 7T85 INSTRUCTIONS (P. 3) BEDIENUNGSANLEITUNG (S. 27) INSTRUCTIONS (P. 51) ISTRUZIONI (P. 75) INSTRUCCIONES (P. 99) INSTRUÇÕES (P. Cal. 7T85 INSTRUCTIONS (P. 3) BEDIENUNGSANLEITUNG (S. 27) INSTRUCTIONS (P. 51) ISTRUZIONI (P. 75) INSTRUCCIONES (P. 99) INSTRUÇÕES (P. 123) (147 ) You are now he proud owner of a SEIKO Analogue Quarz Wach

More information

The safe ships trajectory in a restricted area

The safe ships trajectory in a restricted area Scienific Journals Mariime Universiy of Szczecin Zeszyy Naukowe Akademia Morska w Szczecinie 214, 39(111) pp. 122 127 214, 39(111) s. 122 127 ISSN 1733-867 The safe ships rajecory in a resriced area Zbigniew

More information

Guidance Statement on Calculation Methodology

Guidance Statement on Calculation Methodology Guidance Saemen on Calculaion Mehodology Adopion Dae: 28 Sepember 200 Effecive Dae: January 20 Reroacive Applicaion: No Required www.gipssandards.org 200 CFA Insiue Guidance Saemen on Calculaion Mehodology

More information

connection Glen Smale discusses racing engine con rod technology with specialist manufacturers from around the world

connection Glen Smale discusses racing engine con rod technology with specialist manufacturers from around the world Making he connecion Glen Smale discusses racing engine con rod echnology wih specialis manufacurers from around he world Making he connecion necessary beween he op end and he boom end of he racing engine

More information

INSTALLATION AND OPERATION MANUAL

INSTALLATION AND OPERATION MANUAL EUROPEN USERS 400V 0Hz SUPPLY DETILS RE IN- CLUDED WITH ELECTRICL CONTROL BOX. DISREGRD SUPPLY WIRING DETILS IN THIS MNUL IMPORTNT SFETY INSTRUCTIONS SVE THESE INSTRUCTIONS PLESE RED THE ENTIRE CONTENTS

More information

Citation for final published version: Publishers page: <http://dx.doi.org/ / >

Citation for final published version: Publishers page:  <http://dx.doi.org/ / > This is an Open Access documen downloaded from ORCA, Cardiff Universiy's insiuional reposiory: hp://orca.cf.ac.uk/38772/ This is he auhor s version of a work ha was submied o / acceped for publicaion.

More information

Development of Urban Public Transit Network Structure Integrating Multi-Class Public Transit Lines and Transfer Hubs

Development of Urban Public Transit Network Structure Integrating Multi-Class Public Transit Lines and Transfer Hubs Developmen of Urban Public Transi Nework Srucure Inegraing Muli-Class Public Transi Lines and Transfer Hubs Zhenbao Wang 1, Anyan Chen 2 1College of Civil Engineering, Hebei Universiy of Engineering Handan,

More information

Urban public transport optimization by bus ways: a neural network-based methodology

Urban public transport optimization by bus ways: a neural network-based methodology Urban Transpor XIII: Urban Transpor and he Environmen in he 21s Cenury 347 Urban public ranspor opimizaion by bus ways: a neural nework-based mehodology M. Migliore & M. Caalano Deparmen of Transporaion

More information

QUANTITATIVE FINANCE RESEARCH CENTRE. Optimal Time Series Momentum QUANTITATIVE FINANCE RESEARCH CENTRE QUANTITATIVE F INANCE RESEARCH CENTRE

QUANTITATIVE FINANCE RESEARCH CENTRE. Optimal Time Series Momentum QUANTITATIVE FINANCE RESEARCH CENTRE QUANTITATIVE F INANCE RESEARCH CENTRE QUANTITATIVE FINANCE RESEARCH CENTRE QUANTITATIVE F INANCE RESEARCH CENTRE QUANTITATIVE FINANCE RESEARCH CENTRE Research Paper 353 January 15 Opimal Time Series Momenum Xue-Zhong He, Kai Li and Youwei

More information

MFP14-PPU (Vented) Automatic Packaged Pump Units

MFP14-PPU (Vented) Automatic Packaged Pump Units 681060/2 IM-P681-02 ST Issue 2 MFP14-PPU (ented) Automatic Packaged Pump Units Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Single MFP14 - PPU installation

More information

AMURE PUBLICATIONS. Working Papers Series

AMURE PUBLICATIONS. Working Papers Series AMURE PUBLICATIONS Working Papers Series N D-20-2006 < A Cos-Benefi Analysis of Improving Trawl Seleciviy: he Nephrops norvegicus Fishery in he Bay of Biscay > Claire MACHER */** Olivier GUYADER * Caherine

More information

Smart Beta Multifactor Construction Methodology: Mixing versus Integrating

Smart Beta Multifactor Construction Methodology: Mixing versus Integrating THE JOURNAL OF SPRING 2018 VOLUME 8 NUMBER 4 JII.IIJOURNALS.com ETFs, ETPs & Indexing Smar Bea Mulifacor Consrucion Mehodology: Mixing versus Inegraing TZEE-MAN CHOW, FEIFEI LI, AND YOSEOP SHIM Smar Bea

More information

Dynamics of market correlations: Taxonomy and portfolio analysis

Dynamics of market correlations: Taxonomy and portfolio analysis Dynamics of marke correlaions: Taxonomy and porfolio analysis J.-P. Onnela, A. Chakrabori, and K. Kaski Laboraory of Compuaional Engineering, Helsinki Universiy of Technology, P.O. Box 9203, FIN-02015

More information

Overreaction and Underreaction : - Evidence for the Portuguese Stock Market -

Overreaction and Underreaction : - Evidence for the Portuguese Stock Market - Overreacion and Underreacion : - Evidence for he Poruguese Sock Marke - João Vasco Soares* and Ana Paula Serra** March 2005 * Faculdade de Economia da Universidade do Poro ** (corresponding auhor) CEMPRE,

More information

DIMENSIONS AC Road travel

DIMENSIONS AC Road travel DIMENSIONS AC 10009 Road ravel 04 DIMENSIONS AC 10009 Lifing operaion OUTRIGGER BASES TO CHOOSE FROM: A 13.54m x 13.538m B 12.0m x 12.0m (NEW) C 9.671m x 9.885m 05 HA /SSL (HA50) AC 10009 AC 10009 17 HA

More information

Betting Against Beta

Betting Against Beta Being Agains Bea Andrea Frazzini and Lasse H. Pedersen * This draf: Ocober 5, 2010 Absrac. We presen a model in which some invesors are prohibied from using leverage and oher invesors leverage is limied

More information

ITG Dynamic Daily Risk Model for Europe

ITG Dynamic Daily Risk Model for Europe December 2010 Version 1 ITG Dynamic Daily Risk Model for Europe 2010 All righs reserved. No o be reproduced or reransmied wihou permission. 121610 29140 These maerials are for informaional purposes only,

More information

Water Hammer In Irrigation Systems 1

Water Hammer In Irrigation Systems 1 CIR828 1 G. A. Clark and D. Z. Haman 2 Irrigation system design includes pump sizing and selection, valve sizing and selection, and pipe sizing as well as the proper selection and placement of many other

More information

DRINKING WATER PIPE SYSTEM. The blue line

DRINKING WATER PIPE SYSTEM. The blue line DRINKING WATER PIPE SYSTEM The blue line Hanbook 2014 Inex The following coonly use abbreviaions are foun in his caalogue. Abbreviaion Descripion Uni A Cross-secional area 2 Ousie iameer of pipe i Insie

More information

Asset and Liability Management, Caisse. a manager of public debt

Asset and Liability Management, Caisse. a manager of public debt Asse and Liabiliy Managemen by CADES, a manager of public deb Name Deparmen & affiliaion Mailing Address e-mail address(es) Phone number 331 55 78 58 19, 331 55 78 58 00 Fax number 331 55 78 58 02 Eric

More information

FLUID POWER FLUID POWER EQUIPMENT TUTORIAL ACCUMULATORS. This work covers part of outcome 2 of the Edexcel standard module:

FLUID POWER FLUID POWER EQUIPMENT TUTORIAL ACCUMULATORS. This work covers part of outcome 2 of the Edexcel standard module: FLUID POWER FLUID POWER EQUIPMENT TUTORIAL ACCUMULATORS This work covers part of outcome 2 of the Edexcel standard module: UNIT 21746P APPLIED PNEUMATICS AND HYDRAULICS The material needed for outcome

More information

A Statistical, Age-Structured, Life-History-Based Stock Assessment Model for Anadromous Alosa

A Statistical, Age-Structured, Life-History-Based Stock Assessment Model for Anadromous Alosa American Fisheries Sociey Symposium 35:275 283, 2003 2003 by he American Fisheries Sociey A Saisical, Age-Srucured, Life-Hisory-Based Sock Assessmen Model for Anadromous Alosa A. JAMIE F. GIBSON 1 Acadia

More information

Solenoid Valves, one - or two step, on/off ICLX

Solenoid Valves, one - or two step, on/off ICLX MAKING MODERN LIVING POSSIBLE Technical brochure Solenoid Valves, one - or two step, on/off ICLX 32-150 ICLX servo valves belong to the ICV (Industrial Control Valve) family. ICLX are used in suction lines

More information

Centre for Investment Research Discussion Paper Series. Momentum Profits and Time-Varying Unsystematic Risk

Centre for Investment Research Discussion Paper Series. Momentum Profits and Time-Varying Unsystematic Risk Cenre for Invesmen Research Discussion Paper Series Discussion Paper # 08-0* Momenum Profis and Time-Varying Unsysemaic Risk Cenre for Invesmen Research O'Rahilly Building, Room 3.0 Universiy College Cork

More information

THE INFLOW OF UNWANTED AIR

THE INFLOW OF UNWANTED AIR IN PRESSURIZED PIPES The main reason for the inflow of air in public water distribution systems is excessive water velocity. Air traveling with water in pressurized pipes can result in high turbulence

More information

Paul R. Drake Management School, University of Liverpool, Liverpool, UK

Paul R. Drake Management School, University of Liverpool, Liverpool, UK The curren issue and full ex archive of his journal is available a www.emeraldinsigh.com/0960-0035.hm Analysis of he bullwhip effec wih order baching in muli-echelon supply chains Maloub Hussain College

More information

On convexity of SD efficiency sets - no short sales case

On convexity of SD efficiency sets - no short sales case 4. mezinárodní konference Řízení a modelování finančních rizik Osrava VŠB-U Osrava Ekonomická fakula kaedra Financí.-. září 008 On conveiy of SD efficiency ses - no shor sales case Miloš Kopa Absrac his

More information

Making Sense of Genetics Problems

Making Sense of Genetics Problems Bio 101 Ms. Bledsoe Making Sense of Geneics roblems Monohbrid crosses Le s sar wih somehing simle: crossing wo organisms and waching how one single rai comes ou in he offsring. Le s use eas, as Mendel

More information

Rolling ADF Tests: Detecting Rational Bubbles in Greater China Stock Markets

Rolling ADF Tests: Detecting Rational Bubbles in Greater China Stock Markets Singapore Managemen Universiy Insiuional Knowledge a Singapore Managemen Universiy Disseraions and Theses Collecion (Open Access) Disseraions and Theses 2008 Rolling ADF Tess: Deecing Raional Bubbles in

More information

CVS10 Sanitary Check Valves

CVS10 Sanitary Check Valves 0299050/4 IM-P029-11 ST Issue 4 CVS10 Sanitary Check Valves Installation and Maintenance Instructions 1. Safety information CVS10 with soft seat 2. General product information 3. Operation 4. Installation

More information

Methods for Estimating Term Structure of Interest Rates

Methods for Estimating Term Structure of Interest Rates Mehods for Esimaing Term Srucure of Ineres Raes Iskander Karibzhanov Absrac This paper compares differen inerpolaion algorihms for consrucing yield curves: cubic splines, linear and quadraic programming,

More information

Unit 24: Applications of Pneumatics and Hydraulics

Unit 24: Applications of Pneumatics and Hydraulics Unit 24: Applications of Pneumatics and Hydraulics Unit code: J/601/1496 QCF level: 4 Credit value: 15 OUTCOME 2 TUTORIAL 9 ACCUMULATORS The material needed for outcome 2 is very extensive so there are

More information

DF1 and DF2 Diffusers

DF1 and DF2 Diffusers 1550650/4 IM-P155-07 ST Issue 4 and Diffusers Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Installation 4. Commissioning 5. Operation 6. Maintenance

More information

S and SF Inverted Bucket Steam Traps

S and SF Inverted Bucket Steam Traps 0772150/6 IM-P077-02 ST Issue 6 S and SF Inverted Bucket Steam Traps Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Installation 4. Commissioning 5. Operation

More information

Evaporator pressure regulator Type KVP

Evaporator pressure regulator Type KVP Data sheet Evaporator pressure regulator KVP The KVP is mounted in the suction line after the evaporator and is used to:. Maintain a constant evaporating pressure and thereby a constant surface temperature

More information

Real-time Stochastic Evacuation Models for Decision Support in Actual Emergencies

Real-time Stochastic Evacuation Models for Decision Support in Actual Emergencies Real-ime Sochasic Evacuaion Models for Decision Suppor in Acual Emergencies ARTURO CUESTA, DANIEL ALVEAR, ORLANDO ABREU and DELFÍN SILIÓ Transpors and echnology projecs and processes Universiy of Canabria

More information

An Autonomous Blimp for the Wall Following Control.

An Autonomous Blimp for the Wall Following Control. An Auonomous Blimp for he Wall Following Conrol. Seung-Yong Oh *,**, Chi- Won Roh *, Sung- Chul Kang *, Eun-ai Kim ** * Inelligen Roboics Research Cener, Korea Insiue of Science an echnology, Seoul, Korea

More information

Standard Pressure Powered Pump Packaged Units to Size 3 x 2 Type PPEC, PTC & PTF with vented and ASME coded receivers

Standard Pressure Powered Pump Packaged Units to Size 3 x 2 Type PPEC, PTC & PTF with vented and ASME coded receivers INSTALLATION & MAINTENANCE INSTRUCTIONS IM-5-203-US October 201 Standard Pressure Powered Pump Packaged Units to Size 3 x 2 Type PPEC, PTC & PTF with vented and ASME coded receivers Safety Information

More information

Economic Growth with Bubbles

Economic Growth with Bubbles Economic Growh wih Bubbles AlberoMarin,andJaumeVenura March 2010 Absrac We develop a sylized model of economic growh wih bubbles. In his model, financial fricions lead o equilibrium dispersion in he raes

More information

FIVE RISK FACTORS MODEL: PRICING SECTORAL PORTFOLIOS IN THE BRAZILIAN STOCK MARKET

FIVE RISK FACTORS MODEL: PRICING SECTORAL PORTFOLIOS IN THE BRAZILIAN STOCK MARKET Revisa Caarinense da Ciência Conábil, ISSN 1808-3781 - eissn 2237-7662, Florianópolis, SC, Brazil, v. 16, n. 48, p. 81-98, May/Aug. 2017 doi: 10.16930/2237-7662/rccc.v16n48.2376 Available a hp://revisa.crcsc.org.br

More information

Fig 1, Fig 12, Fig 13, Fig 14HP, Fig 16, Fig 16HP and Fig 16L Strainers

Fig 1, Fig 12, Fig 13, Fig 14HP, Fig 16, Fig 16HP and Fig 16L Strainers 16355/8 IM-S6-17 ST Issue 8 Fig 1, Fig 12, Fig 13, Fig 14HP, Fig 16, Fig 16HP and Fig 16L Strainers Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Installation

More information

Joint industry project on foam

Joint industry project on foam Joint industry project on foam, E.D. Nennie (TNO Fluid dynamics) W. Schiferli (Shell Projects & Technology) 2 Introduction Foamers are used for gas well deliquification. Lab tests are being used to evaluate

More information

INSTALLATION AND OPERATION MANUAL

INSTALLATION AND OPERATION MANUAL EUROPEN USERS 400V 50Hz SUPPLY DETILS RE INCLUDED WITH ELECTRICL CONTROL BOX. DISREGRD SUPPLY WIRING DETILS IN THIS MNUL IMPORTNT SFETY INSTRUCTIONS SVE THESE INSTRUCTIONS PLESE RED THE ENTIRE CONTENTS

More information

Tube rupture in a natural gas heater

Tube rupture in a natural gas heater Tube rupture in a natural gas heater Dynamic simulation supports the use of a pressure safety valve over a rupture disk in the event of a tube rupture HARRY Z HA and PATRICK STANG Fluor Canada Ltd A fast

More information

Received August 16, 2013; revised September 27, 2013; accepted October 26, 2013

Received August 16, 2013; revised September 27, 2013; accepted October 26, 2013 Journal of Mahemaical Finance 7-8 Published Online November (hp://wwwscirporg/journal/jmf) hp://dxdoiorg//jmf Opimal Variaional Porfolios wih Inflaion Proecion raegy and Efficien Fronier of Expeced Value

More information

Protecting the African Elephant: A Dynamic Bioeconomic Model of. Ivory Trade

Protecting the African Elephant: A Dynamic Bioeconomic Model of. Ivory Trade Proecing he African Elephan: A Dynamic Bioeconomic Model of Ivory Trade G. Cornelis van Kooen Deparmen of Economics Universiy of Vicoria P.O. Box 1700, Sn CSC Vicoria, BC V8W 2Y2 Canada Email: kooen@uvic.ca

More information

Evaporator pressure regulator Type KVP

Evaporator pressure regulator Type KVP Data sheet Evaporator pressure regulator KVP The KVP is mounted in the suction line after the evaporator and is used to:. Maintain a constant evaporating pressure and thereby a constant surface temperature

More information

PV4 and PV6 Piston Valves

PV4 and PV6 Piston Valves 1181250/1 IM-P118-05 ST Issue 1 PV4 and PV6 Piston Valves Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Installation 4. Commissioning 5. Operation 6.

More information

Measuring Potential Output and Output Gap and Macroeconomic Policy: The Case of Kenya

Measuring Potential Output and Output Gap and Macroeconomic Policy: The Case of Kenya Universiy of Connecicu DigialCommons@UConn Economics Working Papers Deparmen of Economics Ocober 2005 Measuring Poenial Oupu and Oupu Gap and Macroeconomic Policy: The Case of Kenya Angelica E. Njuguna

More information

Breeding Incentive Programs and Demand for California Thoroughbred Racing: The Tradeoff Between Quantity and Quality. Martin D.

Breeding Incentive Programs and Demand for California Thoroughbred Racing: The Tradeoff Between Quantity and Quality. Martin D. Breeding Incenive Programs and Demand for California horoughbred Racing: he radeoff Beween Quaniy and Qualiy by Marin D. Smih Deparmen of Agriculural and Resource Economics Universiy of California, Davis

More information

Over-center valves type LHT with oscillation damping, zero leakage

Over-center valves type LHT with oscillation damping, zero leakage Over-center valves type LHT with oscillation damping, zero leakage Flow rate Q max = 250 lpm Operation pressure p max = 450 bar See also: o Over-center valve type LHK acc. to D 7100 o Over-center valve

More information

my SYSTEM A guide to common applications in water distribution systems

my SYSTEM A guide to common applications in water distribution systems my SYSTEM A guide to common applications in water distribution systems WWW.SINGERVALVE.COM INDEX This short guide is intended to offer guidance on some of the common problems, applications and questions

More information

Exclusive Distriutor in North America Norstat Inc. 300 Roundhill Drive, Rockaway, NJ Tel:

Exclusive Distriutor in North America Norstat Inc. 300 Roundhill Drive, Rockaway, NJ Tel: Exclusive Disriuor in Norh America Norsa Inc. 300 Roundhill Drive, Rockaway, NJ 07866 www.norsa.com Tel: 973-586-2500 Produc Caalog Abou MP-Sensor MP-SENSOR a Technology Company locaed in Neuhausen in

More information

FTGS14 Ball Float Steam Trap DN15 (½") to DN25 (1")

FTGS14 Ball Float Steam Trap DN15 (½) to DN25 (1) 1458050/5 IM-P145-12 ST Issue 5 FTGS14 Ball Float Steam Trap DN15 (½") to DN25 (1") Installation and Maintenance Instructions 1. Safety information 2. General product information 3. Installation 4. Commissioning

More information

Chronic Wasting Disease in Deer and Elk: a Critique of Current Models and Their Application

Chronic Wasting Disease in Deer and Elk: a Critique of Current Models and Their Application Souhern Illinois Universiy Carbondale OpenSIUC ublicaions Deparmen of Zoology 2003 Chronic Wasing Disease in Deer and Elk: a Criique of Curren Models and Their Applicaion Eric M. Schauber Souhern Illinois

More information