☀️ Soak Up the Savings with Our Summer Deals ☀️ ️

Recently Viewed

General

Filter By

Sort By:

Display Type:
Filters
  • Book
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines and Propellers by H.M. Atassi 9781461393436

    Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines and Propellers by H.M. Atassi 9781461393436

    Booksplease Price: £91.36
    The first International Symposium on Unsteady Aerodynamics and Aero elasticity of Turbomachines was held in Paris in 1976, and was followed by symposia at Lausanne in 1980, Cambridge in 1984, Aachen in 1987, Bei jing in 1989, and Notre Dame in 1991. The...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £91.36
    Subtotal:
  • Fundamentals of Applied Dynamics by Roberto A. Tenenbaum 9781441918444

    Fundamentals of Applied Dynamics by Roberto A. Tenenbaum 9781441918444

    Booksplease Price: £71.68
    A translation of the highly acclaimed text by Roberto Tenenbaum (originally published in Portuguese). Tenenbaum's book covers the full range of topics included in a complete basic course designed for undergraduate students in engineering. Requiring no...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £71.68
    Subtotal:
  • Fluid Mechanics: An Introduction to the Theory of Fluid Flows by Franz Durst 9783662639139

    Fluid Mechanics: An Introduction to the Theory of Fluid Flows by Franz Durst 9783662639139

    RRP: £99.99
    Booksplease Price: £90.56
    This book provides the fundamental knowledge allowing students in engineering and natural sciences to enter fluid mechanics and its applications in various fields where fluid flows need to be dealt with. Analytical treatments of flows are provided based...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £99.99
    Booksplease Price: £90.56
    Subtotal:
  • Classical Newtonian Gravity: A Comprehensive Introduction, with Examples and Exercises by Roberto A. Capuzzo Dolcetta 9783030258481

    Classical Newtonian Gravity: A Comprehensive Introduction, with Examples and Exercises by Roberto A. Capuzzo Dolcetta 9783030258481

    Booksplease Price: £46.28
    This textbook offers a readily comprehensible introduction to classical Newtonian gravitation, which is fundamental for an understanding of classical mechanics and is particularly relevant to Astrophysics. The opening chapter recalls essential elements...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • High-Pressure Shock Compression of Solids II: Dynamic Fracture and Fragmentation by Lee Davison 9781461275015

    High-Pressure Shock Compression of Solids II: Dynamic Fracture and Fragmentation by Lee Davison 9781461275015

    Booksplease Price: £90.86
    This volume concerns the fracture and fragmentation of solid materials that occurs when they are subjected to extremes of stress applied at the highest possible rates. The plan for the volume is to address experimental, theoretical, and com putational...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • The Crack Tip Opening Displacement in Elastic-Plastic Fracture Mechanics: Proceedings of the Workshop on the CTOD Methodology GKSS-Forschungszentrum Geesthacht, GmbH, Geesthacht, Germany, April 23-25, 1985 by K. H. Schwalbe 9783642828201

    The Crack Tip Opening Displacement in Elastic-Plastic Fracture Mechanics: Proceedings of the Workshop on the CTOD Methodology GKSS-Forschungszentrum Geesthacht, GmbH, Geesthacht, Germany, April 23-25, 1985 by K. H. Schwalbe 9783642828201

    Booksplease Price: £90.56
    In April 1985 two workshop meetings were arranged in two consecutive weeks: the Second CSNI Informal Workshop on Ductile Fracture Test Methods was organised and hosted by OECD, Paris, and chaired by F.J. Loss. It took place on 17th-19th April 1985. It...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Proceedings of the Third International Conference on Numerical Methods in Fluid Mechanics: Vol. I General Lectures. Fundamental Numerical Techniques by Henri Cabannes 9783540061700

    Proceedings of the Third International Conference on Numerical Methods in Fluid Mechanics: Vol. I General Lectures. Fundamental Numerical Techniques by Henri Cabannes 9783540061700

    Booksplease Price: £46.74
    Apologies but we at Booksplease don't have a full description for this book.Book InformationISBN 9783540061700Author Henri CabannesFormat PaperbackPage Count 188Imprint Springer-Verlag Berlin and Heidelberg GmbH & Co. KPublisher Springer-Verlag...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.74
    Subtotal:
  • Pattern Formation in Viscous Flows: The Taylor-Couette Problem and Rayleigh-Benard Convection by Rita Meyer-Spasche 9783764360474

    Pattern Formation in Viscous Flows: The Taylor-Couette Problem and Rayleigh-Benard Convection by Rita Meyer-Spasche 9783764360474

    Booksplease Price: £90.56
    It seems doubtful whether we can expect to understand fully the instability of fluid flow without obtaining a mathematical representa tion of the motion of a fluid in some particular case in which instability can actually be ob served, so that a...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Boundary Integral Equations in Elasticity Theory by Alexander M. Linkov 9781402005749

    Boundary Integral Equations in Elasticity Theory by Alexander M. Linkov 9781402005749

    Booksplease Price: £90.86
    by the author to the English edition The book aims to present a powerful new tool of computational mechanics, complex variable boundary integral equations (CV-BIE). The book is conceived as a continuation of the classical monograph by N. I...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • Fracture mechanics of concrete: Material characterization and testing: Material Characterization and Testing by Alberto Carpinteri 9789024729593

    Fracture mechanics of concrete: Material characterization and testing: Material Characterization and Testing by Alberto Carpinteri 9789024729593

    Booksplease Price: £46.28
    In this volume on the mechanics of fracture of Portland cement concrete, the general theme is the connection between microstructural phenomena and macroscopic models. The issues addressed include techniques for observation over a wide range of scales,...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Kinetic Theory and Fluid Dynamics by Yoshio Sone 9781461265948

    Kinetic Theory and Fluid Dynamics by Yoshio Sone 9781461265948

    Booksplease Price: £90.56
    This monograph is intended to provide a comprehensive description of the rela tion between kinetic theory and fluid dynamics for a time-independent behavior of a gas in a general domain. A gas in a steady (or time-independent) state in a general domain...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Optical Methods in Dynamics of Fluids and Solids: Proceedings of an International Symposium, held at the Institute of Thermomechanics Czechoslovak Academy of Sciences Liblice Castle, September 17-21, 1984 by M. Pichal 9783642824616

    Optical Methods in Dynamics of Fluids and Solids: Proceedings of an International Symposium, held at the Institute of Thermomechanics Czechoslovak Academy of Sciences Liblice Castle, September 17-21, 1984 by M. Pichal 9783642824616

    Booksplease Price: £90.86
    The General Assembly of the International Union of Theoreti cal and Applied Mechanics decided in Cambridge, United King dom, in 1982 to arrange the Symposium on Optical Methods in the Dynamics of Fluids and Solids. This decision was stimu lated by the...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • Elements of Newtonian Mechanics: Including Nonlinear Dynamics by Jens Martin Knudsen 9783540676522

    Elements of Newtonian Mechanics: Including Nonlinear Dynamics by Jens Martin Knudsen 9783540676522

    Booksplease Price: £56.42
    In the third edition a number of minor misprints that appeared in the second edition have have been corrected. Furthermore, 17 new problems have been added, at the end of chapters 6, 8, 9, 11, 12, 13, and 14. The answers to these 17 problems have not...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £56.42
    Subtotal:
  • Stochastic Structural Dynamics 1: New Theoretical Developments Second International Conference on Stochastic Structural Dynamics, May 9-11, 1990, Boca Raton, Florida, USA by Y. K. Lin 9783642845338

    Stochastic Structural Dynamics 1: New Theoretical Developments Second International Conference on Stochastic Structural Dynamics, May 9-11, 1990, Boca Raton, Florida, USA by Y. K. Lin 9783642845338

    Booksplease Price: £90.56
    This volume contains eighteen selected papers presented at the Second International Conference on Stochastic Structural Dynamics, which are related to new theoretical developments in the field. This and a companion volume, related to new practical...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Plates and shells with cracks: A collection of stress intensity factor solutions for cracks in plates and shells by George C. Sih 9789401012942

    Plates and shells with cracks: A collection of stress intensity factor solutions for cracks in plates and shells by George C. Sih 9789401012942

    Booksplease Price: £46.28
    This third volume of a series on Mechanies of Fraeture deals with eraeks in plates and shelIs. It was noted in Volume 2 on three-dimensional eraek problems that additional free surfaees can lead to substantial mathematical complexities, often making the...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • The application of flow birefringence to rheological studies of polymer melts by J. L. S. Wales 9789029801027

    The application of flow birefringence to rheological studies of polymer melts by J. L. S. Wales 9789029801027

    Booksplease Price: £46.28
    1. 1 Preamble The science to which this work is appended is termed rheology and rheology means the study of flow and deformation of liquids and solids with emphasis on the underlying physical processes. Characteristic for solids is that they respond to a...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Continuous and Discontinuous Modelling of Cohesive-Frictional Materials by Pieter A. Vermeer 9783642074790

    Continuous and Discontinuous Modelling of Cohesive-Frictional Materials by Pieter A. Vermeer 9783642074790

    Booksplease Price: £46.58
    A knowledge of the mechanical behaviour of both naturally occurring materials, such as soils and rocks, and artificial materials such as concrete and industrial granular matter, is of fundamental importance to their proper use in engineering and...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.58
    Subtotal:
  • Wave Propagation and Time Reversal in Randomly Layered Media by Jean-Pierre Fouque 9781441921628

    Wave Propagation and Time Reversal in Randomly Layered Media by Jean-Pierre Fouque 9781441921628

    Booksplease Price: £61.34
    The content of this book is multidisciplinary by nature. It uses mathematical tools from the theories of probability and stochastic processes, partial differential equations, and asymptotic analysis, combined with the physics of wave propagation and...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £61.34
    Subtotal:
  • New Directions in Mathematical Fluid Mechanics: The Alexander V. Kazhikhov Memorial Volume by Andrei V. Fursikov 9783034601511

    New Directions in Mathematical Fluid Mechanics: The Alexander V. Kazhikhov Memorial Volume by Andrei V. Fursikov 9783034601511

    Booksplease Price: £90.86
    On November 3, 2005, Alexander Vasil'evich Kazhikhov left this world, untimely and unexpectedly. He was one of the most in?uential mathematicians in the mechanics of ?uids, and will be remembered for his outstanding results that had, and still have, a c-...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • The Navier-Stokes Equations by Gunawan Nugroho 9783838376943

    The Navier-Stokes Equations by Gunawan Nugroho 9783838376943

    RRP: £40.67
    Booksplease Price: £37.03
    Apologies but we at Booksplease don't have a full description for this book.Book InformationISBN 9783838376943Author Gunawan NugrohoFormat PaperbackPage Count 92Imprint LAP Lambert Academic PublishingPublisher LAP Lambert Academic PublishingWeight(grams)...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £40.67
    Booksplease Price: £37.03
    Subtotal:
  • Transferability of Fracture Mechanical Characteristics by Ivo Dlouhy 9781402007941

    Transferability of Fracture Mechanical Characteristics by Ivo Dlouhy 9781402007941

    Booksplease Price: £46.58
    Five laboratories from France, Hungary and the Czech Republic have solved a Project supported fmancially by NATO within the Science for Peace Program (under Nr. 972655) for three years. The project, titled Fracture ResistanceofSteelsfor Containers of...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.58
    Subtotal:
  • Non-Linear Finite Element Analysis in Structural Mechanics by Wilhelm Rust 9783319342610

    Non-Linear Finite Element Analysis in Structural Mechanics by Wilhelm Rust 9783319342610

    RRP: £109.99
    Booksplease Price: £102.20
    This monograph describes the numerical analysis of non-linearities in structural mechanics, i.e. large rotations, large strain (geometric non-linearities), non-linear material behaviour, in particular elasto-plasticity as well as time-dependent...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £109.99
    Booksplease Price: £102.20
    Subtotal:
  • Dynamics of Multibody Systems: IUTAM/IFToMM Symposium, Udine, Italy, September 16-20, 1985 by Giovanni Bianchi 9783642827570

    Dynamics of Multibody Systems: IUTAM/IFToMM Symposium, Udine, Italy, September 16-20, 1985 by Giovanni Bianchi 9783642827570

    Booksplease Price: £90.56
    A first Symposium on Dynamics of Multibody Systems was held August 29 September 3, 1977 , under the chairmanship of - Prof. Dr. K. Magnus in Munich, FRG. Since that -time considerable progress has been made in the dynamics of multibody systems, a...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Fracture Mechanics of Ductile and Tough Materials and Its Applications to Energy Related Structures: Proceedings of the USA-Japan Joint Seminar Held at Hyama, Japan November 12-16, 1979 by H. W. Liu 9789401183925

    Fracture Mechanics of Ductile and Tough Materials and Its Applications to Energy Related Structures: Proceedings of the USA-Japan Joint Seminar Held at Hyama, Japan November 12-16, 1979 by H. W. Liu 9789401183925

    Booksplease Price: £46.28
    This volume contains the proceedings of the USA-Japan Joint Seminar on "Fracture Mechanics of Ductile and Tough Materials and Its Applications to Energy Related Structures". The seminar was supported jointly by the National Science Foundation...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Mechanics: An Intensive Course by Masud Chaichian 9783642163906

    Mechanics: An Intensive Course by Masud Chaichian 9783642163906

    Booksplease Price: £71.18
    Mechanics is one of the oldest and at the same time newest disciplines, in the sense that there are methods and principles developed first in mechanics but now widely used in almost all branches of physics: electrodynamics, quantum mechanics, classical...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £71.18
    Subtotal:
  • Non-Smooth Thermomechanics by Michel Fremond 9783642085789

    Non-Smooth Thermomechanics by Michel Fremond 9783642085789

    Booksplease Price: £90.86
    Based on practical problems in mechanical engineering, here the author develops the fundamental concepts of non-smooth mechanics and introduces the necessary background material needed to deal with mechanics involving discontinuities and non-smooth...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • Non-Newtonian fluid models and Boundary Layer flow by Manisha Patel 9786203198614

    Non-Newtonian fluid models and Boundary Layer flow by Manisha Patel 9786203198614

    RRP: £52.00
    Booksplease Price: £46.78
    Apologies but we at Booksplease don't have a full description for this book.Book InformationISBN 9786203198614Author Manisha PatelFormat PaperbackPage Count 152Imprint LAP Lambert Academic PublishingPublisher LAP Lambert Academic PublishingWeight(grams)...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £52.00
    Booksplease Price: £46.78
    Subtotal:
  • Experiments and Video Analysis in Classical Mechanics by Vitor L. B. de Jesus 9783319848983

    Experiments and Video Analysis in Classical Mechanics by Vitor L. B. de Jesus 9783319848983

    RRP: £44.99
    Booksplease Price: £41.36
    This book is an experimental physics textbook on classical mechanics focusing on the development of experimental skills by means of discussion of different aspects of the experimental setup and the assessment of common issues such as accuracy and...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £44.99
    Booksplease Price: £41.36
    Subtotal:
  • Low Cycle Fatigue and Elasto-Plastic Behaviour of Materials-3: Volume 3 by K-.T. Rie 9781851668939

    Low Cycle Fatigue and Elasto-Plastic Behaviour of Materials-3: Volume 3 by K-.T. Rie 9781851668939

    Booksplease Price: £47.88
    Proceeds of the Third International Conference on Low Cycle Fatigue and Elasto-plastic Behaviour of Materials, Berlin Congress Center, Berlin, Germany, 7-11 September 1992Book InformationISBN 9781851668939Author K-.T. RieFormat HardbackPage Count...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £47.88
    Subtotal:
  • The behavior of structures composed of composite materials by Jack R. Vinson 9789024735785

    The behavior of structures composed of composite materials by Jack R. Vinson 9789024735785

    Booksplease Price: £46.58
    While currently available texts dealing with the subject of high perfor mance composite materials touch upon a spectra of topics such as mechanical metallurgy, physical metallurgy, micromechanics and macro mechanics of such systems, it is the specific...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.58
    Subtotal:
  • Basic Concepts on Mechanics of Continuous Media (MMC) by Oualid Chahaoui 9786200910585

    Basic Concepts on Mechanics of Continuous Media (MMC) by Oualid Chahaoui 9786200910585

    RRP: £40.34
    Booksplease Price: £36.75
    Apologies but we at Booksplease don't have a full description for this book.Book InformationISBN 9786200910585Author Oualid ChahaouiFormat PaperbackPage Count 180Imprint Sciencia ScriptsPublisher Sciencia ScriptsWeight(grams) 272g
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £40.34
    Booksplease Price: £36.75
    Subtotal:
  • The Design of A Manual Well Drinking Water Pump by Eric Achu Ndangoh 9786138479628

    The Design of A Manual Well Drinking Water Pump by Eric Achu Ndangoh 9786138479628

    RRP: £33.12
    Booksplease Price: £30.52
    Apologies but we at Booksplease don't have a full description for this book.Book InformationISBN 9786138479628Author Eric Achu NdangohFormat PaperbackPage Count 56Imprint Editions Universitaires EuropeennesPublisher Editions Universitaires...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £33.12
    Booksplease Price: £30.52
    Subtotal:
  • Time-Dependent Fracture: Proceedings of the Eleventh Canadian Fracture Conference, Ottawa, Canada, June 1984 by A. S. Krausz 9789401087483

    Time-Dependent Fracture: Proceedings of the Eleventh Canadian Fracture Conference, Ottawa, Canada, June 1984 by A. S. Krausz 9789401087483

    Booksplease Price: £46.28
    The understanding of time dependent crack propagation processes occupies a central place in the study of fracture. It also encompasses a wide range of conditions: failure under sustained loading in a corrosive environment, fracture under cyclic loading...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Kinematics and Trajectory Synthesis of Manipulation Robots by M. Vukobratovic 9783642821974

    Kinematics and Trajectory Synthesis of Manipulation Robots by M. Vukobratovic 9783642821974

    Booksplease Price: £90.56
    A few words about the series "Scientific Fundamentals of Robotics" should be said on the occasion of publication of the present monograph. This six-volume series has been conceived so as to allow the readers to master a contemporary approach to...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Sedimentation and Sediment Transport: Proceedings of the Symposium held in Monte Verita, Switzerland, from September 2nd - to September 6th, 2002 by A. Gyr 9781402012662

    Sedimentation and Sediment Transport: Proceedings of the Symposium held in Monte Verita, Switzerland, from September 2nd - to September 6th, 2002 by A. Gyr 9781402012662

    Booksplease Price: £90.86
    It is evident, that for a number of ecological and technical problems in rivers and lakes a better knowledge of sediment transport and sedimentation is needed together with the ability to predict and simulate sediment behaviour. On the other hand, a...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.86
    Subtotal:
  • Introduction to the mechanics of plastic forming of metals by W. Szczepinski 9789400995499

    Introduction to the mechanics of plastic forming of metals by W. Szczepinski 9789400995499

    Booksplease Price: £46.28
    The plastic forming of metals is a branch of technology, in which great progress has been achieved mainly by collecting practical data resulting from long-time experience. The contribution of theoretical analysis to this progress is not significant. The...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Wave Propagation in Structures: An FFT-Based Spectral Analysis Methodology by James F. Doyle 9781468403466

    Wave Propagation in Structures: An FFT-Based Spectral Analysis Methodology by James F. Doyle 9781468403466

    Booksplease Price: £46.28
    The study of wave propagation seems very remote to many engineers, even to those who are involved in structural dynamics. I think one of the reasons for this is that the examples usually taught in school were either so simple as to be inapplicable to...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £46.28
    Subtotal:
  • Mechanics of Electromagnetic Solids by J.S. Yang 9781461379577

    Mechanics of Electromagnetic Solids by J.S. Yang 9781461379577

    Booksplease Price: £90.56
    The mechanics of electromagnetic materials and structures has been developing rapidly with extensive applications in, e. g. , electronics industry, nuclear engineering, and smart materials and structures. Researchers in this interdisciplinary field are...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Breaking Waves: IUTAM Symposium Sydney, Australia 1991 by Michael L. Banner 9783642848490

    Breaking Waves: IUTAM Symposium Sydney, Australia 1991 by Michael L. Banner 9783642848490

    Booksplease Price: £90.56
    Wave breaking is a commonly occurring phenomena associated with wave motion in fluids, often inducing significant effects which are of fundamental and technological importance, A familiar illustration is provided with white-capping and microbreaking of...
    Qty in Cart: 0
    Quantity:
    Price:
    Booksplease Price: £90.56
    Subtotal:
  • Theory and Simulation of Hard-Sphere Fluids and Related Systems by Angel Mulero 9783540787662

    Theory and Simulation of Hard-Sphere Fluids and Related Systems by Angel Mulero 9783540787662

    RRP: £109.99
    Booksplease Price: £103.00
    Hard spheres and related objects (hard disks and mixtures of hard systems) are paradigmatic systems: indeed, they have served as a basis for the theoretical and numerical development of a number of fields, such as general liquids and fluids, amorphous...
    Qty in Cart: 0
    Quantity:
    Price:
    RRP: £109.99
    Booksplease Price: £103.00
    Subtotal:
  • Total: items /

Adding your books to cart