diff --git a/src/thermophysicalModels/specie/thermo/eConst/eConstThermo.H b/src/thermophysicalModels/specie/thermo/eConst/eConstThermo.H
index baceabe201..fa8e624946 100644
--- a/src/thermophysicalModels/specie/thermo/eConst/eConstThermo.H
+++ b/src/thermophysicalModels/specie/thermo/eConst/eConstThermo.H
@@ -128,7 +128,7 @@ public:
 
     // Member Functions
 
-        // fundamaental properties
+        // Fundamaental properties
 
             //- Heat capacity at constant pressure [J/(kmol K)]
             inline scalar cp(const scalar T) const;
@@ -152,10 +152,8 @@ public:
 
     // Member operators
 
-        inline eConstThermo& operator=
-        (
-            const eConstThermo&
-        );
+        inline void operator+=(const hConstThermo&);
+        inline void operator-=(const hConstThermo&);
 
 
     // Friend operators
diff --git a/src/thermophysicalModels/specie/thermo/eConst/eConstThermoI.H b/src/thermophysicalModels/specie/thermo/eConst/eConstThermoI.H
index c6ef9e4e97..2f7d1faf4c 100644
--- a/src/thermophysicalModels/specie/thermo/eConst/eConstThermoI.H
+++ b/src/thermophysicalModels/specie/thermo/eConst/eConstThermoI.H
@@ -24,15 +24,9 @@ License
 
 \*---------------------------------------------------------------------------*/
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-namespace Foam
-{
-
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-// Construct from components
-inline eConstThermo::eConstThermo
+inline Foam::eConstThermo::eConstThermo
 (
     const specieThermo& st,
     const scalar cv,
@@ -47,8 +41,11 @@ inline eConstThermo::eConstThermo
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-//- Construct as named copy
-inline eConstThermo::eConstThermo(const word& name, const eConstThermo& ct)
+inline Foam::eConstThermo::eConstThermo
+(
+    const word& name,
+    const eConstThermo& ct
+)
 :
     specieThermo(name, ct),
     CV(ct.CV),
@@ -56,10 +53,9 @@ inline eConstThermo::eConstThermo(const word& name, const eConstThermo& ct)
 {}
 
 
-// Construct and return a clone
 template<class equationOfState>
-inline autoPtr<eConstThermo<equationOfState> > eConstThermo<equationOfState>::
-clone() const
+inline Foam::autoPtr<eConstThermo<equationOfState> >
+Foam::eConstThermo<equationOfState>::clone() const
 {
     return autoPtr<eConstThermo<equationOfState> >
     (
@@ -68,10 +64,9 @@ clone() const
 }
 
 
-// Selector from Istream
 template<class equationOfState>
-inline autoPtr<eConstThermo<equationOfState> > eConstThermo<equationOfState>::
-New(Istream& is)
+inline autoPtr<eConstThermo<equationOfState> >
+Foam::eConstThermo<equationOfState>::New(Istream& is)
 {
     return autoPtr<eConstThermo<equationOfState> >
     (
@@ -82,37 +77,40 @@ New(Istream& is)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-//- Heat capacity at constant pressure [J/(kmol K)]
-inline scalar eConstThermo::cp(const scalar) const
+inline Foam::scalar Foam::eConstThermo::cp(const scalar) const
 {
     return CV*W() + RR;
 }
 
 
-//- Enthalpy [J/kmol]
-inline scalar eConstThermo::h(const scalar T) const
+inline Foam::scalar Foam::eConstThermo::h(const scalar T) const
 {
     return cp(T)*T + Hf*W();
 }
 
 
-//- Entropy [J/(kmol K)]
-inline scalar eConstThermo::s(const scalar T) const
+inline Foam::scalar Foam::eConstThermo::s(const scalar T) const
 {
     notImplemented("scalar eConstThermo::s(const scalar T) const");
     return T;
 }
 
 
-//- Temperature from Enthalpy given an initial temperature T0
-inline scalar eConstThermo::TH(const scalar h, const scalar T0) const
+inline Foam::scalar Foam::eConstThermo::TH
+(
+    const scalar h,
+    const scalar T0
+) const
 {
     return (h - Hf)/Cp(T0);
 }
 
 
-//- Temperature from internal energy given an initial temperature T0
-inline scalar eConstThermo::TE(const scalar e, const scalar) const
+inline Foam::scalar Foam::eConstThermo::TE
+(
+    const scalar e,
+    const scalar
+) const
 {
     return (e - Hf)/CV;
 }
@@ -120,7 +118,7 @@ inline scalar eConstThermo::TE(const scalar e, const scalar) const
 
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
-inline  eConstThermo& eConstThermo::operator=
+inline Foam::eConstThermo& Foam::eConstThermo::operator=
 (
     const eConstThermo& ct
 )
@@ -136,7 +134,7 @@ inline  eConstThermo& eConstThermo::operator=
 
 // * * * * * * * * * * * * * * * Friend Operators  * * * * * * * * * * * * * //
 
-inline eConstThermo operator+
+inline Foam::eConstThermo Foam::operator+
 (
     const eConstThermo& ct1,
     const eConstThermo& ct2
@@ -153,7 +151,7 @@ inline eConstThermo operator+
 }
 
 
-inline eConstThermo operator-
+inline Foam::eConstThermo Foam::operator-
 (
     const eConstThermo& ct1,
     const eConstThermo& ct2
@@ -170,7 +168,7 @@ inline eConstThermo operator-
 }
 
 
-inline eConstThermo operator*
+inline Foam::eConstThermo Foam::operator*
 (
     const scalar s,
     const eConstThermo& ct
@@ -185,7 +183,7 @@ inline eConstThermo operator*
 }
 
 
-inline eConstThermo operator==
+inline Foam::eConstThermo Foam::operator==
 (
     const eConstThermo& ct1,
     const eConstThermo& ct2
@@ -195,8 +193,4 @@ inline eConstThermo operator==
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-} // End namespace Foam
-
 // ************************************************************************* //
diff --git a/src/thermophysicalModels/specie/thermo/hConst/hConstThermo.H b/src/thermophysicalModels/specie/thermo/hConst/hConstThermo.H
index a615dd3415..1355cb67d3 100644
--- a/src/thermophysicalModels/specie/thermo/hConst/hConstThermo.H
+++ b/src/thermophysicalModels/specie/thermo/hConst/hConstThermo.H
@@ -108,6 +108,7 @@ class hConstThermo
             const scalar hf
         );
 
+
 public:
 
     // Constructors
@@ -127,7 +128,7 @@ public:
 
     // Member Functions
 
-        // fundamaental properties
+        // Fundamaental properties
 
             //- Heat capacity at constant pressure [J/(kmol K)]
             inline scalar cp(const scalar T) const;
@@ -141,10 +142,8 @@ public:
 
     // Member operators
 
-        inline hConstThermo& operator=
-        (
-            const hConstThermo&
-        );
+        inline void operator+=(const hConstThermo&);
+        inline void operator-=(const hConstThermo&);
 
 
     // Friend operators
diff --git a/src/thermophysicalModels/specie/thermo/hConst/hConstThermoI.H b/src/thermophysicalModels/specie/thermo/hConst/hConstThermoI.H
index 264bce3653..acc976de05 100644
--- a/src/thermophysicalModels/specie/thermo/hConst/hConstThermoI.H
+++ b/src/thermophysicalModels/specie/thermo/hConst/hConstThermoI.H
@@ -24,16 +24,10 @@ License
 
 \*---------------------------------------------------------------------------*/
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-namespace Foam
-{
-
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-// Construct from components
 template<class equationOfState>
-inline hConstThermo<equationOfState>::hConstThermo
+inline Foam::hConstThermo<equationOfState>::hConstThermo
 (
     const equationOfState& st,
     const scalar cp,
@@ -48,9 +42,8 @@ inline hConstThermo<equationOfState>::hConstThermo
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-// Construct as named copy
 template<class equationOfState>
-inline hConstThermo<equationOfState>::hConstThermo
+inline Foam::hConstThermo<equationOfState>::hConstThermo
 (
     const word& name,
     const hConstThermo& ct
@@ -62,10 +55,9 @@ inline hConstThermo<equationOfState>::hConstThermo
 {}
 
 
-// Construct and return a clone
 template<class equationOfState>
-inline autoPtr<hConstThermo<equationOfState> > hConstThermo<equationOfState>::
-clone() const
+inline Foam::autoPtr<Foam::hConstThermo<equationOfState> >
+Foam::hConstThermo<equationOfState>::clone() const
 {
     return autoPtr<hConstThermo<equationOfState> >
     (
@@ -74,10 +66,9 @@ clone() const
 }
 
 
-// Selector from Istream
 template<class equationOfState>
-inline autoPtr<hConstThermo<equationOfState> > hConstThermo<equationOfState>::
-New(Istream& is)
+inline Foam::autoPtr<Foam::hConstThermo<equationOfState> >
+Foam::hConstThermo<equationOfState>::New(Istream& is)
 {
     return autoPtr<hConstThermo<equationOfState> >
     (
@@ -88,68 +79,73 @@ New(Istream& is)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-//- Heat capacity at constant pressure [J/(kmol K)]
 template<class equationOfState>
-inline scalar hConstThermo<equationOfState>::cp(const scalar) const
+inline Foam::scalar Foam::hConstThermo<equationOfState>::cp(const scalar) const
 {
     return CP*this->W();
 }
 
 
-//- Enthalpy [J/kmol]
 template<class equationOfState>
-inline scalar hConstThermo<equationOfState>::h(const scalar T) const
+inline Foam::scalar Foam::hConstThermo<equationOfState>::h(const scalar T) const
 {
     return (CP*T + Hf)*this->W();
 }
 
 
-//- Entropy [J/(kmol K)]
 template<class equationOfState>
-inline scalar hConstThermo<equationOfState>::s(const scalar T) const
+inline Foam::scalar Foam::hConstThermo<equationOfState>::s(const scalar T) const
 {
-    notImplemented("scalar hConstThermo<equationOfState>::s(const scalar T) const");
+    notImplemented
+    (
+        "scalar hConstThermo<equationOfState>::s(const scalar T) const"
+    );
     return T;
 }
 
-/*
-//- Temperature from Enthalpy given an initial temperature T0
-template<class equationOfState>
-inline scalar hConstThermo<equationOfState>::TH(const scalar h, const scalar T0) const
-{
-    return (h - Hf)/Cp(T0);
-}
-
-
-//- Temperature from internal energy given an initial temperature T0
-template<class equationOfState>
-inline scalar hConstThermo<equationOfState>::TE(const scalar e, const scalar T0) const
-{
-    return (e - Hf)/Cv(T0);
-}
-*/
 
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 template<class equationOfState>
-inline hConstThermo<equationOfState>& hConstThermo<equationOfState>::operator=
+inline void Foam::hConstThermo<equationOfState>::operator+=
 (
-    const hConstThermo& ct
+    const hConstThermo<equationOfState>& ct
 )
 {
-    equationOfState::operator=(ct);
+    scalar molr1 = this->nMoles();
 
-    CP = ct.CP;
-    Hf = ct.Hf;
+    equationOfState::operator+=(ct);
 
-    return *this;
+    molr1 /= this->nMoles();
+    scalar molr2 = ct.nMoles()/this->nMoles();
+
+    CP = molr1*CP + molr2*ct.CP;
+    Hf = molr1*Hf + molr2*ct.Hf;
+}
+
+
+template<class equationOfState>
+inline void Foam::hConstThermo<equationOfState>::operator-=
+(
+    const hConstThermo<equationOfState>& ct
+)
+{
+    scalar molr1 = this->nMoles();
+
+    equationOfState::operator-=(ct);
+
+    molr1 /= this->nMoles();
+    scalar molr2 = ct.nMoles()/this->nMoles();
+
+    CP = molr1*CP - molr2*ct.CP;
+    Hf = molr1*Hf - molr2*ct.Hf;
 }
 
 
 // * * * * * * * * * * * * * * * Friend Operators  * * * * * * * * * * * * * //
 
 template<class equationOfState>
-inline hConstThermo<equationOfState> operator+
+inline Foam::hConstThermo<equationOfState> Foam::operator+
 (
     const hConstThermo<equationOfState>& ct1,
     const hConstThermo<equationOfState>& ct2
@@ -158,7 +154,7 @@ inline hConstThermo<equationOfState> operator+
     equationOfState eofs
     (
         static_cast<const equationOfState&>(ct1)
-        + static_cast<const equationOfState&>(ct2)
+      + static_cast<const equationOfState&>(ct2)
     );
 
     return hConstThermo<equationOfState>
@@ -171,7 +167,7 @@ inline hConstThermo<equationOfState> operator+
 
 
 template<class equationOfState>
-inline hConstThermo<equationOfState> operator-
+inline Foam::hConstThermo<equationOfState> Foam::operator-
 (
     const hConstThermo<equationOfState>& ct1,
     const hConstThermo<equationOfState>& ct2
@@ -193,7 +189,7 @@ inline hConstThermo<equationOfState> operator-
 
 
 template<class equationOfState>
-inline hConstThermo<equationOfState> operator*
+inline Foam::hConstThermo<equationOfState> Foam::operator*
 (
     const scalar s,
     const hConstThermo<equationOfState>& ct
@@ -209,7 +205,7 @@ inline hConstThermo<equationOfState> operator*
 
 
 template<class equationOfState>
-inline hConstThermo<equationOfState> operator==
+inline Foam::hConstThermo<equationOfState> Foam::operator==
 (
     const hConstThermo<equationOfState>& ct1,
     const hConstThermo<equationOfState>& ct2
@@ -219,8 +215,4 @@ inline hConstThermo<equationOfState> operator==
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-} // End namespace Foam
-
 // ************************************************************************* //
diff --git a/src/thermophysicalModels/specie/thermo/janaf/janafThermo.H b/src/thermophysicalModels/specie/thermo/janaf/janafThermo.H
index 8a1a205ec4..db7807a642 100644
--- a/src/thermophysicalModels/specie/thermo/janaf/janafThermo.H
+++ b/src/thermophysicalModels/specie/thermo/janaf/janafThermo.H
@@ -35,8 +35,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef janafThermo2_H
-#define janafThermo2_H
+#ifndef janafThermo_H
+#define janafThermo_H
 
 #include "scalar.H"
 
@@ -85,11 +85,6 @@ Ostream& operator<<
 );
 
 
-#ifdef __GNUC__
-typedef scalar coeffArray2[7];
-#endif
-
-
 /*---------------------------------------------------------------------------*\
                            Class janafThermo Declaration
 \*---------------------------------------------------------------------------*/
@@ -122,13 +117,7 @@ private:
         inline void checkT(const scalar T) const;
 
         //- Return the coefficients corresponding to the given temperature
-        inline const 
-#       ifdef __GNUC__
-        coeffArray2&
-#       else
-        coeffArray&
-#       endif
-        coeffs(const scalar T) const;
+        inline const coeffArray& coeffs(const scalar T) const;
 
 
 public:
@@ -170,8 +159,6 @@ public:
         inline void operator+=(const janafThermo&);
         inline void operator-=(const janafThermo&);
 
-        inline void operator*=(const scalar);
-
 
     // Friend operators
 
diff --git a/src/thermophysicalModels/specie/thermo/janaf/janafThermoI.H b/src/thermophysicalModels/specie/thermo/janaf/janafThermoI.H
index c859f76f8b..f9dc5e7a0e 100644
--- a/src/thermophysicalModels/specie/thermo/janaf/janafThermoI.H
+++ b/src/thermophysicalModels/specie/thermo/janaf/janafThermoI.H
@@ -26,16 +26,10 @@ License
 
 #include "janafThermo.H"
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-namespace Foam
-{
-
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-// Construct from components
 template<class equationOfState>
-inline janafThermo<equationOfState>::janafThermo
+inline Foam::janafThermo<equationOfState>::janafThermo
 (
     const equationOfState& st,
     const scalar Tlow,
@@ -58,9 +52,8 @@ inline janafThermo<equationOfState>::janafThermo
 }
 
 
-// Check given temperature is within the range of the fitted coeffs.
 template<class equationOfState>
-inline void janafThermo<equationOfState>::checkT(const scalar T) const
+inline void Foam::janafThermo<equationOfState>::checkT(const scalar T) const
 {
     if (T <  Tlow_ || T > Thigh_)
     {
@@ -75,15 +68,9 @@ inline void janafThermo<equationOfState>::checkT(const scalar T) const
 }
 
 
-// Return the coefficients corresponding to the given temperature
 template<class equationOfState>
-inline const 
-#ifdef __GNUC__
-coeffArray2&
-#else
-typename janafThermo<equationOfState>::coeffArray&
-#endif
-janafThermo<equationOfState>::coeffs
+inline const typename Foam::janafThermo<equationOfState>::coeffArray&
+Foam::janafThermo<equationOfState>::coeffs
 (
     const scalar T
 ) const
@@ -103,9 +90,8 @@ janafThermo<equationOfState>::coeffs
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-// Construct as a named copy
 template<class equationOfState>
-inline janafThermo<equationOfState>::janafThermo
+inline Foam::janafThermo<equationOfState>::janafThermo
 (
     const word& name,
     const janafThermo& jt
@@ -126,9 +112,8 @@ inline janafThermo<equationOfState>::janafThermo
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-// Heat capacity at constant pressure [J/(kmol K)]
 template<class equationOfState>
-inline scalar janafThermo<equationOfState>::cp
+inline Foam::scalar Foam::janafThermo<equationOfState>::cp
 (
     const scalar T
 ) const
@@ -138,9 +123,8 @@ inline scalar janafThermo<equationOfState>::cp
 }
 
 
-// Enthalpy [J/kmol]
 template<class equationOfState>
-inline scalar janafThermo<equationOfState>::h
+inline Foam::scalar Foam::janafThermo<equationOfState>::h
 (
     const scalar T
 ) const
@@ -155,9 +139,8 @@ inline scalar janafThermo<equationOfState>::h
 }
 
 
-// Entropy [J/(kmol K)]
 template<class equationOfState>
-inline scalar janafThermo<equationOfState>::s
+inline Foam::scalar Foam::janafThermo<equationOfState>::s
 (
     const scalar T
 ) const
@@ -175,7 +158,7 @@ inline scalar janafThermo<equationOfState>::s
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 template<class equationOfState>
-inline void janafThermo<equationOfState>::operator+=
+inline void Foam::janafThermo<equationOfState>::operator+=
 (
     const janafThermo<equationOfState>& jt
 )
@@ -210,7 +193,7 @@ inline void janafThermo<equationOfState>::operator+=
 
 
 template<class equationOfState>
-inline void janafThermo<equationOfState>::operator-=
+inline void Foam::janafThermo<equationOfState>::operator-=
 (
     const janafThermo<equationOfState>& jt
 )
@@ -244,20 +227,10 @@ inline void janafThermo<equationOfState>::operator-=
 }
 
 
-template<class equationOfState>
-inline void janafThermo<equationOfState>::operator*=
-(
-    const scalar s
-)
-{
-    equationOfState::operator*=(s);
-}
-
-
 // * * * * * * * * * * * * * * * Friend Operators  * * * * * * * * * * * * * //
 
 template<class equationOfState>
-inline janafThermo<equationOfState> operator+
+inline Foam::janafThermo<equationOfState> Foam::operator+
 (
     const janafThermo<equationOfState>& jt1,
     const janafThermo<equationOfState>& jt2
@@ -301,7 +274,7 @@ inline janafThermo<equationOfState> operator+
 
 
 template<class equationOfState>
-inline janafThermo<equationOfState> operator-
+inline Foam::janafThermo<equationOfState> Foam::operator-
 (
     const janafThermo<equationOfState>& jt1,
     const janafThermo<equationOfState>& jt2
@@ -345,7 +318,7 @@ inline janafThermo<equationOfState> operator-
 
 
 template<class equationOfState>
-inline janafThermo<equationOfState> operator*
+inline Foam::janafThermo<equationOfState> Foam::operator*
 (
     const scalar s,
     const janafThermo<equationOfState>& jt
@@ -364,7 +337,7 @@ inline janafThermo<equationOfState> operator*
 
 
 template<class equationOfState>
-inline janafThermo<equationOfState> operator==
+inline Foam::janafThermo<equationOfState> Foam::operator==
 (
     const janafThermo<equationOfState>& jt1,
     const janafThermo<equationOfState>& jt2
@@ -374,8 +347,4 @@ inline janafThermo<equationOfState> operator==
 }
 
 
-// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
-
-} // End namespace Foam
-
 // ************************************************************************* //