diff --git a/Documentation/Examples/stack_example.cc b/Documentation/Examples/stack_example.cc
index b38d07250f0303fb12daccd27150faa78ea45383..940247698d8bbd561887d08bae628dc57fb14eb6 100644
--- a/Documentation/Examples/stack_example.cc
+++ b/Documentation/Examples/stack_example.cc
@@ -1,25 +1,29 @@
 #include <stack/super_stupid/SuperStupidStack.h>
+#include <fwk/Particles.h>
 
 #include <iomanip>
 #include <iostream>
 
 using namespace std;
-
-// using namespace fwk;
+using namespace fwk::literals;
+// using namespace fwk::io;
 
 void fill(stack::super_stupid::SuperStupidStack& s) {
   for (int i = 0; i < 11; ++i) {
     auto p = s.NewParticle();
-    p.SetId(i);
-    p.SetEnergy(1.5 * i);
+    p.SetId(fwk::particle::InternalParticleCode::Electron);
+    p.SetEnergy(1.5_GeV * i);
   }
 }
 
 void read(stack::super_stupid::SuperStupidStack& s) {
   cout << "found Stack with " << s.GetSize() << " particles. " << endl;
-  double Etot = 0;
-  for (auto p : s) { Etot += p.GetEnergy(); }
-  cout << "Etot=" << Etot << endl;
+  fwk::quantity<fwk::energy_d> Etot;
+  for (auto p : s) {
+    Etot += p.GetEnergy();
+    cout << "particle: " << p.GetId() << " with " << p.GetEnergy()/1_GeV << " GeV" << endl;
+  }
+  cout << "Etot=" << Etot << " = " << Etot / 1_GeV << " GeV" << endl;
 }
 
 int main() {
diff --git a/Framework/Particles/Particles.h b/Framework/Particles/Particles.h
index cf1fbdaa468b15ee458dafa06860d999984c9d82..3b443a687ca1058447a7634bdb205be06954fd94 100644
--- a/Framework/Particles/Particles.h
+++ b/Framework/Particles/Particles.h
@@ -13,57 +13,57 @@
 
 #include <fwk/GeneratedParticleProperties.inc>
 
-
 namespace fwk {
 
   /**
    * @namespace particle
-   * 
-   * The properties of all elementary particles is stored here. The data 
+   *
+   * The properties of all elementary particles is stored here. The data
    * is taken from the Pythia ParticleData.xml file.
-   * 
+   *
    */
-  
+
   namespace particle {
 
     /**
      * @function GetMass
-     * 
+     *
      * return mass of particle
      */
-    auto constexpr GetMass(InternalParticleCode const p)
-    {
+    auto constexpr GetMass(InternalParticleCode const p) {
       return masses[static_cast<uint8_t const>(p)];
     }
-    
-    auto constexpr GetPDG(InternalParticleCode const p)
-    {
+
+    auto constexpr GetPDG(InternalParticleCode const p) {
       return pdg_codes[static_cast<uint8_t const>(p)];
     }
-    
-    auto constexpr GetElectricChargeNumber(InternalParticleCode const p)
-    {
+
+    auto constexpr GetElectricChargeNumber(InternalParticleCode const p) {
       return electric_charge[static_cast<uint8_t const>(p)] / 3;
     }
-    
-    auto constexpr GetElectricCharge(InternalParticleCode const p)
-    {
+
+    auto constexpr GetElectricCharge(InternalParticleCode const p) {
       return GetElectricChargeNumber(p) * (phys::units::e);
     }
-    
-    auto const GetName(InternalParticleCode const p)
-    {
+
+    auto const GetName(InternalParticleCode const p) {
       return names[static_cast<uint8_t const>(p)];
     }
-    
-    std::ostream& operator<< (std::ostream& stream, InternalParticleCode const p)
-      {
-	stream << GetName(p);
-	return stream;
+
+    namespace io {
+
+      std::ostream& operator<<(std::ostream& stream, InternalParticleCode const p) {
+        stream << GetName(p);
+        return stream;
       }
 
-  } // end namespace
-    
-} // end namespace
+    } // namespace io
+
+  } // namespace particle
+
+} // namespace fwk
+
+// to inject the operator<< into the root namespace
+using namespace fwk::particle::io;
 
 #endif
diff --git a/Framework/StackInterface/CMakeLists.txt b/Framework/StackInterface/CMakeLists.txt
index 5388bb05152d83a422cb690a3ed62f211d6276a0..9c3ab779ae5b339725daf2e64bbfe4934bc4127e 100644
--- a/Framework/StackInterface/CMakeLists.txt
+++ b/Framework/StackInterface/CMakeLists.txt
@@ -23,13 +23,6 @@ target_include_directories (
   $<INSTALL_INTERFACE:include>
   )
 
-#add_custom_command (
-#  TARGET
-#  CORSIKAstackinterfaceerface
-#  PRE_BUILD
-#  COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CORSIKAstackinterfaceerface_HEADERS} ${PROJECT_BINARY_DIR}/include/corsika
-#  )
-
 install (
   FILES
   ${CORSIKAstackinterface_HEADERS}
diff --git a/Framework/Units/PhysicalUnits.h b/Framework/Units/PhysicalUnits.h
index d9bb61ac4d78826cc4a5c2bfdbc2c90ee661e89e..b5ee98bff29baf44223e0aa02aded7e7fb7cc091 100644
--- a/Framework/Units/PhysicalUnits.h
+++ b/Framework/Units/PhysicalUnits.h
@@ -1,15 +1,15 @@
 #ifndef _include_PhysicalUnits_h_
 #define _include_PhysicalUnits_h_
 
-#include <phys/units/quantity.hpp>
 #include <phys/units/io.hpp>
 #include <phys/units/physical_constants.hpp>
+#include <phys/units/quantity.hpp>
 
 /**
-   @file PhysicalUnits
-   
-   Define _XeV literals, alowing 10_GeV in the code.     
-*/
+ * @file PhysicalUnits
+ *
+ * Define _XeV literals, alowing 10_GeV in the code.
+ */
 
 /*using namespace phys::units::io;
 using namespace phys::units::literals;*/
@@ -17,16 +17,27 @@ using namespace phys::units::literals;*/
 namespace phys {
   namespace units {
     namespace literals {
-      QUANTITY_DEFINE_SCALING_LITERALS(eV, energy_d, magnitude(eV) )
+      QUANTITY_DEFINE_SCALING_LITERALS(eV, energy_d, magnitude(eV))
     }
-  }
-}
+  } // namespace units
+} // namespace phys
 
-using Length = phys::units::quantity<phys::units::length_d, double>;
-using Time = phys::units::quantity<phys::units::time_interval_d, double>;
-using Speed = phys::units::quantity<phys::units::speed_d, double>;
-using Frequency = phys::units::quantity<phys::units::frequency_d, double>;
-using ElectricCharge = phys::units::quantity<phys::units::electric_charge_d, double>;
+namespace fwk {
 
-#endif
+  using namespace phys;
+  using namespace phys::units;
+  // using namespace phys::units::literals;
+  
+  using Length = phys::units::quantity<phys::units::length_d, double>;
+  using Time = phys::units::quantity<phys::units::time_interval_d, double>;
+  using Speed = phys::units::quantity<phys::units::speed_d, double>;
+  using Frequency = phys::units::quantity<phys::units::frequency_d, double>;
+  using ElectricCharge = phys::units::quantity<phys::units::electric_charge_d, double>;
+  using Energy = phys::units::quantity<phys::units::energy_d, double>;
 
+} // end namespace fwk
+
+// we want to call the operator<< without namespace... I think
+using namespace phys::units::io;
+
+#endif