diff --git a/additional_nodes/recirculation-pump.js b/additional_nodes/recirculation-pump.js
index 2a02932..d9f2003 100644
--- a/additional_nodes/recirculation-pump.js
+++ b/additional_nodes/recirculation-pump.js
@@ -9,7 +9,7 @@ module.exports = function(RED) {
 
         node.on('input', function(msg, send, done) {
             switch (msg.topic) {
-                case "Fluent":
+                case "Fluent": {
                     // conserve volume flow debit
                     let F_in = msg.payload.F;
                     let F1 = Math.max(F_in - F2, 0);
@@ -24,6 +24,7 @@ module.exports = function(RED) {
 
                     send([msg_F1, msg_F2]);
                     break;
+                }
                 case "clock":
                     break;
                 default:
diff --git a/additional_nodes/settling-basin.js b/additional_nodes/settling-basin.js
index dd3d697..131043c 100644
--- a/additional_nodes/settling-basin.js
+++ b/additional_nodes/settling-basin.js
@@ -9,7 +9,7 @@ module.exports = function(RED) {
 
         node.on('input', function(msg, send, done) {
             switch (msg.topic) {
-                case "Fluent":
+                case "Fluent": {
                     // conserve volume flow debit
                     let F_in = msg.payload.F;
                     let C_in = msg.payload.C;
@@ -41,6 +41,7 @@ module.exports = function(RED) {
 
                     send([msg_F1, msg_F2]);
                     break;
+                }
                 case "clock":
                     break;
                 default:
diff --git a/src/nodeClass.js b/src/nodeClass.js
index a9e53d3..ec80df7 100644
--- a/src/nodeClass.js
+++ b/src/nodeClass.js
@@ -48,12 +48,13 @@ class nodeClass {
                 case "Dispersion":
                     this.source.setDispersion = msg;
                     break;
-                case 'registerChild':
+                case 'registerChild': {
                     // Register this node as a parent of the child node
                     const childId = msg.payload;
-                    const childObj = this.RED.nodes.getNode(childId); 
+                    const childObj = this.RED.nodes.getNode(childId);
                     this.source.childRegistrationUtils.registerChild(childObj.source, msg.positionVsParent);
                     break;
+                }
                 default:
                     console.log("Unknown topic: " + msg.topic);
             }
@@ -137,7 +138,7 @@ class nodeClass {
                 new_reactor = new Reactor_PFR(this.config);
                 break;
             default:
-                console.warn("Unknown reactor type: " + uiConfig.reactor_type);
+                console.warn("Unknown reactor type: " + this.config.reactor_type);
         }
 
         this.source = new_reactor; // protect from reassignment
diff --git a/src/reaction_modules/asm3_class Koch.js b/src/reaction_modules/asm3_class Koch.js
index e5e98b3..8291b8c 100644
--- a/src/reaction_modules/asm3_class Koch.js	
+++ b/src/reaction_modules/asm3_class Koch.js	
@@ -19,7 +19,7 @@ class ASM3 {
       nu_NO:    0.5,  // anoxic reduction factor        [-]
       K_O:      0.2,  // saturation constant S_0        [g O2 m-3]
       K_NO:     0.5,  // saturation constant S_NO       [g NO3-N m-3]
-      K_S:      10.,  // saturation constant S_s        [g COD m-3]
+      K_S:      10.0, // saturation constant S_s        [g COD m-3]
       K_STO:    0.1,  // saturation constant X_STO      [g X_STO g-1 X_H]
       mu_H_max: 3.,   // maximum specific growth rate   [d-1]
       K_NH:     0.01, // saturation constant S_NH3      [g NH3-N m-3]
diff --git a/src/specificClass.js b/src/specificClass.js
index d34e6cc..fc33d90 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -322,10 +322,11 @@ class Reactor_PFR extends Reactor {
 
   _updateMeasurement(measurementType, value, position, context) {
     switch(measurementType) {
-      case "quantity (oxygen)":
+      case "quantity (oxygen)": {
         let grid_pos = Math.round(position / this.config.length * this.n_x);
         this.state[grid_pos][S_O_INDEX] = value; // naive approach for reconciling measurements and simulation
         break;
+      }
       default:
         super._updateMeasurement(measurementType, value, position, context);
     }