diff --git a/src/test/java/neqsim/thermodynamicoperations/flashops/TVFlashTest.java b/src/test/java/neqsim/thermodynamicoperations/flashops/TVFlashTest.java
index f7a5cb1a12..807c502d9b 100644
--- a/src/test/java/neqsim/thermodynamicoperations/flashops/TVFlashTest.java
+++ b/src/test/java/neqsim/thermodynamicoperations/flashops/TVFlashTest.java
@@ -5,6 +5,7 @@
 import org.apache.logging.log4j.Logger;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import neqsim.thermo.mixingrule.EosMixingRuleType;
 import neqsim.thermodynamicoperations.ThermodynamicOperations;
 
 /**
@@ -30,7 +31,7 @@ void setUp() {
     testSystem.addComponent("ethane", 0.0);
     testSystem.addComponent("n-pentane", 9E-1);
     testSystem.addComponent("nC16", 1E-1);
-    testSystem.setMixingRule("classic");
+    testSystem.setMixingRule(EosMixingRuleType.CLASSIC);
     testOps = new ThermodynamicOperations(testSystem);
     testOps.TPflash();
     testSystem.initProperties();
diff --git a/src/test/java/neqsim/thermodynamicoperations/flashops/saturationops/HydrateInhibitorwtFlashTest.java b/src/test/java/neqsim/thermodynamicoperations/flashops/saturationops/HydrateInhibitorwtFlashTest.java
index 6a22ab1033..a49add3bdc 100644
--- a/src/test/java/neqsim/thermodynamicoperations/flashops/saturationops/HydrateInhibitorwtFlashTest.java
+++ b/src/test/java/neqsim/thermodynamicoperations/flashops/saturationops/HydrateInhibitorwtFlashTest.java
@@ -3,6 +3,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import neqsim.thermo.mixingrule.EosMixingRuleType;
 import neqsim.thermo.system.SystemInterface;
 import neqsim.thermo.system.SystemSrkCPAstatoil;
 import neqsim.thermodynamicoperations.ThermodynamicOperations;
@@ -22,7 +23,7 @@ void testRun() {
     testSystem.addComponent("MEG", 0.000001);
     testSystem.addComponent("water", 0.0010);
     testSystem.createDatabase(true);
-    testSystem.setMixingRule(10);
+    testSystem.setMixingRule(EosMixingRuleType.byValue(10));
 
     testSystem.init(0);
     testSystem.setMultiPhaseCheck(true);
diff --git a/src/test/java/neqsim/thermodynamicoperations/phaseenvelopeops/multicomponentenvelopeops/PTPhaseEnvelopeTest.java b/src/test/java/neqsim/thermodynamicoperations/phaseenvelopeops/multicomponentenvelopeops/PTPhaseEnvelopeTest.java
index 9c1f4b2c17..15d465e9ff 100644
--- a/src/test/java/neqsim/thermodynamicoperations/phaseenvelopeops/multicomponentenvelopeops/PTPhaseEnvelopeTest.java
+++ b/src/test/java/neqsim/thermodynamicoperations/phaseenvelopeops/multicomponentenvelopeops/PTPhaseEnvelopeTest.java
@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import neqsim.thermo.mixingrule.EosMixingRuleType;
 import neqsim.thermodynamicoperations.ThermodynamicOperations;
 
 public class PTPhaseEnvelopeTest {
@@ -25,22 +26,23 @@ void testDewP() {
     testSystem.addComponent("nitrogen", 0.01);
     testSystem.addComponent("CO2", 0.01);
     testSystem.addComponent("methane", 0.98);
-    testSystem.setMixingRule("classic");
+    testSystem.setMixingRule(EosMixingRuleType.byName("classic"));
 
     testOps = new ThermodynamicOperations(testSystem);
     testOps.TPflash();
     testSystem.initProperties();
     testOps.calcPTphaseEnvelope();
     double[] dewPointPressures = testOps.get("dewP");
-    double[] expectedDewPointPressures = new double[] { 1.1051709180756477, 1.2214027581601699, 1.3498588075760032,
-        1.4918246976412703, 1.6652911949458864, 1.8794891289619104, 2.1418131227502055,
-        2.4690864123141987, 2.881197018974799, 3.404779997613969, 4.075230307874481,
-        4.938583914869986, 6.051801019586486, 7.477304695462727, 9.260793952051571,
-        11.364101185282063, 13.480106047577934, 14.53423776629387, 13.607498029406681,
-        11.181207439509638, 9.189487040488075, 9.612827246459474, 10.706126846063928,
-        12.501491987760147, 15.075672692089958, 18.51283799420178, 23.330378296334104,
-        29.71319711031059, 37.25532259549197, 43.660805656603934, 45.75836660678656,
-        46.42490219574348, 46.83203503669948, 46.869568345957006, 46.903557772489435 };
+    double[] expectedDewPointPressures =
+        new double[] {1.1051709180756477, 1.2214027581601699, 1.3498588075760032,
+            1.4918246976412703, 1.6652911949458864, 1.8794891289619104, 2.1418131227502055,
+            2.4690864123141987, 2.881197018974799, 3.404779997613969, 4.075230307874481,
+            4.938583914869986, 6.051801019586486, 7.477304695462727, 9.260793952051571,
+            11.364101185282063, 13.480106047577934, 14.53423776629387, 13.607498029406681,
+            11.181207439509638, 9.189487040488075, 9.612827246459474, 10.706126846063928,
+            12.501491987760147, 15.075672692089958, 18.51283799420178, 23.330378296334104,
+            29.71319711031059, 37.25532259549197, 43.660805656603934, 45.75836660678656,
+            46.42490219574348, 46.83203503669948, 46.869568345957006, 46.903557772489435};
     // System.out.println(Arrays.toString(dewPointPressures));
     assertArrayEquals(expectedDewPointPressures, dewPointPressures, 10E-10);
   }
@@ -58,7 +60,8 @@ void testFailingCaseWithWater() {
     testOps.TPflash();
     testSystem.initProperties();
 
-    Exception exception = assertThrows(ArrayIndexOutOfBoundsException.class, () -> testOps.calcPTphaseEnvelope());
+    Exception exception =
+        assertThrows(ArrayIndexOutOfBoundsException.class, () -> testOps.calcPTphaseEnvelope());
   }
 
   @Test
@@ -132,7 +135,8 @@ void testFailingCase1() {
   void testFailingCase2() {
     // testSystem.setTemperature(40, "C");
     // testSystem.setPressure(50, "bara");
-    neqsim.thermo.system.SystemInterface fluid0_HC = new neqsim.thermo.system.SystemUMRPRUMCEos(298.0, 50.0);
+    neqsim.thermo.system.SystemInterface fluid0_HC =
+        new neqsim.thermo.system.SystemUMRPRUMCEos(298.0, 50.0);
     fluid0_HC.addComponent("nitrogen", 2.5);
     fluid0_HC.addComponent("CO2", 4.5);
     fluid0_HC.addComponent("methane", 79.45);